efficient systems and renewable energies - bdh-koeln.de · pdf filemessage from the patron i...

Technology and Energy Panel

Efficient systems and renewable energies

2 — 3

Message from the patron

I am pleased to act as patron of the Tech-

nology and Energy Panel at the ISH 2015. I

welcome this opportunity to highlight the

importance of energy policy, specifi cally in

relation to energy effi ciency, before a large

professional audience. Energy effi ciency,

particularly in the building sector, is the es-

sential second pillar of the energy revolu-

tion. In keeping with the Federal Govern-

ment’s concept to develop climate-neutral

buildings by 2050, we must make improve-

ments both to the building envelope and

heating systems. In this regard, the leading

trade fair, especially its Technology and En-

ergy Panel, is sure to provide important in-

sights into a variety of potential solutions

to the challenges that we face.

Sigmar GabrielFederal Minister for Economic Affairs and Energy

4 — 5

Foreword

Under the aegis of the Federation of German Heating Industry (Bundesverband der Deutschen Heizungsin-dustrie e. V.) (BDH), Frankfurt Trade Fair and BDH are organising the Technology and Energy Panel for the 6th time at the ISH 2015 in Frankfurt. Once again, the most important organisations in the energy industry are par-ticipating in the exhibition, as are industrial associations in the fi eld of energy-effi cient system technology. This strong alliance between the energy sector and industry refl ects the dual strategy of effi ciency and renew-able energy. The exhibition shows long-term strategies for a secure energy supply in the heating market in ad-dition to technical and commercial solutions that ensure effi cient use of all energy sources.

With the Technology and Energy Panel, the Frankfurt Trade Fair, BDH and their partners have made a valuable contribution to the ISH international trade fair, and particularly to ISH Energy. Together, political parties, the general public and international experts will receive extensive yet concise information about the state of the art, innovations and trends in the heating market.

Key issues and current industry challenges to be addressed: At both European and German levels, which political conditions are central to the heating market’s active

business communities? What are the market development trends in Europe, Germany and at the international level? Which technologies are state of the art in the heating market? What are the latest innovations and trends?

What potential do energy sources offer to the heating market?

Up to 200,000 visitors from industry are expected at the leading international trade fair for the optimum combination of water and energy. In the ISH Energy area, these visitors will be given a comprehensive over-view of technical and commercial solutions for increased energy effi ciency in the heating market, unlike at any other event. The diversifi ed, medium-sized German heating industry, but also the world market leaders, pres-ent an extensive range of products and innovative solutions for the heating market. In Frankfurt, internation-al experts will fi nd answers to the most pressing challenges faced by the contemporary heating market. .

Iris Jeglitza-MoshageSenior Vice President,Messe Frankfurt Exhibition GmbH

Andreas LückeManaging Director BDH

Table of contents

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Table of contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Frameworks in the heating marketStrong alliance for effi ciency and renewable energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Energy effi ciency in buildings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Energy sources in the heating marketNatural gas: High availability in conjunction with renewable energies . . . . . . . . . . . . . . . 18Heating oil – future-proof and reliable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Wood as biomass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Electricity in the heating market . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Renewable energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Effi cient technologies and hybrid systemsGas condensing technology with solar thermal systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Oil condensing technology in hybrid heating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Principle of heat pump and variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Hybrid heat pump systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36Gas heat pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38Solar Thermal Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40Solar Thermal Systems: Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42Heat from wood (single-room furnaces) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Heat from wood (central heating systems and hybrid systems) . . . . . . . . . . . . . . . . . . . . . 46The power-generating heating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48CHP with fuel cell technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Heat distribution, heat emission, system componentsHeat distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54Embedded surface heating and cooling system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Radiators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58Residential ventilation systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60House ventilation systems with heat recovery/moisture recovery . . . . . . . . . . . . . . . . . . . 62Storage technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Flue gas systems – fl exible systems for various fi elds of application . . . . . . . . . . . . . . . . . 66Tank systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68Smart control and communication technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Examples of modernisationEnergy consultancy and energy performance certifi cate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74Energy label for heat generators and combination heaters . . . . . . . . . . . . . . . . . . . . . . . . . 76Modern heating systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78Examples of modernisation – Variants with gas/oil condensing boilers . . . . . . . . . . . . . . 82Examples of modernisation – Variants with heat pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . 84Examples of modernisation – Variants with wood burning systems/CHP systems . . . . 86

Industrial heat generatorsLarge combustion systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90

Smart Grid and Smart Home Smart Grid and Smart Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

StandardisationStandardisation in the area of heating, ventilation and air-conditioning . . . . . . . . . . . . 94

BDH members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

6 — 7

Frameworks in the heating marketStrong alliance for effi ciency and renewable energies

Energy effi ciency in buildings

8 — 9

The energy mix in the German heating market consists of several energy sources. The main fuel, natural gas, is followed by heat-ing oil with shares of 49 % and 30 % respectively. Other energy sources include renewable energies (mainly solid biomass, solar thermal energy, geothermal energy and ambient heat, electrici-ty as well as liquid biomass), district heat and electricity.

As a result of intensive and expensive research and develop-ment, optimum systems exist for all of the aforementioned en-

ergy sources, which utilise fossil fuels in a highly effi cient man-ner and, at the same time, allow the coupling of renewable energies.

The organisers and partners of the Technology and Energy Panel establish a direct connection between the heating market’s fu-els and the systems developed for their utilisation. Hence, an al-liance was formed six years ago to link effi ciency and renewable energies:

BDH: Association for Effi ciency and Renewable Energies

The Technology and Energy Panel is organised by the BDH and Messe Frankfurt. The BDH unites 103 member companies and 2 associations. The association represents the entire range of products in the heating market from 4 kW to 36 MW. At the in-ternational level, the German heating industry organised in the BDH, assumes a leading position, in terms of both technology and market importance. In 2014, BDH members achieved sales worth 13.2 billion Euros and had 68,600 employees.

At the political level, the BDH promotes the interests of its mem-ber companies through its focus on “energy, environmental and economic policy”. It offers its members a platform for the ex-change of views on technological trends as well as national, Eu-ropean and international standardisation. For its members, the BDH provides product statistics and conducts an overall market survey. Apart from this, the association also commits to sponsor-ship of the ISH as well as regional and international fairs.

Strong alliance for efficiency and renewable energies

for effi ciency and renewable energies

for energy effi ciency in buildings

for heat pumps for wood and pellets, as well as the corresponding technology

NHRS

for standardisation for the gas industry and the standardisation body

for air-conditioning technology and ventilation systems

for building energyeffi ciency

for the electricity industry for effi cient single room furnaces

for the heating oil industry for the natural gas industry

BDH2014 103 companies

2 associations

Market shares:

Turnover:Employees:R & D:

90 % in Germany60 % in the EU13.2 billion euros worldwide68,600 worldwide488 million euros worldwide

Products and Systems:

Gas, oil and wood boilers Heat pumpsSolar thermal systems and photovoltaicsHeat distribution and emission systemsVentilation systemsAir-conditioningFlue systemsCHP systemsStorage tanks and tank systemsLarge boilers and burners up to 36 MW

“No energy revolution without a heating revolution”

(Federal Minister Dr Barbara Hendricks on the occasion of the BDH German Heat Conference (Deutsche Wärmekonferenz) 2014 )

More than 50 % of European and German fi nal energy consump-tion is attributable to the heating market, in almost the same proportion. The biggest share of the energy demand in the Ger-man heating market is covered by natural gas with almost 50 %, followed by heating oil with 30 %. According to the booklet “Re-newable energies in numbers“ (“Erneuerbare Energien in Zahl-en”), published by the Federal Ministry for Economic Affairs and Energy, renewable energies had a share of 9.1 % in 2013. 79 % of this share can be attributed to solid biomass.

Despite this high share, the heating markets in Europe and Ger-many have not received much attention in the energy policy fi eld. Until now, electricity liberalisation, especially the electricity-dominated energy revolution in Germany, have taken priority as far as energy policy is concerned. However, the enormous energy saving and CO2-reduction potential in the heating market could be increased considerably faster if the focus were not exclusively on the expansion of renewable energies in the electricity market.

At least to some extent, the European and German debates on energy policy consider to unlock these potentials: “Energy effi -ciency and renewable energies” is the magic formula, leading to a win-win situation:

High energy effi ciency and renewable energies save dwindling fossil fuels, and thereby reduce European and German dependency on imports.

Cost reduction potential through more effi cient use of fossil fuels and the utilisation of renewable energies.

High energy effi ciency reduces CO2-emissions and therefore contributes to climate protection.

Measures for increasing energy effi ciency in buildings and the industry generate jobs and prove to be an economic stimulant.

A broad range of energy sources is available to the sector with

the greatest final energy consumption –the heating market

Strong alliance for efficiency and renewable energies S

ourc

e: B

DEW

Fig. 1: Final energy consumption in Germany by application area in 2013

Fig. 2: Win-win situation in the process of modernising the existing outdated systems

Mobility 25 %

Electricity 21 %

Process heat and others 21 %

Building area/Space heating 33 %

BDH- dual strategy

Efficiency and renewable energies

Energy efficiency and renewable

energies generate jobs

Energy efficiency and renewable energies reduce

CO2-emissions

Energy efficiency and renewable energies save resources and reduce the dependency on imports

Less burden for the citizens due to

cost reduction

10 — 11

This is based on the following facts:

Only around 29 % of the 20.5 million heat generators installed in German buildings refl ect the state of the art technology.

Only 4.2 million gas condensing boilers corresponding to the state of the art are installed compared to 8.9 million boilers with lower heating value or standard boilers, which are less effi cient.

Of the 6 million heating oil boilers installed in Germany, only about 600,000 are energy-effi cient condensing boilers.

About 0.6 million heat pumps use geothermal and ambient heat.

About 0.9 million biomass boilers use wood as renewable energy.

Only about 9 % of the heat generators installed in Germany also use renewable solar thermal energy.

If the outdated systems were to be reconditioned and adapted to the state of the art, then around 13 % of the fi nal energy could be saved in Germany. The equally great potential for improve-ments to the building envelope has not yet been taken into ac-count.

BDH and dena conducted a survey on the status of industrial heat within an output range of 100 kW to 36 MW.

Figure 5 shows that only one-sixth of the 300,000 systems are state of the art. If they were to be upgraded to save energy and adapted to the state of the art, then an additional 2 % of the fi nal energy could be saved in Germany. This corresponds to a CO2-re-duction of 18 million tonnes.

The potentials of the heating market

122 million heat generator systems are currently installed in eu-rope. Almost 80 % of these heat generators use natural gas as the main source of energy, followed by heating oil – however, only in a few countries such as Belgium, Austria, France and Germany. On the basis of the energy labelling system, which has been mandatory for new heat generators since 2015, we arrive at the classifi cation shown in Figure 3.

Nearly 90 % of the heat generators installed in Europe do not correspond to the state of the art. Thus, there is enormous po-tential, not only for industry and manufacturers, but also for re-source and climate protection. These potentials are illustrated using the example of Germany (Fig. 5).

Heating revolution in Germany: Far from it

The land of the energy revolution now also focuses on increas-ing energy effi ciency. Apart from the subject “Electricity, nuclear phase-out and bridging the supply gap with renewable ener-gies”, which was in the foreground in Germany for several years, the Grand Coalition defi ned energy effi ciency as the second most important pillar of the energy revolution. This change of direction is also due to the new energy policy’s recognition that the enormous energy-saving and CO2-reduction potentials may be able to bridge the electricity shortfall created by the nuclear phase-out.


Fig. 3: Number of existing systems in Europe, about 122 million, 2010

Gas and oil low-temperature boilers 108.9 million (89 %)

Heat pumps1.4 million (1 %)

Gas and oil condensing boilers

12.1 million (10 %)

Mini-micro CHP systems

0.04 million (< 0,1 %)

A++

A+

A++

A+

A

CD

Heating systems in Europe

Sour

ce: E

uros

tat,

Euro

heat

and

Pow

er, J

RC IP

TS

122 millionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillionmillion


Fig. 5: If all the industrial heat generators between 100 kW and 36 MW in Germany would correspond to the state of the art, 2 % of Germany’s total energy consumption could be saved

Fig. 4: If all of the heating systems in Germany would correspond to the state of the art,13 % of the entire fi nal energy consumption in Germany could be saved

Saving

13 % of the total German

final energy con-sumption

Only 29 % of the systems are state of the art

Installed collector surface, solar thermal systems

Approx. 17.5 million m2

~ 1.9 million systems~ 20.5 million heat generators in stock

Low-tempera-ture gas boilers

8.9 million

Heat pumps0.6 million

Biomass boilersabout 0.9 million

Gas condensing boilersabout 4.2 million

Oil condensing boilersabout 0.6 million

Low-temperature oil boilers5.3 million

Saving

2 % of the total German

final energy con-sumption

300,000 systems with outputs ranging from 100 kW and 36,000 kW in the commercial sector in Germany

Only 17 % of the systems are state of the art



Sour

ce: B

DH

, ZIV

Sour

ce: B

DH

, den

a

20.5 20.5 20.5 20.5 20.5 20.5 20.5 millionmillionmillionmillionmillionmillionmillion

Heating systems in Germany

Industrial heat in Germany

12 — 13

15 % of the fi nal energy used in Germany corresponds approxi-mately to the energy generation of the 17 original nuclear power plants (Fig. 6).

This potential saving can be roughly compared to the natural gas imports from Russia calculated on the basis of fi nal energy use.

Modernisation backlog impedes heating revolution

The speed of modernisation with respect to natural gas-operat-ed heat generators is approx. 3 %, while that for heating oil-op-erated heat generators is 1 %, considering the total number of systems to be modernised. According to the information of the Federal Government, the pace of modernisation of the building shell is also only 1 %. If we are to achieve the Federal Govern-ment’s ambitious aim to have a climate-neutral building stock by 2050, the current low modernisation speed will lead us no-where.

For this reason, the BDH and other social groups have been de-manding, for some time now, that the pace of modernisation of the existing systems be doubled. This can be achieved based on the BDH positions, which are completely refl ected in the Nation-al Action Plan for Energy Effi ciency (Nationaler Aktionsplan für Energieeffi zienz) (NAPE) – not with coercive measures enforced

by law, but with an attractive and stable policy of incentives. The ample private capital available for investments in energy effi -ciency and renewable energies must be mobilised further.

Europe’s strategy for the heating market

Europe’s extreme dependency on energy imports – particularly of oil and gas – and its ambitious objectives of climate and re-source protection, made it necessary for the EU to further tight-en the present “20-20-20” targets and set higher goals for 2030 (see Fig. 7).

1. The EPBD was implemented in Germany in the form of the En-ergy Saving Ordinance, EnEV. The EPBD and therefore also the EnEV puts forth the minimum requirements for the energy standards or consumption of new buildings. Since 2015, real estate ads for renting or selling buildings have to specify the building’s key energy fi gures in form of an energy perfor-mance certifi cate.

The EnEV was amended in 2014. By 2016, the requirements for new buildings will also be intensifi ed. In 2016, the primary en-ergy factor for electricity will reduce from the current 2.4 to 1.8.


Fig. 6

470 TWh

209 TWh

329 TWh

159 TWh227 TWh

0 %

100 %

80 %

60 %

40 %

20 %

Heat market 2011 Heat market 2020Around 100 % of the nuclear

power plant output in Germany could be replaced

in 2011 (108 TWh)

Used in CCGT plants

Relief

Gas

Oil


Fig. 7: Framework conditions for the EU heating market

EPBDEnergy Performance of Buildings Directive

EU definition of energy standards for buildings

Energy Saving Ordinance, EnEV

Relevance for building and products

EEDEnergy Efficiency Directive

The EED makes it manda-tory to the Member States to realise an annual energy saving of 3 % in public sector buildings and of 1.5 % for end users – the latter under the responsi-bility of the energy supplier.

Eco ErPDirective and Eco design requirement for energy relevant products

The ErP defines the minimum requirements via the ecological properties of energy consuming and energy-relevant products. These include heat boilers, water heaters, pumps, fans as well as air-conditioning and ventilation systems. The guideline is often linked to the introduction of an energy efficiency label for the concerned products.

Targets until 2030

EU27 % share of renewable energies

40 % CO2 reduction

27 % increase in efficiency

RESDirective on the promotion of the use of energy from renewable energy sources

The RES Directive aims to increase the share of renewable energies in the EU substantially. It requires the Member States to adopt measures with which the share of renewable energies in the EU can rise to at least 20 % on average.



14 — 15

The high energy-saving and CO2-reduction potentials in Europe lie in the existing buildings. Usually, the heat demand of existing buildings is signifi cantly higher than that of new buildings. In other words: Generally, the building shell is made of brickwork, concrete or other primary materials such as wood without insu-lation. Often, the windows are not state of the art either.

If the shell of the existing building does not have to be renovat-ed anyway, the insulation measures to be taken on the building shell generally make little economic sense. For this reason, the heat demand remains very high for the year as a whole but shows a strongly cyclical trend. During spring and autumn, we have mainly average outdoor temperatures with a relatively low heat demand – during summer hardly any heating output is re-quired except for the preparation of domestic hot water. Howev-er, during winter a modern heating system often has to deal with severe cold conditions with outdoor temperatures of 0 °C and below. A modern low-temperature heating system with high effi ciency such as gas and oil condensing technology, gen-erally operates in the so-called partial load range during spring and autumn. Here, the maximum overall effi ciency is achieved. During this time of the year, the system temperatures generally range from 30 to 50 °C, i.e. the low-temperature range. For cover-ing the heat demand under severe cold conditions, the heating system must also be able to reach system temperatures up to 70 °C. The oil and gas condensing technology is particularly suit-ed to fulfi lling this requirement.

The correlation between building shell and heating system

What do designers, craftsmen and investors have to bear in mind? The defi nitions of the Energy Saving Ordinance give very little room for variation options in view of new buildings. Quite in contrast to this, the energetic modernization in existing build-ings allows a lot more options and investment strategies. In all cases, the investor assesses the cost-benefi t ratio and if required, also the sustainability of his investment strategy. The cost-bene-fi t ratio for the energetic modernization of existing buildings proves to be particularly favourable for the heating system.

Sometimes experts have controversial discussions about the so-called “correct sequence of measures”. Scientifi c fi ndings clearly indicate that investors face no disadvantages whether they start modernising the building shell fi rst or the heating system. In general, however, the renovation of old buildings should involve the energetic modernisation of the heating system as well as of the building shell. Since an investment in the building shell and heating system puts a great fi nancial burden on most of the in-vestors, modernisation measures can and should be taken in in-dividual steps. It is advisable to initiate the least costly measure fi rst.

The house as a system consisting of the building shell and the heating system

The rise in fuel prices in the past 10 years, stricter energy require-ments for buildings and the discussion about the energy revolu-tion have shifted the focus of owners and tenants more and more to the energy effi ciency of buildings. In addition, there is an ongoing debate about the security of supply and extreme de-pendency on energy imports like natural gas and oil in particular.

Currently, the European and German energy and environmental policy is focusing increasingly on the utilisation of the enormous energy-saving and CO2-reduction potentials in the existing build-ings, the largest energy consumption sector of Europe. For tapping these potentials, it is necessary to increase the energy effi ciency of the buildings. By taking advantage of the energy effi ciency po-tentials, up to 15 % of the entire fi nal energy consumption can be saved.

A building is a complex system. The energy quality of the build-ing shell depends upon the insulation and quality of the win-dows. Generally, the so-called heat demand of the building is ex-clusively defi ned by the energy quality of the building shell. The heat demand is defi ned as the fi nal energy requirement per m2 per year. According to the applicable ordinances, the standard for the annual primary energy demand is 50 to 70 kWh per m2 per year (low-energy house standard as per the EnEV (Energy Saving Ordinance)). For existing buildings, the demand values range from 160 kWh per m2 per year to 300 kWh per m2 per year or even beyond that. In other words: According to the EnEV, the energy consumption of new buildings is only one-third to one-eighth of the consumption of existing buildings.

The EnEV puts forth certain specifi cations pertaining to the thickness of the insulation as well as quality requirements and makes it mandatory to use triple glazed windows and make practically the entire building airtight. In contrast, heating sys-tem technology offers a variety of system solutions for every available energy type. In new buildings, low-temperature sys-tems are used for the condensing technology and heat pumps. The low system temperatures correspond ideally with the low heat demand of the building. This means low radiation and transmission losses, and at the same time a low surface temper-ature of the embedded surface heating/fl oor heating system or of an appropriately dimensioned radiator. Low system tempera-tures are a prerequisite for high effi ciency values of the heat generators.

Energy efficiency in buildings

About the role of renewable energies: Ideally, all systems based on fossil fuels such as natural gas, heating oil or electricity should be coupled with technologies which use renewable ener-gies (heat pumps, wood boilers, solar thermal systems etc.). Hy-brid systems such as condensing technology with solar thermal

energy and/or built-in wood furnaces or heat pumps with gas or oil condensing boilers are also available. Renewable energies re-place fossil fuels and thereby clearly increase the energy effi -ciency of the heating system. Appropriate funding is provided by the Federal Government and regional states.

Policymakers bet on the enormous energy-saving and

CO2-reduction potentials

Energy efficiency in buildings

16 — 17

Energy sources in the heating marketNatural gas: High availability in conjunction with renewable energies

Heating oil – future-proof and reliable

Wood as biomass

Electricity in the heating market

Renewable energies

18 — 19

More than 90 % of the natural gas used in the world is derived from the so-called “conventional production”. Besides, the de-mand is also catered to via the so-called “non-conventional sources” such as biogas, Liquefi ed Natural Gas (LNG) and also the so-called power-to-gas in future. These non-conventional gas sources are described in detail below.

Natural gas from biomass

Gas obtained from renewable energies, i.e. biogas, is becoming increasingly important. Biomass also includes waste material containing biomass, such as sewage sludge, biowaste, manure or plant parts.

