rehau renewable energy cpd

Building SolutionsAutomotive

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RENEWABLE AND SUSTAINABLE SOLUTIONSREHAU RENEWABLE ENERGY CPD


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Ground-source probes/collectors

Stormwater management

Rainwater harvesting

Ground-air heat exchanger

Solar thermal / PVLow energy windows / curtain walling

Underfloor heating/cooling

RENEWABLE ENERGY SOLUTIONSWHAT IS GROUND-SOURCE ENERGY?

District heating


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Deep geothermal (from within the ground) (> 400m)

- Hydrothermal systems (using water stores)- Petrothermal systems (artificially pumping water deep underground)- Deep geothermal probes (using a closed loop system)

Ground-source (from the sun & rain) (< 400m)

- Ground-source collectors (sub-surface, at a depth of 1.5m)- Ground-source probes (depths of around 100m)- Ground-source energy piles (using the building foundations)- Ground water bore holes (using ground water)- Ground-air heat exchanger (controlled ventilation)

INTRODUCTIONWHAT TYPES OF GEOTHERMAL ENERGY ARE THERE?


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Ground-source probes/collectors

Stormwater management

Rainwater harvesting

Ground-air heat exchanger

Solar thermal / PVLow energy windows / curtain walling

Underfloor heating/cooling

RENEWABLE ENERGY SOLUTIONSWHAT IS GROUND-SOURCE ENERGY?

District heating


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INTRODUCTIONHOW A GROUND-AIR HEAT EXCHANGER WORKS


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EXAMPLE OF DOMESTIC APPLICATIONCOMBINATION WITH HEAT RECOVERY UNIT

1 Suction of fresh air

1

2Pre-warming of fresh air by ground

2

3Ventilation appliance incl. heat recovery

3

4 Distribution of fresh air4

5 Warm internal air extracted from the rooms

5

Expel the extracted air from the building (after heat recovery)

6

6


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INTRODUCTIONCOMBINATION WITH A HEAT RECOVERY UNIT

Expelled warm, stale air from inside the house passes alongside the external air drawn into the house (pre-warmed by a ground-air heat exchanger)

Pre-warmed external air (from G.A.H.E)

Inside

Expelled air

Heat exchanger

Warm, stale air from the building

Heat recovery unit

Outside

Warmed, fresh ventilation air


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INTRODUCTIONWHAT IS CONTROLLED VENTILATION?

Controlled ventilation is required when there is not enough air exchange between the air inside the building and the outside air.

For low-energy and passive houses, controlled ventilation is considered essential due to excellent insulation standards.


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Disadvantages of natural ventilation

- Poor air quality (e.g. odours, air humidity too high/low)

- High CO2 concentration

- Noise pollution- Window ventilation can be hazardous (security and

height risk)

INTRODUCTIONWHY CONTROLLED VENTILATION?

Advantages of controlled ventilation

- Constant filtered, fresh air supply- Savings of up to 20% of heating energy and 80% of

cooling energy - No mould growth and inhibited dust mite growth- Ventilation in noisy areas possible


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CONDENSATION DISCHARGEWHY CONDENSATION BUILDS UP

Cooling of air from approx. 30°C to 16°C produces significant amounts of condensation in the pipe system, especially in summer.

This must be removed to:

- Ensure the continual performance of the G.A.H.E

- To avoid microbial growth

- Avoid potential musty smells


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ANTI-MICROBIAL INNER LAYERINTEGRATION OF SILVER PARTICLES

- Pseudomonas aeruginosa - Staphylococcus aureus – rod bacteria- Bacillus subtilis - bacteria- Aspergillus niger - mould- Candida albicans – yeast bacteria- Escherichia coli – faecal germs

Standard PP

Antimicrobial inner layer

An antimicrobial effect is achievable via integration of silver particles into the pipe inner layer.

An experiment by the Institut Fresenius (Jan 2003) confirmed a significant reduction in microbe growth using this method:


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Source: Ergebnis Institut Fresenius Jan 2003

ANTI-MICROBIAL INNER LAYERINTEGRATION OF SILVER PARTICLES


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Domestic:

- Air flow rate between 150 - 300 m³/h

- Pipe size DN200 sufficient

- Usually pipes laid as a ring in an existing

trench (min. 40m total length)

Commercial / industrial:

- Air flow rate < 20,000m³/h

- Pipes laid in a Tichelmann layout

- DN 200 – 250 pipes for heat transfer

- Pipe size of distribution pipe DN 500-1200

PIPE LAYOUTSYSTEM DESIGN

Air inlet House

Building

Air inlet


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SYSTEM DESIGNINSTALLATION REQUIREMENTS

- Laying depth approx. 1.5 m to 2 m

- Gradient of around 2 % to the

condensation discharge

- Lay in existing backfill, do not backfill

with sand

- Distance between pipes is at least 1m

(between each pipe, not pipe centres)

- Air velocity between 1-3 m/s

- Pressure losses must also be

considered (20-30Pa maximum)


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SYSTEM DESIGNDESIGN SOFTWARE FOR GROUND-AIR HEAT EXCHANGER

REHAU have bespoke design software to calculate the following:

The software can be obtained on a CD free from REHAU.

