low carbon building design advice report -...

Low Carbon Building Design Advice Report for Valleys Church

19/7/2013 by Carbon Management Consultants Ltd

Customer Advice Line 0800 085 2005 www.carbontrust.com/energy

RESTRICTED – COMMERCIAL

Low Carbon Building Design Advice Report

Assessment Of Energy Saving Opportunities For

Valleys Church

Prepared for

Phillip Wood

Tabor Baptist Church

Davies Street

Brynmawr

Blaenau Gwent

NP23 4AD

Prepared by

David Thomas

Carbon Management Consultants Ltd

Castle House

Market Street

Laugharne

SA33 4SA

Tel

Email

07548951592 Tel

Email

07939133560

[email protected]

Account manager

Russell Davey Tel

Email

0800 085 2005

[email protected]

CT Ref.

PO Reference

Country

Date

Version

OPP-100667

6030145

Wales

19/7/2013

0.1 Draft

mailto:[email protected]

mailto:[email protected]



CONTENTS

EXECUTIVE SUMMARY 3

1. INTRODUCTION & BACKGROUND 4

2. RECOMMENDATIONS 5

3. WHERE NEXT AFTER YOUR SURVEY 17

APPENDIX 1 REPORT DETAILS ERROR! BOOKMARK NOT DEFINED.



EXECUTIVE SUMMARY

This report presents the results of a Design Review consultation by phone and email. This survey

and report are provided by the Carbon Trust. The Carbon Trust receives funding from the Welsh

Government.

The agreed scope of work was to provide energy saving advice and savings calculations for the

refurbishment of the Church and attached Café area.

Estimated Carbon Savings

Implementing all of the measures will reduce emissions associated with this building by XXX Tonnes

CO2.

IMPORTANT NOTICE

All costs and savings stated in this report are based on the data available at the time of the report.

For further liability information, see the Important Notice section.



1. INTRODUCTION & BACKGROUND

IMPORTANT NOTICE: Whilst reasonable steps have been taken to ensure that the information contained within this Report

is correct, you should be aware that the information contained within it may be incomplete, inaccurate or may have become

out of date. Accordingly, Carbon Management Consultants Ltd, the Carbon Trust, its agents, contractors and sub-contractors

and the Government make no warranties or representations of any kind as to the content of this Report or its accuracy and,

to the maximum extent permitted by law, accept no liability whatsoever for the same including without limit, for direct,

indirect or consequential loss, business interruption, loss of profits, production, contracts, goodwill or anticipated savings.

Any person making use of this Report does so at their own risk. © Queen’s Printer and Controller of HMSO. Any trademarks,

service marks or logos used in this publication are the property of the Carbon Trust, and copyright is licensed to the Carbon

Trust. Nothing in this publication shall be construed as granting any licence or right to use or reproduce any of the

trademarks, service marks, logos, copyright or any proprietary information in any way without the Carbon Trust prior written

permission. The Carbon Trust enforces infringements of its intellectual property rights to the full extent permitted by law.

The Carbon Trust is a company limited by guarantee and registered in England and Wales under Company Number 04190230

with its Registered Office at: 4th Floor, Dorset House, 27-45 Stamford Street, London SE1 9PY.

1.1. General

This consultation was carried out on 26th June 2013 by David Thomas of Carbon Management

Consultants Ltd. Our main site contact was Philip Wood and Stuart Wheatman.

This report presents the results of a Design Review, which is a single intervention, typically at

detailed design stage, whereby the client will receive consultancy support from a Design Advice

consultant.

1.2. Organisation Background

Situated in Davies Street in the centre of Brynmawr, the Chapel was built in 1835 and was one of

the first to be built in this area. Surprisingly, it is not listed, therefore there are few limitations on

what can be undertaken at the Chapel. The owners have had a full survey performed on the building

and there are various areas which need attention in order to make the building practical for it’s

continued use as a Church building. The main issue is that of damp penetration due to damaged

external render and broken down rainwater goods. The good news is that the roof on the main

building and also the roof on the Sunday School extension have quite recently been replaced, so

there are no problems here.