Biogas has a high space effi ciency. Biogas can be produced con-tinuously throughout the year and stored as easily as natural gas. As there is no dependence on wind and sun, biogas can secure base loads in the area of renewable energies. As a renewable source of energy, biogas is CO2-neutral. Since 2007, biogas is mixed with conventional natural gas and fed into the natural gas grid. The gas obtained is known as bio-natural gas. It passes through the existing infrastructure to all of the users. Thus, nat-ural gas users are gradually changing over to renewable ener-gies because of the increased feeding of bio-natural gas.

Natural gas from surplus green power: Power-to-Gas

Another option for a practical use of the current peaks with a large share of wind energy or photovoltaic infeed is known as Power-to-Gas.

Fig. 8: How the natural gas comes to Germany

Fig. 9: The resources all over the world have a static reach of more than 200 years

Natural gas: Properties and reserves

Natural gas is a combustible, natural product containing meth-ane and the third most important fuel in the world, next to crude oil and coal. The share of primary energy consumption in the world in 2012 was 24 %. The global reserves that can be tapped economically satisfy the energy demand also over the long-term. In 2012, the production of natural gas amounted to 3.389 billion m3. Half of the global production was divided amongst USA, Russia, Iran, Qatar and Canada. Along with China and Germany, these countries also count amongst the largest consumers of natural gas.

Gas infrastructure in Germany and Europe

Germany has an extremely well-developed infrastructure for natural gas. The transport network and infrastructure available all over the country covers a pipe system of 510,000 km. Apart from this, Germany offers the maximum natural gas storage capacities in Europe. They allow a storage of gas reserves for a period of approx. four months.

Natural gas is transported via pipelines or in the form of Lique-fi ed Natural Gas (LNG). Around 35 % of the natural gas is ob-tained from Russia, while the remaining 56 % comes from Euro-pean countries, particularly Norway, the Netherlands, Denmark and Great Britain. 9 % of the natural gas used is produced in Ger-many itself.

Natural gas from Russia comes to us via different routes: Via Ukraine, Belarus, Poland and also directly via the Nord Stream pipeline.

Natural gas: High availability in conjunction with renewable energies

18 %

17 %

27 % from Norway

5 %

24 % from the

Netherlands

from other countries (e.g. Denmark, Great Britain)

from Russia via Nord Stream and Poland

from Russia via the Czech Republic

9 % own production

Conventional natural gas resourcesNon-conventional natural gas resources

Asia-Pacific

North AmericaEurope Eurasia

Middle East

Africa

South America

Static reach more than 200 years

Sour

ce: B

AFA

4/20

14, B

MW

i

Power obtained from renewable sources is highly dependent up-on weather conditions. Accordingly, the returns are fl uctuating. Considering the rapid build-up of wind energy and photovoltaic systems accompanied by a slow development of the power sup-ply systems, the occasional extreme peaks at the time of power production are not being suffi ciently utilised or transported.

Hence, the expansion of renewable energies urgently requires storage technology that will help to adapt the fl uctuating power supply to demand. Electric storage systems such as batteries are suitable to only a limited extent. It is also diffi cult to build pumped storage hydro power stations in suffi cient quantity.

The Power-to-Gas technology (P2G) enables the utilisation of current peaks and their partial storage. The surplus current is converted to hydrogen or methane via electrolysis and can be fed along with natural gas into the gas distribution system, the largest energy storage in Germany. This supply and energy reserve is available to all users via the extensive gas network system, and hence also to the heat market.

Fig. 10: Feed capacity for bio-natural gas rises continuously

Fig. 11: The Power-to-Gas process: Areas of application

Thanks to the global natural gas reserves, which

can be economically tapped, the energy demand can be covered for a long period of time

Natural gas: High availability in conjunction with renewable energies

2009

158million m3/year

449million m3/year

900million m3/year

Constantly rising feeding capacity

2011

2013

Climate protection with an indigenousenergy source

Electrolysis

Natural gas network

Industrial use

H2

H2 H2 CH4

Mobility Power generation Heat supply

Gas storage

Fluctuating power generation from renewable energies

Methanation

Sour

ce: D

euts

che

Ener

gie-

Agen

tur

Sour

ce: d

ena,

BD

EW

20 — 21

Modern technology also requires modern fuel – low-sulphur heating oil

Low-sulphur heating oil is a DIN-standardised and reasonably priced quality fuel. Besides its extremely low content of sulphur, low-sulphur heating oil features a very clean combustion and a high degree of effi ciency. Hence, it was specially developed for the oil condensing technology.

One litre of heating oil corresponds to 10 kilowatt hours of ener-gy. This is, for example, suffi cient for heating 200 litres of water from 10 °C to 55 °C. With a fl ash point of more than 55 °C, heating oil is also a product that can be stored easily and safely.

Benefi ts of low-sulphur heating oil: Burns with hardly any residue Allows a uniform energy utilisation, thus resulting in lower consumption of heating oil

Reduces the maintenance expenses and increases the service life of the heating system

Has a sulphur content of maximum 50 mg/kg(for comparison: Standard heating oil may contain up to 1,000 mg of sulphur per kilogram of heating oil.)

Has a guaranteed lubricity Is storable

Fig. 12: More effi cient systems always ensure high outputs and considerably lower consumption

In Germany, nearly 20 million people use oil for heating. More than 5.6 million oil heating systems provide warmth to 11 million households. Most of these systems are used in one- or two-fam-ily houses. More than 50 % of the residents use renewable ener-gy sources in addition to heating oil – mostly solar thermal sys-tems or wood burning stoves.

More and more residents bank upon oil condensing devices, which convert nearly 100 % of the fuel to heat. There is also an increasing share of renewable energies, where heating oil, as a storable energy carrier, ensures security of supply.

Modernisation of a heating system has maximum infl uence on the energy savings of a building. A modern oil condensing device stays highly effi cient if the heat demand is reduced through sub-sequent insulation measures.

Heating oil – future-proof and reliableSo

urce

: ZIV

repo

rt 0

1.05.

2014

; BAF

A Ap

ril 2

014

0

1.4

2.8

4.2

6.6

7.0

0

12

24

36

48

60

1993 1995 1997 1999 2001 2003 2005 2007 2009 2011 2013

19,829

5,647,600

38,518

5,375,655

Number of oil heating systems

Consumption per system [m3]

Domestic sales of heating oil EL100 %

42 %

million tmillion

Bio-heating oil: Heat from plant-based raw materials

Bio-heating oil is low-sulphur heating oil with an admixture of liquid fuels from renewable resources.

Bio-heating oil should be used just like conventional heating oil, exclusively with effi cient heating technology, since renewable resources are not available in unlimited quantities. Also, the re-sources used must be produced in a sustainable manner.

The petroleum industry has expressed its commitment to the goals of the sustainability regulation of the EU: The entire pro-cess of production of bio-fuels is taken into account here. An im-portant feature is that the greenhouse gas emissions must be signifi cantly lower than those of fossil fuels.

Social and ecological standards must also be complied with. Thus, the protection of natural habitats is invariably taken into account and any competition with the food production is ruled out.

How long will crude oil last?

Probably much longer than we need it. Thanks to modern heat-ing technology and better insulation of the buildings, reserves are being used more effi ciently. Also, the increasing use of renew-able energies such as solar thermal energy and biofuels, reduces the demand for fossil fuel for heat supply.

The oil supply is guaranteed

The supply of crude oil is guaranteed for many decades. This is verifi ed by recent data of the Bundesanstalt für Geowissen-schaften und Rohstoffe (BGR) (Federal Institute for Geosciences and Natural Resources). According to the information provided by this institute, more than 219 billion t of crude oil reserves are available worldwide – more than ever before.

Considering the present day consumption of crude oil all over the world, the secured reserves should last for more than 50 years.

The crude oil reserves are increasing continuously

A review shows: Although the consumption of oil has constantly increased in the past 60 years, the secured oil reserves are also growing steadily. In 1940, the confi rmed reserves of crude oil all over the world amounted to approx. 6 billion t. In 1980, the re-serves climbed to 88 billion t, in 2000 to around 140 billion t and in 2013 to around 219 billion t.

Fig. 13: Oil reserves and resources worldwide

Heating oil,as a storable energy carrier,

guarantees security of supply

Heating oil – future-proof and reliable

Approx. 655 billion t oilReserves and resources

4.2 billion t oil consumptionworldwide in year 2013

219 billion t oil reservestechnically and economically viable

436 billion t oil resourcesverifi ed or geologically feasible,but currently technically or economicallynot viable

Sour

ce: B

unde

sans

talt

für G

eow

isse

nsch

afte

n un

d Ro

hsto

ffe „R

eser

ven,

Res

sour

cen

und

Verf

ügba

rkei

t von

Ene

rgie

rohs

toffe

n 20

14“,

ener

gy su

rvey

; im

age:

IWO

; as o

f: 20

13

22 — 23

Good for the forest – good for the climate

A sustainable use of wood has positive effects on the mainte-nance and protection of the forest: A forest that is thinned out well, is stable against environmental impacts. Even the notions of natural forests and utilisation are not contradicting each oth-er. On the contrary, forests subjected to sustainable use have a high ecological value.

Moreover, the use of wood is good for the climate. This is be-cause wood, as a renewable resource, is CO2-neutral: When burned, only the amount of CO2 that was absorbed by the tree during its growth is released.

Wood is on the rise

Wood as a fuel is becoming more and more attractive: It has a very good life cycle assessment and a nearly constant price trend. In addition, wood is a regional renewable fuel, and thus the economy can benefi t from short transport routes, local jobs and domestic value creation. So, there are good reasons why nearly 20 % of the households in Germany rely on wood for heat gener-ation nowadays. A fi fth of these consumers even have central-ised wood-fi red heating, which is also used for domestic hot wa-ter heating.

No wonder: Modern automated fi replaces now make the opera-tion as comfortable as never before. Wood almost matches the traditional fuels, oil or gas, in terms of its comfort.

Wood as biomass

Fig. 14: Wood reserves of selected European countries in 2010

1285million m3

3466million m3

738million m3

2092million m3

2651million m3

2024million m3

1107million m32453

million m3

Sour

ce: E

uros

tat

Pellets, split logs and wood chips

Modern heating systems use the energy source wood in the form of pellets, wood chips or split logs.

Wood pellets are small, standardised, cylindrical pellets made from natural, untreated wood. In order to produce pellets, the wood chips in the sawmill are fi rst dried and then pressed into pellets in matrices. The chips join naturally, owing to their own lignin. The production of pellets often takes place directly in the sawmill. 2 kg wood pellets correspond to the energy content of about 1 litre heating oil.

Split logs are also increasingly used for heating since a few years. Basically, any tree species is suitable for this purpose. To ensure a high energy output and a clean combustion, the wood must be as dry as possible. 2 years storage in air under rain water protec-tion is ideal. Wood with a water content between 15 and 20 % has an average energy value of 4 kWh/kg. For making split logs, the cut tree trunks are sawed to the desired length and split.

Wood chips are manufactured in various ways. Coniferous wood trunk pieces that are accumulated in the saw mills and are not usable as sawn wood are chopped directly. Generally, they are al-so used for manufacturing paper. The commonly used method for manufacturing wood chips for energy generation is the chop-ping of round timber from the forest, which is otherwise not us-able (e.g. so-called residual forest wood), or round wood from landscape maintenance.

Since 2012, there is a European standard (EN 14961-2) defi ning the product for all wood fuels. This standard was replaced by the worldwide valid ISO 17225 in 2014. For pellets, this standard has been implemented in the ENplus certifi cation, whereby the compliance with the specifi cations of the standard as well as compliance with certain stringent requirements related to the standard is controlled.

Sustainably available

Nearly one-third of Germany is covered by forest, and this forest area has been constantly increasing over decades: After the 2nd World War, by approx. 1 million hectare. Between 2002–2012, the growth was still 50,000 hectares.

The forests in Germany have a usable wood reserve of 3.7 billion m3. Every year, there is a growth of more than 11 m3 of wood per hec-tare – which is over 121 million m3 on the entire forest area. This puts Germany in the second position in Europe, after Russia, even ahead of the “traditional” forest countries such as Finland and Sweden.

One reason for this is sustainable management, in which only as much wood is cut as can be regrown. This economic approach was fi rst described in 1713. In Germany, it has led to a strict forest legislation. Today, sustainable management of forests has fi rmly taken roots throughout Europe – mainly because of the certifi ca-tion systems.

Almost 20 % of the house-holds in Germany use wood

for heat generation

Wood as biomass

Fig. 15: Pellets Fig. 16: Split logs Fig. 17: Wood chips

DecayA

CombustionB

Fig. 18: If there is decay in the forest (A), the same amount of CO2 is generated as during combustion (B)

24 — 25

Power-to-Heat: another opportunity for effi cient electrically operated heating systems

The signifi cant growth of wind power, electricity and photovol-taics leads to sometimes extreme production peaks during the generation of electricity due to strong winds and high solar radi-ation. The consumers cannot really benefi t from these produc-tion peaks because of the still completely insuffi cient expansion of the power grids. Neighbouring countries of Germany, such as Poland, Austria and Netherlands increasingly refuse to utilise the peaks in the German grids.

Power-to-Heat is part of a strategy for making practical use of these production peaks in future. If, during periods of high sup-ply by fl uctuating producers such as photovoltaics or wind power systems, the electricity demand is low or if the high supply can-not be fed via the existing networks, the surplus energy generat-ed can be partially converted into heat.

Again, heat pumps are particularly suitable for the implementa-tion of the Power-to-Heat strategy. Well known manufacturers offer them already as smart grid ready. The electricity consump-tion of the heat pump is regulated by using additional heat stor-age and adapted to the supply of renewable energies. Buffer storage tanks act as thermal storage tanks, which can compen-sate daily peak loads. Likewise, the heat pump allows also cool-ing and air-conditioning.

The coupling of electricity and heat can effectively contribute to the transformation of the energy system in future. Electricity-based heat generators such as heat pumps can also assume sys-tem services for the power grids:

Control operations in virtual networks Thermal storage of surplus power generated from renewable resources

Highly effi cient thermal utilisation and storage of surplus power generated from renewable resources

Electricity: Flexible and sustainable

Nearly 10 % of the fi nal energy consumption in the heating mar-ket can be attributed to electricity-based system solutions. The fl exibility and sustainability of electricity convince many build-ing owners. Modern electrical heat applications such as electric heat pump and versatile systems in the ventilation technology stand for energy effi ciency and comfort.

Renewable energies modify the electricity mix in Germany

The signifi cant expansion of renewable energies in the electricity sector affects the use of electricity-driven heating systems in the heat market. Nearly one-fourth of the electricity currently pro-duced in Germany is obtained from wind power, photovoltaics and biomass. This development is refl ected in a clear reduction in the primary energy factor for electricity – from 2.4 to 1.8 – in the amendment of the EnEV (Energy Saving Ordinance) in 2014. Primary energy factor means to calculate how much primary en-ergy is spent per kWh fi nal energy in the building.

With a primary energy factor of 2.4, electricity could hardly com-pete with natural gas or heating oil which have primary energy factors of 1.1 (which corresponds to approx. 10 % loss). According to the philosophy of EnEV, the primary energy factor 2.4 meant a practical ban on direct electric heating systems. On the other hand, electrical heat pumps with a coeffi cient of performance ranging from 3.3 (air-water) to 4.5 (brine-water) were and are competitive when compared to gas and oil systems, because they over-compensate the high primary energy consumption of electricity with a very high share of renewable energies.

By reducing the primary energy factor from 2.4 to 1.8, electrical-ly operated heating systems, e.g. heat pumps, will gain signifi -cance as they will be using a high share of renewable energies. This has an impact on the important role which heat pumps play already in new buildings, because the low heat demand of these buildings means that heat pumps and their low-temperature principle fi nd especially favourable possibilities and conditions. Today, nearly one-fourth of the new buildings are equipped with heat pumps. The amendment of the EnEV, which also puts forth a further regulatory reduction in the heat demand starting from 2016, could further increase the opportunities for the use of elec-trically operated systems in new buildings.


Fig. 19: Functional principle Power-to-Heat

The expansion ofrenewable energies has changed the role

of electricity in the heat market


Renewablepower generation

Power grid

Conventionalpower generation

Multi-utility controllerSmart grid

The multi-utility controller controls all the components in the house and can exchange load data with other consumers and producers via an intelligent power grid in real time. Geothermal probe

321

6

5 4

9

8

Heat pump Electrical devices Radiators

Domestic hot water storage tank Electric car Floor heating system

Buffer storage tank Photovoltaics Light3

2

1

6

5

4

9

8

7

7

Sour

ce: B

WP

26 — 27

Increase in the forest area in Germany since the 2nd World War by 1 million hectares, with an annual growth in the Ger-man forest area by approx. 5,000 hectares

Annual growth in the German forest area by total 121 million m3, approx. 3 % more than what was cut

Thermal recovery (split logs, pellets, wood chips) approx. one-third of the quantity cut every year

Out of 14 million single room furnaces, a major part is operated with split logs. A small percentage of these systems uses pellets or wood chips. In approx. 900,000 wood centralised heating sys-tems, split logs, wood chips and pellets are used, each represent-ing about 30 %.

Biogas, sewage gas and landfi ll gas

Around 13 % of the share of renewable energies in the heating market is attributed to biogas, sewage gas and landfi ll gas. The renewable energies in gaseous form can be converted to elec-tricity on site, or to thermal power, or for the escpecially effi cient cogeneration of heat and power. A usage of the gas network, which is more than 500,000 km long can be taken into account when the gaseous renewable energies have been conditioned to the quality of natural gas and are fed into the network. Thus, the largest energy storage in Germany, the gas network, can be used optimally.

Geothermal energy and environmental heat

The utilisation of near-surface geothermal energy and environ-mental heat reaches a share of 4.2 %. It takes place via air-water, brine-water or water-water heat pumps (see page 34). The utili-sation of near-surface geothermal energy and environmental heat via heat pump systems can be optimally combined with the “Power-to-Heat” concept. According to this concept, surplus electricity generated from wind and photovoltaics under strong wind and sunlight conditions should be used or stored in the heat market in future. Thanks to their high effi ciency with re-spect to primary energy and storing capacity as well as compat-ibility with the smart grid, heat pumps are particularly suitable as an interface between the power sector and heating market.

Solar heat: ideal addition for all heating systems

Figure 21 shows the solar coverage rate during the year. In sum-mer, a modern solar thermal system can cover the entire domes-tic hot water demand and heat demand of a house for four months or more. During this period, the radiators are switched off. Solar energy for the heating market can provide optimum support for all the primary heat generators in the market and, depending upon the design, substitute up to 30 % of the fossil fuels used otherwise.

Fig. 20: Share of renewable energies in the fi nal energy consumption in the heat market (1990-2020)

BDH: Dual strategy of effi ciency and renewable energies for the protection of climate and natural resources

Based on the Renewable Energies for Heating and Cooling Direc-tive (RES Directive), the EU prescribes that the share of renewa-ble energies in Europe must be signifi cantly increased. Consider-ing the extremely heterogeneous starting situation in the indi-vidual EU countries, specifi c national objectives had to be de-fi ned. The objective for Germany is that the share of renewable energies must be increased to at least 18 % by 2020. The heating market must make a signifi cant contribution towards this goal and, the share of renewable energies must be increased from to-day 9 % to at least 14 % by 2020.

Solid biomass

The largest share of renewable energies in the heating market is accounted for by solid biomass, at 73 %. During the wood growth, trees absorb the quantity of CO2, which is later released into the atmosphere once again during subsequent thermal use. The CO2-balance for the renewable energy from wood also includes CO2-emissions, which are released at the time of processing of wood, because of the use of fuels and fossil auxiliary energy dur-ing thermal use of wood. According to the EnEV (Energy Saving Ordinance), the so-called primary energy factor for wood is 0.2. Thus, the actual share of renewable energy during thermal use is 80 % with the simultaneous use of 20 % fossil energy.

Because of sustainable forestry in Germany, a basis is created for an increased utilization of wood in terms of material and energy.

Renewable energies* S

ourc

e: Fe

dera

l Min

istr

y fo

r Env

ironm

ent,

Nat

ure

Cons

erva

tion

and

Nuc

lear

Sa

fety

: Ren

ewab

le e

nerg

ies 2

012,

page

9 a

nd w

orkg

roup

rene

wab

le e

nerg

y st

atis

tics (

AGEE

-Sta

t), a

s of:

Dec

embe

r 201

3

0 %

3 %

6 %

9 %

12 %

15 %

1990 1995 1998 2005 2010 2013 2020

*Objective of the Federal Government

*

Market trend for renewable energies not satisfactory

Nearly half of the newly installed heating systems were operat-ing with renewable energies in the boom year 2008. The boom was triggered by the high prices of natural gas and heating oil as well as political signals about the security of supply which were disquieting for investors. The World Economic Crisis, which started

towards the end of 2008, and collapsing energy prices in the be-ginning of 2009, brought this boom to an end, thus reducing in-vestments in renewable energies to a level of 20 to 22 %. This was a missed opportunity not only for the protection of natural resources and the climate but also for investors to increase the share of renewable energies in the heating market and to con-tribute to climate and resource protection.

Fig. 21: Solar coverage rate during the year

The objective in Germany is to

increase the share of renewable energies in the heat market to 14 % by 2020

Renewable energies

Fig. 22: Investments in systems using renewable energies

2002 2004 2006 2008 2009 2010 2011 2012

Low-temperature technology Condensing technology Renewable energies

75 %

50 %

25 %

0 %

100 %

2013

751,000 794,000 762,000 618,500 638,000 612,500 629,000 650,500 686,500

* An extension of the reporting scope in the product statistics for biomass boilers in 2014 has shown higher quantities as compared to previous year. However, the trend in percentage as compared to the previous year is negative.

2014

681,000*

21 %22 %

10 %15 %

32 %

45 %

27 %23 % 26 % 24 %

Ener

gy

Jan. Feb. March April May June July Aug. Sep. Oct. Nov. Dec.