Requirements for calculation:

• Air flow rate OR building volume + air change rate

• Location / weather region

• Laying depth

• Laying pattern

• Area for laying


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INTRODUCTIONVARIOUS SYSTEMS TO EXPLOIT GROUND-SOURCE ENERGY

Energy piles Horizontal collectorsProbes


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INTRODUCTIONEXAMPLES OF GROUND-SOURCE APPLICATIONS

Offices

Station platforms

Houses/flats Industry

Airports Schools, sports halls


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Line 1: 1st February

Line 2: 1st May

Line 3: 1st November

Line 4: 1st August

SEASONAL VARIATIONS OF GROUND TEMPERATUREINTRODUCTION

Temperature

Depth


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INTRODUCTIONHOW DOES A HEAT PUMP WORK?

0°C

5°C

25°C

35°C

Compressor

Expansion valve

CondensorEvaporator

Lower pressure Higher pressure

HeatingHeat pumpGround-source system


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* at 1800 hours in service per year according to VDI 4640

INFLUENCE OF GROUND CONDITIONS INTRODUCTION

Poor soil

Average soil

Very good soil

25 W/m

50 W/m

80 W/m

10 W/m²

20-30 W/m²

40 W/m²

25 W/m

50 W/m

80 W/m

Circuit temperature 0 to 6°C -3 to 5°C 4 to 10°C


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GROUND-SOURCE PROBESRELIABLE ENERGY EXTRACTION


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- Double-U probes provide built-in reliability – ‘bury and forget’

- 2 flow and 2 return circuits

- If any probe failure occurs, still having working circuit

- Additional thermal outputs of around 10-15% per probe

GROUND-SOURCE PROBESDOUBLE-U PROBES


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PE-Xa probe with no jointing:

The flow and return of the probe form a continuous circuit without the potential damage point at the probe tip.

PE 100 probes have welded joints at tip.

GROUND-SOURCE PROBESMAXIMUM RELIABILITY WITH PE-Xa PROBES


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Due to the high temperature resistance of PE-Xa (from -40°C to 95°C), PE-Xa probes can be combined with solar thermal installations

GROUND-SOURCE PROBESIN COMBINATION WITH SOLAR ENERGY


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GROUND-SOURCE PROBESSPIRAL PROBES

- 5m deep borehole – simple to drill

- For new builds and refurbishments

- Low storage, transport and installation costs

- Expands from 1.1m to 3m

- High-quality PE-Xa material for safe installation and long-term reliability

- Optimized regeneration due to special PE foil membrane


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GROUND-SOURCE PROBESSPIRAL PROBES

- Average 400 W / probe (up to 700W for

excellent soil)

- 40m of 25x2.3mm pipe

- Up to 3 probes can be connected in series

- Distance between probes 3-4m


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GROUND-SOURCE COLLECTORS

PE 100 collectors

PE-Xa collectors

IDEAL FOR LARGE AREAS OVER 250m²


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68.5% of the thermal energy requirements

are obtained from ground-air heat

exchanger plus ground source energy

coupled with underfloor heating / cooling in

the Passivhaus “0 Liter House“

RENEWABLE ENERGY SOLUTIONSHARNESSING ENERGY FROM SELF REPLENSIHING ON-SITE

TOTAL ENERGY REQUIREMENT 21,170kWh (100%)

Ground-source energy 14,543 kWh (68.5%)

+


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Photovoltaics effectively

top-up the total buildings

energy to 100%

++

ZERO ENERGY BUILDINGPHOTOVOLTAICS INCORPORATED IN THE PASSIVHAUS MODEL

TOTAL ENERGY REQUIREMENT: 21,170kWh (100%)

Ground-source Energy 14,543 kWh (68.5%)

Solar Thermal Energy 1,780 kWh (8.5%)

Photovoltaic electricity 4,847 kWh (23%)


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THANK YOU FOR YOUR ATTENTIONANY QUESTIONS?

rehau renewable energy cpd

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