When considering the reduction of your heat spending and also the carbon footprint, you must have heard about air source heat pumps. These systems have gained popularity in the UK over gas boilers. Get advice on system setup from our boiler upgrade tips for first-time homeowners.
But one of the top questions people asked was: how much electricity does an air source heat pump use? This guide will describe factors that influence the consumption of electricity in air source heat pumps, provide realistic examples, and present tips that can be used in order to ensure the running expenses are low.
What is an Air Source Heat Pump?
The air source heat pump (ASHP) uses a combination of electricity and that heat to warm your home by tapping into the warmth of the air outside of your house. It operates in reverse of a fridge:
“A refrigerant draws heat out of the air, a compressor raises the temperature and a heat exchanger places warm water in radiators or your underfloor heating or can heat a water cylinder.”
Efficiency: The fact that the heat is not generated by electricity, but by the air makes these systems potentially much more efficient than ordinary electric heaters.
How the Consumption of Electricity is Measured?
You will tend to find efficiency measured in terms of the coefficient of performance (COP) or the seasonal coefficient of performance (SCOP). Nineteen kilowatts of heat per kilowatt of electricity is known as the COP.
Important: To demonstrate, COP of 3 implies that you get 3 kW of heat in exchange to 1 kW of electricity. SCOP is an annual average that is based on the performance in the real world throughout the year.
Some Influential Aspects Related to Electricity Consumption
1. Outdoor temperature
The colder the weather is outside the more the pump needs to work. COP drops at lower temperatures, so your air source heat pump electricity consumption will be higher in cold months.
2. Home insulation and demand for heat
With a well insulated home, you need less energy to heat your home using your pump. Consumption was increased by draughts, ineffective loft insulation, or single glazing.
3. System size and design
The right sized system is key to an efficient system. In case it was oversized, it ran on and off and consumed more electricity. Small sized systems worked round-the-clock and they still could not keep up.
4. Flow of temperature and distribution
The temperature of lower flow say (35-45 degree celsius) is more suitable to underfloor heating, and more efficient. Old radiators were run at high flow temperatures which compelled the pump to exert special effort resulting in consumption of more electricity.
5. Controls and quality of installation
Waste was minimised by good installation and smart controls (timers, weather compensation). The electricity consumed more with poor systems commissioned.
Common Use of Electricity
It is useful to consider some simple and practical examples. Note this is an approximate, your place of residence might be different.
Examples
1. Semi-detached house of size (3 bed), with heat pump that will have SCOP of approximately 3.5, and is quite well insulated.
- Annual heat demand: ~10,000 kWh
- Electricity consumed by pump: 10,000/3.5=2860 kWh/year.
2. These are older, detached houses with lesser insulation (SCOP of about 2.5 or so).
- Annual heat demand: ~18,000 kWh
- Pumps electricity consumption: 18,000/2.5=7 200kWh/annum.
3. Small flat underfloor heating, SCOP -4.0.
- Annual heat demand: ~6,000 kWh
- Consumption of electricity by pump: 6,000/4=1,500 kWh/ year.
Reason: These numbers indicated the reason behind the importance of insulation and proper design of the systems. The better the SCOP is, the lower will be the air source heat pump electricity consumption.
How Much will it Cost to Run?
Take the estimated kWh and multiply it by your price of electricity. Assuming electricity was 30/ kWh on average (discussion is also limited to this case), 2,860 kWh would require approximately 858 pounds per annum. By using intelligent tariffs or time-of-use pricing, you might be able to cut your running bills still further, provided you complete the pump system with solar PV. Check out the Air Source Heat Pump Running Costs here.
Ways to Lower Air Source Heat Pump Electricity Consumption
1. Improve insulation first
The largest savings were on loft, wall and floor insulation, double/triple glazing, and draughtproofing. In many cases, post-insulation decreases the number of heating systems required at their homes.
2. Use low temperature heating
Underfloor radiators or increased radiator size allows the heat pump to operate at reduced flow rates and increases efficiency.
3. Add smart controls
Through weather compensation, room thermostats and scheduling, the pump would only run when in use. The house was zoned and empty rooms were not heated.
4. Regular maintenance
Replacing filters, refrigerant levels and servicing of the unit gets it operating to approximately its nominal COP.
5. Consider hybrid systems
A hybrid environment, with a high efficiency boiler as back-up, maintained reliability of heating in very cold houses and reduced peaks of electricity demand.
6. Combine with solar PV
Have you ever had solar panels in your place? You would have minimised the amount of your electricity spent on heating or hot water, during the day, which would use less electricity throughout the grid and cut down on bills.
Is an Air Source Heat Pump Right for You?
Most people found that an air source heat pump worked best if their home had good insulation and they planned to put it up for several years. The initial price was more expensive than a gas boiler, however, grants and reduced running expenses can oftentimes justify the switch. With older, under-insulated houses the additional job was typically required to achieve the best savings.
Why wait? Check eligibility and get your ASHP grant now.
The Contribution that Home Energy Guide can make
Home Energy Guide ensures this transition process is uncomplicated. We provided objective and accurate tips on selecting the appropriate air source heat pump, the size of the air pump, and the best home modifications. Our guides provided expected running costs, and also assisted you in comparing the various technologies. Home Energy Guide makes sure that you don’t have to guess at each step, and it also ensures that you wouldn’t make certain mistakes. Get a free quote from Home Energy Guide today.
Frequently Asked Questions (FAQs)
It changes according to the size, heat and demand. An average domestic unit could consume 1-4 kW/per hr of active heating. The COP is important: with 1 kW of electricity, 3 kW of heat generated at COP 3.
Yes, units work in low temperatures nowadays.They consume more electricity during very cold weather, therefore, very cold homes are advised to have proper insulation and in some cases, a secondary source of heat.
Absolutely. The electricity supplied by the solar pv is available during the day, which lowers the requirement of grid power, reducing the running costs. A combination of the two is the common method of maximising savings. Explore how solar panels can benefit your home.