28 — 29

Efficient technologies and hybrid systemsGas condensing technology with solar thermal systemsOil condensing technology in hybrid heating systems

Principle of heat pump and variantsHybrid heat pump systemsGas heat pump

Solar Thermal SystemsSolar Thermal Systems: Components

Heat from wood (single-room furnaces)Heat from wood (central heating systems and hybrid systems)

The power-generating heating systemsCHP with fuel cell technology

30 — 31

Different options for effi cient heating

Gas condensing technology in combination with a solar thermal system can be used in various applications:

Preparing domestic hot water using solar energy is the most common. The installation of a corresponding system is easy and cost-effective and the system itself is suffi ciently variable to work effi ciently for large households as well as in smaller one-family houses. During summer, the required hot water is generated almost entirely with the help of solar energy. In the colder months, gas condensing technology bridges this gap effi -ciently.

The system operates even more effi ciently if the solar thermal system is also used for auxiliary heating. Solar auxiliary heating is particularly useful in new buildings, well-insulated old build-ings as well as in houses equipped with low-temperature emis-sion systems, for example an underfl oor heating system. Solar thermal systems contribute to approx. 10 to 30 percent of the heating requirement in modern buildings and even up to 40 per-cent in low-energy houses.

Gas condensing technology with solar thermal systems

The scope of application of fossil fuels in the building sector is mainly determined by their compatibility with renewable ener-gies. Natural gas technologies can be best operated in combina-tion with solar thermal systems.

Solar thermal system for heat generation

As against photovoltaic systems, which generate electricity using solar energy, solar thermal systems support the process of heat generation. This heat can be used for preparing domestic hot water as well as for heating rooms.

In a household of four persons, a solar thermal system with a collector area of approx. four to six sq. metres provides up to 60 percent of the energy required for preparing domestic hot water throughout the year.

Gas condensing boiler and hot water tanks can be installed in the cellar, on the attic or even in the living areas, for example in the bathroom.

Today, Germany has over 2.0 million solar thermal systems. Since 2006, their number has increased by more than double. For new buildings, gas condensing technology combined with a solar thermal system is one of the most favourable heating options for builders, considering the investment and heating costs.

Gas condensing technology with solar ther mal systems

Fig. 23: Duo for heating of rooms and water: Natural gas condensing technology and solar thermal system

Natural gas condensing heating system

Solar thermal system

In the absence of the sun, the natural gascondensing heating system heats the water effi ciently and reliably.

When the sun is shining,the water is heated only with the solar energyvia the collectors onthe roof.

Sour

ce: Z

ukun

ft E

RDGA

S e.V

.

Natural gas in combination with

solar thermal energy is an eff icient duo for heating of rooms and water

Gas condensing technology with solar ther mal systems

Fig. 24: Diagram of a gas condensing boiler

Air

Blower

Gas valve

Flue gas

Condensateoutfl ow

H

G

F

E

D

B

A

C

A

B

C

D

E

Fig. 25: Carbon dioxide emissions

0 %10 %20 %30 %40 %50 %60 %70 %80 %90 %

100 %

DCB A E

Standard boiler (before 1978)

Low-temperature boiler

Gas-fi red condensing boiler

Gas-fi red condensing boiler + solar energy (domestic hot water)

Gas-fi red condensing boiler + solar energy (domestic hot water and auxiliary heating)

A

B

C

D

E

F

G

H

Gas

Heating feed

Heating return fl ow

Fig. 26: Comparison of the effi ciency of old boilers and gas condensing boilers

Natural gas condensing boilerOld natural gas boiler

10 % 10 % Condensation heat

Unusablecondensation heat

100 % Energy input 100 % Energy input(At a system temperature of 40/30 °C)

Rate of utilisation (Reference: Higher heating value)

90 %

13 %77 %

20 %

57 %

98 %

1 % Flue gas losses

97 %

1 % surface losses

96 %

+10 % 8 % 2 %

32 — 33

Utilisation options of condensing technology

To be able to utilise the energy contained in the fuel in the best possible manner for the heating system, the fl ue gases must be cooled down as much as possible. Different procedures are used for this, mostly combined:

The heat contained in the fl ue gases is transferred to the re-turn fl ow of the heating system via heat transfer surfaces. This takes place either directly in the boiler (“internal condensa-tion”) or in a heat exchanger connected downstream. To enable an optimum heat transfer, the return fl ow temperature should not be increased (using a 4-way mixer or overfl ow valves).

The heat contained in the fl ue gases is utilised for pre-heating the combustion air. This takes place e.g. during the operation of condensing boilers in concentric air-fl ue gas systems (LAS) independent of the ambient air.

In practice, depending on the heating system, about 0.5 to up to 1 litre condensate are accrued during the combustion of one litre of heating oil (energy content approx. 10.68 kWhHs). In modern oil condensing boilers, the fl ue gas temperature is only slightly higher than the return fl ow temperature that is supplied to the device. Thus, the dissipation of fl ue gases from oil condensing boilers can take place through the air-fl ue gas system (LAS) via a plastic fl ue gas pipe. According to the DWA worksheet 251 (Ab-wassertechnische Vereinigung/German Wastewater Association, edition Aug. 2003), oil condensing devices having an output of up to 200 kW do not require any neutralisation of the conden-sate when low-sulphur heating oil is used.

Effective heating with proven technology

The modern oil condensing heating system is a highly effi cient technology for generating heat in the house. More than two-thirds of the newly installed oil heating systems in Germany are now condensing devices – and the percentage is rising.They are technically designed such that they use virtually the entire energy content of the fuel – the so-called higher heating value. In contrast to systems based on standard and low-tem-perature technology, condensing devices also use the heat of condensation of the water vapour contained in the fl ue gas.This results in an effi ciency of 98 % to 99 % relative to the high-er heating value (see Fig. 27).The oil condensing technology is suitable for the modernisation of the heating system as well as for new constructions. Since most of the radiators in existing buildings have fairly large di-mensions, the return temperature of the usual heating systems is below the dew point temperature of the fl ue gas most of the year. Thus, it is possible to condense the water vapour contained in the fl ue gas in the condensing device or in the connected air-fl ue gas system and to supply the heat released in this process to the heating system. If the heating demand is further reduced (because of an insulat-ed building shell or new windows), the return temperature also reduces further, thereby improving the conditions for a particu-larly effi cient use of the condensing technology. If an old standard boiler is replaced with a condensing boiler, the fuel utilisation in-creases from 68 % to 98 % (see Fig. 28).

Oil condensing technology in hybrid heating systems

Fig. 27: Effi ciency of an oil condensing heating system

Low-temperature technologyFlue gas temperature approx. 160 °C

Condensing technologyFlue gas temperature approx. 40 °C

Heating oil EL Heating oil EL6 %

6 %

12 %

0.5 %

0.5 %

1 %

Unusedcondensation heat

Loss of fl ue gas

Totalfl ue gas losses

Unusedcondensation heat

Loss of fl ue gas

Totalfl ue gas losses

Fuel(heating oil ELor natural gas)

Fuel(heating oil ELor natural gas)

Useful heat Heatexchanger

Condensate

Low-temperature

device

Condensing device

11 %

6 %

17 %

0.5 %

0.5 %

1 %

Natural gas Natural gas


Oil condensing technology can be easily combined with solar thermal systems. The solar collectors support domestic hot wa-ter preparation and sometimes also the heating of the building. The combination of a solar thermal system and an oil condens-ing boiler reduces oil consumption by 10 % to 20 %. Therefore, al-most every other oil heater is combined with a solar thermal sys-tem as part of the modernisation of heating systems. For additional information, see page 40 – 41 and 46 –47.

Biomass

Besides the heating concept of oil condensing technology and solar thermal energy, systems that integrate multiple renewable energies are increasingly being set up, e.g. solar thermal system and solid biomass using a wood burning stove.Some special burning stoves have so-called collection basins with heat exchangers, which are connected to the heating system of the house. Thus, the burning stove can transfer a part of its heat to the heat distribution system. This heat is supplied to a buffer storage tank, which in turn is feeding it into the domestic hot wa-ter heating system and the radiators or the fl oor heating system.

Oil condensing heating system as the basis of a hybrid heating system

Because of the high density of energy, heating oil is particularly suitable for cost-effective and compact storage of energy. Thus, it is pre-destined as a medium for fulfi lling the requirements for a decentralised energy supply, as well as for ensuring an effec-tive and safe integration of renewable energies. The energy reserve available with individual users forms a se-cure basis for the “cold season” or a fl exible buffer during short-term weather fl uctuations, whenever renewable energies such as solar heat, wood or RES electricity do not cover the energy de-mand completely. At such times, the oil condensing device switches on automatically without delay and directly accesses the energy reserve.An oil condensing boiler is an ideal module for a hybrid heating system. Extended with a storage tank, it can be easily combined with one or more of the following components:

Solar thermal systems (auxiliary heating and/or preparation of domestic hot water), wood burning stove (with and with-out hydraulic integration in the heating system)

Electric heat generators (Power-to-Heat) for the integration of: – Surpluses from the in-house photovoltaic system – otherwise, regulated quantities of electricity from the main

power supply network

A temporary disconnection of the generation and consumption of thermal energy plays an important role in hybrid systems. Various storage concepts are available for this purpose.

68 % of the new oil devices installed

in Germany in 2013 are condensing devices

Oil condensing technology in hybrid heating systems

Fig. 28: Savings resulting from the use of condensing technology

* IW

O ca

lcul

atio

ns co

mpa

ring

heat

ing

syst

ems i

n m

oder

nisa

tion

proj

ects

, as o

f: 20

13

Oldstandard oil

boiler

Energy utilisation Losses

Example: Single-family house (150 m2) with an average annual consumption of*3,500 litres 2,900 litres 2,500 litres

Low-temperature

oil boiler

Oilcondensing

boiler

32 %

68 % 87 % 98 %

13 % 2 %

34 — 35

vestment costs are lower, because this cost is eliminated com-pletely. Due to the fl uctuating ambient air temperatures that are also low during the heating period, decrease in effi ciency should be reckoned with. Modern heat pumps are used to heat, provide domestic hot wa-ter when required and can also be used for ventilating and cool-ing a building, depending on the model. They work very quietly and are virtually maintenance-free. In particular, a high standard of comfort is assured when using large surfaces for heat transfer. If they receive their drive current from renewable sources, such as wind power or photovoltaic power, they even work emis-sion-free and contribute to climate protection. Many power supply companies also offer special electricity tariffs for operators of heat pumps.

Types of heat pumps

One can distinguish between three types of heat pumps that are used frequently:

Brine-water heat pumps

The brine-water heat pump uses the earth’s heat (geothermal energy) or absorber systems as a heat source. There are two ways to make near-surface geothermal energy usable: Vertical probe systems and horizontal ground collectors.Geothermal probes are placed up to 200 meters deep in the ground through holes – they use an average soil temperature of about 10 °C there. If the land is large enough, the ground can also be tapped by a fl at horizontal collector.Brine-water heat pumps use “brine” for tapping the heat source. This liquid circulates in the geothermal probes.

Free environmental energy from air, water and earth

A heat pump makes the renewable energy stored in the soil, groundwater or air usable for heating purposes. Electric heat pumps are very effi cient: A heat pump with a coef-fi cient of performance of 4.0 can generate four kilowatt-hours of heat from one kilowatt-hour drive current. The heat pump should be designed exact to the individual heat demand, so as to make them achieve this high effi ciency in daily operations.

A closed circuit

The functional principle of a heat pump resembles that of a re-frigerator – only that the refrigerator uses the dissipation of heat, whereas the benefi t of the heat pump is the heating of the heating water: A refrigerant draws heat from the environment and evaporates. Subsequently, the refrigerant is compressed in a compressor. This increases the pressure and temperature of the refrigerant automatically. The refrigerant brought to a higher temperature level in this way then delivers the stored heat to the heating water and condenses again. Expansion and cooling of the refrigerant creates the condition that this circuit can re-start from the beginning.

Heating, cooling and ventilation

Heat pumps work all the more effi cient, the higher the source temperature. Therefore, it is worthwhile to make a heat source with a high and constant temperature usable, for example, the ground: Geothermal heat pumps generate high yields, because the temperature of the soil varies little during the year, and is continuously at a comparatively high level. This is opposed by the cost to tap the heat source. With an air heat pump, the in-

Principle of heat pump and variants

Fig. 29: Functional principle of a motor-driven heat pump

Electrical energy

Compressor

Condenser

Expansion valve

Evaporator

Forward flow

Return flow

3

2

4

1

Environ-mental heat

Thermal heat

A cooled liquid refrigerant is led to the heat exchanger (evaporator) of the heat pump. On account of the temperature gradient, it absorbs energy from the environment. In the process, the refrigerant passes onto the gaseous state.

In the compressor, the gaseous refrigerant is compressed. There is an increase in temperature due to the increase in pressure.

A second heat exchanger (condens-er) transports this heat to the heating system, the refrigerant is liquefi ed again and cooled down.

The refrigerant pressure is reduced in the expansion valve. The process begins anew.

2

1

3

4

The heat extracted from the ground is transferred to the respec-tive heating system after being increased to the heating water temperature. Brine-water heat pumps can reach a coeffi cient of performance of up to 5.0. They are available in different confi gu-rations, with and without integrated domestic hot water storage tank.If the heat pump has a cooling function, it can also be used to keep the temperature of rooms low in summer: Then, the heat extracted from the rooms is delivered to the geothermal probe.

Water-water heat pumps

Water-water heat pumps extract the heat from the groundwa-ter. A suction well draws the water up, the heat pump extracts the heat from it. Then the cooled water is returned to the groundwater by means of an injection well. Since the water-wa-ter heat pump uses the almost uniform high temperature level of the groundwater, approx. 10–15 °C, the coeffi cient of perfor-mance can reach beyond 5.0. Water-water heat pumps are of-fered just like the other heat pump types with or without hot water storage tank. They too have an optional cooling function. In order to install them, a permission must be usually obtained from the local wa-ter authority.

Air-water heat pumps

Air-water heat pumps extract heat from the surrounding air.They can draw energy from the outdoor air even when the tem-perature is -20 °C or less. Air-water heat pumps can achieve only annual coeffi cients of performance from 3.0 to 4.0, because the heat source temperature fl uctuates and is often lower than for other types of heat pumps during the heating period. Tapping of heat sources, which is necessary for brine-water and water-wa-ter heat pumps, is not required for this. Some air-water heat pumps also provide a cooling function that can be used in sum-mer.

A heat pump heats, prepares the domestic hot water and can

also be used for cooling

Principle of heat pump and variants

Fig. 30: Ground-coupled heat pump with vertical probe system

Fig. 31: Water-water heat pump with suction and injection wells

Fig. 32: Air-water heat pump as a split system

36 — 37

Optimisation of operating costs:Depending upon the current energy prices, the hybrid system can determine on its own, which heat generator should be oper-ated so that the operating costs are reduced.

Minimisation of the CO2 emission:For minimising the environmental burden, the hybrid system in-dependently decides, depending upon the expected CO2 emis-sions, which heat generator features minimum environmental burden at the current operating point.

Long-term sustainability due to gradual renovation: An option for a gradual energy related modernisation is the ex-tension of the existing heating system with a heat pump. By ren-ovating the building shell, the heat load of the building reduces and the existing boiler can be put out of operation at a later point of time.

Redundancy:Since varied fuels are used, the hybrid heat pump offers greater security of supply.

Grid capacity:If the technical conditions for connection do not allow the oper-ation of just the heat pump alone, the bivalent operation of the hybrid heat pump reduces the maximum electrical power con-sumption.

Two components for optimum heating

These are heating systems with an electrically operated heat pump in combination with at least one fossil heat generator (e.g. oil, gas or solid fuel boiler) and one comprehensive control system. Hybrid heat pumps are either available as one complete unit or individual components are brought together to form one hybrid system.

There is a number of good reasons for using hybrid heat pumps:

Supply temperature of the heating system (heating and prepa-ration of domestic hot water):If the heat pump is unable to provide the supply temperature re-quired for the heating system throughout the year on its own, the second heat generator steps in. Instead of renewing the heat distribution system for reducing the system temperatures, the hybrid heat pump offers a more economic alternative.

Heat output (heating and preparation of domestic hot water):If a heat pump is unable to provide the essential heat output throughout the year on its own, the second heat generator helps in covering the peak load.

Temperature of the heat source:If the heat source temperature falls below the minimum permis-sible value (e.g. when an air-water heat pump is used in colder regions), the hybrid heat pump system balances the tempera-ture difference.

Hybrid heat pump systems

Fig. 34: Bivalent parallel operation

External temperature (°C)

-10 0 +10 +20

100

80

60

40

20

0

Hea

t loa

d (%

)

B

A

Fig. 33: Monovalent operation


-10 0 +10 +20

100

80

60

40

20

0

Hea

t loa

d (%

)

A

Heating limit temperature

Heat load

Heat pump

A Bivalence point A


B

Heat load

Heat pump

Secondheat generator

The heat pump and the second heat generator complement

each other in the hybrid system

Modes of operation for heat generation in the hybrid heat pump system:

Monovalent operation (Fig. 33) The heat is provided exclusively by the heat pump. No other

heat generator is required.

Bivalent parallel operation (Fig. 34) Above the bivalence point, the heat is provided exclusively by

the heat pump. Below the bivalence point, other heat genera-tors are simultaneously operated with the heat pump.

Bivalent alternate operation (Fig. 35) Above the switching off point, heat is provided exclusively by

the heat pump. Below the switching off point, other heat gen-erators are used, which provide the entire thermal heat.

Bivalent partially parallel operation (Fig. 36) Above the bivalence point, the heat is provided exclusively by

the heat pump. Below the switching off point, other heat gen-erators are used, which provide the entire thermal heat. Be-tween the bivalence point and the switching off point, the heat pump and additional heat generators are working simul-taneously.

Mono-energetic operation: Here, an auxiliary electrical heating system is used as another

heat generator. All the modes of operation mentioned above are possible.

A variable system with a wide range of applications

Hybrid heat pumps are suitable for installation in new buildings as well as in existing buildings. They guarantee that the building is heated at the most favourable prices at any given point of time; because they can easily react to any fl uctuations in the energy price by using the second heat generator. This function is gener-ally integrated in the control of most of the hybrid heat pumps.

Hybrid heat pumps could be a key to resolving the current mod-ernisation backlog.

Careful planning is an important prerequisite for the selection of a hybrid heat pump. First of all, the output of the heat pump and other heat generators must be optimally aligned, to ensure that hybrid heat pumps always work economically.

Hybrid heat pump systems


-10 0 +10 +20

100

80

60

40

20

0

Hea

t loa

d (%

)

Switching off point


B

A

A

B

Fig. 35: Bivalent alternate operation

Heat load

Heat pump



-10 0 +10 +20

100

80

60

40

20

0

Hea

t loa

d (%

)

Fig. 36: Bivalent partially parallel operation

Bivalence point

Switching off point


C

AB

A

B

C

Heat load

Heat pump


38 — 39

The gas heat pump in new buildings:

During the construction of a new building, the requirements of the EnEV (Energy Saving Ordinance) as well as EEWärmeG (Re-newable Energy Heat Act) must be fulfi lled.

Internally, all gas heat pumps use a circulating working medium, which constantly changes its physical state by absorbing and giving out heat: This medium vaporises when the ambient heat is absorbed (free of cost) and turns into liquid when the useful heat is released.

Adsorption gas heat pump

In the adsorption technology, the refrigerant (e.g. water) vapor-ises when ambient heat is supplied at a low temperature. The vaporised refrigerant is deposited (adsorbed) on the surface of a solid material (e.g. zeolite). Heat is released at a higher tempera-ture in this process. After the sorbent saturates, the refrigerant is once again released in the desorption phase. For this purpose, heat is utilised from a gas condensing unit integrated in the de-vice. The water vapour gets liquefi ed and the condensation heat in the condenser is released.The process takes place at negative pressure. In both the phases (adsorption and desorption phase), energy is released to the heating circuit in the form of heat.

Adsorption phase (Fig. 38):The refrigerant, water is vaporised through ambient heat from outside (free of cost) and adsorbed by the solid material (e.g. ze-olite). In this process, the sorbent is heated to the fl ow tempera-ture.

Desorption phase (Fig. 39):The refrigerant (e.g. water) is released from the sorbent by heat-ing with a gas condensing boiler, liquefi ed by the condenser, through which the heating water fl ows, and collected in the col-lecting tank.

Maximum effi ciency with natural gas/liquid gas by using renewable energies

The gas-fi red heat pump combines high effi ciency gas condens-ing technology with the use of environmental heat.Hitherto unreached effi ciency, high ratio of renewable energies, high degree of suitability in practical use, thanks to versatile en-vironmental heat sources and a very good CO2 balance make this system one of the most economically and ecologically viable heat generators in new buildings as well as existing buildings.

The gas heat pump in existing buildings:

Gas heat pumps enable simple and effective energetic moderni-sation of the existing gas heating systems. The existing heat dis-tribution and heat emission system, a solar thermal system and the existing gas infrastructure can be largely retained.

Gas heat pump

Fig. 37: Example of existing building (150 m2 living space)Primary energy demand based on the example of different heat generators with the energy carrier, gas during the period 1970 – 2014

Sour

ce: I

TG D

resd

en

Fig. 38: Adsorption phase Fig. 39: Desorption phase

238

Ref

207

180166

146135

13 %24 %

30 %

7%21% 26%

39 %43 %

Old

atm

osph

eric

boi

ler,

year

of c

onst

ruct

ion

1970

kWh/

m2 a

Gas

-fire

d he

at p

ump

+ so

lar D

WH

Gas

-fire

d he

at p

ump

Cond

ensi

ng b

oile

r + so

lar D

WH

Cond

ensi

ng b

oile

r

Curr

ent l

ow te

mpe

ratu

re b

oile

r

Primary energy demand of gas devicesShare of renewable energies in %CO2 reduction in gas devices

Gas adsorption heat pumps for supplying heat to single-family houses always work together with a gas condensing boiler inte-grated in the device. Besides the thermal driving power for the system, the condensing boiler also offers other benefi ts – cover-ing of peak loads as an effective heat generator, particularly for very high temperatures (e.g. for domestic hot water heating ≥ 60 °C).

