What are Air Source Heat Pumps?

Posted by: John Temple on 28th April 2022

Air source heat pumps have become increasingly popular over the last few years as they generate their own heat for your household renewably. With environmental concerns increasing, heat pumps offer the technology to efficiently create sustainable energy.

Taking heat from the air, an air source heat pump will boost the air to an increased temperature with the use of a compressor. Then it transfers the heat over to the household heating system. As heat pumps give heat to the home at a lower temperature to traditional gas and oil boilers, they take longer to warm up the home to the desired temperature. It is important for your home to be well insulated to reap the rewards of a heat pump as the heat that is creates can escape much more quickly.

How does it actually work?

  1. Firstly, heat from the air outside is absorbed by the heat pump and stored at a low temperature in a liquid refrigerant.
  2. In order to increase the temperature, the liquid is compressed by the pump with the use of electricity. Then it is condensed back to its liquid form for the heat to be released.
  3. The captured heat is then fed to your household radiators or underfloor heating. Your hot water cylinder can also hold the remaining heat.
  4. The heated water that is being held in your hot water cylinder can be used for a bath, shower, or simply from a hot tap.

Pros and cons of air source heat pumps


  • Low carbon and energy efficient – air source heat pumps create significantly less CO2 than most standard heating systems
  • Less disruptive installation compared to a ground source heat pump
  • Air-to-water heat pumps are eligible for Renewable Heat Incentive payments
  • Possibility of saving on your bills compared with using older, more conventional heating


  • The external condenser unit can take up a lot of outdoor space
  • Condenser units are often noisy and push cold air into the area around them
  • The consender’s pump requires electricity; therefore they are not zero-carbon. The only exception is if you get your electricity from a renewable source such as a wind turbine or solar panels.

How efficient are heat pumps and will I save on my energy bills?

How much savings can be made by having a heat pump installed all depends on the type of heating system that is being replaced. You will see significant savings if you are having a heat pump replace an electrical storage heater; but if you are changing an oil or Liquid Petroleum Gas (LPG) boiler you may not save as much, or it will take longer to make savings. If your property is currently being heated with mains gas, it would be more beneficial for you to consider having a gas hybrid heat pump installed.


The amount of savings to be made when having a heat pump installed can vary significantly depending on property size, current insulation, desired home temperature and existing heating system type. We would always recommend taking steps to reduce your energy consumption – our recent blog gave simple tips on how to save on your energy bills.

air source heat pumps
Back to All Posts

© Carshalton Boilers 2024. All Rights Reserved. Created by Your Marketing Team