Internally there are some areas which need attention. The boiler and heating system needs updating

in line with modern heating requirements. There is carpentry repair work to be done where damp

has caused damage, as well as internal plastering and decoration.

1.3. Objectives

To work out the energy saving calculations for

1. Lighting in the main areas

2. Provide Energy savings Calculations on loft insulation

3. Undertake Heat loss Calculations for the Church and Café and estimate the required boiler

size

4. Assess the viability of under floor heating

5. Provide savings on Solar water heating

6. Provide Calculations on PV panels



2. RECOMMENDATIONS

Measure Estimated Identified Annual Savings* Estimated

Cost of

Measure*

Payback

Energy

Savings*

tCO2e

Savings*

Financial

Savings*

kWh tonnes £ £

Lighting in the main areas 2,748 1.44 £329.76 £6,600.00 20.01

The installation of the insulation

above the roof

32,816 6.03 £1,148.56 £3,628.08 3.16

Solar water heating 3,884 0.71 £881.76 £6,000.00 6.80

PV panels 42,100 22.09 £9,586.17 £60,000.00 6.26

Total 81,548 30.27 £11,946.25 £76,228.08 6.38

2.1. Lighting in the main areas

3 main lighting assessments have been undertaken, which are presented in the attached PDF files.

The assessments have been undertaken using Philips LED light fittings, although other fittings can

be substituted, subject to the replacement fittings having a similar Luminous flux (amount of light

from the lamp) and Luminaire efficiency (% of light that actually usefully leaves the fitting). Note

the Cost of measure and therefore the payback is the marginal cost of the LEDs over conventional

T5 or high frequency fittings.

The Chartered Institution of Building Services Engineers (CIBSE) has produced a “Code for Internal

Lighting”. The values below are abstracted from this code to indicate the level of lighting intensity to

be provided in various areas of the Church:

Body of Church (Nave etc) 100 – 200 lux

Pulpit/Lectern 300 lux

Choir Stalls 200 lux

Religiously significant areas (eg Altars etc) 300 lux

Chancel, Sanctuary, Platform 200 lux

Vestries 150 lux

Organ (Music reading facility) 300 lux

General purpose rooms 500 Lux

In the main hall a grid of 5 x 6 suspended 27W LED fittings would supply an average of 195 lux.



In the Café more visually appealing LEDs were chosen, it was found that a grid of 2x 3 of these twin

31W fittings would give an average of 444 lux, which is thought to be sufficient.

In the lower hall, a 3 x 3 grid of 42W suspended tray fittings would give an average light level of

500 lux



Relevant

Publications

CTL027 – How to implement office lighting refurbishment.



2.2. The installation of the insulation above the roof

Currently the building has a suspended ceiling in both areas, (The Café area has a standard

“commercial” type suspended tile ceiling and the Church has an ornate wooden celling. There is no

insulation between this and the un-insulated roof. It is therefore considered that the installation of

insulation will both improve energy efficiency.

The ceiling area was measured off the plans as 86.7 m2 in the café and the church roof of 190m2.

Building Main Church has a roof area of 190m2 suitable for insulating. It was calculated using EN

ISO 6946:2007 and EN ISO 13370:2007, that the existing roof has an insulation U value of 1.5

adding further 300mm of rock wool insulation to improve the insulation U value to 0.14, saving

21,059kWh, and £737 with a payback of 3.09 years.

Building Café has a roof area of 112.34m2 suitable for insulating. It was calculated using EN ISO

6946:2007 and EN ISO 13370:2007, that the existing roof has an insulation U value of 1.5 adding

further 300mm of rock wool insulation to improve the insulation U value to 0.14, saving 11,757kWh,

and £411 with a payback of 3.28 years.

Alternatively, you could install solid board insulation, although you would need about 150mm for an

equivalent amount.