Absorption gas heat pump

Absorption heat pumps (Fig. 40) operate with a continuous refrig-erant circuit under overpressure. The temperature level required for this is achieved with the help of a thermal compressor. First, gaseous refrigerant (e.g. NH3 – ammonia) is released from the solvent (e.g. water) by means of heat supplied by a built-in gas condensing device (desorption) and then condensed in the condenser by releasing the useful heat to the heating system.Passing the expansion valve, the liquid refrigerant reaches the evaporator, where the ambient heat is absorbed and transmit-ted to the refrigerant. The refrigerant, in the gaseous state, fl ows to the absorber, meets the expanded solvent and is absorbed by it. The heat released in this process is also supplied to the heat-ing system. As compared to all the other heat generators using fossil fuels, the gas heat pump features the lowest primary energy demand and maximum heat yield per kilowatt hour of natural/liquid gas used.

Conclusion

Low primary energy demand and low CO2-emissions as compared to conventional heat generators, thanks to the integration of regenerative environmental heat

Future-oriented new constructions: Fulfi lment of legal requirements for primary energy

consumption and integration of renewable energies. Economic modernisation:

Existing radiators or fl oor heating systems, pipe networks and systems for fl ue gas evacuation can stay in use most of the times. An existing solar thermal system can be integrated.

Flexible combination options with all environmental heat sources, e.g. sun, earth, air and water

Low installation and maintenance cost The range of devices includes solutions with various device

confi gurations and output classes.

The gas heat pump is a systematic further development of the

established gas condensing technology

Gas heat pump

Fig. 40: Absorption gas heat pump

Refrigerant, liquid

Thermal heat

Pressure reducingvalve

Pressure reducingvalve

Refrigerant Vaporous

Evaporator

Environmental heat

Condenser

Solutionpump

Natural gas

Generator

Absorber

Thermal heat

Thermal compressor

40 — 41

Solar Thermal Systems

Collector fi eldA

Solar stationB

Solar storage tankC

Heat generatorD

Fig. 41: Standard solar thermal system in one-family house

Solar storage tank

D

A

BC

Application in the system

In solar thermal systems, the solar energy is used to extract ther-mal energy for heating. Solar collectors convert sunlight into heat that is used for heating systems in buildings. This saves a lot of energy and thus, fuels as well. Solar thermal systems are usually designed bivalent. Thus, to make use of solar energy, the system must be well-matched with the other heat generators – the components should not work against each other. Because in the end the desired savings can be achieved only with an overall system with optimised con-trol technology and hydraulics.

Domestic hot water preparation

If the solar thermal system is used to prepare domestic hot wa-ter, solar collectors will be installed at fi rst on the roof to heat up the heat transfer medium by solar energy. Generally, a frost-proof and heat-resistant medium is used as the heat transfer medium in the solar circuit. The heat produced in this process heats the solar storage tank via a heat exchanger. Only when the solar en-ergy is not enough, the conventional heat generator is turned on. Other components of the system are pumps, temperature dis-play, expansion tank, vent and controller for regulating the solar pump.

Auxiliary heating

If space heating is required besides domestic hot water prepara-tion, the collector surface must be increased by 2 to 2.5 times. Depending on the heat insulation of the building, this saves 10 % – 30 % of fuel. In case of low-energy buildings, you can save up to 50 % on fuel.

Storage tank

In auxiliary solar heating, either a second storage tank (buffer storage) or a combined storage tank with built-in domestic hot water preparation unit is used. All systems are also available with batch loading facilities.

Large potential

Solar thermal systems for domestic hot water preparation and auxiliary heating are now mainly installed in residential build-ings – especially in one and two-family houses. But also for multi-family residential buildings high growth rates are expected in the future. Grants and low-interest loans accelerate this trend. Even hospi-tals, hotels and sports facilities can save energy using a solar sys-tem. Almost all heat consumers can make use of auxiliary heat-ing using solar thermal systems.

Solar thermal systems allow combination

with all heat generators

Solar Thermal Systems

Fig. 44: System example – Flat plate collector Fig. 45: System example – Vacuum tube collector

CollectorA

Solar stationB

Solar storage tank

C

Heat generatorD

A

B

C

D

Fig. 42: Standard solar thermal system for domestic hot water preparation in one-family house

CollectorA

Solar stationB

Combined storage tank

C

Heat generatorD

A

B

C D

Fig. 43: Solar thermal system for supporting space heating and domestic hot water preparation with combined storage tank

Compliance with legal requirements

The energy requirements for new buildings and system moderni-sation all over the world are increasing. Often, solar thermal sys-tems help in fulfi lling these requirements. As regards classifi ca-tion of the energy label, the use of solar thermal energy ensures a higher energy effi ciency class of the original heat generator.

Other applications

Solar collectors can also produce hot water for outdoor and indoor swimming pools, thus saving a substantial part of the energy costs. In southern countries, there are systems that operate on the thermo-siphon principle with a heat-insulated storage tank above the collector. The support given by solar thermal energy to commercial or in-dustrial processes is still in its infancy, but offers huge potential.

Wide scope of applications

Almost all the requirements and technical systems in the heat-ing market can be meaningfully combined with a solar thermal system. Ready-made system solutions are now available for most applications. These pre-assembled systems shorten the set-up time signifi cantly. The unit pre-assembled as a solar station allows quick and safe commissioning. High workmanship and good material ensure reliability and secure the energy savings over decades.

42 — 43

Solar Thermal Systems: Components

Collectors

The member companies of BDH produce collector types with dif-ferent parameters and dimensions. All collectors are characterised by their high quality and particularly long service life. Besides ar-chitectural considerations, the selection of the collector always depends on the intended application.

The solar liquid fl owing into the solar collectors is frost-proof down to -30 °C and biologically safe. The pump for the solar cir-cuit is very economical to use and is regulated, depending upon the solar radiation. All fi ttings and pipes are suitable for high temperatures and operate with glycol.

Flat plate collectors

Flat plate collectors are currently the mostly used collector type in Germany and Europe. During operation, selectively coated high-performance absorbers always ensure maximum possible heat yields.

Besides, these collectors allow versatile architectural design op-tions and are suitable for both in-roof installation as well as on-roof or fl at roof mounting.

Vacuum tube collectors

Vacuum-assisted insulation (evacuated glass tube) allows achievement of high outputs in applications with high target temperatures. In standard applications, the vacuum tube collec-tor requires a smaller area than a fl at plate collector, based on the average annual output.

Storage tank

For all applications, sophisticated types of storage tanks are available to the consumers (bivalent domestic hot water storage tank, buffer storage tank and combined storage tank). Common quality characteristics are their slim, tall design and seamless in-sulation, with which the stored heat can be best maintained.

Control

Modern controls ensure safe and effi cient operation of the entire system. Often, the functions of the solar thermal system are al-ready integrated in the control for the heating system. This guar-antees the perfect interplay of all components.

Fig. 46: Practice example for the application of solar thermal system with vacuum tube collectors

Fig. 47: With an external refl ector

Fig. 48: Without refl ector

The different components allow a versatile use of

solar thermal systems

Solar Thermal Systems: Components

Fig. 49: Practice example for the application of solar thermal system with fl at plate collectors

Fig. 50: Installation of a fl at plate collector

B

A

C

Selectively coated absorbers

Insulation

Absorber tubing

A

B

C

44 — 45

Living room devices with collection basin

In living room devices with so-called collection basins, the heat-ing water circulates inside the fi replaces. The devices are inte-grated into the centralised heating and hot water system of the house via a built-in heat exchanger. In addition to direct heat emission to the room in which the fi replace is installed, heat for auxiliary heating and/or domestic hot water preparation is also produced in the furnace.

In low-energy buildings, such a pellet furnace or wood burning stove with collection basin can signifi cantly relieve the load of the main heating system.

If living room devices with collection basin have to be used for domestic hot water preparation, they should also be in opera-tion during summer – even when heating of the indoor air is not necessary. Therefore, this heating system is best combined with a solar thermal system: Thus, each of the two heating systems can prove its unique strengths during the appropriate season and completely replace the central heating system in the passive house.

Example: Pellet furnaces for the living room

Pellet furnaces for the living room offer numerous advantages: The pellets are led automatically from the storage container di-rectly into the furnace. The control is electronic – depending on the desired room temperature. It is more accurate, convenient and effi cient and features better emission properties as com-pared to manual fi ring.

Heating devices of the latest generation have high effi ciencies of over 90 %, radiate a pleasant warmth and have low emissions.

Interested parties can choose from a wide range of models in various designs, sizes and price ranges. Automatic operation be-comes very convenient through the use of modern control sys-tems, such as indoor or time-controlled thermostats; moreover, remote control via mobile phone is also possible. Of course, oper-ation can be controlled irrespective of the indoor air tempera-ture upon request.

Pleasant warmth from nature

Modern heating systems were operated for many years almost exclusively with oil or gas. Today, a fuel with a long tradition is used more intensely: Wood is a constantly renewable resource, which can be obtained relatively easily with little energy ex-penditure. Especially in Germany, which follows the principle of sustainable forestry, not more wood is cut from forests than is regrown. This makes wood particularly environmentally-friend-ly. Moreover, thanks to the high volume of wood in Europe, the long-term supply of wood is secured.

Wood can be used in various forms for heating: The most com-mon is the use of split logs, wood pellets and wood chips. Wood is suitable for heating individual rooms and as a fuel for central-ised heating of the entire building. The heat demand, the stor-age options, manual labour associated with the wood and the individual preferences of the owners and residents are primarily decisive factors for the selection of the wood boiler device.

Single-room furnaces for the living room

Two effective device types are available for the heating of indi-vidual living rooms: Air-guided living room devices and living room devices with collection basin. In both types, split logs, wood pellets and wood chippings are especially used.

Air-guided living room devices

This category includes especially wood burning stoves and pellet furnaces: Both furnace types burn the wood in a separate com-bustion chamber, emitting less pollutants. Air ducts in which the indoor air heats up go past the combustion chamber. The indoor air is then passed back into the living room.

Moreover, the furnace itself dissipates radiant heat which is felt by many people as particularly pleasant.

These single-room furnaces with direct heat radiation have an output range of up to 10 kW. They are used primarily for heating individual rooms, as additional or transitional heating and to cover peak loads

Heat from wood

Efficient single room furnaces with wood supplement

the heating system

Heat from wood

Fig. 51: Wood and wood pellets are CO2-neutral fuels Fig. 52: Pellet furnace with pellet storage container

Pellet primary furnace

Adapter assembly for hydraulic connection of the furnace to the buffer storage tank

Central heating boiler

Buffer storage tank

Hot water consumer

Radiators

Solar collectors

1

2

2

3

3

4

4

5

5

6

6

66

67

7

Fig. 53: Integration of a wood burning stove with collection basin in the heating system

1

46 — 47

vals of once or twice daily are possible – even in winter. This en-sures a signifi cantly higher operating comfort.

Wood chip heating systems

As in the case of pellet heating systems, the combustion material in wood chip heating systems is also automatically transported from the storage room to the wood boiler – often with a screw conveyor or using a similar technology. In order to ensure a high degree of system effi ciency, an electronic control system con-stantly regulates the combustion process. With this control sys-tem, varying fuels also do not affect the combustion values sig-nifi cantly, thus ensuring an output adjustment to 30 % of the rated heat output.

The output range of wood chip central heating systems ranges from 30 kilowatts to several megawatts. Since the economic ef-fi ciency of a wood chip heating system increases with its size, these systems are often used in multi-family houses, in the food service industry as well as in large residential or industrial com-plexes. Wood-processing companies often use wood chip heat-ing systems, since the routes for transporting the fuel are short-er and this increases the benefi ts of the system considerably.

Pellet heating system

Central heating systems which are operated with pellets, offer a very comfortable method of generating heat from wood. Gener-ally, wooden pellets are transported from the storage room or tank to the boiler via a suction or screw conveyor system. Thanks to the fuelling and conveying techniques available, the system can be installed in almost every object. The pellet boilers achieve a high degree of effi ciency of over 90 % during a fully automatic

Wood fi red central heating

Whether single- or multi-family houses, commercial enterprises or local heating networks: Modern central heating systems based on wood, supply heat to buildings of every size fl exibly – with the renewable fuel wood, in an environmentally friendly and CO2-free manner. Wood central heating systems are often the key to tapping favourable funding sources, because they can benefi t from public support programmes. Besides manually op-erated split log boilers, automatic central heating systems are al-so available for the use of wood chips and pellets. A common factor is the advanced technology and the resultant effi cient and low-emission combustion.

Split log boilers

In modern split log boilers, the so-called wood gasifi cation boil-ers, both the combustion stages (gasifi cation and combustion) are separated locally. This effi cient technology ensures a high degree of effi ciency of the boiler, low fl ue gas temperatures and minimum emission – provided the heat exchanger surfaces of the system are suffi ciently dimensioned. The induced draught fan and the combustion air supply also have a decisive infl uence. They ensure an appropriate and suffi cient air supply. While the primary air supply guarantees optimum wood gasifi cation (out-put), the secondary air supply provides a complete combustion (low emission).

A properly dimensioned buffer storage tank is not only pre-scribed by law, but also technically essential, as contemporary split log boilers work intermittently. The boiler is fi lled and then the fuel is completely burnt within several hours, after which it is fi lled again. Because of the buffer storage tank, refi lling inter-

Heat from wood

Fig. 54: Wood central heating system operated with pellets, with fuelling system

Fig. 55: Sectional view of a wood chip heating system

operation, while maintaining low emission values. These fea-tures coupled with a modulated performance put pellet heating systems absolutely at par with oil and gas fi ring systems.

Heat from wood in the hybrid system

Wood central heating systems can easily be combined with solar thermal systems and thus, become even more environmentally friendly. If both systems are used together, the wood heating system will be the primary heat source. When space heating is not required, e.g. in summer, the wood heating system can re-main switched off – the solar system will then assume the task of supplying domestic hot water.

Even in winter, the solar thermal system distinctly supports the wood heating system, given the correct design. Often, one buffer storage tank is suffi cient for both systems. It stores the energy of the solar thermal system and also of the wood fi ring system.

A wood heating system can also be combined with an oil or gas fi ring system. In most cases, such a system is a combination of a manually fed wood heating system and an automatic oil and gas heating system, which acts as a “backup” or helps in increasing the degree of comfort . If the generated heat output of the wood heating system is too low, for example because there is nobody in the house to refi ll, the oil and gas fi ring system starts auto-matically.

The wood central heating system is a genuine alternative

to oil and gas

Heat from wood

Fig. 56: Schematic presentation of a hybrid system, a combination of pellet heating system and solar thermal system

48 — 49

The decentralised CHP is particularly profi table if heat and elec-tricity are produced where they are needed, no heating grids are required and the equipment are operated at the base load (i.e. with operating times of more than 3,000 hours per year).

In many countries, the use of decentralised CHP is particularly encouraged. As a rule, self-generated electricity is subsidised, and there are incentives in the payment of taxes on energy.

Generates not only heat but also electricity

Conventional heating systems work according to a clear principle: The used energy medium is converted into heat.

The so-called decentralised cogeneration of heat and power (CHP) system generates both electricity and heat. This saves fuel and increases the fuel effi ciency of the system. Very high overall effi ciency of over 90 % can be achieved through simultaneous production of electricity and heat. Losses due to waste heat, re-sulting in separate power generation in power plants, are avoided.

A power-generating heating system reduces energy costs and the primary energy demand, as well as climate-damaging CO2 emissions. Thus, it makes a direct contribution to environmental protection.

The power-generating heating systems

Fig. 57: Comparison on the basis of primary energy

Power generationEffi ciencyEnergy use

Primary energy

Losses

Separate generation

55 %

100 %

62 %

2 % power transmission losses

6 %

157 %

Decentralised cogeneration of heat and power87 %

100 %

Condensationpower plant

100 % 36.0 %

100 %Oil/gas

Cogeneration of heatand power

70 % 13 %

36 %

51 %

Saving by

Power plant Coal = 38 %

Oil/gas boiler = 90 %

Fields of application and their advantages

The range of decentralised CHP solutions offered is as broad as the demand:

For single and two-family houses, there are so-called “micro-CHP systems” with a power range up to about 2 kWel.

For apartment houses and small and medium-sized businesses, there are “mini-CHP systems” with a power range up to 50 kWel.

In the industrial sector and large residential complexes, CHP systems with more than 50 kWel power are used.

Decentralised cogeneration of heat and power is a technology with a great future. Many decentralised CHP systems – together as a kind of “virtual power plant” – could soon help compensate for voltage fl uctuations in the public grid, e.g. to pick up peak loads. This is necessary, e.g. in weather-related power fl uctua-tions – a predictable consequence of the development of solar and wind power plants. CHP systems are designed according to either the power de-mand of an object (power oriented) or the heat demand of an object (heat oriented). Generally, most of the systems are de-signed according to the heat demand of buildings.

However, the heat from decentralised CHP systems is used not only to supply the building with heat and domestic hot water. It is also used as process heat, for technical refrigeration, com-pressed air supply and allows other technical applications.

There is no standard classifi cation of CHP systems. But small sys-tems are usually classifi ed as follows depending on their electri-cal power:

Micro-CHP < 2 kWel

Mini-CHP 2–50 kWel

Small-CHP 50 kWel –2 MWel

The so-called micro-CHP systems with specifi ed power outputs of 0.3–2 kW (electric) and 2.8–35 kW (thermal) cover the lowest power segment of the CHP technology.

In terms of their dimensions and weight, micro-CHP systems are comparable with conventional heating technologies.

Micro- and Mini-CHP systems are generally operated with con-densing devices. They are suitable for installation in the cellar and on the roof same as in the living room. The systems are eas-ily integrated into existing heating systems and help to reduce the consumption of electricity from the public grid. Excess power generated can be fed into the public grid. The local power utility company takes it off and pays for it as well.

Micro CHP technologies

Micro-CHP systems from several manufacturers are currently available. They can be primarily distinguished

by the technology used, by their power and thermal output and their ratio to each other (coeffi cient of power),

by the possibility of modulation and the fuel used.

Heat and power units and fuel cells are available as basic tech-nologies. The former units are classifi ed as follows:

Internal combustion engines (e.g. petrol engine) External combustion engines (e.g. Stirling engine and steam expander)

and micro-sized gas turbines.

The most developed micro-CHP systems that are already availa-ble in the market are based on combustion and Stirling engines.

Stirling engine

The Stirling engine works with external combustion, through which a working gas (such as helium) is heated from the outside.

All-in-one system: Heat, power and

domestic hot water

The power-generating heating systems

50 — 51

Stirling engines operate quietly, with low emissions and wear-less. Similar to refrigerators they have hermetically sealed work-spaces, which reduces maintenance costs considerably. Relative-ly low electrical effi ciencies (about 10–15 %) are combined with high thermal effi ciencies, so that an overall effi ciency of over 95 % can be achieved.

The gas expands and fl ows into the region which is cooled with water from the heating circuit of the building. There, a working piston is pushed upwards, as a result of which the piston in the hot area displaces more gas into the cooler area. After the piston has reached the top dead centre in the cold region, it pushes the cooled air back into the hot area. There, it is reheated, expands and the process restarts from the beginning.

Sour

ce: A

SUE

Fig. 58: Functional principle of Stirling engine

1. Working medium is heated byan external heat source, expands and fl ows into the cooler area.

2. There piston A is pushed upwards, as a result of which piston B displaces more hot gas in the cooler area.

3. Piston A presses the cold air into the hot area, where it is reheated, expands and the process restarts from the beginning.

Now, a current can be generated between the cathode and an-ode. If both the electrodes are connected, the electrons will fl ow from the anode to the cathode and generate driving power in this process. The heat generated during the reaction can also be used for heating. Hydrogen can be supplied directly. Natural gas can also be introduced with an upstream reformer.

The DIN SPEC 32737 describes a set of rules for the energy evalu-ation of fuel cells, which is derived from DIN V 18599-9 for energy evaluation of CHP systems and takes into account the pre-de-fi ned marginal conditions of the Energy Saving Ordinance. The procedure refers to fuel cells with a thermal output between 0.3 kW and 5 kW, which are used in residential buildings or other objects with similar use and are operated on the basis of heat. Prerequisite for the use of DIN SPEC 32737 is the availability of parameters such as outputs and effi ciencies, which are formu-lated in DIN EN 50465.

Heating devices with fuel cells also offer the possibility of pro-ducing heat and power in one’s own home.

How they work

Fuel cell heating devices make use of the principle of reversed electrolysis. This implies a “oxyhydrogen reaction” of the hydro-gen used, under controlled conditions without external power supply. This process is known as “cold combustion”. In this pro-cess, electrical energy and heat as well as water are generated.

A fuel cell is made up of two electrodes – the anode (negative pole) and cathode (positive pole). They are separated from the electrolyte with a fi xed, ion-permeable membrane. Each elec-trode is coated with a catalyst, e.g. nickel or platinum. After hy-drogen is supplied to the anode, the hydrogen breaks up into electrons and protons.

The free electrons are used as a useful electric current by the ex-ternal circuit. The protons spread to the cathode through the electrolyte. On the cathode, oxygen from the air combines with the electrons from the outer circuit and the protons. The result is water and heat.

All-in-one system: Heat, power and

domestic hot water

CHP with fuel cell technology

Fig. 59: Functional principle of a fuel cell

-

-

-

-

-

-

- - - - --

V- +

H2O2

H O2Water Cathode

Air

DC current

Anode Electrolyte membrane

O2-

H+

52 — 53

Heat distribution, heat emission, system componentsHeat distribution

Embedded surface heating and cooling systemRadiators

Residential ventilation systemsHouse ventilation systems with heat recovery/moisture recovery

Storage technology

Flue gas systems – fl exible systems for various fi elds of application

Tank systems

Smart control and communication technology

54 — 55

Heat distribution

Fig. 60: Fittings

Fig. 61: Hydraulic balancing

Heating surfaces (radiator (left) or embeddedheating/cooling system (right)) – Volume fl ows balanced properly – cold return fl ow

Heating surfaces (radiator (left) or embeddedheating/cooling system (right)) – Volume fl ows not balanced properly – hot return fl ow

Hydraulic balancing saves costs and reduces emis-sions

A major part of the energy utilised in Germany, is consumed by residential buildings, particularly as heating energy. Hydraulic balancing is an effective means of saving heating energy. In hy-draulic balancing, the aim is to coordinate the individual compo-nents of a heating system exactly in such a way that the heat reaches where it is required. This sounds logical, but is rarely im-plemented: Very few heating systems in Germany – only about 15 % – are currently hydraulically balanced. Taking climate-pro-tection goals into account, this means that an annual reduction potential of around 10 to 15 million tonnes of CO2 remains un-tapped.

