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Data Sheet:
Air Source Heat Pumps Data Sheet

Information suitable for:
New build
  • Sustainable
  • Renewable energy
  • Recycled content
  • Healthy
  • Responsible sourcing
  • Energy saving

Technical information

Heat Pumps use refrigeration technology to provide heat from a condensing unit. The evaporator side of the heat pump absorbs energy from the air outside the house using it as a source of heat. The efficiency of a heat pump is denoted by its coefficient of performance know as ‘COP’. This is the ratio of energy extracted from the source and energy used by the heat pump itself. Typical COP values for ground source heat pumps are 3.5-4.5, whereas air source heat pumps tend to have a CoP of between 2.5-3.5. With the current mix of fuels for electricity production, using a heat pump produces slightly less emissions compared with conventional gas heating.

There are two types of air source heat pumps, air-to-air and air-to-water. Air to water pumps are used for heating and hot water by taking heat from the air outside and transferring it to the heating system via a heat pump - this process uses the principles of vapour compression. The air to air heat pumps heat up the air by drawing air into the unit, warming it up and then circulating the heated air around the property via a fan.

All air source heat pumps must be adequately sized and sited away from obstacles that may obstruct air flow. If the evaporator is inadequately sized or air flow is restricted, the unit may freeze, causing it to go into defrost mode which reverses the heat pump and uses electrical energy to melt the ice. This process reduces the COP of the unit and makes it less fuel efficient. The heat pump will be located outside the house on a sunny wall with plenty of room for airflow. This will also allow the heat pump to be easily accessible for servicing.

Hints and Tips

For optimum results you need to ensure that the fabric of the building is well insulated and draught proofed.

Air Source Heat Pumps can work better in conjunction with the use of underfloor heating systems. They operate at more than 3 times the efficiency of conventional heating systems and as a result help to minimise C02 emissions and reduce the heating costs of your property.

Air source heat pumps do not need planning permission from the local council.

Air Source Heat Pump can provide you with an income through the Renewable's Heat Incentive (RHI).

When installing Air Source Heat Pumps, you need to make sure they are suitable, making sure you have adequate space, they work better when replacing oil and LPG.