U-value

(W/m²C)

Total

insulation

Thickness(mm)

0.14 305

0.15 285

0.16 265

0.18 235

0.25 170

0.28 150

0.30 140

0.35 120

0.45 90

Relevant

Publications

CTL064 – How to implement roof insulation



2.3. Undertake Heat loss Calculations for the Church and Café and estimate the required boiler size

An estimated heat load assessment has been undertaken and it is thought that 120kW is the

required heat load. Boilers of this size are available, although, due to the likelihood of different

occupancy of the café and main church areas, it might be prudent to have 2 x 60kW boilers, rather

than one 120kW boiler, although this option is £1365 (inc VAT) more than a single boiler there is

likely to be a marginal payback, although it does give some resilience to boiler failure.

Example prices are shown below.

Ideal Evomax 120kw Commercial Wall Hung Condensing Regular Boiler - 205962

Product Code: 113675

Manufacturer Code: 205962

£2,887.53 (£3,465.04 inc VAT)

Ideal Evomax 60kw Commercial Wall Hung Condensing Regular Boiler - 205959

Product Code: 113672

Manufacturer Code: 205959

£2,012.50 (£2,415.00 inc VAT)

The heating Controls should be an optimizer / compensator type, such as a DC1100, which provides

a simple user interface.

Whatever the controller chosen, the new thermostats should be an electronic type that has a heat

differential (i.e. sensing ability) of less than 0.5⁰C, as this will reduce the amount of heating

overshoot and therefore reduce energy consumption. The thermostat should be positioned in a site

that is representative of the temperature of the building or area to be controlled, about 1.5m (5ft)

off the floor, in a position out of direct sunlight and in an area that is not affected by process heat

gains or draughts. With the DC100, there is the ability to connect two sensors in parallel effectively

averaging out the reading across both of them.

An optimum start controller can be incorporated into the suggested controller, which adjusts start

times automatically for each of the areas of the building controlled and gives typical fuel savings of

10%. It can be set to provide a night-time setback temperature and then will optimise the preheat

time necessary to the required daytime temperature. The suggested controller can also be set up to

provide features such as optimum stop, day economy (reducing the heating when the outside air

temperature reaches a certain level) and automatic frost protection. Additionally it is recommended

that compensator controls are set up on the controller (which varies the water temperature flowing

in the radiators relative to outside air temperatures) this helps reduce over heating in areas not

directly controlled by a thermostat.

With an optimiser controller, you programme in the occupancy hours and the occupancy

temperature required and it then calculates how quickly the building will be able to heat up to that

temperature, rather than you having to guess.



It is suggested that the radiators in the areas not directly controlled by a thermostat, have a TRV

fitted to them, to allow for both independent temperature control of the areas, and to reduce

overheating potential.

If it is deemed that the Café has the longest occupancy place the main controller and thermostats in

this area, then in the main upper and lower halls, it is suggested that the heating to this areas are

controlled by two port valves, connected to a standard electronic thermostat with built in 7 day

timer, this will allow you to vary the times that these areas are heated. However, ensure that the

“start” times on these will have to have guessed “warm up” periods as they are not going to be

optimizers. This will however, give you the best overall control, reducing costs.

Alternatively, as the smaller, less well occupied rooms will have, radiators with TRVs fitted, you

could fit the new electronic TRVs with built in timer programmers, which will allow you to specify a

occupancy and setback temperature and time for each radiator, therefore ensuring that each

radiator or room will be its own individually controlled zone! Each electronic TRV costs from £25(on

top of the cost of the TRV valve itself).

Relevant

Publications

CTL035 – How to implement optimum start control

CTL040 – How to implement thermostatic radiator valves

CTL043 – How to implement heating zone controls



2.4. Assess the viability of under floor heating

The building is not suitable for underfloor heating. The problem is that there is the simple fact that

there is too much heat loss in the building per unit floor area.

Put simply, the heat loss is 120kW or 120,000W, the floor area is in total 466.9m2.Therefore the

average heat loss per meter squared is 257W/m2. Underfloor heating gives a maximum output of

100W/m2, realistically only 80W/m2 therefore, you will get less than half of the required heat output

from underfloor heating.

It is therefore suggested that you install a wet radiator based system.

For the same reason, and due to lack of space in the rear courtyard, an Air source heat pump

system is discounted.



2.5. Provide savings on Solar water heating

The system proposed is a 6 square metre flat plate collector system fitted to the South East facing

apex roof of the building, as requested. The collectors would ideally be mounted above the plant

room to minimise connections of the panels to the hot water cylinder.