The path of least resistance

With hydraulic balancing, a uniform heat distribution can be achieved in a building. Here, the heating system setting is such that the system made up of pipes, pumps and valves offers min-imum possible resistance to the circulating water. This is be-cause the water in the heating system takes the path of least re-sistance, with the consequence that the heating surfaces in distant rooms are occasionally not heated properly. Powerful cir-culation pumps must balance this out and transport the hot wa-ter to the distant heating surfaces. The price of this is very high: Energy consumption and electricity costs shoot up, since the pumps consume more electricity than required.

Moreover, a non-balanced system can signifi cantly reduce the effi ciency of condensing boilers: Oversupply to certain heating surfaces leads to higher return temperatures in the system. The water in the fl ue gases of the heating system can condense only in a limited manner or not at all. Therefore, less heat is used and the savings that are usually achieved with a condensing boiler are nullifi ed.

Sounds as indicators

The typical signs for absence of hydraulic balancing are, for ex-ample, radiators which do not heat up whereas others are over-supplied. Also, noises in valves or pipes indicate that the differ-ential pressure in the valve or the velocity of fl ow is too high. It may also happen that the radiator valves do not open or close at the desired inner temperature due to excessive differential pres-sure. Hydraulic balancing offers several advantages to the resi-dents: The system can be operated with optimum system pres-sure and a lower volume fl ow rate. This reduces the energy and operating costs: Saving of up to 15 percent of the heating energy costs is possible.

EnEV, VOB & Co.

The Energy Saving Ordinance (EnEV) requires that technicians confi rm in writing, as part of the subcontractor declaration, that their services comply with the ordinance, that the hydraulic bal-ancing has also been executed, in case it has been included in the verifi cation procedure. Even according to the German Con-

Hydraulic balancing allows an optimum heat distribution

in a building

Heat distribution

Fig. 63: High-performance pumps according to Eco-Design Directive 2013

Fig. 62: Savings potential of pumps

Typical powerconsumption for a single-

family house (3 persons) – data from

Stiftung Warentest 09/2007

The heating pump: From energy wasterto energy saver

struction Contract Procedures (VOB) Part C and DIN 18380, it is mandatory for technicians to balance the heating pipe networks hydraulically. In addition, it is required by all relevant funding programmes of KfW or the Federal Offi ce of Economics and Ex-port Control (BAFA).

Calculating the heating load, adjusting the heat output

For hydraulic balancing, it is fi rst necessary to calculate the heat load for every room in the building, taking into account the ex-ternal surfaces, walls, ceilings, windows and doors. According to the calculated heating load, the heating surface with the re-quired heating output is chosen. Additionally, the different pres-sure drop en route the heat generator to the heating surface should be taken into account. The setting values for the individ-ual heating surfaces are derived from all these parameters. Hy-draulic balancing is achieved when all parallel systems have the same hydraulic resistance.

Thermostat valves or return fi ttings on the radiators that can be preset, support the hydraulic balancing. It is also important to determine if the concerned system is a dual pipe system, be-cause a single pipe system allows only for restricted balancing. The data for a single-family house is recorded in about one and a half hours and analysed in about 1-2 hours. The setting is done in just fi ve minutes for each heating surface. The costs for hy-draulic balancing depend upon the size of the building; the costs for a single-family house amount to approx. 500 Euro, which can however be redeemed quickly, thanks to the energy savings.

Effi cient circulation pumps controlled based on the demand

Inspection of the installed pump is always a prerequisite for hy-draulic balancing. Overdimensioned and unregulated pumps need to be replaced so that the benefi ts of hydraulic balancing can be fully utilised. Since 2013, newly integrated circulating pumps must comply with the Eco-design requirements put forth by the EU directive; these are more stringent than the compli-ance requirements of the previous effi ciency class A. Thus, the corresponding pumps fulfi l two important aspects: They are much more effi cient and adapt to the changing volume fl ow de-mand of the system. Thus, they not only save valuable electrical driving power in the full load state, but also in the predominant-ly encountered partial load condition of the heating system.

Fig. 64: Valve with valve core that can be preset for adaptationof the volume fl ows to the required heat load

38 Euro200 kWh

63 Euro330 kWh

85 Euro445 kWh

36 Euro190 kWh

47 Euro245 kWh

63 Euro330 kWh

350-800 kWh 67-150 Euro

11-29 Euro60-150 kWh

Washingmachine

Fridge

Electric cooker

Television set

Dishwasher

Lighting

Central heatingpump, old

Central heatingpump, new

56 — 57

Embedded surface heating and cooling system

Heating and cooling in one system

A majority of builders opt for an embedded surface heating and cooling system in new buildings. The heating system is perma-nently installed in the fl oor, wall or ceiling during the construc-tion phase itself. Because of the large-area span, the embedded surface heating and cooling system is able to bring about a uni-form temperature distribution, thus, ensuring a pleasant room temperature throughout the year. Considering larger window areas and increasing building insulation, the option of cooling in summer is constantly gaining importance and possible with the same system. This functionality is not only applicable in apart-ments, but also in offi ce buildings or halls.

Wide range of solutions also for building stock

Often, conventional underfl oor heating systems cannot be in-stalled in existing buildings, since the additional base structure is too high or the ceilings are subjected to extreme static load. Hence, special embedded heating and cooling systems are of-fered for subsequent integration in fl oor, wall and ceiling with-out any structural changes. The versatility of wet systems (screed or plaster), dry systems and special thin-layer systems offers op-timum solutions to the builder for the use in new buildings as well as for modernisation.

Practically unlimited range of application

Apart from the already described fi eld of residential buildings, the embedded surface heating and cooling system can be used in offi ce buildings and halls. As part of a central heating system, the embedded surface heating and cooling system also ensures a pleasant thermal comfort throughout the year as well as energy effi ciency.

More comfort, less costs

In embedded heating systems, only low system temperatures are generally required (35 °C fl ow temperature/28 °C return tem-

perature). Thus, they are an energy-effi cient supplement for con-densing boilers, heat pumps and solar thermal systems. The low system temperatures benefi t the residents in two ways: they provide energy saving potential and an enormous increase in cosiness and comfort. This can be additionally supported with intelligent single-room controls.

Last but not the least, the invisible embedded surface heating and cooling system in the fl oor, wall and ceiling offers the advantage of leaving ample space for the residents for interior decoration.

Effective cooling in summer

In summer, the embedded heating system can also be used for simple room cooling, cost-effectively, with the help of an extra “Cooling” function. In this process, cold water circulates through the pipes and lowers the temperature of the fl oor, wall or ceiling and thereby of the rooms by up to 6 Kelvin (K), without the oc-currence of any draughts.

The effi ciency of an embedded cooling system is determined by the difference between the fl ow and return fl ow temperature of the coolant. While the temperature difference during the heat-ing process is about 8 K normally, an embedded cooling system should not be operated with a spread of more than 3 K. Due to the low temperature difference between the temperature of the coolant and ambient air, e.g. 18 °C coolant fl ow temperature, an embedded cooling system is also ideal for making use of natural heat sinks such as ground water or soil for allowing an energy-saving cooling operation.

Controller prevents condensation

A controller which covers both the heating and cooling function is required to regulate the system temperature during cooling operation. The controller maintains the temperature of the em-bedded cooling system above the dew point, thus preventing condensation on distribution pipes and transition areas.

Fig. 65: Easy installation of the embedded surface heating and cooling system with different installation systems.

Two functions (heating and cooling) freely connected

to all heat generators

Embedded surface heating and cooling system

Fig. 67: A suitable control system enables optimum use of the embedded surface heating and cooling system.

The different designs of the embedded cooling system in the liv-ing areas of a residential building or offi ce building reach a cool-ing capacity of about 35 W/m2 in the fl oor, about 35 to 50 W/m2 in the wall (depending on the layout) and about 50 to 110 W/m2 in the ceiling (depending on the layout) on an average.

Remote-controlled room temperature

The options offered by the current control technology for em-bedded surface heating and cooling systems can be utilised fully only in combination with state-of-the-art communication tech-nology. Thus, the embedded surface heating and cooling system can be controlled from home, remotely or via App, through WLAN, or also via Internet when not at home. An embedded surface heating and cooling system can be controlled from a central com-puter that manages all data, programmes and information. In principle, such an “on-board computer” can be intuitively operated via a touch screen.

Thus, residents can create individual heating profi les for every room and also modify them, defi ne a basic temperature or ad-just the same or control the functionality of the entire system (e. g. day mode/lower mode/frost protection mode). Sensors de-tect the ambient conditions, which are evaluated by the system and implemented accordingly. Thus, the control and communi-cation technology facilitate an energy management system that is tailored precisely to the needs of residents.

Conclusion

The heat load of a building is always fully covered by using an embedded heating and cooling system. In summer, the ambient temperature can be reduced to a comfortable/pleasant level. Thus, the ambient temperature can be set to a comfortable range throughout the year – in apartments and offi ce buildings as well as halls.

Fig. 66: The correct system for different areas of application (refurbished buildings or new buildings as well as apartments or offi ce buildings and halls).

58 — 59

Radiators

Effi cient, comfortable and sustainable

Thanks to the latest technologies, heating systems are becom-ing increasingly economical and effi cient in terms of energy con-sumption. Be it natural gas, oil, wood, electricity or solar energy: Radiators can be reliably, in a sustainable and long-lasting way integrated in any heating system, irrespective of the respective source of energy. For long-lasting benefi ts, heating surfaces that can react quickly to changes of the heat demand are required. This requirement is fulfi lled by modern radiators with low instal-lation depths, low water content and high emission surfaces. The variety is huge – solutions are available for new buildings and refurbishment, ranging from products for low-temperature areas, e.g. the use of a heat pump, to adaptation to district heat-ing systems. With the appropriate design, the right installation and the optimum radiator, the ambient temperature can be adapted instantly to the wishes of the residents creating maxi-mum cosiness through radiant heat, thereby saving energy.

Quality, effi ciency and design

The quality of heat emission is not only determined by the out-put of a radiator: The heat can be optimally delivered only if the radiator is mounted at the right place. The classical space under the window is still recommended. The right positioning from the energy aspect combined with the design requirements from the room gives an optimum tailored solution. For effi cient heat emission, the radiator should not be hidden behind furniture or curtains.

Comfortable temperature – exactly to the desired degree

A heating system works through the interaction of many com-ponents – from the heat generator to thermostatic valves to the

individual radiators. Maximum effi ciency of the system can be achieved when all components are precisely matched with each other in terms of both energy and hydraulics.

An important role in this is played by thermostatic valves that keep the indoor heat constantly at the desired temperature. For this purpose, they have to rely on the correct differential pres-sure on the radiator, which is determined by hydraulic balancing: Hydraulic balancing ensures a uniform fl ow through the heating system and improves controllability. It eliminates noise and helps to reduce the consumption of energy and operating current.

In order to achieve maximum heat dissipation even with reduced water fl ow, modern thermostatic valves and fi ttings for hydrau-lic balancing support the heating system in exactly setting the individual “comfortable” temperature also at different heating times. Time-controlled thermostatic valves pre-set the time, at which the radiator should start with the heating – exactly to the desired temperature, automatic shut-off included.

Beautiful design and intelligent features

The many variations in shape, colour and design allow an attrac-tive, individualised interior and create new scope of designing for the residents, since the radiators fi t seamlessly into the archi-tectural environment. New radiators are available in several col-ours – chrome variants are also possible. If you want something special, the radiator can e.g. be powder-coated with a matt fi n-ish or made available in a stainless steel design. Additional fea-tures and smart accessories such as towel rods, mirrors or racks, hooks and lighting create feel-good accents. Often radiators are also used as design objects which fi t into the ambience and match with the colour and design of the room.

Fig. 68: Innumerable design options and intelligent accessories

Comfort and design ensure a feel-good ambience

Radiators

Between modernisation and comfort

Radiators are subject to wear and tear, which affects notably their quality and functionality. Thus, the increase in the techni-cal service life often is accompanied by a higher energy con-sumption, increased wear and tear of heating components as well as loss of comfort. Therefore, modernisation of existing equipment aims at increased effi ciency through energy-saving operation and optimum heat emission using modern radiators.

When planning the modernisation of heating systems, owners particularly weigh the costs against the benefi ts. This is because renovations, disturbances, dirt and noise are often unavoidable during refurbishment. The fi tting accuracy to the existing con-nections is taken into account while planning and designing new radiators, so that the replacement of old radiators with new high-performance models is no longer a problem in practice. Simple and quick installation of the radiators is the rule: empty, unscrew, screw, fi ll – done!

Fig. 69: Modern radiators for individual living comfort

Fig. 71: Easy replacement

Fig. 70: Fitting accuracy at the time of modernisation of the radiators

60 — 61

The minimum requirements for ventilation systems with heat recovery are clearly defi ned: Ensuring a good ambient air quality and minimum air exchange for humidity protection, effi cient heat transfer (recommended 75 %), a power demand of less than 0.45 Wh/m3. Apart from fi ltering of extract air and outdoor air for ensuring good hygiene, condensate discharge and overfl ow openings between the fresh air and exhaust air rooms must be provided for.

Specifi c requirements

If a ventilation system with heat recovery is used, condensate is occasionally formed in the heat exchanger, which must be dis-charged. In addition, the heat exchangers should be protected against frost by means of, e.g. pre-heating battery, brine or geothermal air exchanger. As a welcome side effect, the use of geothermal air exchangers also reduces the heat demand. They are also able to control the air temperature at a pleasant level both in sum-mer and winter.

Comfort without limitations

Ventilation systems supply fresh outdoor air in a controlled manner to living rooms. Usually, they are equipped with multi-level control and perform several functions at once:

They exchange extract air with unpleasant odours and perspi-rations with fresh air, and thus guarantee hygienically neces-sary air exchange.

They reduce CO2 and the so-called “VOC content” in the air. The abbreviation “VOC” refers to volatile organic compounds, namely chemicals that are released from, e.g. building materi-als, adhesives and paints, but are also found in tobacco smoke and exhaust fumes.

They provide effective protection against unpleasant sounds and noise from the outside.

They improve air quality and reduce humidity. This protects the building stock and helps to prevent ventilation-related mould formation. At the same time, the reduced humidity curbs propagation of house dust mites. (Mites are the most common allergens in the interior.)

If desired, the outdoor air can be cleaned additionally with a pol-len fi lter (F7 fi lter), which limits the exposure to pollen and aller-gens to a large extent.Thus, living room ventilation systems offer numerous opportu-nities to fi nd a customised solution for each individual require-ment.

Systems with heat recovery

You can’t do without ventilation. As a rule, it is associated with thermal loss because fresh air fl ows from the outside into the building. Only automatically operating ventilation systems can guarantee optimum balance between the required outdoor air supply and minimal thermal loss. Maximum energy savings result when the energy of the warm extract air is used to preheat the cooler outdoor air (heat recov-ery). Modern systems are able to recover up to 90 % of the heat present in the extract air. For this, plate heat exchangers (mostly as reverse fl ow heat exchangers), rotary heat exchangers and ex-haust air heat pumps are used.

Residential ventilation systems

A Air exchange = 0

B Hygienic limit value

C Air exchange = 0.4 per hour recommended

D CO2-content in fresh air

Other infl uencing parameters: Number of persons and room size

0,3

CO2 Vol.-%

0,2

0,1

0 2 4 60,04 D

C

A

B

Length of retention in h

Fig. 72: Increase in the CO2-concentration because of a resting person

Fig. 73: Energy share of ventilation heat loss in heat demand

0

50

100

150

200

250 Heat demand in kWh/(m2a)

Old buildings

WSV 1977

WSV 1995

EnEV 2002/2007

EnEV 2009 EnEV 2014 EnEV 2014with CRV

Heat transmission losses

Ventilation heat demand

Example: multi-family building

Current share of ventilation heat losses without heat recovery, up to 50 % of the thermal heat demand, reduction up to 50 % possible

The simple solution is in the air: Fresh air supply

with increased comfort

Residential ventilation systems

Fig. 74: Demand-based exhaust air system Fig. 75: Exhaust air system, centralised with heat pump

CC

CCExhaust airOutdoor airExtract air

B

A

C

B

B

A

Fig. 77: Fresh air and exhaust air system, centralised with HRS per living unit

B

Exhaust airOutdoor airExtract airSupply air

B

A

C

D


B

A

C

D

A

A

B

B

C

C

D

D

A

C

C

D

D

Exhaust airOutdoor airExtract airSensor(e.g. CO2 or humidity)

B

A

A

C

S

S

S

S

S

Fig. 76: Fresh air and exhaust air system, room-wise (decentralised) with HRS

Fig. 78: Supply air and exhaust air system, centralised with HRS for multi-family houses


B

B

B

A

AA

C

C

C

C

C

C

C

C D

D

D

D

D

D

D

D

B

B

62 — 63

evaporates. Thereafter, the refrigerant is compressed in a com-pressor, so that the stored heat energy can be delivered to the domestic hot water. Here, a system variant with auxiliary heat-ing supply is possible.

The low-energy house

In a low-energy house, the heat demand is greatly reduced right from the beginning through air-tight type of construction and very good insulation. This also applies to renovation and mod-ernisation measures, in which the windows are replaced and ad-ditional insulation is applied.

The ventilation system assumes major importance in renovation and new construction: The sealed design prevents the loss of moisture which hardly can escape because of the low infi ltration rate; and also, the residual infi ltration air exchange cannot pro-vide a good indoor air quality.

Only the residential ventilation systems ensure adequate air ex-change. At the same time, they reduce the energy consumption and heating costs through additional reduction of the ventila-tion heat losses.

Plan early and save

Builders and home owners should inform themselves right at the beginning about modern and reliable ventilation systems, while planning or upgrading a building. Thus, the energy-saving potential will be optimally utilised and costs minimised.

In any case, a ventilation concept should be created in advance: In doing this, it is checked whether technical ventilation meas-ures are necessary in new building construction or renovation, and if yes, what measures are relevant.

Benefi ts at a glance

In addition to high energy and cost savings, users of ventilation systems can also enjoy a higher comfort level: Modern systems ensure optimum air quality and a comfortable indoor climate with excellent sound insulation at the same time. Other advan-tages are thorough sanitation, pollution reduction and protec-tion against pollens, mites and mould formation. Moreover, a professional ventilation system protects the building structure in the long term.

Mechanical ventilation systems are classifi ed as room-wise (de-centralised) and apartment-wise (centralised) ventilation systems, with or without heat recovery.

Room-wise (decentralised) ventilation systems

In the corresponding supply air rooms and extract air rooms, in-dividual devices are installed in every room, directly in the outer wall. Thus, an air distribution system is not necessary.

Here, one can select from two modes of operation: Devices which secure a simultaneous fl ow of supply and extract air in every room and devices which alternate between supply air and ex-tract air: This requires two devices which correspond with one another for a balanced ventilation. Both modes of operation have the heat recovery feature.

Since they are mounted in the outer wall, decentralised ventila-tion devices are particularly suitable for the subsequent integra-tion during the process of modernisation.

Centralised exhaust air system without heat recovery

The extract air from kitchens and bathrooms is extracted here via a central fan. The cold supply air fl ows into the living room and bedrooms via outdoor air valves located in the outer wall. Here, the correct direction of fl ow is important: The air is direct-ed out of the living room, bedroom and children’s rooms in the direction of the wet rooms (kitchen, bathroom and toilet). The outdoor air supplied is heated by the existing heating system. An air distribution system is not a must.

Centralised ventilation system with heat recovery

Centralised ventilation devices only work in conjunction with an air distribution system: While one fan transfers the outdoor air into the building, another one sucks the warm extract air from the rooms. A heat exchanger ensures that the heat from the ex-tract air is transferred to the outdoor air coming in. In this way, up to 90 % of the heat is recovered and used to preheat the out-door air. The effect: Up to 50 % of the heating energy can be saved.

Centralised exhaust air system with domestic hot water heat pump for heat recovery

In this system, the ventilation system is combined with a domes-tic hot water heat pump for domestic hot water preparation: The extract air fl ows through the heat pump. A refrigerant removes the majority of the heat energy from the extract air fl ow, and

Residential ventilation systems with heat recovery/moisture recovery

Comfortable indoor climate through energy-saving

ventilation system

Residential ventilation systems with heat recovery/moisture recovery

Fig. 79: Reduction of ventilation heat losses*

A Underground heat exchanger (optional)

B Air-air-heat exchanger

C Fan

D Sound absorber

FiltersE

Outdoor airF

Supply airG

Extract airH

Exhaust airI

A B C DEF G

HI

E

E DC

Fig. 80: Diagram of the ventilation system

Fig. 81: Presentation of room-wise (decentralised) ventilation device

Fig. 82: Room-wise (decentralised) ventilation device

Centralised air supply/Exhaust air system with heat recovery

Air supply/exhaust air system with heat recovery – remote/

room-wise + exhaust air system with heat pump

Demand-driven Exhaust air system

Exhaust air + air supply system without heat recovery

Windowventilation

High Low

* Energy evaluation without power consumption by devices

64 — 65

In the monovalent domestic hot water heating, the domestic water in the storage tank is heated by a heat exchanger. This is supplied with heat by a centralised heat generator such as a gas or oil boiler.

On the contrary, in the bivalent storage tank, the domestic hot water is heated by two heat exchangers: Heat generated by a so-lar thermal system is introduced via a heat exchanger to the lower portion of the hot water storage tank. With suffi cient ex-posure to sunlight, the total storage volume can be heated with renewably. In the upper part of the storage tank, there is a sec-ond heat exchanger, by means of which the standby part of the storage tank is maintained at a constant temperature through reheating by the centralised heat generator. This ensures the supply of domestic hot water even if the solar radiation is insuf-fi cient.

