Air Source Heat Pumps collects thermal energy from the outside air. The heat pump is located externally, either next to an outside wall, or connected to the property with pre-insulated pipes buried in a trench. The main internally located items are the hot water cylinder, a buffer tank and two expansion vessels.

As with all types of heat pumps, it is important to specify the right size (kW) heat pump. For this a room by room heat loss assessment of the property is required. A heat pump produces less hot water than a boiler and the lower temperature it can operate at, the more efficient the system is. Therefore, the overall efficiency of the heating system requires heating distribution (underfloor heating, radiators or fan coil units) which can deliver comfortable room temperatures at low operating temperatures.

FAQ's about Air Source Heat Pumps:

1. Where can the heat pump be located?

For a retrofit, the first location to consider would be outside a wall as close as possible to the current boiler location. For a new build, as close as possible to the plant room/installation cupboard. The heat pump needs to be located in a way which allows for a good flow of air through the unit. If placed parallel to a wall, the minimum distance to the wall is 150 mm. A minimum clear distance of 1 meter in front of the heat pump is required. If you consider sitting the heat pump close to an adjacent property, the noise impact has to be assessed. If no suitable location is found next to the property, it is possible to site the unit at a distance from the outside wall. This will require the heat pump to be connected to the property with a high spec pre-insulated pipe buried in a trench.

2. Are they noisy?

All air source heat pumps emit a noise. We use heat pump for the manufacturer Nibe for almost all our installations. One of the reasons we like to use Nibe is that the noise level is very low. However, sensitivity to noise is very individual. If you are concerned about the noise, we are happy to take you to an installation and listen to the unit.

3. What equipment is required inside the house?

You will need a hot water cylinder, a buffer tank (40 or 100 litre depending of the size of heat pump) and two expansion vessels.

4. What are the planning requirements?

The installation of an air source heat pump on domestic premises is considered to be permitted development, not needing an application for planning permission, provided ALL the limits and conditions listed below are met. These permitted development rights apply to the installation, alteration or replacement of an air source heat pump on a house or block of flats, or within the curtilage (garden or grounds) of a house or block of flats, including on a building within that curtilage. A block of flats must consist wholly of flats (e.g. should not also contain commercial premises).

Limits to be met: