The term ‘heat pump’ is very descriptive. It’s a device that ‘transfers’ or ‘pumps’ heat from one place to another. 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 that transfers heat in the opposite direction to its natural flow – from cold to hot. Heat pumps do the same and can save energy by extracting heat from the outdoors and deliver it for use inside a building. The concept can seem counter intuitive at first, but it is not too difficult to grasp the basic principles. 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 necessary for refrigeration and air-conditioning, but they can also be used for heating applications. The electrical energy input used to drive them can be considerably less than the total heat delivered.
Compared to normal heating methods such as burning oil / gas or normal electric heaters, heat pumps can save significant amounts of energy. They therefore have an important role to play in reducing our demands of the Earth’s resources.
Heat pumps are often referred to as ‘Renewable energy’, but they not wholly-renewable because they require an external electrical input. However, the renewable heat they extract from outside should be far greater than the electrical input.
Unlike solar, wind and hydro energy, heat pumps are not free to operate, but on the other hand, they can operate in any weather, day or night.
As you will learn, the energy-efficiency of heat pump systems can vary GREATLY. They must be designed and installed correctly, and in the right situation, if they are going to be of most benefit.