For hygienic reasons, either standard or stainless steel tanks coated with enamel or plastic, are used for domestic hot water storage tanks. Built-in sacrifi cial anodes or impressed current anodes protect the enamelled storage tanks additionally against corrosion at the defective spots in the coating.

Storing thermal energy

A buffer storage tank in a heating system is a heat storage tank, which is fi lled with hot water for heating. It can combine heat from various sources and discharge the heat at intervals.

Hot water for all purposes

Domestic hot water storage tanks act as a central component of a modern heating and hot water supply system in residential and offi ce buildings. They can perform different functions due to their great diversity of types.

Domestic hot water storage tanks heat and store the domestic water, which is needed for showering, bathing or cooking.

Buffer storage tanks ensure heating water supply to the heating system over a long period. This allows coupling of heat from re-newable energies and CHP systems.

So-called combined storage tanks combine both functions.

Modern hot water storage tanks have high energy effi ciency. They are characterised by minimal thermal loss and optimised heat transfer and temperature gradient. All the hot water stor-age tanks in the market meet the highest standards of domestic hot water quality and sanitation.

Heating domestic hot water

Hot water storage tanks for domestic water heating prepare the domestic hot water required in the household or in a building, so as to make it available round-the-clock. There is a distinction be-tween monovalent and bivalent domestic hot water heating.

Storage technology

Fig. 83: Market development of storage systems and sizes (applications: Residential units up to three units)

100 l 200 l 300 l 400 l 500 l 600 l 700 lDomestic hot water heating (DWH)

Market development

Energy buffering800 l 900 l 1000 l 1100 l 1200 l 1300 l 1400 l 1500 l

DWH micro-CHP

Solar DWH heat pumps

DWH heat pumps

Solar DWH condensing wall and compact devices

DWH condensingwall and compact devices

DWH solar oil/gas boilerDWH oil/

gas boiler

DWH pellet boiler

DWH wood boilerBuffering wood boiler

Buffering pellet boiler

Solar heating support/multivalent systems

Buffering micro-CHP ?DWH mini-CHP Buffering mini-CHP

Syst

em co

mpl

exity

The buffer storage tank helps compensate for differences be-tween the amount of heat generated and consumed, and thus, level out power fl uctuations in the heating system. Thanks to it, heat generation can be operated largely independent of con-sumption, resulting in better operating characteristics and great-er energy effi ciency for many energy sources. The continuous thermal loss through the outer surface of the storage tank can be minimised through good thermal insulation and avoidance of thermal bridges.

Multitalent combined storage tank

Combined storage tanks allow domestic hot water heating and energy storage in a single device. With the integration of solar thermal energy, combined storage tanks are used for both heat storage for auxiliary heating and preparation and storage of do-mestic hot water. One can distinguish between different types of domestic hot water heating systems.

Combined storage tank with fresh water unit

Here, the domestic hot water heating is via an external heat ex-changer: If domestic hot water is required in the kitchen or bath-room, cold water fl ows through a high-performance plate heat exchanger, which is located outside of the storage tank. There, it is heated by the heating water, which is prepared in a buffer storage tank, directly to the desired hot water temperature.

Combined storage tank with built-in internal heat exchanger

In this model, the domestic water is heated by an internal heat exchanger: By using solar energy, the combined storage tank is charged through a heat exchanger in the lower area of the de-vice. Optionally, a heat conduction tube is used in the stratifi er lance technology. If the solar radiation is not enough for domes-tic hot water heating, reheating is done by the centralised heat generator in the upper region of the storage tank. If suffi cient energy is available in the storage tank, the heating circuit is also supplied via the storage tank. The centralised heat generator is turned on only when the temperature set for the heating circuit in the storage tank is undershot.

Tank-in-Tank system

In this system, there is a second smaller inner tank for domestic hot water inside the buffer storage tank, which holds the heat-ing water. Thus, the solar thermal system can heat the heating water and domestic hot water in one step. The heating water in

the outer jacket of the storage tank is heated by a heat exchang-er using solar energy. This heat reaches the domestic hot water via the surface of the inner storage tank.

The storage tank as a central unit of a heating and

domestic hot water system

Storage technology

Fig. 84: Domestic hot water heating

Monovalent (one heat exchanger)

Bivalent (second heat exchangerfor solar contribution)

Fig. 85: Energy storage

Buffer storage tank

Fig. 86: Combined storage tank (domestic hot water heating + energy storage)

Internal domestic hot water storage tank(Tank-in-Tank system)

External heat exchanger(fresh water unit)

Internal domesticwater heatexchanger

66 — 67

Suitable for every heating system

Stainless steel fl ue gas systems have many capabilities and are suitable for all approved fuels.

Various manufacturers offer systems that differ in the pressure and temperature range. Designs that withstand the maximum fl ue gas temperatures of 200 °C are suitable for oil- and gas-fuelled fi replaces. If a solid fuel system – such as a wood burning stove or a split log boiler – is to be connected, the fl ue gas line should be designed to withstand a temperature of 400 °C in vacuum.

In a pellet-fi red heating system, the condensation inside the chimney has to be taken into account because of the low fl ue gas temperatures. Therefore, the fl ue gas system must be insen-sitive to moisture. If very high demands are placed on the pres-sure resistance due to the operation of a cogeneration system or the connection of an emergency generator or combustion en-gine, there are special systems for overpressure of 5,000 Pa and fl ue gas temperatures of up to 600 °C.

Single-walled, double-walled and fl exible

Flue gas systems made of stainless steel are available in single and double-walled designs. They are suitable for both interior and exterior installation and are often used deliberately as an ar-chitectural feature in buildings. Single-walled stainless steel fl ue gas systems are inexpensive and easy to process. Depending on the design, they are suitable for operation at low and excess pressures in conjunction with gaseous, liquid or solid fuels.

Refurbishing chimneys with stainless steel

The increased demand for heating systems with solid fuels and wood burning stoves place chimneys once again in the focus of builders and planners.

The fl ue gas systems of heating systems need to be optimally adapted to the type of fi ring. The use of stainless steel in fl ue gas systems is highly popular today: The material is durable, requires little space and can be used in all structural conditions. Flue gas systems made of stainless steel are suitable for both new con-structions and subsequent integration, and for both the interior as well as the exterior.

Meeting all requirements

Besides high temperatures, fl ue gas pipes are also exposed to chemical attacks caused by the fl ue gases – it is especially about the acids in this case. If the dew point is undershot, these acids act aggressively on the fl ue gas pipes through condensation. How-ever, contemporary stainless steel fl ue gas systems easily cope with the condensing operation of heating systems used today. At fl ue gas temperatures of about 40 °C and below, falling below the dew point temperature leads to condensation in the fl ue gas line. This moisture collects on the base of the chimney in a drain pan, and is discharged from there.

Flue gas systems – flexible systems for various fields of application

Fig. 87: Existing shafts Fig. 88: Air fl ue gas systems

The biggest limitation is the relatively high minimum distance to other fl ammable components that needs to be maintained. Therefore, single-walled solutions are usually installed in chim-neys, which already have a fi re protection function and also allow any rear ventilation required.

Double-walled systems for the inlet and extract air

Double-walled chimneys made of stainless steel can be mount-ed both, within the building as well as on the outer wall. Their fl exibility in terms of alteration, extension or even dismantling throws light on another advantage of light fl ue gas systems. They are also suitable for retrofi tting, if no suitable chimney is nearby.

Double-walled chimneys can also be used for operation inde-pendent of the indoor air: In such air-fl ue gas systems, the hot fl ue gases and the cold supply air for the heating system are led via two separate pipes. Thus, the residual heat can be removed from the fl ue gases.

Separate air-fl ue gas systems can be installed in ducts, stoves or chimneys as part of the refurbishment measures. In new build-ings, they are created newly as a system chimney.

Flexibility in focus

Flexible piping systems made of stainless steel are used espe-cially if inclined guides are necessary for chimney restoration or if unfavourable, for example, rectangular dimensions exist. Flexible piping systems are manufactured in single or double- layered design, and thus have a corrugated or smooth inner sur-face. Special folding and joining techniques allow safe and yet fl exible pipe runs.

Safety fi rst: CE marking on stainless steel fl ue gas systems indispensable

This especially applies to fl ue gas systems and chimneys. Con-struction products may be used in conformance with the Model Building Regulation or State Building Regulations for the instal-lation, alteration or maintenance of structural works only if these are suitable for the purpose of application. This is ensured by using metal fl ue gas systems if these are put into operation as per the specifi cations of the European Construction Product Regulation. This means that these systems were manufactured in conformance with a harmonised European standard or tech-nical evaluation; and the corresponding technical characteristics have been noted down in a Declaration of Performance by the manufacturer. Besides, they must also bear the CE mark in con-formance with the European Construction Product Regulation.

The specifi cations are applicable to single-walled and double-walled metal fl ue gas systems, lightweight shaft systems as well as connecting pieces. A classifi cation based on different criteria makes the assignment easy. For example, a differentiation is made according to the type (single- or double-walled, lightweight shaft system), temperature, class of resistance to pressure and condensation as well as material and resistance to soot fi re.

Stainless steel flue gas systems, the flexible solution for

all heating systems

Flue gas systems – flexible systems for various fields of application

Fig. 90: Double-walled systems Fig. 89: Stainless steel fl ue gas systems in fi ring systems operated by combustion engine

lation, alteration or maintenance of structural works only if these are suitable for the purpose of application. This is ensured by using metal fl ue gas systems if these are put into operation as per the specifi cations of the European Construction Product Regulation. This means that these systems were manufactured in conformance with a harmonised European standard or tech-nical evaluation; and the corresponding technical characteristics have been noted down in a Declaration of Performance by the manufacturer. Besides, they must also bear the CE mark in con-formance with the European Construction Product Regulation.

The specifi cations are applicable to single-walled and double-walled metal fl ue gas systems, lightweight shaft systems as well as connecting pieces. A classifi cation based on different criteria

lation, alteration or maintenance of structural works only if these are suitable for the purpose of application. This is ensured by using metal fl ue gas systems if these are put into operation as per the specifi cations of the European Construction Product Regulation. This means that these systems were manufactured in conformance with a harmonised European standard or tech-nical evaluation; and the corresponding technical characteristics have been noted down in a Declaration of Performance by the manufacturer. Besides, they must also bear the CE mark in con-formance with the European Construction Product Regulation.

The specifi cations are applicable to single-walled and double-walled metal fl ue gas systems, lightweight shaft systems as well as connecting pieces. A classifi cation based on different criteria

68 — 69

From 1970 to 1990, single-walled plastic storage tanks, which were mounted in walled collection area were sold for the stor-age of heating oil. Since 1990, factory-made, double-walled and odour-proof tanks have established themselves in the market and are replacing the old single-walled tank completely.

The replacement of single-walled tanks is recommended by ex-perts and competent bodies after 30 years of useful life. Firstly, the plastics wear out and secondly, after the expiry of this period, the on-site collection areas no longer conform to the technical safety requirements of impermeability or even the static require-ments. Investigations of the TÜV in Bavaria and Hesse have proven: More than 80 % of the tested collection areas did not show the required secondary protection any more.

Besides, a modernisation backlog can be seen today in the heat-ing oil tanks: Around 45 % of all plastic storage tanks are 25 years old or more.

By buying a modern double-walled heating oil tank, consumers invest in a high-quality product that guarantees easy and safe supply even in the future. This modernisation measure is usually even associated with signifi cant space saving through the easy installation in the boiler room that is possible now.

Mounting on double-walled safety tanks

The principle of double safety applies to storage of heating oil. Thus, a collection area is required by law for single-walled tanks: It prevents release of oil in the water in case of any leakage. This collection area must be oil-tight, have an approved coating and be accessible for inspection. Moreover, the masonry should be structurally suffi ciently stable in the case of a leak. The single- walled tanks should be mounted at a suffi ciently large distance from the walls to allow inspection.

Double-walled heating oil tanks come with the capability of ab-sorbing oil spills completely, already delivered ex-factory. Moreo-ver, they can be mounted in a very space-saving manner: Clear ad-vantages that are extremely signifi cant for market penetration.

Double-walled heating oil tanks are available in different de-signs – as sheet metal-jacketed plastic tanks with optical leak detection as well as with internal and external plastic tanks with the possibility of translucent leak detection. All double-walled tank systems have a long useful life and pro-vide maximum safety without any maintenance cost, which is unavoidable in walled collection areas. Practice has proved that collection areas often lose their protective properties after years of use. Therefore, double-walled tank systems clearly offer safety.

Storing heating oil safely

Heating oil can be stored in different ways. Here, the personal preferences for the installation site, the individual structural conditions and economic considerations are decisive.

Modern tank systems for heating oil ensure maximum security of supply and economic independence. They form an ideal basis for an economic supply of heat.

The fuel storage in a separate tank offers operators of oil heating systems the free choice of suppliers and the option of making a reasonable purchase, because the consumer is free to decide the time of delivery and is able to safely store a larger stock of fuel.

Modern heating oil tanks are double-walled tank systems that do not require more collection space. The factory production en-sures an extremely safe tank system that guarantees the sec-ondary protection required by law for the storage of heating oil for decades.

Requirements

Heating oil can be stored either underground or aboveground. An oil storage tank is considered to be underground, if it is com-pletely or partially embedded in the ground. Storage tanks that are usually set up in closed rooms are considered aboveground, even though the cellar is below the ground level.

Heating oil storage in an underground double-walled steel tank is rather rare in the private sector. Aboveground storage in the basement is common. Formerly, there used to be a separate heat-ing oil chamber (walled collection area); today the storage facili-ty is in the boiler room itself. Basically, the legal requirement of secondary protection that is achieved by the double-walled characteristic of the tank system with an additional leak detec-tor or leak detection system applies here.

The previously common, single-walled tanks made of metal or plastic, which require a collection area for secondary protection, are still found in the old stock of many cellars. However, this col-lection area is deemed as an acceptable secondary protection only if the sealing surface is made of approved materials. More-over, the wall should be suffi ciently stable and the collection area shall be ensured to be permanently leak-proofed.

For over 40 years plastic storage tanks are used for heating oil. They are mainly installed in the cellar or boiler room. Today, Ger-many has approx. 6 million oil heating systems and a corre-sponding number of heating oil storage tanks (2-3 tanks per sys-tem on an average) in the cellars of German one-family houses and apartment houses.

Tank systems

Small dimensions, high fl exibility

Modern insulation and increasingly effi cient heating systems ensure continuous reduction in fuel demand in a lot of buildings. This also reduces the storage quantities of heating oil.

New tank systems require less space, home owners gain valua-ble space. Thanks to the compact dimensions, subsequent inte-gration is also possible. Besides, modern tanks are also approved for low-sulphur heating oil and for oil with biological additives under construction and water law. The tank systems are equipped with limit switches and partly with other safety equipment to prevent an overfi ll when refuelling.

Several automatic monitoring devices ensure easy and safe con-trol. The heating oil storage can be controlled at all times with the level indicator.

New tank systems: Double-walled, flexible

and space-saving

Tank systems

Fig. 91: Ageing structure of the plastic storage tank in the market since 1970

Fig. 92: Modern single- and double-walled safety tanks

45 %

24 %

13 %

5 %

3 %

21 - 25 years

16 - 20 years

11 - 15 years

6 - 11 years

1 - 5 years

0 % 10 % 20 % 30 % 40 % 50 %

10 %

26 years and older

Renovation range

70 — 71

Remote-controlled heating systems

Today’s control technology for heating systems offers many op-portunities to generate and use heat effi ciently. However, their potential can be exploited fully only in combination with mod-ern communications technology: So it is already possible to con-trol the heating system in the basement via radio from the living room, with a remote control that one is used to for a long time from televisions, DVD players and stereo systems.

A further development are the “Apps” for Smartphones or Tab-lets. These applications open up completely new dimensions for heating comfort, since the heating system can be easily and comfortably monitored and regulated even when away from home. The heating system can be controlled or adapted to the personal requirements from offi ce, while shopping or even when away on vacation. For example, simply swipe your fi nger over the display of the Smartphone to set the heating system at home for a later arrival time, while you are still on your way. No problem if you have the right app.

Even faults can be automatically displayed by the app; thus, you can inform the heating engineer even when you are not at home and make arrangements for resolving the problem.

For modern control systems, the technician requires only a lap-top for system diagnosis. Since, as described above, the modern communication technology transmits faults, failures or other incidents automatically to the technician, landlords need not worry about the cold season: The technician immediately receives the necessary information to get the situation under control from his desk. He can take all the necessary steps through online access. In this way, unnecessary maintenance visits can be avoid-ed and the availability of the system is increased without any ex-tra effort and costs for the operator.

Effi ciently managing the energy consumption

A modern heating system can now be controlled by a central computer that manages all data, programs and information. In principle, such an “on-board computer” can be intuitively operat-ed via a touch screen. Here, residents can create heating profi les for each room, set a base temperature or adjust the valves on the radiators. Sensors detect the ambient conditions, which are eval-uated by the system and implemented accordingly. Thus, the control and communication technology facilitate an energy management system that is tailored precisely to the needs of residents.

Technology that thinks along

Today’s heating systems are based on smart systems that make life very comfortable. It has long been taken for granted in many households that the bathroom heating turns on automatically before the alarm rings in the morning and one can shower at a comfortable room temperature. The temperature in the living area can be set such that the personal feel-good temperature in the evening has already been reached. And it almost goes with-out saying that the heating at night is at a low point – by itself.

One cannot imagine modern heating systems without a smart control technology any longer: This is based on innovative micro-electronics and provides an optimal combination of all heating components – including boilers, burners, heat pumps and radia-tors. It ensures that the desired temperature is achieved by the heating system. If the window is opened for a short while in be-tween, the control system is detecting the change and drops down a gear. If the outdoor temperatures are freezing cold, the temperature is automatically set to a higher degree.

The technique is so simple to use and as energy-effi cient as never before. Because of the accurate and demand-oriented heating in certain areas, the control technology constantly assists in reduc-ing the operating costs and protecting the environment. A display also shows the consumption values, records operating condi-tions and also indicates when service is needed.

Residents can easily make corrections to the set programmes, if, for example, a higher temperature is suddenly desired. Should there be a fault, it will be immediately displayed on the screen. The information will help the heating technician to identify the cause directly and fi x as soon as possible.

Heat at the press of a button

Today’s heating systems offer much more than those of previous generations: They allow centralised control of the preparation of domestic hot water, heat output and ventilation.

Moreover, these systems can be bivalent, i.e. operate simultane-ously with two energy sources. Renewable energies are often used – for example solar thermal systems. The control technology couples the energy of the solar collector into the system. If the system does not deliver enough thermal output due to bad weather conditions, the heater steps in, regulated by the control technology in the background. It takes over the control of entire-ly different heating systems, such as micro or mini-CHPs, which generate power and heat simultaneously by the principle of co-generation of heat and power. This control technology feeds the surplus electricity into the local grid, which should be of interest to house owners, as they get paid for their excess power.


Smart control of the heating system: Any time, anywhere


Independence ComfortEffi ciency Generation of heat

Renewable energy Demand-basedtemperature control

DiagnosisFlexibility


72 — 73

Examples of modernisationEnergy consultancy and energy performance certifi cate

Energy label for heat generators and combination heaters

Modern heating systems

Examples of modernisation – Variants with gas/oil condensing boilersExamples of modernisation – Variants with heat pumpsExamples of modernisation – Variants with wood burning systems/CHP systems

74 — 75

Energy performance certifi cates scrutinise the buildings

With the help of the energy performance certifi cate, tenants and purchasers can draw an estimate of the expected energy costs even before the conclusion of the contract. The energy per-formance certifi cate supports owners to start the energetic modernisation. The energy-saving potentials in buildings can be determined with the energy performance certifi cate. In Germa-ny, the issuance of the energy performance certifi cate is regulat-ed by the Energy Saving Ordinance (EnEV).

The existing posting obligation for energy performance certifi -cates has been extended, when EnEV 2014 came into effect on 1st May 2014. In public buildings that are frequented by the gen-eral public and have a usable area of more than 500 m2 (and of more than 250 m2 starting from 8th July 2015), an energy perfor-mance certifi cate (if not already available) must be issued and displayed. Private owners of buildings that are frequented by the general public must display this certifi cate if the usable area exceeds 500 m2.

With the EnEV 2014, the importance of the energy performance certifi cate has been strengthened further. Accordingly, relevant energy-related parameters must be specifi ed already in real es-tate ads for renting out and selling of buildings. Spot checks for the energy performance certifi cate have been introduced as well.

How to modernise

Technical support is required for those who plan extensive mod-ernisation measures or want to replace their heating system. The high demands for thermal protection and energy saving in the EU Member States also make professional energy consultancy increasingly necessary.

Energy consultants determine the actual energy status of the building at fi rst. Based on this, they then come up with propos-als for modernisation measures that improve the quality of the building and the heating technology, as well as increase cosiness and comfort. These measures help property owners reduce their energy consumption specifi cally, protect the environment, while maximising the value of the building. Thus, energy performance certifi cates and consultancy constantly give new impetus to the modernisation market.

Using potential, increasing effi ciency

Buildings are the largest energy consumers in Germany and Eu-rope: Residential buildings and offi ces as well as warehouses, hospitals and schools. Their fi nal energy demand in Europe is around 40 % of the total energy consumption.

About 85 % of this consumption is needed to cover the heat load and domestic hot water heating. The energy effi ciency of build-ings in Europe is still very low. The consequence: Given the cur-rent state of technology, energy consumption is twice as high as it could be.

This is not without reason: Investment in residential buildings has been low over the past few decades. Obsolete heating sys-tems with unnecessarily high energy consumption, unsealed windows and doors and uninsulated buildings are still very com-mon. This modernisation backlog of existing building stock is to be dissolved to fulfi l EU targets.

