The term ‘heat pump’ is very descriptive. It is a device that ‘transfers’ or ‘pumps’ heat from one place to another. Usually, it moves the heat ‘uphill’ from a cold place to a hot place.
You probably own a heat pump without realising it – a refrigerator is actually a type of heat pump. Both fridges and heat pumps transfer heat in the opposite direction to which heat naturally flows. When used for heating, heat pumps can save energy by extracting heat from the outside, and deliver it for use within a building. The concept can seem counter intuitive at first, but it is not too difficult to grasp the basic principles. Heat pumps are becoming more commonly used for home and industrial heating, in-part due to the fact that electricity has got much ‘cleaner’ (lower carbon) very recently. This apparently magical technology is not new: in the 1950’s several heat pumps were installed in a bid to save energy and fuel costs. One of the most famous of these was used to heat the Royal Festival Hall in London by extracting heat from the River Thames.
Heat pumps have been in widespread use since the 1980’s in many countries including Sweden, Europe and North America.
Why heat pumps?
Heat pumps are of course used for refrigeration and air-conditioning, but they can also be used for heating applications. The energy input to drive the mechanism can be only a fraction of the total heat delivered for use. They can therefore save considerable amounts of energy as compared to the normal heating methods using electricity, oil or gas.
Unlike solar, wind and hydro energy, heat pumps are not free to operate.
Heat pumps are often referred to as ‘Renewable energy’. They not wholly-renewable because they require an external electrcal input. However, the renewable heat they extract from outside should be far greater than the electrical input. Heat pumps are one of the many technologies capable of reducing our Carbon Dioxide pollution levels.
As you will learn, the energy efficiency of heat pump systems can vary GREATLY. They must be designed and installed carefully and properly if they are going to perform as expected.