Renewable heating systems are very different from existing options. This post looks at what an air source heat pump is and if you need one.

Air Source Heat Pumps (ASHP) are a renewable heating technology that allows you to generate your own energy – and potentially save money on your energy bills.

ASHPs are currently getting a lot of media attention due to big government announcements in light of COP 26 such as the new £5000 boiler replacement scheme and existing schemes such as the Renewable Heat Incentive (RHI).

But what actually are ASHPs and how do they work?

What is an ASHP?

Most UK households’ heating systems either burn fuel, such as gas, or convert electricity to heat their home. But ASHPs are different because they don’t actually generate heat.

Instead, they move existing heat energy from outside into your home. This makes them more environmentally friendly as they typically deliver more heat energy than the electrical energy they consume.

Therefore, heat pump systems typically cost less to run than a traditional heating system.

So how do they work?

A simplistic way to understand how a ASHP works is like that of a fridge, but in reverse.

  1. Outside air (as low as -20°C) is blown over a network of tubes filled with a refrigerant. This warms up the refrigerant and it turns from a liquid into a gas.
  2. This gas passes through a compressor, which increases the pressure. Compression also adds more heat – like how the air hose warms up when you top up the air pressure in your tyres.
  3. The compressed hot gasses then pass into a heat exchanger surrounded by cool air or water. The refrigerant transfers its heat to this cool air, or water, making it warm.
  4. This air, or water, is then circulated around your home, via radiators or underfloor heating, to provide heating and hot water.
  5. In the meantime, the refrigerant condenses back into a cool liquid and starts the cycle all over again!

Should I get an ASHP installed?

Yes and no.

While ASHPs on the face of them seem like a more efficient and environmentally friendly way of heating your home, this is not always the case.

This is because they use electricity to operate. If your home is not properly insulated or airtight it allows the heat generated to escape more easily. Therefor, the ASHP must work harder to keep your home warm. In this instance it may actually use more electricity to heat your home than gas and therefore increase your energy bills.  

Therefore, before installation or applying for any government grants, and in the face of rising energy prices, it is important to understand if your home is currently suitable for one, and if not, what you can do to change this.

We currently offer Home Energy Surveys to help homeowners get a better understanding of the energy use of their home, how to reduce this and make it more efficient and cheaper to heat.

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