Heat Pumps are now being used widely to provide heat to buildings as well as pools in a cost effective manner. A heat pump essentially acts like air conditioning but in the opposite direction. Rather than cooling down your house and getting rid of excess heat to a radiator and external fan unit, a heat pump cools down the outside air and pump that heat instead into your house or pool. The physics of energy conservation mean that you get out more energy than you pay for because heat energy is transferred from the ground or air) into your house together with the energy you use to drive the system in the first place.
What this means is that if you compare the unit cost of heat provided by a heat pump with the unit cost of heat provided by a standard electric heater, you can usually achieve improvements of 300 percent or more. For space heating then, heat pumps thus offer a cost effective solution which means that your overall energy costs can be substantially reduced with much of the heat energy you use actually being provided by the surrounding outside air or geothermally.
There are two chief types of heat pump: GSHP or ground source heat pumps which extract warmth from the ground via a network of underground pipes, and air source heat pumps which extract heat from air that is fanned over a heat exchanger with a fan. Air source heat pumps are usually easy to install and currently are quite quiet}. They operate even down to sub-zero temperatures.
GSHP or ground source heat pumps rely on a series of underground pipes which contain a pumped liquid that enters the pipe cold, having given up its heat to your home, and then warms up to the surrounding ground temperature as it circulates. Once warm again it enters the heat pump and gives off its heat again to repeat the cycle.
GSHPs are less easy to install than air source heat pumps but have the advantage of working at slightly higher efficiency during very cold weather. The underground pipe network can be laid vertically via a deep bore hole or horizontally and essentially take out geothermal heat from the ground. This energy is always present at a low level but in conjunction with efficient heat pump technology it can be extracted and used to heat houses or pools very efficiently.
When selecting a heat pump you also need to select a good quality heat pump installer and it pays to use a firm that has a lot of experience and is professionally qualified.