How do heat pumps work?
A heat pump is an electrical device that transfers heat from one place to another, but how do heat pumps work? We've compiled a guide to show you how ground source and air source heat pumps work to supply heat to homes or commercial spaces.
Heat pumps are an old technology that has been used around the world for a long time, and there are a few common examples that you may recognise. A fridge, for example, is a kind of heat pump that we all have in our homes. Air conditioning units are another common example of a heat pump that a lot of us use on a daily basis. Heat pumps can work both ways, so they can either increase or decrease the temperature and give you complete temperature control for a wide range of different applications.
Heat pumps can be used as a method for heating your home, and there are three different types that you can use; air source heat pumps; ground source heat pumps; and air to water heat pumps. We all have experience using heat pumps in some form, but how do heat pumps work?
How do Air Source Heat Pumps work?
As the name suggests, an air source heat pump absorbs heat from the air outside of your home. This heated air is then circulated through the home using a system of fans, to heat the property. This is the simplest form of heat pump for heating your home and it works in much the same way as an air conditioner. However, it cannot feed your hot water or central heating system. It is also important that your home is well insulated so you do not lose the heat that is produced.
How do Air to Water Heat Pumps work?
Air to water heat pumps also draw heat from the air outside of your home. This heat can then be transferred into appliances in the home, such as radiators, underfloor heating, or warm air convectors to heat your home. An air-source heat pump can still extract heat from the air outside in temperatures as low as -15 degrees celsius.
Heat from the air is absorbed at a low temperature into a fluid. The fluid will then be passed through a cylinder unit that contains a compressor. The cold fluid is heated by this compressor before being transferred to the heating and hot water circuits inside your home. Air source heat pumps can heat water more effectively than a boiler when the temperature outside is particularly cold.
Air source heat pumps and air to water heat pumps require the installation of an appliance on the outside of your home, which looks very similar to an air conditioner. However, they do not require you to dig pipes into the garden like a ground source heat pump does.
How do Ground Source Heat Pumps work?
Ground source heat pumps utilise the natural heat under the ground to heat your home. A loop of pipe, known as a ground loop, will be buried outside of your home. A mixture of water and antifreeze will then be passed through the loop. The antifreeze ensures that the water does not freeze during the winter months when the temperature drops.
The liquid is heated by the natural heat from the ground and then passed through a heat exchanger. The extracted heat can then be used to produce hot water, heat radiators, and run underfloor heating systems in your home. Although the surface temperature varies a lot between winter and summer, the heat underneath the ground stays relatively constant, which means that ground source heat pumps can be used all year round.
A larger ground loop will generate more heat, but it does require more space. If you are particularly short on outside space, you can still use a ground source heat pump to heat your home but a vertical borehole will be used instead of a large ground loop.
Ground source heat pumps produce more heat than an air source heat pump or an air to water heat pump, but they do require more extensive installation work.
Hybrid Heat Pumps
Hybrid heat pumps are systems that incorporate a heat pump with another heating system, like a boiler or solar panels. Heat is generated by the heat pump and added to the heat generated by other sources, so you are less reliant on a boiler or solar panels to heat your entire home. If you install a hybrid heat pump, you can continue to use the existing central heating system that is already in your home.
Hopefully, that answers the question of how do heat pumps work? They are an effective alternative to traditional heating methods and as such, they are becoming a lot more popular.
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