Air Source Heat Pumps
An air source heat pump provides a clean way to heat buildings, free of all carbon emissions on site. It makes use of energy in the ambient air to provide an energy-efficient way of heating buildings.
Air source heat pumps are suitable for a wide variety of buildings and are particularly appropriate for low environmental impact projects.
They can be installed anywhere in the UK to provide space heating and domestic hot water.
The only energy used by a heat pump is electricity to power the compressor and the circulation pumps which transfer heat energy from the external air into the building. A well designed air source heat pump installation will deliver up to three times as much thermal energy (heat) as is used in electrical energy to drive the system. For a particularly environmental solution, green electricity can be purchased.
Air source heat pumps have been widely used in North America, Sweden, Germany and Switzerland for many years. Typically they cost more to install than conventional heating systems. However, they have very low maintenance costs and can be expected to provide safe, reliable and emission-free heating for many years.
Air source heat pumps work best with heating systems which are optimised to run at a lower water delivery temperature than is commonly used in radiator systems. As such, they make an ideal partner for underfloor heating systems.
The Advantages of Air Source Heat Pumps
Air Source Heat Pumps save money. Heat pumps are much cheaper to run than direct electric heating systems. ASHPs are cheaper to run than oil boilers and can be cheaper than runing gas boilers.
Because heat pumps can be fully automated they demand much less work than biomass boilers.
Heat pumps save space. There are no fuel storage requirements.
No need to manage fuel deliveries.
No risk of fuel being stolen.
Heat pumps are safe. There is no combustion involved and no emission of potentially dangerous gases. No flues are required.
ASHPs require less maintenance than combustion based heating systems. They also have a longer life than combustion boilers.
Heat pumps save carbon emissions. Unlike burning oil, gas, LPG or biomass, a heat pump produces no carbon emissions on site (and no carbon emissions at all, if a renewable source of electricity is used to power them).
Heat pumps can also provide cooling in summer, as well as heating in winter.
Renewable Heat Incentive
The Renewable Heat Incentive is a financial encouragement to install heat pumps in commercial buildings: Ofgem will pay 2.69 pence per kWhour generated every quarter for the next 20 years. For domestic buildings Ofgem will pay 10.49 pence per kWhour generated every quarter for the next 7 years.
Heat pumps have a key part to play in meeting the UK's binding renewable energy targets.
Performance of Heat Pumps
The performance of a heat pump is measured under standard conditions as the "coefficient of performance": this measures the heat output in kilowatts in relation to the electrical input in kilowatts. However, the CoP of a heat pump is greatly influenced by the output temperature delivered to the heat distribution system in the building and the input temperture from the heat source.
In cold conditions a ground source heat pump with access to a temperture of 10°C from the ground will deliver a significantly higher CoP than an air source heat pump with access to -5°C from ambient air. The design, installation quality and controls of a ground source heat pump installation are critical to achieving good performance.
Installation of Heat Pumps
To get the full benefit of a heat pump installation you will need to employ someone with design and installation experience. A heat pump may not perform well unless it is incorporated in a good design by someone who understands the needs of the building and the use to which the building is being put.
For more information on installation of heat pumps from an experienced source please contact one of our members.
