Air Source Heat Pumps

Air source heat pumps are suitable for many types of homes and are the most common type of domestic heat pump, with tens of thousands of installations across the UK. However, there are a few things you should consider before deciding whether a heat pump is right for you.

Air source heat pumps work at low temperatures which are much lower than those of conventional heating systems like oil or gas boilers. Before you consider installing a heat pump, you will need to assess the state of the insulation of your home and you may need to improve it. Essentially, the heat loss through the walls, roof and floors needs to be minimised which in turn will mean that, when the property is heated to a lower temperature by a heat pump, there will be no issue.

Usually you will need a hot water cylinder because a standard heat pump doesn’t provide hot water on demand like a combi boiler, so you will need a way of storing hot water for when you need it. The size of hot water cylinder required will depend on the amount of hot water that your household typically uses, but the cylinder can usually be fitted inside any cupboard that measures around 80x80cm.

If you don’t have space for a hot water cylinder, you still have options. Some hybrid systems are designed with the heat pump providing heating and a boiler providing hot water on demand. Instantaneous hot water heaters are also available and can be installed under your kitchen sink to provide a smaller amount of hot water and you could opt for electric showers.

Air source Heat Pumps work best in well insulated properties so you should consider how well your property is insulated

Loft insulation
Loft insulation is an easy one to get started with. Ideally, to get the required u-value of 0.16W/m2k (a technical term and value which plays an important part of the planning phase for a heat pump installation), you need to lay 270mm of wool insulation in the loft. This is something homeowners can do themselves over a weekend at a cost of about £6 per m2 or, alternatively, you could use an outside company that could cost you around £11 to £15 per m2.

Wall insulation
If your home was built after 1935, the chances are it will more than likely have cavity walls and these are relatively simple to insulate. Cavity wall insulation involves the walls being drilled into and the insulation is injected within. This job does need to be carried out by a professional and should cost approximately £10 per m2 of wall. Meanwhile, for properties with solid walls, insulating these can be more of an issue but there are options available. These homes can either be clad with insulation on the outside or have insulation attached inside. Solid wall insulation procedures are more costly and can cost upwards of £15,000.

If you live in a property which was built since the late 1990s, the good news is it will already have more than adequate insulation. Therefore, installing a heat pump becomes an easy decision since these homes will retain more heat and are much better suited to low temperature heating systems. Current building regulations mean that homes built today are incredibly well insulated, allowing a heat pump to be the ideal heat source for such properties and helping the running costs to be significantly cheaper.

Double glazing
Installing double glazed windows is another measure which can help a home become ideally suited for a heat pump. Windows are an outlet for heat to escape a home so improving their insulation can greatly reduce a property’s heat loss. According to the Energy Saving Trust, by installing double glazing, a single-glazed detached home could save over £100 on their energy bills every year. In addition to the potential financial payback, installing double glazing can deliver several other benefits to your home which are well worth considering.

Running costs will depend on how your heat pump is designed and how it is operated.

Savings on your energy bill will also depend on the system you are replacing.