Heat Pump FAQ

No. Both ASHPs and GSHPs can be installed into new builds, listed buildings, mansions, schools, churches, bungalows, in fact any type of property you can think of. As long as the installer understands the bespoke nature of every building, a viable renewable solution can be achieved. Isoenergy specialises in just such a service, and has challenged misconceptions about where a heat pump can be installed for over 5 years.

The environmental impact of a heat pump depends greatly on it's efficiency. Heat pumps are powered by electricity. For the time being, this mostly comes from fossil fuels or imported nuclear supplies. What is key with a heat pump, however, is it's Coefficient of Performance (COP). This is the ratio of heating and hot water produced (in kWs) versus the amount of electricity required to run the system.

Our Whitbread Premier Inn project in Tamworth is producing a COP of 6.25. That means that for every 1kW of electricity being used to run the pump, the machine is producing 6.25kWs of heating and hot water. This significantly reduces the emissions of the building, making the heat pump extremely environmentally friendly. What's more, the latent solar energy in the ground providing the heat for the heat pump to work is renewable if the system is correctly designed and installed.

Both Ground Source and Air Source Heat Pumps can be linked into existing heating and hot water systems. Isoenenegy was one of the first installers in the country to challenge the misconception that heat pumps cannot operate with radiator systems. However, some changes may be needed to maximise efficiency in existing systems.

That depends on the size of the property, what pump is required and whether the property is new build or older.

Roughly speaking, for a newly built four bedroom property with good insulation, in 11 kW pump will need about 300m of ground loops. 

A 1,000sqm country house might require a 60kW pump and 2km of ground loops.

Isoenergy never installs coils of collectors in the ground, called Slinkies, as we believe they over-extract and damage the long term efficiency of ground source heating systems. We have frequently encountered slinky systems that permanently freeze the ground due to excessive extraction.

When isoenergy started, government grants were available, however they were stopped.

Currently, the government has confirmed the Renewable Heat Incentive (RHI), which intends to reward and incentivise micro generation. Just as the Feed in Tariff for solar rewards each kW of electricity generated, the RHI will pay money for heating generated by renewable means. Head over to our Renewable Heat Incentive FAQ for up to date news on the state of the scheme.

In reality, the inevitable rise of fossil fuels and the UK's move towards cheaper electricity from nuclear power means that a heat pump is a viable solution even without grants and tariffs.

Yes. An ASHP is at its most efficient in the summer months, when most people do not want heating in the home, but want to utilise their pool. Thus the ASHP can divert it's heat into the pool.

Both ASHPs and GSHPs are suitable for heating a pool.

For example, a 10m x 10m pool with an average depth of 2m being heated by a heat pump saves £2600 vs natural gas, £3000 vs oil, £5600 vs LPG and a huge £6600 vs electricity, based on 2010 prices.

Yes, a GSHP can cool a building as well as heat it. In a large scale project such as the GSHP at Premier Inn Burgess Hill, the heat pump provides simultaneous heating and cooling for the entire hotel throughout the year.

We do not recommend using a well or water borehole for heat extraction for several reasons:

• Typically wells are not deep enough
• The walls prevent a high level of thermal conductivity, thus reducing the amount of heat available
• The diameter of the well is too wide. Our extraction boreholes are typically around 30cm
• The well would need to be refilled with thermal grout to improve thermal efficiency, which is costly and a nuisance