Ground Source Heat Pumps in low-income housingGround Source Heat Pumps in low-income housing

Presented by Denys Stephens Presented by Denys Stephens Sustainability Manager, Penwith Housing AssociationSustainability Manager, Penwith Housing AssociationA member of the Devon & Cornwall Housing GroupA member of the Devon & Cornwall Housing Group

Penwith Housing AssociationA member of the Devon & Cornwall Housing GroupA member of the Devon & Cornwall Housing Group

�� Manages 6000 homes throughout CornwallManages 6000 homes throughout Cornwall�� Manages 6000 homes throughout CornwallManages 6000 homes throughout Cornwall

�� Has pursued best practice in energy efficiency Has pursued best practice in energy efficiency since stock transfer in 1994since stock transfer in 1994since stock transfer in 1994since stock transfer in 1994

�� First RSL to install GSHP in First RSL to install GSHP in newbuildnewbuild 19981998

First RSL to retroFirst RSL to retro--fit multiple fit multiple GSHPsGSHPs in 2004in 2004�� First RSL to retroFirst RSL to retro--fit multiple fit multiple GSHPsGSHPs in 2004in 2004

Ground Source Heat Pump HeatingGround Source Heat Pump Heating

�� Uses closed loop ground source heat pump Uses closed loop ground source heat pump technology to access mainly technology to access mainly solar solar energyenergytechnology to access mainly technology to access mainly solar solar energyenergy

�� The ground absorbs solar heat and maintains a The ground absorbs solar heat and maintains a relatively constant temperaturerelatively constant temperaturerelatively constant temperaturerelatively constant temperature

�� Usable almost anywhere in the U.K.Usable almost anywhere in the U.K.

�� Very low CO2 emissionsVery low CO2 emissions

�� Backup heating is not necessary if you choose a Backup heating is not necessary if you choose a �� Backup heating is not necessary if you choose a Backup heating is not necessary if you choose a well designed systemwell designed system

�� Runs on electricityRuns on electricity�� Runs on electricityRuns on electricity

�� 1 kW electricity generates about 3.2 kW heat 1 kW electricity generates about 3.2 kW heat (Coefficient of performance 3.2 (Coefficient of performance 3.2 –– radiator system)radiator system)(Coefficient of performance 3.2 (Coefficient of performance 3.2 –– radiator system)radiator system)

Why use Ground Source Heat Pumps?Why use Ground Source Heat Pumps?

�� Many rural areas are off the gas networkMany rural areas are off the gas network

Difficult to achieve Affordable Warmth with Difficult to achieve Affordable Warmth with �� Difficult to achieve Affordable Warmth with Difficult to achieve Affordable Warmth with conventional electrical heatingconventional electrical heating

�� Cost & unsustainability of oil & LPG fired central Cost & unsustainability of oil & LPG fired central heating. heating. heating. heating.

�� GSHPs provide affordable heating with very low GSHPs provide affordable heating with very low CO2 emissions & low maintenanceCO2 emissions & low maintenanceCO2 emissions & low maintenanceCO2 emissions & low maintenance

�� Currently one of the most accessible renewable heat Currently one of the most accessible renewable heat technologiestechnologiestechnologiestechnologies

�� Will benefit from Renewable Heat Incentive in 2011Will benefit from Renewable Heat Incentive in 2011

Grid electricity as a heating fuelGrid electricity as a heating fuel

�� It has a carbon consequence (0.517 kg/kW hr), It has a carbon consequence (0.517 kg/kW hr), BUTBUT

GSHPs reduce that by 60 GSHPs reduce that by 60 –– 75%75%�� GSHPs reduce that by 60 GSHPs reduce that by 60 –– 75%75%

�� CO2 content of the grid will reduceCO2 content of the grid will reduceCO2 content of the grid will reduceCO2 content of the grid will reduce

�� GSHPs zero carbon when run on green electricityGSHPs zero carbon when run on green electricity

�� Insufficient supplies of biomass fuel for general useInsufficient supplies of biomass fuel for general use�� Insufficient supplies of biomass fuel for general useInsufficient supplies of biomass fuel for general use

�� Gas supplies are depleting and reliance on foreign Gas supplies are depleting and reliance on foreign supply is increasing supply is increasing –– thethe carbon footprint of gas carbon footprint of gas supply is increasing supply is increasing –– thethe carbon footprint of gas carbon footprint of gas increases when it’s shipped furtherincreases when it’s shipped further

Electricity available almost everywhere, hence Electricity available almost everywhere, hence �� Electricity available almost everywhere, hence Electricity available almost everywhere, hence importance of heat pumps in off gas areasimportance of heat pumps in off gas areas

Effect of Fuel Price Increases 2005 - 2009100m2 house annual heating costs

Effect of Fuel Price Increases on Annual Heating & HWS Costs for 100m2 L.A. House[2005 - 2009]

