Air heat pumps or air source heat pumps, as they’re also referred to, are potentially a great way of reducing the heating costs for your home.
However, there are some things that you'll need to consider, which you may not have thought of.
It’s all too easy to get carried away with the sales pitch and brochure which will normally bestow the virtues of the given technology without pointing out the disadvantages of the system.
Thankfully I’m here to tell it as it is, and air heat pumps are no exception.
An air source heat pump is basically an energy efficient boiler and as such works in the same way any of the traditional energy efficient boilers work. They heat water which then heats your under floor heating pipes or large panel radiators and your domestic hot water.
They just use electricity as a fuel instead of gas or oil.
They also work on the same principle as ground source and water source heat pumps. They extract heat from the surrounding media (air, water or ground) and transfer it into the hot water in your heating system (for more detailed information read my article on how heat pumps work).
There is no hard and fast rule to choosing one over the other.
Ground source heat pumps are quite popular in the UK and Ireland but the cost of digging the trenches or drilling the bore holes tends to be quite expensive, which can put them out of the reach of many of us.
On the plus side, a ground source heat pump will work at lower air temperatures, provided you have buried the pipe-work deep enough.
Water source heat pumps aren’t as common as few of us own a pond (which is large enough) or a lake. If however you do own a suitable expanse of water then a water source heat pump may be a viable option for you and works the exact same way as a ground source system.
It’s only with recent technological advances that air source heat pumps have really come into their own.
In the past they used single speed heat pumps, which meant they ran at a constant speed and used a lot of electricity. Now however, most are manufactured with inverters which vary the heat output to when it is needed, thus reducing the running costs and therefore your electricity bill.
I’m sure like me you’re constantly trying to think of ways to lessen the running costs of your home. You may be surprised to hear that around three quarters of the total energy used in your house goes to heating your domestic hot water and domestic heating.
So if you can reduce the running costs of your heating and hot water you could make a sizeable difference to your bills.
When looking at heat pumps you should look at the CoP figures (Coefficient of Performance) which is the ratio of heat delivered by the heat pump to the power the unit consumes.
Also ask what the CoP figures are at various temperatures such as -5ºC during the winter. The CoP will drop as the outside temperature drops.
Before you rush out to buy an air heat pump, as with any green technologies you’ll read about on this site, you really need to carry out some basic home improvements before fitting in order to get the best out of your heat pump.
These improvements involve basic things like increasing or adding insulation to the walls and roof of your home and reducing any drafts.
By increasing the thermal efficiency of your home before installation you'll maximise the benefits and reduce the running costs of your air source heat pump.
The longer you can keep the heat in your home, the less heat your air heat pump will have to produce.