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Module 3. Ground Source Heat Pumps. Plan. Intro: Why and what is a Ground Source Heat Pump (GSHP)? Advantages of GSHPs How a fridge works? How a liqui/water heat pump works? Works Co-efficient of preformance (COP) Effficiencies Sizing Futher information Micro CHP.
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Module 3 Ground Source Heat Pumps www.sara-project.net
Plan Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • Intro: Why and what is a Ground Source Heat Pump (GSHP)? • Advantages of GSHPs • How a fridge works? • How a liqui/water heat pump works? • Works • Co-efficient of preformance (COP) • Effficiencies • Sizing • Futher information • Micro CHP
Why Ground Source Heat Pumps ? Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • Relies on fairly constant temperature of the ground • Can be used for heating and cooling • High capital costs, very low running costs
Ground and Air Temperatures Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 Source: Geoscience
What is a Ground Source Heat Pumps ? Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118
Advantages of GSHPs Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • high reliability (few moving parts, no exposure to weather) • high security (no visible external components to be damaged or vandalised) • long life expectancy (typically 20-25 years and up to 50 years for the ground coil) • low noise • low maintenance costs (no regular servicing requirements) • no boiler or fuel tank • no combustion or explosive gases within the building • no flue or ventilation requirements • no local pollution.
How a fridge works Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 Diagram: BBT Thermotechnology UK
How a liquid/water heat pump works Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 Diagram: BBT Thermotechnology UK
Ground Source Heat Pumps Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • Horizontal collectors can be less expensive to install but require an area of approximately 120-150% of the floor area to be heated • Capital cost around EUR 6 000 per household (depending on civils)
A Typical drilling rig for a borehole based GSHP installation Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 Photo: Geoscience
Trench for a ground loop heat exchanger Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 Photo: Geoscience
Co-efficient of Performance (COP) Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118
Efficiencies Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • Heat pump efficiencies improve as the temperature differential between ‘source’ and demand temperature decreases • Therefore a low temperature heat distribution system is required
Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 BRE Good Practice Guide 339
Sizing Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • Crucial to operation • Energy efficiency very important • Usually designed to meet 50% of peak demand and 80-85% of heat demand over the year • Usually pre-heats hot water, electrical immersion heater used for top up heating
Further Information Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • IEA Heat Pump Centre www.heatpumpcentre.org • Canadian Earth Energy Association www.earthenergy.ca • www.earthenergy.co.uk
Micro CHP Sustainable Architecture Applied to Replicable Public Access Buildings www.sara-project.net Contract:TREN/04/FP6EN/S07.31838/503118 • CHP (Combined Heat and Power) • Replaces gas boiler and also produces electricity • Whispergen • £3000 + VAT • Available from Powergen in East Anglia, East Midlands, Yorkshire, the North West and London regions • £150 savings per year (EST report, 3-4 bedroom house) • CO2 savings of 1.5 tonnes a year • Floor mounted, against an outside wall • Microgen • Similar system, to be launched in the UK in 2007 • Further info at www.chpa.co.uk