1600

1700

1200

1300

1400

1500

1600

800

900

1000

1100

1200

l Fue

l Cos

t (£

) GSHP

Gas

Oil

Electricity

400

500

600

700

800

Ann

ual F

uel C

Electricity

Coal

Lpg

0

100

200

300

400

0

01/01/05 01/01/06 01/01/07 01/01/08 31/12/08 31/12/09

Features of a GSHP SystemFeatures of a GSHP System

Heat distribution system –

Hot water cylinder

Heat distribution system –radiators or under-floor

Heat pump & circulatingHeat pump & circulatingpump – can be inside or in external enclosure

Ground loop – (not to scale)can be vertical or horizontalcan be vertical or horizontal

Ground source heat pump system with horizontal ground loop

Ground source heat pump system with vertical ground loop

Specifying GSHPs – key issuesSpecifying GSHPs – key issues

�� Engage the interest & support of tenantsEngage the interest & support of tenants

�� Pick dwellings that are (or can be) well insulatedPick dwellings that are (or can be) well insulated�� Pick dwellings that are (or can be) well insulatedPick dwellings that are (or can be) well insulated

�� Choose a reliable GSHP that can comfortably meet the heat Choose a reliable GSHP that can comfortably meet the heat loss levels of the dwellings.loss levels of the dwellings.loss levels of the dwellings.loss levels of the dwellings.

�� An expert installer is needed, particularly to correctly design An expert installer is needed, particularly to correctly design the ground loop.the ground loop.the ground loop.the ground loop.

�� Pay attention to design for noise reductionPay attention to design for noise reduction

�� M&E contractor who installs heat distribution system must M&E contractor who installs heat distribution system must �� M&E contractor who installs heat distribution system must M&E contractor who installs heat distribution system must understand GSHPs.understand GSHPs.

Design Issues - Drilling WorkDesign Issues - Drilling Work

� Need to avoid underground services

� Location as close as possible to dwelling

� Need to avoid damage to gardens� Need to avoid damage to gardens

� Disposal of any ground water

Design Issues – location of heat pumpDesign Issues – location of heat pump

� Preferably close to ground loop

� Internal or external?

� Ground loop condensation � Ground loop condensation

� Sound insulation

Connection of flow & return to plumbing� Connection of flow & return to plumbing

� Connection of electricity supply

Design Issues – heat distributionDesign Issues – heat distribution

� Underfloor - very difficult in retrofit� Warm air - availability? Popularity?� Radiators - can be retrofittedRadiators - can be retrofitted� Radiator sizes need not be excessive� High water content radiators for thermal storage� High water content radiators for thermal storage� TRV’s in bedroom/s & kitchen only� Hot water storage – simultaneous space & hw � Hot water storage – simultaneous space & hw

heating not possible

Design Issues - controlsDesign Issues - controls

Diverter valve or dual pump?

Room thermostatRoom thermostat ProgrammerProgrammer Heat Pump ControlHeat Pump Control

� Diverter valve or dual pump?

� Conventional 2 channel programmer

� Conventional room thermostat

� Probe thermostat in h/w tank� Probe thermostat in h/w tank

4 Bungalows at Bodinnar Close Newbridge4 Bungalows at Bodinnar Close Newbridge

Grant Aided by the Low Carbon Buildings ProgrammeGrant Aided by the Low Carbon Buildings Programme & Cornwall CC& Cornwall CC

Penwith HA’s Fourth GSHP retrofit project Penwith HA’s Fourth GSHP retrofit project –– April 2008April 2008An E.ON HeatPlant Project An E.ON HeatPlant Project –– GSHP Installer EarthEnergyGSHP Installer EarthEnergy

Project DetailsProject Details

�� 4 bungalows fitted with 3.5 kW systems4 bungalows fitted with 3.5 kW systems�� Retrofitted to existing buildingsRetrofitted to existing buildings�� Bungalows already fitted with cavity fill, double Bungalows already fitted with cavity fill, double �� Bungalows already fitted with cavity fill, double Bungalows already fitted with cavity fill, double

glazing & loft insulationglazing & loft insulation�� GSHP GSHP installer installer EarthEnergyEarthEnergy�� GSHP GSHP installer installer EarthEnergyEarthEnergy�� Plumbing systems by local Plumbing systems by local contractor MV contractor MV ClatworthyClatworthy

Drilling rig in actionDrilling rig in action

Protecting garden areas Protecting garden areas

Inserting the ground loopInserting the ground loop

Installed ground source heat pump

Ground loop

Flow & return toheating system

Heat pump

Ground loop pipes

Ground loop circulating pump

Ground loop pipes

Pre-formed enclosure

Plumbing Completed

GSHP performancePHA GSHP heated property – performance 28th – 30th November 2010

Hot water temperature

Internal air temperature

External air External air temperature

GSHP performancePHA GSHP heated property – March 2010 – February 2011PHA GSHP heated property – March 2010 – February 2011

