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How does an Air Source Heat Pump Work?

 Q) How Do Heat Pumps Work?

A) There are 4 processes (with a few sensors and valves in between) to how a heat pump works. These are:


  1. Evaporation Heat pumps take in heat from the air or ground or sometimes water, transferring it to a heat exchanger that contains a liquid refrigerant. This refrigerant absorbs heat from the outside and evaporates, turning it into a low-pressure, low-temperature gas.  

  2. Compression The gas is transferred to an electrically powered compressor that compresses the refrigerant. This compression increases the pressure of the gas, which raises the gas temperature.  

  3. Condensation The hot gas reaches the heat exchanger, where it’s circulated and transfers its heat to a cold water circuit. This causes the water to heat up as it absorbs heat from the gas. Once the water has reached the desired temperature, usually around 55 degrees, it’s sent to your home’s radiators and underfloor heating to warm your house. By transferring heat to the water circuit, the refrigerant cools down enough to turn it back into a liquid.

  4.  Expansion The cooled refrigerant moves through an expansion valve, which lowers the pressure and allows it to absorb more heat energy. From there it’s pumped back into the heat exchanger to repeat the cycle.

Q)   Will an air source heat pump heat my house in the winter?

A)    Yes. If designed correctly and to MCS criteria heat pumps will operate to provide your home with the internal temperatures required with external temperatures between -3 and -5 depending on your UK location. All design temperatures should be made available to you with a design pack prior to having the heat pump installed.

Q) Are Heat Pumps new technology?

A) Not at all. They have been around for many years. Their refrigerant has changed and has become less ozone depleting. The technology has improved along with the design of the compressor. To aid efficiency DCR only install heat pump with inverter driven technology.

Lewis worked on his first heat pump back in 1999. Quote: The company I completed my apprenticeship with fitted heat pumps in lofts, or high factory roof spaces. These where installed to supplement solar thermal hot water systems. They were extremely basic but had the same basis as modern day equivalents (less a few sensors and the scroll compressor design) Being able to work on these and understand their functions for many years has enabled me to integrate this knowledge into DCR from our initial design team through to installation and the service team.


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