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Key Issues for Developers to Consider when Utilising Ground Source Technology
UK legislation now increasingly requires developers to fully explore the opportunities for incorporating embedded low carbon and renewable energy technologies as part of the planning application process. This requirement has been driven via the planning framework through the introduction of policies such as PPS22 and SPP6. This has in turn resulted in a widespread adoption of Merton Rule type policies by individual councils. Consultants are becoming key to this area particularly on larger commercial properties, advising their clients as to which technology will work in which application and how it can be integrated within the building.
Kensa, as the UK manufacturer of a complete range of ground source heat pumps, can help advise on this exciting technology and help you provide reports to your clients outlining the benefits and issues of installing heat pumps.
Some of the key issues that need to be considered with heat pumps are outlined below and include:-
- Merton Rule
- Building regulations
- Integration of heat pumps into heating and cooling systems
- Energy Sources
- Code for Sustainable Homes
- Funding and the Renewable Heat Incentive
1. Merton Rule
The target was originally set at a 10% reduction for all new major developments (major developments are classed as developments of dwellings of 10 or more and for all other uses: where the floor space will be 1000sq metres or more.) However North Devon currently require a 15% CO2 reduction from renewables and Kirklees Council are proposing that by 2011, 30% of energy consumption in every one of its new buildings is from renewable sources. This has drawn a large amount of interest from local authorities across the UK, with over 75 councils drawing up similar policies.
Due to their high efficiencies installing a ground source heat pump to provide the building’s heating will reduce the CO2 emission rate and help meet the building’s 10% (or greater) renewable obligation.
To maximise the benefits of installing a ground source heat pump and indeed any renewable technology, the building needs to be designed to minimise the need for energy with strategies such as effective insulation, passive ventilation, etc. By effectively designing a building, the amount and size of any renewable technology can be considerably reduced compared to a building where energy efficiency has been ignored.
2. Building Regulations
In 2006 the UK Building Regulations changed and one of the main requirements for meeting the energy efficiency criteria of the regulations (Part L, in England and Wales, Part J in Scotland) is now based on CO2 emissions from the proposed building.
Standard Assessment Procedure (SAP) is the Government’s standard methodology for assessing the energy consumption (CO2 emissions) in new domestic dwellings and the Simplified Building Energy Model (SBEM) is used for any other building not classed as a dwelling. The lower the CO2 emission the more energy efficient the building is. Installing a ground source heat pump will increase a building’s SAP rating and help the building meet current Building Regulations.
Ground source heat pumps have significantly lower CO2 emissions than traditional fossil fuel heating systems due to their high efficiencies. Using figures produced by the DTI in conjunction with BRE, a ground source heat pump can show up to a 43% saving in CO2 over gas and a 57% saving over oil.
Indeed, such is the CO2 reduction, there might be an opportunity, in some cases, to downgrade the insulation specification and still achieve an acceptable CO2 emission rate. However, this tactic is not recommended simply because any increase in the property’s heat load will result in a higher flow temperature, a less efficient heat pump and higher running costs.
3. Integration of heat pumps into heating and cooling systems
Heat pumps work most efficiently delivering water at the coolest possible temperature into the heat distribution system. For this reason, underfloor heating – with its larger heat emitting area – is generally preferred. If radiators are favoured, they should generally be designed with a flow temperature of 45oC which means they will need to be slightly larger than any radiator linked to a conventional boiler and due to the higher temperature will have higher running costs.