The size of each collector is 2060mm x 1060mm (incorporating an absorber plate sized 2000mm x

1000mm). They will be fitted in two arrays of 3 collectors each (one array positioned above the

other), using a standard fixing/weatherproofing system and utilising reverse return plumbing

configuration.

Basis of sizing:

The exact water requirement is unknown; the solar heating is intended to act as a supplement to

the conventional water heating system and has been designed:

To supply around 300 litres of water @ 600C, per day, at peak performance on a cloudless

day in midsummer.

Solar water storage to be 300 litres.

Solar collectors will each provide, including system losses, 2.75kWh per day, peak

midsummer, to the storage cylinders.

The system proposed is predicted to provide output from the collectors of 3,884 kWh per annum.

This is based on the following factors:

(i) Solar collector efficiency over the range of operating temperatures likely to be

encountered in an average year has been estimated to be 65% for flat plate collectors

based on test data derived on the panel at Cardiff University (tests performed to

BS6757).

(ii) Radiation data obtained from 21 year average year figures from Kew Observatory gives a

figure of 1,100 kWh / m2 for the site. At 65% efficiency this results in a solar collector

output of 715 kWh / m2 / year for the flat plate collectors.

(iii) The figures stated above are estimates of heat energy collected by the solar collectors.

Within the solar primary circuit connecting the solar collectors to the heat exchange coil in

the cylinder heat losses may be in the order of 10% of the heat collected by the solar

collectors.

solar collector system efficiency 65%

size of solar array m2 6

annual solar fraction 55%

Value of displaced heat £/kWh £ 0.035

RHI payment for solar thernal £ 0.192

solar output 3,884

value of heat £ 135.95

Estimated value of RHI £ 745.80

Total Value of solar £ 881.76

Cost of panels £ 6,000.00

Payback (years) 6.80



Variation of performance with orientation and tilt



2.6. Provide Calculations on PV panels

Solar cells convert energy from sun light (direct and to a lesser extent diffuse) into direct current

(DC) electricity via the photovoltaic effect. Photovoltaic modules (also called solar or PV panels), are

made of multiple interconnected solar cells; these modules are linked together to form an array.

Most PV arrays use an inverter to convert the DC power produced by the modules into alternating

current (AC) that can connect into the existing infrastructure to power lights, motors, and other

loads.

The Department of Energy and Climate Change (DECC) has used powers in the Energy Act 2008 to

introduce a system of feed-in tariffs (FIT) to incentivise small scale, low carbon electricity

generation. The FIT scheme went live on 1 April 2010. Through the use of FITs DECC hope to

encourage deployment of additional low carbon electricity generation, particularly by organisations,

businesses, communities and individuals who are not traditionally engaged in the electricity market.

This “clean energy cash back” will allow many people to invest in small-scale low carbon electricity,

in return for a guaranteed payment both for the electricity they generate and export.

The Feed-in Tariff scheme is based on a few key elements:

The contract term is 20 years for solar photovoltaic projects: this means that, on

commissioning the tariff rate you receive is guaranteed for the 25 years for Solar PV

generators (reduced to 20 years from the 1st August 2012).

The tariff made available to generators will be subject to digression. That is, the tariff level

available for new generators will decrease with each review. The rate of digression will vary

by renewable energy technology. The price for individual renewable energy generating plants

is fixed once the plant becomes operational.

Costs for the programme will be borne by all British electricity consumers proportionally: all

consumers will bear a slight increase in their annual bill, thus allowing electricity utilities to

buy renewable energy generated from green sources at above-market rates set by the

government.

The new UK's Feed-in Tariff Programme review is scheduled for 2013.

When the government review the current Feed-in Tariff in 2012/2013 they are expected to

reduce the amount paid out and continue to reduce it every quarter.

Solar PV is a very visible indication of an organisations commitment to reducing its carbon footprint.

Whilst other energy saving measures such as pipe insulation give much quicker paybacks and

require lower levels of investment, they are often not noticed by employees and others.

The economics for solar PV rely heavily on the support given under the Government’s feed in tariff.

