October 25, 2023

Air Source Heat Pumps – The Basics

Here at Panel X, we realise that insulating your conservatory roof is only one way of saving on energy costs. Here is our explainer on air source heat pumps.

Air source heat pumps (ASHPs) have become an increasingly popular form of renewable heating in the UK in recent years. As an energy-efficient and low-carbon alternative to traditional fossil fuel boilers, ASHPs can help homeowners reduce their carbon footprint and energy bills.

What is an Air Source Heat Pump?

An air source heat pump works a bit like a refrigerator in reverse. It uses a refrigerant gas and a compressor to absorb heat from the outside air and amplify it to provide heating for your home. Even when external temperatures are as low as -15°C, ASHPs can extract heat from the air.

Inside the heat pump is a loop containing refrigerant which passes through an evaporator and absorbs heat from the outside. This refrigerant turns from liquid to gas as it warms up. The gas then passes through a compressor where its temperature is increased further. From here it passes through a condenser which transfers the heat into your central heating system and hot water.

Benefits of Air Source Heat Pumps

  • Renewable and sustainable heating – ASHPs use electricity to move heat, rather than burning fossil fuels. The heat is renewable as it comes from the outside air.
  • Reduce carbon emissions – As they don’t burn fuel, ASHPs produce 2-3 times less carbon dioxide than a gas boiler. This helps homeowners reduce their carbon footprint.
  • Lower energy bills – Properly installed ASHPs can provide energy savings of 20-40% compared to conventional heating systems.
  • Available grants and incentives – The UK government offers grants via the Renewable Heat Incentive (RHI) to encourage uptake of renewable heating like ASHPs.

Considerations for ASHPs

  • Higher upfront costs – The initial purchase and installation cost of an ASHP is usually higher than a new gas boiler. However, lower running costs offset this over time.
  • Require larger radiators – As ASHPs operate at lower temperatures than gas boilers, a larger radiator surface area is needed to heat a room to the same temperature.
  • Performance in cold weather – ASHPs become less efficient in extremely cold weather. Additional electric heating may be needed as a top-up.
  • Space needed outside – The external heat pump unit takes up space outside the property and makes some noise when operating.

ASHPs provide an energy efficient heating solution that can help UK homeowners reduce their environmental impact. With running cost savings and government incentives, ASHPs are an increasingly attractive technology despite higher initial purchase costs. Correct system sizing and design is important to ensure optimal performance, especially in colder weather.