Heat pumps are an alternative way to heat hot water by absorbing heat from either the air or the ground into a fluid which is then compressed to further drive up the temperature and then passed through a heat exchanger which transfers the heat to water in your heating system. Air source heat pumps extract heat from outside air whereas ground source heat pumps draw heat from the soil beneath the surface. Both are considered green and renewable energy heating solutions.
Traditionally, electricity is considered to be the most expensive way to heat a home in the UK as a kilowatt hour of electricity costs 3 to 4 times that of gas. However, heat pumps do not work like traditional electric heaters and can convert one unit of electricity into three or more units of useful heat. So heat pumps powered by electricity are actually really efficient way to heat a home even though the water temperature produced may not be as high as the temperatures produced by traditional boilers. But to take advantage this efficiency you need to ensure that the home is very well insulated.
Both ground and air source heating pumps work in the same way but the cost of installing them all vary considerably. A typical cost for installing an air source heat pump would be around £7500, whereas the costs for installing a ground source heat pump system will be around three times as much. Much of this additional cost is caused by the fact that a borehole needs to be drilled in your back garden which is a very labour-intensive and costly process.
When it is not possible or desirable to drill a deep borehole then the heat pump piping can also be installed horizontally across a much larger area rather than vertically but this requires a large amount of space so is only possible for those with extremely large gardens. There is another option which is a hybrid heat pump which uses a combination of renewable energy and fossil fuels, this would typically be a ground or air source heat pump installation in addition to a conventional gas central heating boiler system.
In terms of energy efficiency horizontal ground source heat pump system is the most cost-effective over the long-term. Although this is partly down to the fact that the government renewable heat incentive tariff for grain source pumps is more than double that for air source heat pumps. Another advantage of horizontal systems is that the installation is cheaper and does not require any complex equipment. The next best choice is a vertical ground source heat pump system which will typical be used where there is insufficient space for horizontal system. Vertical systems will benefit from the same government incentives but the installation costs will be higher.
All full ground source heat pumps are nearly always the most efficient option here so she points still offer good efficiency and are the easiest and most affordable in terms of installation. If source heat pumps do benefit from government incentives even for they are not quite as attractive as the incentives offered for a ground source heating systems.
The heat pumps look just like those air-conditioning units you may see installed outside office buildings. The size will of course vary depending on the heating requirements of the building, but a typical heat pump unit will be around 1 m³. The government Renewable Heat Incentive rewards those who install heat pumps with some generous financial subsidies these subsidies are calculated using the heat demand for the property and the seasonal performance factor for the heat pump installed. Ground source heat pumps offer bigger financial incentives but are more costly to install, whereas air source heat pumps come with a smaller government subsidy but are cheaper in terms of the initial installation.