Heat Pumps
There are two different types of heat pump available:
All heat pumps work on the same principle, by extracting solar energy stored in the ground, air or water. The solar energy is supplemented by electricity to reach required temperatures for domestic hot water and central heating.
Heat pumps are rated by their Coefficient of performance (CoP), where:
Energy In : Energy Out = CoP, usually 2.5 - 5.0
The CoP improves dramatically when the heat source temperature is higher, and also with lower demands on the heat distribution temperature, which is why they are extremely compatible with underfloor heating systems which work efficiently at lower temperatures than radiators.
Ground Source Heat Pumps
- Horizontal trench requires large(ish) area (20-25m per kW), depth of a borehole depends on geology and heat required
- Pipe is normally laid out in loops 1m apart and 1-2m deep
- Trenches need to be 1m apart
- Ideal for new build as the trench can be dug while heavy plant is on site and piping laid, thus avoiding disturbance and allowing ground time to recover
- Potential for CoP to fall during the winter months due to falls in normal outdoor temperature
- Costs around £300/kW
- Can also be laid out in water, utilising a pond or lake
- likely that planning permission will be required
- CoP reduced in the winter months
- No ground works required apart from getting the pipes back to the house
Air Source Heat Pumps
- Planning permission and building warrants are both normally required
- Significantly cheaper to install than other types of heat pump as no ground works required
- Usually have a CoP of 2.0 – 2.5
- CoP is affected by outside temperature therefore a back up (immersion heater) is necessary
- Ideal for retro-fit
- Limited space requirement
RHI payments will be made for ground and air source heat pumps, but they must be installed by an MCS approved installer.
Click here for a list of Heat Pump installers willing to work in the Locahber area
Heat Pump case studies to follow