There is need for action: Therefore, European policy tries hard to comprehensively improve energy effi ciency in the building sec-tor since the beginning of the millennium. With various statuto-ry provisions, the building sector should signifi cantly contribute to the overall objective of the EU, to achieve 20 % energy savings by 2020. State funding assists owners in energy-effi cient con-struction and renovation.

Making energy consumption comparable

One of these rules at the EU level is the 2010/31/EU Directive (EPBD Energy Performance of Buildings Directive) on the total energy effi ciency of buildings. It forms the basis for the widespread in-troduction of energy performance certifi cates in the Member States.

Energy performance certifi cates assess buildings in terms of their energy demand or consumption – regardless of whether it is a residential building, a factory or an offi ce building. During the construction, renovation, extension, sale and re-leasing of buildings, it is mandatory to issue an energy performance certif-icate for the building.

Energy consultancy and energy performance certificate

Energy consultancy helps to increase the low energy efficiency of

buildings in Europe

Energy consultancy and energy performance certificate

Fig. 93: Infrared image of a house

Fig. 94: Energy consultancy Fig. 95: Excerpt from an energy performance certifi cate

Sour

ce: B

ausp

arka

sse

Schw

äbis

ch H

all

76 — 77

Package label (label of a composite system)

The package label must be issued if the space heater, the combi-nation heater or the domestic hot water device, on which the product label has to be affi xed, are put together along with oth-er components to form a package and offered by the installer for sale (so-called composite system as per the EU ordinances no. 811/2013 and no. 812/2013). The components which make a man-datory issuance of the package label necessary, are temperature controllers, solar packages and solar tanks as well as other heat generators (auxiliary heaters). Generally, the issuance of a pack-age label leads to a higher energy effi ciency class. It is mandatory for the installer to inform the end user of the energy effi ciency class of the composite system they are offering. This means: For example, the combination of a gas or oil condensing boiler with a solar thermal system.Package labels can be issued and shown by the manufacturer in advance if they offer all the components as a pre-confi gured package. The heating installer can refer to the package label of the manufacturer at the time of selling this package. If a pack-age of components is offered for sale by different manufactur-ers, the installer or the wholesaler himself must determine the energy effi ciency class of the package on the basis of the key en-ergy data of the components and inform the end user in the of-fer accordingly.

Special case – combination heater

Combination heaters are provided with a so-called “double la-bel”: for the space heating and domestic hot water preparation function. One energy effi ciency class is specifi ed for each func-tion. The double label can be included in the product label as well as the package label.

Energy label in the fi eld of heating

End users have got used to this long time back, while purchasing washing machines, light bulbs, television sets and other house-hold appliances: An energy label informs us about the energy consumption of the products with the help of a colour chart from green to red and provides information about the energy effi ciency class. The energy label gives guidance about the selection of prod-ucts that consume less energy. This well-established energy effi -ciency label will soon be introduced in the heating industry too. Starting from 26th September 2015, manufacturers of boilers, heat pumps, cogeneration units (so-called space heaters as per the ErP directive), combination heaters as well as manufacturers of domestic hot water devices and hot water storage tanks must label their products. As against the conventional product label, which only considers the product itself, energy labels in the heat-ing industry are also created for the sale of so-called product packages (heat generators or domestic hot water devices along with other components of the heating system or domestic hot water preparation system). In such a case, the label is called a package label or a label of a composite system.

Product label

Product labels are created by the manufacturer. Using calcula-tion procedures, the key energy data of the product is used to de-termine the energy effi ciency of the space heater, combination heater and/or domestic hot water device (rated output of up to 70 kW) or the heat loss of the domestic hot water storage tank (storage volume of up to 500 l). The calculation procedures are specifi ed in the EU ordinances (EU) no. 811/2013 and no. 812/2013 and in the accompanying documents of the EU Commission as well as in the harmonised European standards. Based on the en-ergy effi ciency, the product is classifi ed in the provided scale G to A++ (for heaters) and G to A (for domestic hot water devices and storage tanks).

Energy label for heat generators and combi nation heaters

Fig. 96: Energy effi ciency class of the common heat generators (only for the space heating function)

A+++

Condensing boiler

Low-temperature boiler

Brine-water heat pumpWater-water heat pump

Air-water heat pump

The energy effi ciencyclass A+++ will beintroduced on the product label only in 2019.

Cogenerationsystem

A++

A+

ABCD

Gas heat pump

Gas/oil Electricity

Energy labels offer guidance for the selection of products

that require less energy

Energy label for heat generators and combi nation heaters

Fig. 97: Product labels for heat generators

Heat pump Low temperatureheat pump

Oil and gas condensing boilers

Mini and micro CHP system (up to 50 kWel)

I II

A-80%

A-60%

A-40%

A-20%

A+++

A++

A A B C D EFG

+

A++

A+

A B C D E F G

A

YZ dB

2015 811/2013

YZ kW

Fig. 98: Energy labels of combination heaters Fig. 99: Package label for the space heating and combination heating function

I II

A

B

C D E F G

A

A

L

2015 811/2013

YZ dB

YZ kW

A++

A+

A B C D E F G

L

2015 811/2013

A++ A A

B

C D E F G

A++

A+

A B C D E F G

I II

YZ dB

YZ dB

YZ kW

YZ kW

YZ kW

I II

A+

A-80%

A-60%

A-40%

A-20%

A+++

A++

A A B C D EFG

+

A++

A+

A B C D E F G

YZ kWYZ dB

2015 811/2013

I II

A++ A++

55 °C 35 °C

YZ dB

YZ dB

YZYZYZkW

YZYZYZkW

2015 811/2013

A++

A+

A B C D E F G

I II

A++

A-80%

A-60%

A-40%

A-20%

A+++

A++

A A B C D EFG

+

A++

A+

A B C D E F G

35 °C

YZ dB

YZ dB

YZ kW

YZ kW

YZ kW

2015 811/2013

I II

+

+

A

+

+

A-80%

A-60%

A-40%

A-20% A A B C D EFG

+ A++ A+++

A A B C D EF

+

A+++

A++

A+

A

B

C

D

E

F

G

A+

2015 811/2013

I II

A+

A+

A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

78 — 79

A special feature is shown by decentralised cogeneration of heat and power (CHP), which are also known as “power-generating heating systems”: They produce heat and electricity simultane-ously. The scope of this technology extends from the small one-family houses (micro-CHP systems, up to 2 kWel) to apartment houses and medium-sized businesses (mini-CHP plants up to 50 kWel) to the industrial sector. By using such systems, a primary energy ef-fi ciency of over 90 % can be achieved. Installing a hot water storage tank is particularly important as the heat provided by the heat generator is not always immedi-ately used at 100 %. Today, hot water storage tanks form a central component of the heating system and domestic hot water supply system in resi-dential and offi ce buildings. Thanks to their great diversity of types, they can perform differ-ent functions.

Domestic hot water storage tanks store the heated domestic hot water which is needed for showering, bathing or cooking.

Buffer storage tanks ensure that the heating system is secure-ly supplied with domestic hot water for a long time. Thus, they allow coupling of heat from renewable energies and CHP sys-tems.

Combination storage tanks combine both functions together.

The thermal losses can be kept low only through minimal thermal loss and an optimised heat transfer and temperature gradient in the storage tank. In this way, hot water storage tanks enable the reliable supply of domestic hot water and energy at intervals of demand and supply of heat.

Heat generation and heat storage

Heat generation is the starting point for the operation of the heating system: In a centralised heat generator, the fuels (gas, oil or electricity) used will be converted into heat. This is then used for heating and/or domestic hot water. Thus, it becomes the link between the fuel and the desired useful energy. Moreover, re-newable energies such as solar thermal energy, ambient heat, geothermal energy and wood can be integrated into a central heating boiler or a pellet or wood burning stove with collection basin.

Energy effi ciency and renewable energies

Today, in new construction and renovation of old buildings, opti-mal system solutions for heating technology are available for all fuels. Therefore, the right system at the end always depends on the framework conditions: The heat load of the building, its pur-pose of use, the user behaviour, the size of land and, of course, the preferences of building owners should be considered here in particular. The systems presented in this brochure for the heat supply of buildings, domestic hot water and apartment ventilation are in-ternationally considered as state of the art. They convert fuels such as gas, oil and electricity very effi ciently into heat and also use renewable energies during this process.

The system concept is always at the forefront

All the components of the heating system must be perfectly matched to be able to realise the energy-saving potential of modern heat generators optimally. Therefore, heat generation, storage, distribution and emission are to be considered always as a total system.


Fig. 100: The system concept is at the forefront

Fig. 101: Interaction between heat generation and storage

HIGHLY EFFICIENT USE OF FOSSIL FUELS

OPT

IMIS

ATIO

N OF THE SYSTEM COMPONENTS

EFFICIENT ENERGY STORAGE

INTEGRATION OF RENEWABLE EN

ERGI

ES

A H

eat g

ener

atio

n + storage

B Heat distribution

C Heat emission

B

A

A

A

CC

Optimal distribution of heat in the heating system also requires insulation of the forward and return fl ow as well as hydraulic balancing of the entire heating system. For hydraulic balancing, modern thermostatic valves or lockshield valves on the radiators are required. Modern thermostatic valves are characterised by a presettable valve body and visually responding thermostat sensors with high control performance. Timed controllers are worthwhile es-pecially for professionals who are away from home almost every day.One thing is clear: Only effi cient heat distribution allows the re-duction of system and indoor air temperatures and high control-lability of the system.

Heat emission

The heat emission is the link between heat distribution and the consumer. Either an embedded heating system or radiator is available as a heat emission system. They can be installed in combination when requested. Both systems can be combined freely with all types of heat gen-erators of a hydraulic heating system. This makes them sustain-able and future-proof. Low system temperatures in the heating system are a prerequi-site to achieve the high effi ciencies of heat pumps, gas or oil-fi red condensing boilers and effectively integrate solar thermal systems. Huge and properly installed heat emission systems en-sure and increase the comfort in the room and at the same time the effi ciency of the heating system.

Heat distribution

The heat distribution forms the link between heat generation/storage and heat emission. The heat distribution system includes heat circulating pumps, the forward and return fl ow of the hy-draulic heating system and the fi ttings and valves. From January 2013, in accordance with the European ErP directive, the market has access only to circulating pumps with an energy effi ciency index better than 0.27 – the so-called high-performance pumps. These are much more effi cient and adapt to changing perfor-mance requirements of the system continuously. Compared to conventional pumps they use 80 % less electricity.

For an efficient heating system, all components

must be matched


Biomass boiler about 0.9 million pieces

Heat pumps0.6 million pieces

Gas-fired low temperature

boilers 8.9 million pieces

Gas-fired condensing boilers about 4.2 million pieces

Oil-fired condensing boilers about 0.6 million pieces

Oil-fired low temperature boilers 5.3 million pieces

~ 20.5 million Heat generators in existence

Installed collector surfaces, solar thermal system

about 17.5 million m2~ 1.9 million systems

Fig. 102: Total number of centralised heat generators in Germany (2013)

Fig. 103: Infl uencing factors for effi cient heat distribution

EFFICIENT PUMPS

CO

NTR

OLL

ED B

ASED

ON TH

E D

EMA

ND

HYDRAULIC BALANCING

INSULATION OF PIPES

DEM

AN

D-O

PTIMISED

CONTROL

SELF-REGULATING VALVES

80 — 81

The many variations in shape, colour and design of radiators al-low the builders and planners an attractive, individual interior design and create new design freedom for the residents. Addi-tional functions and smart accessories such as towel bars or racks, hooks or even lighting allow conscious setting of feel-good accents by the radiators.An embedded surface heating and cooling system is installed permanently during the construction phase in the fl oor, wall or ceiling and is an integral part of the building. Apart from the heating in winter, it can also be used for cooling in summer. Thus, to the owners they are an investment for the future. The large-ar-ea installation allows a uniform distribution of heat in the room and ensures a constantly comfortable indoor climate.


Pages 82 – 83 Variants with gas/oil condensing boilersModern gas/oil condensing boilerModern gas/oil condensing boiler with solar domestic hot water heating and auxiliary heatingModern gas/oil condensing boiler with solar domestic hot water heating and auxiliary heating, renovation as per the KfW Effi ciency House-70-Standard, controlled residential ventilation with heat recovery

Pages 84 – 85 Variants with heat pumpsModern air-water heat pumpModern brine-water heat pumpModern air-water heat pump, renovation as per the KfW Effi ciency House-70-Standard, controlled residential ventilation with heat recovery

Pages 86 – 87 Variants with wood burners and CHP systemsModern gas/oil condensing boiler with solar domestic hot water heating and incorporation of a burning stove with collection basinMicro CHP system with gas condensing boilerModern pellet/split log boiler with solar domestic hot water heating

Other components of an effi cient heating system

Modern fl ue systems ensure safe removal of the fl ue gases and low fl ue gas temperatures. While operating an oil-fi red heating system, nowadays modern oil tank systems in various variants are available to consumers.Solar thermal energy can be used in all types of heating systems as a support for domestic hot water and as an auxiliary heating system.Independent of the heating system, facilities for controlled resi-dential ventilation with heat recovery reduce the energy de-mand of the building signifi cantly and, at the same time, ensure the required hygienic ambient conditions. Moreover, the use of a photovoltaic system is also possible in every case: Since the generation of electricity using PV systems always runs independent of the heating system, the solar power generation can be operated in parallel with all systems men-tioned here and also used for heating the building and domestic hot water preparation with an electric heat pump.Smart control and communication facilities enable the optimal interaction of all components. The heating can be remotely con-trolled and diagnosed via radio or online access. This makes op-eration very convenient.However, the optimised use of modern heating systems should always be considered in agreement with the energy-related quality of the building envelope.Examples of modernisation in the energy fi eld are given on the following pages, based on a typical partially refurbished sin-gle-family house constructed in 1970. The examples must be seen as an approximation, considering the improvement that might take place in the quality of energy in the heating system. In the next step, an energy consultant and/or a heating special-ist fi rm should be consulted. The following energy-related mod-ernisation measures are taken into account:

Fig. 104: Infl uencing factors for effi cient heat emission

REDUCING TH

E RO

OM

TEM

PERA

TURE

HYDRAULIC BALANCINGHIGH AND FAST CONTROLLABILITY

HIG

HLY EFFICIEN

T HEAT DISTRIBUTION

REDUCING THE SYSTEM TEMPERATURE


Fig. 105: Modern heating systems


Ventilation system with heat recovery

Floor heating system Radiators

Hot water storage tank

Heat pump (air-water, brine-water, water-water)

Oil condensing boiler Gas condensing boiler Wood boiler (pellet, split logs, wood chips)

Micro or mini CHP

system

H

F

J

I

EDCBA

G

Energy effi ciency and renewable energies

Oil condensing boiler Wood boiler (pellet, split

For an efficient heating system, all components

must be matched

82 — 83

200>250Primary energy demand

kWh/(m2a)175225

Examples of modernisation – Variants with gas/oil condensing boilers

House before the renovation

Partially renovated detached single-family house, year of con-struction 1970, usable fl oor space 150 m2, solid construction/plas-tered, standard boiler – oil/gas, with indirectly heated domestic hot water storage tank, unregulated circulation pump.

Renovation variant – gas/oil condensing technology

Modern condensing boiler (oil/gas) and indirectly heated do-mestic hot water storage tank, adaptation of the heating surfac-es, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, modern fl ue gas system.

Annual oil consumption 3,263 litres 2,126 litres 1,775 litres 602 litresAnnual gas consumption 3,263 m3 2,126 m3 1,775 m3 602 m3

Annual saving of oil – 1,137 litres 1,488 litres 2,661 litresAnnual saving of gas – 1,137 m3 1,488 m3 2,661 m3

Primary energy saving – 83 kWh/(m2a) 109 kWh/(m2a) 192 kWh/(m2a)

Energy effi ciency class for space heating

D A A+ A+

Energy effi ciency class for domestic hot water heating

– A A+ A+

I II

A

B

C D E F G

A

A

L

2015 811/2013

45 dB

15 kW

A++

A+

A B C D E F G

164248

3,263 litres3,263 m3

D D

B

C

D

E

F

0100150 75 50 25125

Examples of modernisation – Variants with gas/oil condensing boilers

Renovation variant – gas/oil condensing technology with solar thermal system, controlled residential ventilation and renovation of the building envelope

Modern condensing boiler (oil/gas), solar thermal system for do-mestic hot water and auxiliary heating, adaptation of the heat-ing surfaces, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, modern fl ue gas system, additionally controlled residential ventilation with heat recovery and renovation of the building shell in con-formance with KfW-Effi ciency House-70 standard.

Renovation variant – gas/oil condensing technology with solar thermal system

Modern condensing boiler (oil/gas), solar thermal system for do-mestic hot water and auxiliary heating, adaptation of the heat-ing surfaces, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, modern fl ue gas system.

Annual oil consumption 3,263 litres 2,126 litres 1,775 litres 602 litresAnnual gas consumption 3,263 m3 2,126 m3 1,775 m3 602 m3

Annual saving of oil – 1,137 litres 1,488 litres 2,661 litresAnnual saving of gas – 1,137 m3 1,488 m3 2,661 m3



D A A+ A+


– A A+ A+

I II

A+ A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

A+

I II

A+ A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

A+

139 56

84 — 85


kWh/(m2a)175225

Examples of modernisation – Variants with heat pumps



Renovation variant – Air-water heat pump

Air-water heat pump, buffer storage and domestic hot water storage tank, adaptation of the heating surfaces, high-perfor-mance pumps, new thermostat valves, insulation of the distribu-tion pipes, hydraulic balancing.

Annual oil consumption 3,263 litres – – –Annual gas consumption 3,263 m3 – – –Annual electricity demand – 8,100 kWh 5,910 kWh 2,310 kWhPrimary energy saving – 113 kWh/(m2a) 144 kWh/(m2a) 200 kWh/(m2a)


D A+ A++ A+


– A A A+

L

2015 811/2013

A A

B

C D E F G

A++

A+

A B C D E F G

I II

YZ dB

48 dB

11 kW

16 kW

13 kW

A+

135248

3,263 litres3,263 m3

D D

B

C

D

E

F

0100150 75 50 25125


Renovation variant – Air-water heat pumpwith solar thermal energy, controlled residential ventilation and renovation of the building shell

Air-water heat pump, buffer storage and domestic hot water stor-age tank, adaptation of the heating surfaces, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, additional solar domestic hot water system, controlled residential ventilation with heat recovery and renovation of the building shell in conformance with the KfW-Ef-fi ciency House-70 standard.

Renovation variant – Brine-water heat pump

Brine-water heat pump, buffer storage and domestic hot water storage tank, adaptation of the heating surfaces, high-perfor-mance pumps, new thermostat valves, insulation of the distribu-tion pipes, hydraulic balancing.



D A+ A++ A+


– A A A+

L

2015 811/2013

A++ A A

B

C D E F G

A++

A+

A B C D E F G

I II

YZ dB

41 dB

13 kW

13 kW

13 kW

I II

A+ A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

A+

104 48

84 — 85


kWh/(m2a)175225




Renovation variant – Air-water heat pump

Air-water heat pump, buffer storage and domestic hot water storage tank, adaptation of the heating surfaces, high-perfor-mance pumps, new thermostat valves, insulation of the distribu-tion pipes, hydraulic balancing.



D A+ A++ A+


– A A A+

L

2015 811/2013

A A

B

C D E F G

A++

A+

A B C D E F G

I II

YZ dB

48 dB

11 kW

16 kW

13 kW

A+

135248

3,263 litres3,263 m3

D D

B

C

D

E

F

0100150 75 50 25125


Renovation variant – Air-water heat pumpwith solar thermal energy, controlled residential ventilation and renovation of the building shell

Air-water heat pump, buffer storage and domestic hot water stor-age tank, adaptation of the heating surfaces, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, additional solar domestic hot water system, controlled residential ventilation with heat recovery and renovation of the building shell in conformance with the KfW-Ef-fi ciency House-70 standard.

Renovation variant – Brine-water heat pump

Brine-water heat pump, buffer storage and domestic hot water storage tank, adaptation of the heating surfaces, high-perfor-mance pumps, new thermostat valves, insulation of the distribu-tion pipes, hydraulic balancing.



D A+ A++ A+


– A A A+

L

2015 811/2013

A++ A A

B

C D E F G

A++

A+

A B C D E F G

I II

YZ dB

41 dB

13 kW

13 kW

13 kW

I II

A+ A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

A+

104 48

86 — 87


kWh/(m2a)175225

Examples of modernisation – Variants with wood burning systems/CHP systems



Renovation variant – gas/oil condensing technology with solar thermal energy and wood burning stove/pellet furnace with collection basin

Modern condensing boiler (oil/gas), solar domestic hot water system, pellet furnace/wood burning stove with built-in collec-tion basin, adaptation of the heating surfaces, high-performance pumps, new thermostat valves, insulation of the distribution pipes, hydraulic balancing, renovation of the fl ue gas system.

Annual oil consumption 3,263 litres 1,352 litres – –Annual gas consumption 3,263 m3 1,352 m3 3,017 m3 –Annualpellet/split logs demand

– 2.0 t/5.0 stère – 4.8 t/12 stère

Amount of electricity produced annually

– 6,353 kWh –


Energy-effi ciency class for space heating

D A A+ –

Energy-effi ciency class for domestic hot water heating

– A+ – –

123248

3,263 litres3,263 m3

D D

B

C

D

E

F

I II

A A

A A+++

A++

A+

A B C D E F G

A+++

A++

A+

A B C D E F G

+

+

+

+L

2015 811/2013

L

A+

0100150 75 50 25125

Examples of modernisation – Variants with wood burning systems/CHP systems

Renovation variant – pellet/split log boiler

Wood pellet/split log boiler and solar domestic hot water system, adaptation of the heating surfaces, regulated pumps, new ther-mostat valves, insulation of the distribution pipes, hydraulic bal-ancing, renovation of the fl ue gas system.

Renovation variant – micro CHP system

Micro CHP system with modern gas condensing boiler, buffer storage tank and domestic hot water storage tank, adaptation of the heating surfaces, high-performance pumps, new thermo-stat valves, insulation of the distribution pipes, hydraulic balanc-ing, renovation of the fl ue gas system.

