Air Source Heat Pumps
Heat your home with energy absorbed from the air around you.
Air source heat pumps absorb heat from the outside air. This heat can then be used to warm water for radiators, underfloor heating systems, warm air convectors or hot water in your home.
How do air source heat pumps work?
An air source hat pump extracts heat from the outside air in the same way that a fridge extracts heat from it's inside. It can extract heat from the air even when the outside temperature is as low as minus 15 degrees centigrade. Heat pumps have some impact on the environment as they need electricity to run, but the heat they extract from the ground, air or water is constantly being renewed naturally.
There are two main types:
- An air-to-water system - uses the heat to warm water. Heat pumps heat water to a lower temperature than a standard boiler system would, so they are more suitable for underfloor heating systems than radiator systems.
- An air-to-air system - produces warm air which is circulated by fans to heat your home. Heat from the air is absorbed into a fluid which is pumped through a heat exchanger in the heat pump. Low grade heat is then extracted by the refrigeration system and, after passing through the heat pump compressor, is concentrated into a higher temperature useful heat capable of heating water for the heating and hot water circuits of the house.
The efficiency of air source heat pump systems is measured by a coefficient of performance (CoP) - the amount of heat they produce compared tot he amount of electricity needed to run them. A
typical CoP for an air source heat pump is around 2.5 when used with under floor heating, it can be less when used with radiators. The CoP means that for every unit of electricity used to power the
pump, 2.5 units of heat could be generated.
The benefits of air source heat pumps?
- Reduce your fuel bills: air source heat pumps run on electricity, so there is not need to pay for gas, oil or solid fuels to heat your home. Emissions can be reduced further if the heat pump is powered by another renewable technology, such as solar electricity (PV)
- No fuel deliveries required
- Can provide space heating and hot water
- Can lower fuel bills, depending on what heating fuel you are replacing
- It is often classed as a 'fit and forget' technology because it needs little maintenance
- Can be easier to install than a ground source heat pump, but efficiencies are often lower
Is an air source heat pump suitable for my home?
To tell if an air source heat pup is right for you, there are a few key questions to consider:-
Q. Do you have somewhere to put it?
A. You will need a place outside your house where a unit can be fitted to a wall or placed on the ground. It will need plenty of space around it to get a good flow or
air. A sunny wall is ideal.
Q. Is your home well insulated?
A. Since air source heat pumps produce less heat than traditional boilers, it is essential that your home is insulated and draught proofed well for the heating system
to be effective.
Q. What fuel will you be replacing?
A. The system will pay for itself much more quickly if it is replacing an electricity, Liquid Petroleum Gas (LPG) or coal heating system than a gas or oil one.
Q. What type of heating system will you use?
A. Air source heat pumps perform much better with underfloor heating systems or warm air heating than radiator-based systems because of the lower water temperatures
required.
Q. Is the system intended for a new development?
A. Combining the installation with other building work can reduce the cost of installing the system.
To find out more about whether an air source heat pump is suitable for your home, try the Energy Saving Trust Home Energy Generation Selector tool.
Costs and Savings
Costs for installing a typical system suitable for a detached home range from about £5,000 to £9,000 including
installation. Running costs for space heating and hot water for washing are likely to be around £790 per year. This will vary depending on a number of factors - including the size of your home and
how well insulated it is.
Savings - will vary depending on many factors, some are outlined below. It is important that the system is controlled appropriately for your
needs. Actual savings figures will depend on your exact fuel prices
- The heat distribution system: underfloor heating often provides greater efficiencies than radiators because the water does not need to be heated to such a high temperature.
- Fuel costs: you will still have to pay fuel bills with a heat pump because they are powered by electricity. The saving you achieve can be affected by the price of the fuel you are replacing and the price of the electricity for the heat pump.
- Efficiency of old and new system: the efficiency of the old heating system will affect how much you sent on heating bills previously. If the old heating system was inefficient heating bills could have been high and the difference between the new running costs and the old running costs would be greater, therefore providing a greater saving.
- If the system is providing hot water as well as space for heating: the provision of hot water an lower system efficiencies, therefore making running costs higher.
- Temperature setting: if you heat your home to much higher temperatures with a new heat pump system than you did with an old heating system then you will experience greater comfort benefits, but heating bills will be higher than if you continued with the same heating pattern. It is a good idea to set thermostats to around 18 to 21 degrees centigrade.
- Using the controls: learn how to control the system so you can get the most out of it.
The savings shown below are based on installing a heat pump in a detached property. The system is expected to provide all the heating and half of the hot water, with the remainder being provided
by an electric immersion heater. They assume that is distributed via radiators.
| Fuel Displaced | £ Saving per year | CO 2 saving per year | ||||||||
| Gas | 50 | No saving | ||||||||
| Electricity | 700 | 5 tonnes | ||||||||
| Oil | 20 | No saving | ||||||||
| Solid | 460 | 4.6 tonnes |
To reduce your home's CO2 emissions further, consider installing solar electricity or some other form of renewable electricity generating system to power the compressor and pump.
If you would like further information or wish to contact us click here.
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