An air-source heat pump is a form of renewable energy technology using heat from the outside air to provide heat and hot water inside a home. Its technology works essentially like a refrigerator in reverse. There are many benefits to having this type of renewable heating system installed, often in place of a traditional gas boiler.
What factors impact the cost of running an air source heat pump?
nstallation is just one part of the cost when it comes to air source heat pumps. When weighing up their use, the costs of running this style of heating system need to be taken into consideration. Running costs are not fixed and will vary between heat pump installations, based on two main interrelated factors.
- Heat demand – this varies between properties and refers to the level of heating power needed to keep a property at the optimal temperature.
- Air source heat pump efficiency – this ability of an air source heat pump to effectively heat a house using the minimal amount of electricity possible. It is recorded as the Coefficient of Performance (CoP).
Heat demand has an obvious impact on the running cost of your air source heat pump. To calculate actual heat demand, you should consider what is needed to heat the property, how many rooms there are, and what the desired temperature is. The more heat you require, the bigger the heat pump needed, and the higher the cost will be of operating the system because of the volume of electricity required to operate the unit.
Air source heat pumps efficiency (CoP)
The efficiency of the air source heat pump also impacts the overall cost of running your heating system. A heat pump installed with an underfloor heating system will be more efficient than one using conventional radiators as underfloor heating requires the heat pump to work less hard in order to generate the desired indoor temperature.
Another important factor with a heat pump system is the level of insulation in the property in which it is being installed. If you don’t have sufficient insulation, this will increase the demand for heat, and therefore require more electricity. The more heat the property can retain, the lower the running cost of heat pumps because they don’t have to work as hard.
Also, where you locate your air source heat pump can also affect its efficiency. Ideally, you should select an area that is free from blockages and preferably well exposed to sunlight, so it will be more effective in creating heat.
How much electricity does a heat pump use?
Heat pump efficiency is measured in CoP. This unit is calculated by measuring the level of energy (electricity) required and the amount of energy (heat) that is generated. An air-source heat pump with a CoP of three produces three kW of heat for every one kW of electricity used.
An average sized domestic home requires roughly 12,000-kilowatt hours (kWh) of heat per year. To meet this demand, a heat pump with a CoP of three would have to consume 4,000 kWh of electricity each year. A heat pump with a CoP greater than three would inevitably require less electricity to generate the same amount of heat.
At 4,000 kWh of electricity with the price being 27.35p per kWh unit, it will cost you about £1,094 in your annual heating bill (based on average electricity prices as from October 2023).
In what ways can you lower your electric bill with a heat pump?
If you are using a heat pump as an alternative to a gas boiler to heat the home, your gas consumption will fall but your electricity usage will inevitably increase, though your overall energy bills should reduce as a result. Fortunately, there are some ways you can limit the electricity your heat pump consumes.
Avoid changing the set temperature
When you regularly turn the temperature up or down to regulate the temperature in your home, the heat pump will use more power. It would be beneficial to set the thermostat to a certain temperature and try not to alter it, as your system will require less power to maintain a consistent temperature .
Check the water heating temperature
If this temperature is set at too high a level, your heat pump will be using more electricity than it needs to to get your water to the right temperature. You can lower the temperature of the water to 40 degrees or lower, which will still be enough to heat your home.
Properly maintain your heat pump
Inadequate maintenance of your air source heat pump could result in an increase in your energy bills, sometimes by as much as 25%. Filters that are dirty or blocked restrict airflow through the system, affecting performance. Your heat pump should be serviced every year.
How much does a heat pump cost per hour?
A 2.2kw air source heat pump will create roughly about 11kw worth of hot water for radiators and use 2200 watts from the mains. With a cost of 27.35p per Kwh (based on average prices under the Energy Price Cap as from October 2023), running this system would cost you around 60p per hour in electricity, or £4.80 for an 8 hour ‘running period’.
However, a bigger central system consuming about 11kw would be quite expensive, costing nearly £3.08 per hour to run, but this will create enough heat to warm an average-sized three-bedroom home.
How can you save on ASHP running costs?
You can follow the below steps to increase the efficiency of your air source heat pump and therefore minimise the costs of running your system.
- Install double or triple glazing windows to prevent heat loss
- Install cavity wall insulation (if your property has cavity walls) to stop heat from escaping through your walls
- Have loft insulation installed to restrict heat loss through your roof
- Keep windows closed as much as possible to avoid heat loss
- Shop around for a cheaper electricity supplier or install a solar panels
- Fit bigger radiators
- Install underfloor heating
- Have an annual service of your system to maintain efficiency
- Consider a ground source heat pump as an alternative as these have higher efficiency level (CoP)
With 0% VAT payable by homeowners on all heat pump installations until 2027, there has never been a better time to make the move to heat pumps. Heat Pumps UK can help you find local installers offering the best air source heat pump deals, so get a free no-obligation quote today.
(Article updated to reflect average electricity prices under the Energy Price Guarantee as from October 2023)