Annual oil consumption 3,263 litres 1,352 litres – –Annual gas consumption 3,263 m3 1,352 m3 3,017 m3 –Annualpellet/split logs demand

– 2.0 t/5.0 stère – 4.8 t/12 stère

Amount of electricity produced annually

– 6,353 kWh –


Energy-effi ciency class for space heating

D A A+ –

Energy-effi ciency class for domestic hot water heating

– A+ – –

I II

A

B

C D E F G

A

A

L

2015 811/2013

XY dB

XYkW

A++

A+

A B C D E F G

I II

2015 811/2013

XY dB

XYkW

109 43

ABC

D E F G

A

A

L

A++

A+

A B C D E F G

Energy label to be

introduced in 2018

109

I II

+

+

A

+

+

A-80%

A-60%

A-40%

A-20% A A B C D EFG

+ A++ A+++

A A B C D EF

+

A+++

A++

A+

A

B

C

D

E

F

G

A+

2015 811/2013

88 — 89

Industrial heat generatorsLarge combustion systems

Smart Grid and Smart Home Smart Grid and Smart Home

StandardisationStandardisation in the area of heating, ventilation and air-conditioning

90 — 91

Analysis of potential savings

Based on certain information provided by the Association of Chimney Sweeps (ZIV), TÜV and the companies organised with-in BDH, it is fair to assume that almost 300,000 technical com-bustion systems with a combustion heat output ranging from 100 to 36,000 kW are in service on the German heat market for larger buildings and the industrial sector. In technical terms, 80 % of these systems are no longer state of the art. The following calculations were made on the basis of approx. 250,000 identifi ed systems. There is a high potential for savings:

Reduction in annual consumption of heating oil: 810,000 t/a Reduction in annual consumption of natural gas: 4.43 billion m3

Reduction in the CO2-emissions: 16.3 million t/a Reduction in nitrogen oxide emissions (NOx): 34,885 t/a Reduction in the installed electrical output: 398 MW

Using 2008 as a basis, this constitutes a possible reduction in heating oil consumption of 3.3 % and a reduction in natural gas consumption of 4.6 %. In total, the use of effi cient technology in the largest technical combustion systems can lead to annual fi -nal energy savings of 175 PJ. Including heat recovery, the energy consumption required to generate steam and hot water can be cut by an average of 15 %. The maximum reductions in energy and costs are achieved if the components of the entire heat supply systems are streamlined and designed within an integral, tailored framework.

Procedure for system optimisation

Measures to enhance energy effi ciency within the heat supply system should always be considered as elements of optimising the overall system. The greatest enhancements in energy effi -ciency can be achieved by streamlining all components and by optimising system regulation and control. An initial stage should see a detailed analysis of the system's current state of energy consumption, the heat demand and the individual components within the system. Subsequently, a review of the energy effi ciency of individual components should be con-ducted in order to replace old components, whenever necessary.

The BDH energy effi ciency initiative with dena: Effi cient heat supply systems cut costs

A signifi cant volume of process heat is required in numerous technical methods and processes in industry, which must be pro-duced using substantial energy and at a high cost.Comprehensive energetic optimisation of the heat supply sys-tem can markedly reduce energy consumption and costs in the combustion systems – by 15 % on an average. These kinds of en-ergy effi ciency measures are highly profi table and generally re-deem their cost within one to four years.

High energy consumption of process heat

Various sources of energy are used to generate process heat (for example electricity, oil and gas); there are also different ways of transporting the process heat (as warm water/hot water, as steam or as hot air), and it is required within completely differ-ent ranges of temperatures. Each year, approximately 400 TWh of fi nal energy is used in Ger-many in order to supply thermal processes. The economic poten-tial for energy savings in thermal processes used within the in-dustry is at least 30 TWh per year (i.e. 7.5 %) Further 96 TWh are required every year in order to heat rooms, of which roughly 18 % could be reduced by increasing energy effi ciency.

Steam and hot water production

With a ratio of approx. 30 %, the production of steam and hot water in boiler systems is among the most widespread methods of generating process heat. Today, 80 % of all industrial heat and steam generation systems in Germany are over ten years old and can no longer be seen as state-of-the-art technology. In these old systems, the deploy-ment of effi cient technologies alone would produce annual en-ergy savings of 9.6 TWh. Let us be clear that this adds up to 2 % of the total energy consumption of process heat in Germany. In-cluding heat recovery, this means that energy consumption in the generation of steam and hot water can be cut by 15 %.

Large combustion systems

Fig. 106: Energy consumption and potential energy savings in industrial process heat applications

14012010080604020

0

20

15

10

5

0

Energy consumption in 2007 in terawatt hours Commercial energy savings potential in terawatt hours

Drying and combustion processes

Drying and combustion processes

Other thermalprocesses

Other thermalprocesses

Room heat Room heat

9693 19 12 18306

Further savings can be achieved by optimising the regulation and control of the combustion system. Whenever constructing new systems, even the preliminary plans should take care to ensure energy effi ciency of the compo-nents and the overall system. As things stand, roughly 40 % of the energy used in the genera-tion of industrial process heat is lost in the form of waste heat. In the event that upstream measures to reduce thermal loss have been exhausted, it is certainly worthwhile to exploit the waste heat by means of heat recovery. It is helpful in this context to create a heat circuit diagram, presenting all temperatures and the heat volumes transported and transferred within the process. A pinch analysis can then be used to determine the most effi -cient method for exploiting the waste heat available in every case.

Optimising the overall system

Before optimising the individual components of a heat supply system, it is important to fi rst initiate measures to minimise the heat demand and losses. Here, the following applies: Electrical energy has greater value than steam; and steam has greater val-ue than hot water. Therefore, depending on the requirements on hand, the supply medium with the lowest possible value should be selected in each of the respective process stages. The effi ciency can be increased from 10 to 15 % simply by using hot water instead of steam. In many cases, a reduction in the temperature of the supply medium enables the use of heat re-covery and the cogeneration of heat and power for further re-duction of the energy demand. In order to minimise losses, the heat insulation on the heat gen-erators, the pipes and also the heat storage should be analysed and improved wherever necessary.

Exploiting heat recovery

Measures targeted at heat recovery maximise the effi ciency of the overall system and therefore the system's energy effi ciency. Generally, the following applies: Heat recovery is all the more sensible, the greater the difference between waste heat temper-ature and the required temperature. Thermal potential should be used locally and as directly as pos-sible. For instance, waste heat can be used to heat industrial or process water, for preparing domestic hot water, to preheat com-bustion and drying air or as room heat. It is also worthwhile to use an economiser, for example to preheat the feed water. In condensing technology, an additional heat exchanger is fi tted downstream from the economiser, which cools the fl ue gases to below the condensation temperature of water. This means that the condensation heat of the water contained in the fl ue gas can also be exploited.

Using energy effi cient components

Equally, the target in using energy effi cient components should always be the optimisation of the overall system. This is achieved by effectively streamlining all new and existing components.Modulating (controllable) burners can be operated in many par-tial load ranges and are far more effi cient than burners that have to be fi red up and shut down individually. Flue gas temperatures and energy consumption can be reduced using boilers with large heat transfer surfaces. It is sensible to use energy effi cient condensing boilers in hot water systems, as their deployment leads to signifi cantly lower fl ue gas temperatures. Furthermore, their effi ciency is substan-tially higher. Speed controlled drive motors for forced air burners and pumps also permit pronounced savings in energy consump-tion.

Optimising regulation and control

Large combustion systems should always be tailored to suit the actual heat demand. For instance, a multi-boiler control ensures that only the required number of boilers are operated at any giv-en time . Installation of fl ue gas sensor control ensures continu-ous measurement of the fl ue gas composition. Air intake control takes place in line with the best possible oxygen ratio in the fl ue gas at any given time (O2ratio). Simply cutting the O2 ratio by just one percentage point leads to increased effi ciency, by 0.5 to 1 %, depending on the age of the system. Regulating and controlling other combustion parameters such as CO content, fl ue gas temperature, soot fi gure or combustion chamber pressure and the installation of automatic fl ue gas or combustion fl aps can cut the energy consumption still further.

Optimisation potential in the major output range:

30 TWh could be saved each year

Large combustion systems

Fig. 107: Five gas-powered high-pressure generators for up to 16 tonnes of steam per hour and 10 bars operating pressure each.

92 — 93

Smart meters

Smart electronic meters offer a number of advantages over con-ventional Ferraris meters: They provide the customer a direct overview of consumption and costs and thus, contribute to a more energy-effi cient behaviour. Energy supply companies would also benefi t: A better load distribution can be planned; attractive tariffs could provide incentives to use electricity during low-load periods. Electronic counters also form the communica-tion interface to the building. This makes them an indispensable part of the new energy landscape in the long term.

Smart home: Your home thinks along!

A prerequisite for the energy effi ciency of a building is the right interplay between the building envelope, systems engineering and building automation. If all three areas are aligned closely, they can contribute substantially to an effi cient building opera-tion. Smart building automation optimises, for example, the en-ergy consumption in a house or apartment. The functions of heating, cooling and ventilation as well as of sun protection, pri-vacy protection and glare protection are connected with each other via communication interfaces to form a common system network. This integration or communication and automated tuning between individual parameters and functionalities leads to an optimised operational management of the building and thus, has a signifi cant infl uence on the energy consumption and cost-effectiveness. Apart from energy aspects, Smart Home sys-tems also increase user comfort and safety of the resident and building.

On the way to generation-oriented consumption

Formerly, electric energy was almost exclusively generated in large power plants from oil, gas, coal or nuclear energy. Today, however, more and more small decentralised systems feed the public grid – for example, photovoltaic or wind. While photovol-taic systems generate a lot of power when the sun is shining, the yield of wind power plants increases with the strength of the wind. In the absence of sun and wind, the systems are at a stand-still. As a result, there are severe fl uctuations in the supply. On the other hand, during peak production times – when the wind is blowing very strongly and the sun is shining brightly – the sys-tems are switched off so that the electricity grid is not overload-ed. The entire energy system has to face a lot of challenges: In the fi rst half of 2014, the ratio of electricity generated from renew-able energies was more than 28 % and is expected to increase to even 60 % by 2025. Thus, a paradigm shift is needed: Away from consumption-oriented generation and towards generation-ori-ented consumption.

Systematic energy management: Smart grids and storage

Smart grids can help in stabilising the power supply system. They allow a better coordination between generation and con-sumption. The most important aspect in this case is the smart load control. Another crucial prerequisite for balancing genera-tion and consumption are storage facilities. They can be used to bridge periods without wind or solar power and balance out power peaks. Both, electrical and thermal storage facilities can be used for stabilisation of the overall system. These are facilities that convert electrical energy into heat or cold and store it, such as heat pumps, domestic hot water storage tanks, freezers or cold storages. With more than 600,000 systems already existing today, heat pumps offer much potential for use in smart grids. As a switchable and controllable system, they can fl atten out local power peaks during power generation and store the environ-mental energy in the form of heat energy. In addition to this, they obtain free energy from the environment and thus increase their positive environmental impact.

In the end, more electricity could be used effectively from renew-able sources and the renewable value, for example of a heat pump, could be increased further. The electricity and heat market are getting connected in a sensible way. Decentralised mini and mi-cro-CHP systems can also contribute to grid stability due to their quick standby feature.

Smart Grid and Smart Home

Fig. 108: Interaction of Smart Home, Smart Grid and Smart Metering

Feed-in ofthe utility

Smart Homes

Smart Grids

Smart Metering

Electricalhouse meter

Internet

Intelligent energymanagement

123456

2-way communication

Monitoring Intelligent house devices

A paradigm shift is necessary from

consumption-oriented generation towards generation-oriented consumption

Smart Grid and Smart Home

Fig. 109: Smart Grid diagram

Conventionalelectricitygeneration

Electricity flowCommunication

Control

Heat pump and heat storage tank

Electricity generation from renewable sources

Consumer and generator

Electrical devices Heat pump

PhotovoltaicsOther renewable energiesMicro-CHPs

Controller

Power grid

Electric carVentilationLight

94 — 95

Section 4 – Facility Management Section 5 – Energy Effi ciency of Buildings – Standardisation of HVAC Systems

Each of the fi ve sections is composed of several working com-mittees, where the actual standardisation work is done. A de-tailed list can be found on the NHRS website (www.nhrs.din.de). Anyone who wants to participate can send an application for participation at any time to the respective working committee.

Besides small- and medium-sized enterprises, mainly industry and trade associations are committed towards standardisation. One of them is the Federation of German Heating Industry (BDH), which brings along a broad spectrum of views and experience for the standardisation work.

Financing

The DIN group (DIN e. V., Beuth Verlag GmbH, DIN Software GmbH) gets 70 % of the funds from its own returns, obtained from the products and services it offers. At NHRS, the ratio of DIN is a good 43 %. A slightly larger proportion, currently approx. 45 %, comes from project funds of the industry. The remaining funds are obtained via public funding.

The standardisation work in the NHRS is also being directly spon-sored by associations and companies. Therefore, the non-profi t voluntary “foundation to promote standardisation work of the NHRS” (VF NHRS) was founded. It takes care of the promotion of science and research in the fi eld of heating, ventilation and air- conditioning and the fi nancial support of the NHRS. The BDH is a member of VF NHRS.

Questions and answers

Standardisation in the fi eld of heating and ventilation and air-conditioning is done in the Standards Committee for Heating and Ventilation (NHRS) of the Deutsches Institut für Normung e.V. (German Institute for Standardisation), “DIN”. The NHRS pro-cesses all standardisation applications in the fi eld of heating and indoor air-conditioning systems and their components (in-cluding the control, protection and safety devices). Some of the fundamental questions will be addressed in the following, be-cause the topic of standardisation can lead to uncertainty for misunderstanding for many users.

Fundamental purpose

Through standardisation, technical standards are defi ned and made available for everyone. This allows a large group of users to resort to the same know-how (for example, dimensions and tol-erances, or testing and safety requirements).

Why participation in standardisation work is worth-while

Active participation in standardisation work provides many ad-vantages to users and fi nal consumers, as well as manufacturers, designers, executors and authorities. Besides the information advantage over future technical regulations, which contributes signifi cantly to the planning security, the following points could be listed:

Monitoring trends in the industry Good basis to implement the company technologies on the

market Shaping the future technical regulations Prerequisite for the global market access

The liability of standards

Standards do not have any legal liability as such. Therefore, the standards are applied at fi rst for everyone on a voluntary basis. However, the user can be confi dent of acting in a technically proper manner when observing the standards.

A standard is always mandatory only if it is bindingly cited or in-cluded in, for example, laws, ordinances, administrative regula-tions or contracts.

The tasks of the NHRS

The work of the NHRS is classifi ed under fi ve sections:

Section 1 – Heating technology Section 2 – Ventilation Section 3 – HVAC control engineering

Standardisation in the area of heating, ventila tion and air-conditioning

Fig. 110: The German Institute of Standardisation in Berlin

Benefi ts

In the following, with reference to some industry-specifi c exam-ples, the benefi ts of standardisation are shown.

DIN EN 215: Thermostatic radiator valves – requirements and testing.

This standard specifi es requirements for dimensions and design of the connection (continuous and corner form) of thermostatic radiator valves. With reference to DIN EN 215, it is easily possible to get the right connector from the whole lot of manufacturers. Without the standard, there would be many different connec-tion geometries in the market, which would complicate the de-sign of products and systems and the installation of a heating system considerably. Furthermore, DIN EN 215 sets the require-ments for mechanical properties, operating characteristics, du-rability and temperature resistance, as well as the testing meth-ods. If a connector is designed according to DIN EN 215, it can be assumed that there are no problems with the application of con-ventional thermostatic valves. And of course these defi nitions not only help customers but also the manufacturers in the de-velopment, market launch and application.

DIN EN 12831: Heating systems in buildings – Method for calculation of the design heat load

The heat load calculation, basis for the design of each heating system is carried out today according to the method described

by DIN EN 12831. Thus, DIN EN 12831 contributes signifi cantly to the fact that heating systems are designed so that they reach the required internal temperature required. DIN EN 12831 pro-vides a uniform applicable method that allows the comparison of different systems. So DIN EN 12831, in simple terms, ensures that the heating system is able to heat the fl at and apartment house to a comfortable temperature in winter.

DIN EN 12828: Heating systems in buildings – design for water based heating systems

Due to the low strain capacity of pipes, the change in volume of the water caused by change in the temperature may lead to the fact that the pressure is increased greatly even with slight tem-perature increase. Without additional measures, such as expan-sion vessels, this increase in pressure leads to the destruction of pipelines and pressure vessels. Diaphragm pressure expansion vessels help to compensate for these changes in volume of water in piping systems.

DIN EN 12828 gives clear indications how diaphragm pressure expansion vessels must be designed and allows correct dimen-sioning. Without a correct sizing, there is a danger of pipe break. Dimensioning according to DIN EN 12828 provides confi dence to both the user and the designer: Finally, any diaphragm pressure expansion vessel properly designed according to DIN EN 12828 can be considered technically reliable.

Standards support access to global markets

Standardisation in the area of heating, ventila tion and air-conditioning

Business

Science and Research

Consumer

Occupational Insur-ance Associations

Public Authorities

Associations

Skilled Crafts

Trade

Application

Draft of standards

Statements

NHRS

Economy | Science and Research | ConsumerOccupational Insurance Associations | Public Authorities | Associations Skilled Crafts | Trade

STANDARD

Fig. 111: Participation in the standardisation process

96 — 97

BDH Members

Flamco GmbHFröling Heizkessel- und Behälterbau Ges. mbHGeneral Solar Systems GmbH Sonnenkraft Deutschland GmbHGlen Dimplex Deutschland GmbHGreiner PURtec GmbHGRUNDFOS GmbHHANNING Elektro-Werke GmbH & Co. KGHautec GmbHHDG Bavaria GmbH Heizomat Gerätebau-Energiesysteme GmbHHerrmann GmbH & Co. KGH.M. Heizkörper GmbH & Co. KGHoneywell GmbHHoval GmbHHuch GmbH BehälterbauIVT GmbH & Co. KGIWO – Institut für Wärme und Oeltechnik e. V.jeremias GmbHKermi GmbHKOF Abgastechnik GmbHKORADO a.s.Kutzner & Weber GmbH & Co. KGMAGONTEC GmbHMARANI G. S.p.A.MEKU Energie Systeme GmbH & Co. KGMHG Heiztechnik GmbH

AEROLINE Tube Systems Baumann GmbHAFG Arbonia-Forster-Riesa GmbHait-deutschland GmbHaltmayerBTD GmbH & Co. KG ATAG Heizungstechnik GmbHAustria Email AGBDR Thermea August Brötje GmbH

Remeha GmbHOertli Rohleder Wärmetechnik GmbHSenerTec GmbH

Bertrams AGBosch Industriekessel GmbHBosch Thermotechnik GmbHCaradon Heating Europe B. V.Carl Capito Heiztechnik GmbHDanfoss GmbHDEHOUST GmbHDL Radiators SpAWalter Dreizler GmbH WärmetechnikKarl Dungs GmbH & Co. KGebm-papst Landshut GmbHeka – edelstahlkamine gmbhELCO GmbHElster GmbHEnertech GmbH Division GierschFederal-Mogul Ignition GmbHFerroli Wärmetechnik GmbH

BDH Members

Mitsubishi Electric Europe B.V.Möhlenhoff GmbHMommertz GmbHMüller + Schwarz GmbHNAU GmbH Umwelt- und EnergietechnikNIBE Systemtechnik GmbHOventrop GmbH & Co. KGParadigma Deutschland GmbHPAW GmbH & Co. KGPoujoulat GmbHpro KÜHLSOLE GmbHRettig Austria GmbHRettig Germany GmbH, LilienthalRettig Germany GmbH, VienenburgRiello S.p.A.ROTEX Heating Systems GmbHRoth Werke GmbHSAACKE GmbH Schiedel GmbH & Co. KGK. Schräder Nachf.SCHÜTZ GmbH & Co. KGaASeibel + Reitz GmbH & Co. KGSEM Schneider Elementebau GmbH & Co. KGSiemens AGSolarbayer GmbHSOTRALENTZ HABITATSpirotech bv

Stiebel Eltron GmbH & Co. KGSUNTEC INDUSTRIES (Deutschland) GmbHTEM AGTen Cate Enbi GmbHTesto AGTiSUN GmbHTYFOROP CHEMIE GmbHUponor GmbHVaillant GmbHVasco Group GmbH VHB – Verband der Hersteller von Bauelementen für wärmetechnische Anlagen e. V.Viessmann Werke GmbH & Co. KGWATERKOTTE GmbHWatts Industries Deutschland GmbHMax Weishaupt GmbHWERIT Sanitär-Kunststofftechnik GmbH & Co. KGWieland-Werke AGWILO SEWindhager Zentralheizung GmbHWinkelmann Water Storage GmbHwodtke GmbHWolf GmbHZehnder Group Deutschland GmbH

www.bmwi.de www.bdh-koeln.de www.gebaeude-initiative.de www.waermepumpe.de

NHRS

www.depv.de www.nhrs.din.de www.dvgw.de www.fgk.de

www.geea.info www.hea.de www.hki-online.de www.iwo.de

www.messefrankfurt.com www.zukunft-erdgas.info

98 — 99

Efficient Heating Systems and Renewable Energies

Aircontec – Air-conditioning, Cooling, Ventilation

Frankfurt am Main10 – 14. 3. 2015 Energy

The world’s leading trade fairThe Bathroom Experience, Building, Energy, Air-conditioning Technology Renewable Energies

Issu

ed b

y: In

tere

ssen

gem

eins

chaf

t Ene

rgie

Um

wel

tFe

ueru

ngen

Gm

bH, F

rank

furt

er S

traß

e 72

0–7

26, 5

1145

Köl

n

NHRS

ISH Technology and Energy Panel

www.bdh-koeln.de

efficient systems and renewable energies - bdh-koeln.de · pdf filemessage from the patron i...

Documents