3 options have been considered, and it is recommended to go with a 50kW system for the following

reasons.

It provides for the best balance between reduced capital cost of installation and value of

resultant power (both from FITs and offsetting current grid electrical load).

It is the only solution where you can optimise the output of the panels with regards to

orientation and location.

At level of investment you can arrange for specialist “Green” investment banks to fully fund

the investment.



4kW costs approx. £5,500 (ex VAT), is 16x 250W panels, the size of which is approx. 1640mm x

992mm,

so 4kW covers approx. 26m2

10kW costs approx. £12,500 (Ex VAT) 40 x 250w panels, the size of which is approx. 1640mm x

992mm,

so 10kW covers 65m2

50kW costs approx. £60k (ex VAT) 200 x 250W panels, the size of which is approx. 1640mm x

992mm, so 50kw covers 325m2, likely to be say 2 rows 50m long, each row 2 panels high, the

panels can be mounted off the ground.

Estimated area 15m deep by 30m long on main SW facing roof

This can accommodate a 50kW PV system

PVGIS estimates of solar electricity generation

Location: 51°47'56" North, 3°10'28" West, Elevation: 354 m a.s.l.,

Solar radiation database used: PVGIS-CMSAF

Nominal power of the PV system: 1.0 kW (crystalline silicon)

Estimated losses due to temperature and low irradiance: 7.5% (using local ambient temperature)

Estimated loss due to angular reflectance effects: 3.3%

Other losses (cables, inverter etc.): 14.0%

Combined PV system losses: 23.1%

Fixed system: inclination=35°,

orientation=45° (SW)

Month Ed Em Hd Hm

Jan 0.80 24.9 0.99 30.6

Feb 1.37 38.3 1.69 47.3

Mar 2.45 75.8 3.08 95.4

Apr 3.39 102 4.38 131



May 3.63 113 4.78 148

Jun 3.73 112 4.97 149

Jul 3.46 107 4.66 144

Aug 3.06 94.8 4.10 127

Sep 2.53 75.8 3.32 99.6

Oct 1.57 48.8 2.01 62.4

Nov 1.00 29.9 1.24 37.3

Dec 0.66 20.5 0.81 25.2

Yearly

average 2.31 70.2 3.01 91.5

Total

for year 842 1100

Ed: Average daily electricity production from the given system (kWh)

Em: Average monthly electricity production from the given system (kWh)

Hd: Average daily sum of global irradiation per square meter received by the modules of the given

system (kWh/m2)

Hm: Average sum of global irradiation per square meter received by the modules of the given system

(kWh/m2)

PVGIS © European Communities, 2001-2012

Reproduction is authorised, provided the source is acknowledged

See the disclaimer here

Therefore, the output of the panels for your building are estimated to be 42,100.00kWh, with a

payback of 6.26 years. Although it is to be noted that the income from the Feed in Tariff, is subject

to the current FIT rate. Ofgem has confirmed the feed-in tariff rates (FiT) for solar photovoltaic

technology for the period starting 1 July 2013 until 1 October 2013. The rate used is the current one

and is stated below.

PV size Estimated

Cost Ex VAT

kWh

Generated

FIT Income Elec Offset Total Income Payback

50kW £60,000 42,100.00 £ 5,291.97 £ 4,294.20 £ 9,586.17 6.26

Energy

Source

Scale Type / Rate Tariff

(p/kWh)

Solar PV >10 - 50kW Higher rate 12.57

http://europa.eu/geninfo/legal_notices_en.htm

http://www.ofgem.gov.uk/SUSTAINABILITY/ENVIRONMENT/FITS/TARIFF-TABLES/Documents1/FIT%20Tariff%20Table%201%20July%202013%20PV%20Only.pdf



3. WHERE NEXT AFTER YOUR SURVEY

As part of the survey delivery process you will receive a supplement containing additional generic

information. This is intended to complement your survey report and provide further information to

enable you to implement the opportunities identified.

The supplement is divided into four sections;

Preparation for your Survey

The survey Process

Implementation: advice and support

Implementation: financial Support

Please contact your account manager if you do not receive your site survey supplement.