Today we’ll take an up-close look at air source heat pumps, how they shape up in benefits and disadvantages, how they work, how much they cost versus how much they save, and more, compiled from different sources right here in this review article.
What are air source heat pumps?
An air source heat pump (ASHP) is a low carbon pumping system which transfers heat from the outside air to inside a building, or the other way around. Operating under the scientific principles of vapour compression refrigeration, an ASHP uses a refrigerant system comprising of a compressor and a condenser to absorb heat at one place and release it at another. Basically, an air source heat pump extracts heat from the outside air in the same way that a refrigerator extracts heat from its inside. They can be used as a heater or a cooler.
In domestic situations, the extracted heat can then be used to heat radiators, underfloor heating systems, or warm air convectors and hot water in the home.The pump can often do the reverse in summer, cooling the inside of the house. When designed, placed and installed correctly, an ASHP can offer full central heating and domestic hot water up to 80°C.
It can get heat from the outside even when the temperature is as low as -15° C. Heat pumps have some impact on the environment as they need a fair amount of electricity to run, but then the heat they extract from the ground, air (as is the case here), or water is constantly being renewed in a wholly natural manner.
The benefits of air source heat pumps
- Lower fuel bills
- potential income or returns through the government, depending on where you live
- lower home carbon emissions, depending on which fuel you are replacing
- no need for fuel deliveries
- can heat your home as well as your water at the same time
- an absolute minimum of maintenance required
- Easier to install than a ground source heat pump.
The disadvantages of air source heat pumps
- High start-up cost.
- Notoriously difficult to install
- Some of the fluids used for heat transfer are of questionable sustainability and they raise environmental concerns
- The installation process will mean significant work and disruption to home and garden
- Some heat pumps experiencing trouble in cold areas which can damage the system
- Electricity is required to run the heat pumps which means that they will never be fully carbon neutral.
How do air source heat pumps work?
Heat from the outside air is taken in at low temperature into a fluid. Then it passes through a compressor where its temperature is increased. Finally, the higher temperature heat is brought to the central heating and hot water circuits of the building.
Is an air source heat pump suitable for me?
To gauge effectively whether such a unit would be appropriate for your specific situation, there are a few practical issues to consider, such as:
- Do you have somewhere to put it?
- You’ll need a place outside the house where a unit can be fitted to a wall or placed on the ground. Plenty of open space to get a good air flow going will be needed.
- Is your home well insulated?
- Since air source heat pumps work best when producing heat at a lower temperature than traditional boilers, it’s essential that your home is insulated for it to be effective.
- What fuel will you be replacing?
- The system will pay for itself much more quickly if it’s replacing an electricity or coal heating system, as stated above. If you use gas at your home, an ASHP might not be the best choice for you.
- What type of heating system will you use?
- Air source heat pumps perform better with underfloor heating or warm air heating than with radiator-based systems.
- Is the system intended for a new development?
- Combining the installation with new building work can reduce the cost of installing the unit.
Heat Pump Prices
To help give you an idea of the cost to buy heat pumps for your home, we sourced a variety of different price averages from the following websites. Most of these heat pump costs are based on air-sourced heat pumps for two-storey properties with three or more bedrooms.
Theecoexperts.co.uk – £6000 – 10,000
Homebuilding.co.uk – £8000 – 14,000
Earth.org.uk – £9000 – 14,000
Superhomes.org.uk – £9000 – 16,000
Which.co.uk – £9000 – 17,000
*All prices sourced from relevant websites. Accurate as of August 2013.
Although these figures give you a basic overview of heat pump costs, you should ask for quotes from a variety of different contractors to get an idea of how much installation on your property might really set you back. Potential employers might be willing to offer free preliminary surveys if you show an interest in their work, and once you have their attention they can also provide more detailed information about specific heat pump products, such as the cost of geo-thermal source heat pumps compared to ordinary ground or air source models!
Costs and savings
Running costs will vary depending on a number of factors including the size of your home, how well insulated it is and what room temperatures you’re wanting to get.
How much you can save will depend on what system you use now, as well as what you are replacing it with. In short, savings will be impacted upon by:
- Your heat distribution system.
- If you have the opportunity, underfloor heating can be more efficient than radiators as previously stated. If not possible, get the largest radiators you can. Your installer should be able to advise you on this.
- Your fuel costs.
- You will still have to pay fuel bills with a heat pump because it is powered by electricity, but eventually you will save on the fuel you’re no longer using since getting the unit.
- Your old heating system.
- If your old heating system was inefficient, you are more likely to see lower running costs.
Heat pump systems typically come with a warranty of two to three years. Workmanship warranties for heat pumps can last for up to 10 years. You can expect them to operate for 20 years or more, however they do require regular maintenance. A detailed check by a professionalevery three to five years should be enough to see it through.
Air Source Heat Pumps Installers
The installer should leave you written details of any checks you should undertake to ensure everything is working properly. Be sure to confer with your particular provider for exact requirements before you commit to installing an ASHP.
In your best interest, it’s vital you check beforehand what suppliers and/or installers are operating in your vicinity and what kinds of deals they offer. Compare reputations, prices, and manufacturers they work with, to gauge which one would be best for your particular needs.