Heat Pumps

ground source energy

A Heat Pump operates in the following way

  • The source of heat, which can be outside air or a water mix which is contained within ground collectors, is either blown or pumped over the heat exchange surface of the outside part of the heat pump.
  • This heat (although cold in comparison to a home’s internal air) is warm enough to cause the special refrigerant liquid to evaporate and turn into a gas.
  • This gas is then put through a compressor which increases the pressure of the gas, a factor that causes its temperature to rise. For example you may have noticed that a bicycle pump, gets warm when it is used, the gasses in a heat pump experience the same temperature rise due to compression.
  • The gas (now heated) is passed over the internal heat exchange surface. This heat can then be either blown around a property or be transferred into a home’s central heating or hot water system.
  • The gas falls in temperature as the heat is transferred into the home and it subsequently returns to a liquid state.
  • The refrigerant returns to the outside heat exchange surface and the process repeats itself until sufficient heat is passed into the home.

Ground Source

ground source pump

Aspects for consideration.
Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. Air source heat pumps are usually easier to install than ground source as they don't need any trenches or drilling, but they are often less efficient than ground source heat pumps. Ground source heat pumps are generally better suited to new-build properties than retrofitting to an existing home. This is because costs could be reduced if the heat pump is included as part of the building's specification, rather than having to fit underfloor heating later on. But the RHI could now significantly help with replacing an old or expensive heating system with a heat pump.

ground source coils

Heat pumps can save you more on your heating bills
If you're replacing an oil, LPG or oil system - but might not lead to great savings if you are on the gas network. A well-insulated house is essential to best optimise the heat generated by your ground source heat pump, otherwise the heat the pump generates escapes more easily. The heat produced by a ground source heat pump comes at a lower temperature than other forms of heating. This makes it best suited to underfloor heating, which requires lower temperatures, rather than radiators (or, if radiators are used, they should be properly sized).

Ground Source Benefits

  • Ground source heat pumps generate less CO2 than conventional heating systems.
  • The Energy Saving Trust (EST) says that a 'typical' ground source heat pump could save you between £410 and £2,000 a year depending which existing heating system you are replacing.
  • You can get financial help towards the cost of a ground source heat pump. The Renewable Heat Incentive scheme provides payments to householders who have a heat pump, estimated to be between £2,610 and £3,940 a year for an average four-bedroom detached home.
  • You need to use electricity to power the pump which circulates the liquid in the ground loop, but for every unit of electricity used by the pump, you get between two and four units of heat – making this an efficient way to heat a building.
  • Cheaper Economy 7 electricity tariffs can be used to lower the cost of electricity to power the heat pump, alternatively consider solar photovoltaic panels (if you live in a suitable area) for a greener source of electricity.
  • It could lower your fuel bills, especially if you replace conventional electric heating
  • It could provide you with income through the Government’s Renewable Heat Incentive (RHI)
  • It could lower home carbon emissions, depending on which fuel you are replacing
  • No fuel deliveries needed
  • It can heat your home as well as your water
  • Minimal maintenance required
air source energy

How do Air Source Heat Pumps Work?

  • Heat from the air is absorbed at low temperature into a fluid. This fluid then passes through a compressor where its temperature is increased, and transfers its higher temperature heat to the heating and hot water circuits of the house. There are two main types of air source heat pump systems.
  • Air-to-water- an air-to-water system distributes heat via your wet central heating system. Heat pumps work much more efficiently at a lower temperature than a standard boiler system would. This makes them more suitable for underfloor heating systems or larger radiators, which give out heat at lower temperatures over longer periods of time.
  • Air-to-air- an air-to-air system produces warm air which is circulated by fans to heat your home. They are unlikely to provide you with hot water as well.

Air Source

air source heat pump - how it works

How Green are Air Source Heat Pumps?
An air source heat pump system can help to lower your carbon footprint as it uses a renewable, natural source of heat – air. The amount of CO2 you'll save depends on the fuel you are replacing. For example, it will be higher if you are replacing electric heating rather than natural gas.
A heat pump also requires a supplementary source of power, usually electricity, to power the heat pump, so there will still be some resulting CO2 emissions.

air source heat pump

Unlike gas and oil boilers, heat pumps deliver heat at lower temperatures over much longer periods. During the winter they may need to be on constantly to heat your home efficiently. You will also notice that radiators won't feel as hot to the touch as they might do when you are using a gas or oil boiler.

Air Source Benefits

  • Lower fuel bills, especially if you are replacing conventional electric heating.
  • Potential income through the UK government’s Renewable Heat Incentive (RHI)
  • Lower home carbon emissions, depending on which fuel you are replacing
  • No fuel deliveries needed
  • It can heat your home as well as your water
  • Minimal maintenance required
  • It can be easier to install than a ground source heat pump.