Hot water temperature

Internal air Internal air temperature

External air temperaturetemperature

Annual fuel costs and CO2 Emissions comparison with other systems2 bedroom 3 person house (60 m2)

comparison with other systems

� GSHP - £ 307 1.1 tonnes CO2/yr

ASHP - £ 412 1.5

2 bedroom 3 person house (60 m2)

� ASHP - £ 412 1.5 tonnes CO2/yr

� HE Gas boiler - £ 442 2.0 tonnes CO2/yr

� LPG boiler £ 884 (47 kG bottle) 2.4 tonnes CO2/yr

� Oil boiler £ 442 (28 sec, 899 litre drop) 2.7 tonnes CO2/yrOil boiler £ 442 2.7 � Electricity £ 728 (storage heaters) 3.4 tonnes CO2/yr

� Smokeless coal £ 1056 (back boiler) 6.4 tonnes CO2/yr� Smokeless coal £ 1056 (back boiler) 6.4 tonnes CO2/yr

GSHP data based on 5 years monitored performance in HA homesFuel costs November 2009. Dwelling heat loss 2.1 kWFuel costs November 2009. Dwelling heat loss 2.1 kW

HeatPod ProjectPenwith HA’s Retrofit for the Future Project Penwith HA’s Retrofit for the Future Project –– 2 bed end of terrace house2 bed end of terrace housePenwith HA’s Retrofit for the Future Project Penwith HA’s Retrofit for the Future Project –– 2 bed end of terrace house2 bed end of terrace houseProject partners John Parker Consulting & EarthEnergyProject partners John Parker Consulting & EarthEnergy

�� ‘‘PassivhausPassivhaus’ approach not suitable for all housing, e.g. for ’ approach not suitable for all housing, e.g. for �� ‘‘PassivhausPassivhaus’ approach not suitable for all housing, e.g. for ’ approach not suitable for all housing, e.g. for vulnerable, elderly & special needs groups needing greater warmthvulnerable, elderly & special needs groups needing greater warmth

�� HeatPodHeatPod offers a dynamic solution offers a dynamic solution –– very good fabric standard very good fabric standard �� HeatPodHeatPod offers a dynamic solution offers a dynamic solution –– very good fabric standard very good fabric standard coupled with an innovative GSHP system coupled with an innovative GSHP system –– a Ground / Air / Solar a Ground / Air / Solar Source Heat Pump coupled with an air handling unitSource Heat Pump coupled with an air handling unitEnergy from exhaust air & Energy from exhaust air & HeatPodHeatPod solar gain reduces GSHP solar gain reduces GSHP �� Energy from exhaust air & Energy from exhaust air & HeatPodHeatPod solar gain reduces GSHP solar gain reduces GSHP ground loop size (and cost) and enhances system performanceground loop size (and cost) and enhances system performance

�� System designed to utilise thermal storage capacity of the groundSystem designed to utilise thermal storage capacity of the ground�� System designed to utilise thermal storage capacity of the groundSystem designed to utilise thermal storage capacity of the ground

HeatPod Project - Plans

100 mm external

High performanceExternal doors

100 mm externalWall insulation

Softwood tripleglazingglazing

Wood pelletstove

HeatPod Vertical Section

Exhaust air heat pump system augmentingExhaust air heat pump system augmentingGSHP performance

Pressurised hot water cylinder

Ground source heat pumpGround source heat pump

Ground loop circulating pump

HeatPod Project – CO2 emissions

Comparison of HeatPod Annual CO2 Emissions - [kgCO2/m2 p.a.]

150.0

120.0

130.0

140.0

150.0

90.0

100.0

110.0

120.0

Cooking

Appliances

50.0

60.0

70.0

80.0Appliances

Lighting

Fans & Pumps

Hws

Heating

20.0

30.0

40.0

50.0

0.0

10.0

Existing (coal) Storage heaters Std. gshp Enhanced gshp HeatPod

Data modelling by John Parker Consulting

AcknowledgementsAcknowledgements

Thanks to the following for making this work possible:Thanks to the following for making this work possible:Thanks to the following for making this work possible:Thanks to the following for making this work possible:

The Technology Strategy BoardThe Technology Strategy Board

The Low Carbon Buildings ProgrammeThe Low Carbon Buildings Programme

Cornwall CouncilCornwall CouncilCornwall CouncilCornwall Council

John Parker, John Parker Consulting John Parker, John Parker Consulting

Dr Robin Curtis, EarthEnergy Ltd.Dr Robin Curtis, EarthEnergy Ltd.

Mike Newell, E.ONMike Newell, E.ON

Calorex Heat PumpsCalorex Heat Pumps