Heat pumps (ground, water and air source)
Heat pumps are devices which use a refrigerant to extract low-grade renewable heat energy from the environment (usually from the air; sometimes from the ground or a water source) and transfer this into a building to provide heating and hot water. They work in a similar way to fridges and freezers, which extract heat from their interiors and expel it into surrounding air.
Heat pumps can do this even when the outdoor temperature is low – air source heat pumps (ASHPs) can operate down to -15°C. Some heat pump systems can also be used to provide cooling in summer.
Advantages
Heat pumps make use of a renewable heat source. While they still use electricity to compress and pump the refrigerant, the heat energy extracted from the air or ground can be up to three times the electrical energy needed to run the system, making this a very efficient form of heating. As a result, they have much lower carbon emissions than gas boilers – and these will continue to decrease as the electricity grid decarbonises.
Heat pumps do not produce air pollution, require minimal maintenance and, when combined with energy efficiency improvements, can result in lower energy bills.
What should I do?
If your existing gas or oil boiler has reached the end of its life, please consider replacing it with a heat pump.
The government’s Electrification of Heat demonstration project has indicated that ‘heat pumps can be successfully installed in homes from every style and era’. This includes apartments without outdoor space – as long as the heat load is small enough, it is possible to install a heat pump internally which draws air in though a duct.
However, given the relatively high cost of electricity compared to gas, a sufficient level of energy efficiency will also ensure that heat pumps operate effectively and are therefore cheaper to run for homes switching from gas boilers. Older homes may therefore need additional energy efficiency retrofit measures to ensure cost-effective operation. The government is currently reviewing electricity market arrangements, which may in future result in a reduction in the price of electricity relative to gas and make heat pumps more cost-effective.
Support and advice available
The government has announced that, from April 2022, grants of £5,000 will be available for homeowners to subsidise the cost of installing a heat pump and related works (£6,000 for a ground source heat pump). 30,000 grants will be available each year for three years, on a first-come, first-served basis. Visit gov.uk for more information.
Do I need planning permission?
In most circumstances, neither water source nor ground source heat pumps need planning permission. The Council strongly supports the use of heat pumps to contribute to the achievement of its carbon reduction targets.
Planning permission for an ASHP will usually be required:
- on a site designated as a scheduled monument
- on a listed building (including any building within the listed building’s grounds)
- On a property in a Conservation Area covered by an Article 4 Direction
In sensitive locations and on heritage assets, this equipment should be placed as discreetly as possible to avoid impacting on the character and significance of the asset.
In most other cases, an ASHP would only require permission if it exceeds MCS planning standards (check with the installer), and if it exceeds one of the following criteria:
- The volume of the heat pump (including housing) exceeds 0.6 cubic metres
- As a result of the installation there would be more than 1 air source heat pump on the property
- Any part of the heat pump is less than 1 metre from the boundary of the property
- An ASHP may not be installed on a pitched roof. It may be installed on a flat roof so long as it is located more than 1 metre from the edge of the roof
- An ASHP must not be installed on a front elevation above ground floor level
- Within a conservation area the ASHP must not be installed to the front of the house
In all cases, the ASHP must be located to minimise the effect on the external appearance of the building, must be used for heating purposes and must be removed when no longer needed. Consideration should also be given to placing the unit where it will not cause noise nuisance to neighbours.
