How do heat pumps work?

Most heat pumps are electrically powered, they take heat from the ground or air surrounding your home boosts it and uses it to heat your home.

A heat pump either replaces your current boiler or (in really cold places like Canada) is used alongside it.

A heat pump can be used to create warm air (for space heating) as well as hot water (for central heating and hot water).

The easiest way to think of it is to look at your fridge, it's cold, but if you feel the compressor (that big round thing that is usually at the bottom and hums when it's working) at the back it's hot.

At its most basic a heat pump works like a giant fridge with the door open to the outside and the compressor inside your home, as the fridge cools the air  the heat from the compressor warms your home

Here is how heat pumps work in more detail:

This heat is taken from the air outside (air source heat pumps) or a water mix that is pumped through ground collectors (ground source heat pumps) then either blown (air) or pumped (water mix) over the heat exchange surface of the outside part of the heat pump.

The heat exchanger is full of tiny tubes through which a special liquid called a refrigerant (where the word Fridge come from) is pumped through. The warm air or water mix flowing over these tubes causes the refrigerant to evaporate and turn into a gas.

The heated gas is pumped over an internal heat exchange surface, then either blown out as hot air heating or transferred into a home’s central heating or hot water system.

As the gas releases heat it gas cools and becomes liquid again and is pumped back into the external heat exchanger, and the cycle begins again only stopping when your home is at the required temperature.