What is a heat pump?

The term ‘heat pump’ is very descriptive. It’s a device that ‘transfers’ or ‘pumps’ heat from one place to another.

You probably own a heat pump without realising it – a refrigerator is actually a heat pump, and it transfers heat in the opposite direction to its natural flow – from cold to hot.  It extracts heat from the icebox and rejects the heat to the warm grill at the back of the fridge.

Heat pumps do the same and extract heat energy from the outdoors and deliver it for use inside to warm building.  The good news is that the energy-input required to make this process happen is relatively small.  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. It is now a very well established technology.

Why heat pumps?

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.  This input is rarely truly renewable. However, the total heat they extract from outside should be far greater than the electrical input required to power them.

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, in the right situation, and operated well if they are going to be of most benefit.