Skip to content 
Table of Contents
There are different heating requirements for different households in the UK. Especially, when using smart & renewable heating like heat pumps, a right heating out is essential. Choosing the right size of air source heat pump (ASHP) is as significant as trading off between the cost and efficiency.
If the pump is too small, it will cost less but might not heat your home properly. If it’s too large, you’ll cost too much but give good heating. This guide will show you how to determine heat pump size. We will elaborate what infers in narrowing sizing down and some simple arithmetic. Let’s explore what you need to know to find the right ASHP size for your UK home.
What Is an Air Source Heat Pump?
An air source heat pump makes use of the outside air to provide warmth inside the home. It takes the warm air from the outside and releases it inside the premises of the house. The pump actually works as an air conditioner, but in reverse. It can extract heat from the surrounding air even at low temperatures. Because of the lack of energy in the operation, ASHPs are in high demand in the UK. They save energy, which in return promotes a green environment.
Why Is Proper Sizing Important?
Ensuring proper sizing of an ASHP will guarantee a relaxed home for everybody. In case the unit is undersized, it will continuously operate trying to heat the house. This can be damaging to the pump since it will have to be running all the time. On the contrary, an excessive unit will keep on turning off and on at short intervals. This can lead to energy inefficiencies, therefore increasing the cost of services. A properly fitted pump maintains the house warm without using up too much energy.
Factors That Affect Heat Pump Sizing
Several factors affect the sizing of an air source heat pump. Understanding these can help you make the right choice.
- Home Size: Larger homes need bigger heat pumps to distribute heat evenly.
- Insulation: Better home insulation means less heat loss, so a smaller pump might work.
- Window Quality: High-quality windows help keep heat inside, reducing the need for a larger pump.
- Climate: Colder areas require a larger pump to maintain a warm home.
- Number of Rooms: More rooms may need a larger system to heat the entire space.
How to Calculate Heat Pump Size
Calculating the air source heat pump size requires considering the heat loss in your home. You will need to measure the area of each room in square metres. Then, consider the insulation and window quality. The formula to calculate heat load is:
Heat Load = Area x Insulation Value x Temperature Difference
Once you know the heat load, you can determine the kilowatt (kW) size needed. Most UK homes need between 4 kW to 12 kW heat pumps. It’s wise to consult a professional for accurate calculations.
Heating Output
When referring to heat pumps, kilowatts (kW) is the unit of measurement. A higher kW value means a more powerful pump, for instance, a 5 kW heat pump is able to heat up an adequately insulated small-sized home. In contrast, a 10 kW pump will be installed in larger sized houses with average insulation. The size you select is relative to the heat loss and area of your house. Select the heat output that corresponds to the needs of your house in order to save energy and keep comfort.
Choosing the Right Heat Pump Size for Small Homes
For small homes or apartments, a 4 kW to 6 kW heat pump may be enough. These units are effective in heating spaces less than 100 square metres. Good insulation is very necessary to keep up with the heat provided. Otherwise, people with old window tints may opt to get a pump of a slightly bigger size. Do not forget to consult an experienced installer to size the pump according to the heat losses and dimensions of the house.
Choosing the Right Heat Pump Size for Medium Homes
Such heat pumps fall into the range between 6 kW and 8 kW when installed into medium-sized homes. These pumps are intended for homes 100 to 150 square metres in size. Ensure your house meets the thermal performance level requirements so that there is minimal heat loss. Try to replace very old windows, or add loft insulation. A smaller waisted house can use a pump, and therefore a smaller installation budget, if the house is insulated properly.
Choosing the Right Heat Pump Size for Large Homes
In contrast, large houses from 150 to 200 square metres require bigger pumps usually in the range of 8 kW-12 kW. A 12 kW pump can take more rooms and a bigger area. However, there is the need to find out the quality of the insulation before anything further is done. An energy assessment can be useful in finding out the sizing required for heat pumps in such large homes. Ample amounts of insulation when properly placed can also mean a smaller heat pump used.
Air Source Heat Pump Size Calculator
Home Size | Annual Energy Demand | Air Source Heat Pump Size | Number of Solar Panels Needed |
Single bedroom | 8,000 kWh | 3kW | 7 – 10 |
Double or triple bedrooms | 14,000 kWh | 4-5kW | 15 – 20 |
4 bedrooms | 20,000 kWh | 10kW | 25 – 27 |
5+ bedrooms | 21,000 kWh | 16kW | 35 – 40 |
How to Improve Heat Pump Efficiency
To get the best performance from your heat pump, follow these simple tips:
- Insulate Your Home: Good insulation reduces heat loss, making your pump work efficiently.
- Upgrade Windows: Double-glazing helps keep the warmth inside during winter.
- Seal Gaps and Cracks: Stop drafts to prevent heat from escaping your home.
- Use Smart Thermostats: They help control your heating system more efficiently, saving energy.
- Maintain Your Pump Regularly: Regular servicing ensures the pump operates efficiently.
Cost of Installing Different Sizes of Heat Pumps
The prices for installing a heat pump will vary depending on the heat pump size and the installation works involved. The email might instigate thoughts especially where small units (4 kW to 6 kW) are priced from about £3,000 to about £6,000.
Medium units (6 kW to 8 kW) usually do not go below £6,000 and above £9,000 these days. Larger units (8 kW to 12 kW) can start from £9,000 and at the high end reach, £15,000 or above. These examples include the installation cost but may differ based on where you are and the home requirements you have. Request estimates from various installers instead.
Heat Pump Size (kW) | Suitable Home Size | Estimated Cost Range (£) |
4 kW – 6 kW | Small homes (up to 100 square metres) | £3,000 – £6,000 |
6 kW – 8 kW | Medium homes (100 – 150 square metres) | £6,000 – £9,000 |
8 kW – 12 kW | Large homes (150 – 200 square metres) | £9,000 – £15,000+ |
Some homeowners or private tenants can get free air-to-water heat pumps with zero installation charges. They should check their eligibility to apply for the ECO4 grants and the team of Grant Boilers are happy to assist them for free!
Check Your Eligibilty!
How to Get Help Choosing the Right Size
Determining the right size heat pump can present challenges. Many installers nowadays provide free consultations and this is helpful. They will examine the insulation, the windows, and the dimensions of your rooms in your home.
Thus, they are able to advise on the proper heat pump that will serve your needs efficiently. It is more efficient however to go for companies that have a good reputation and prior experience. One can find such companies under the UK’s Boiler Upgrade Scheme. Scope them to give you access to the grants so that you will pay a lesser installation fee.
Average Air Source Heat Pump Dimensions
Different heat pumps have different sizes. A domestically used air source heat pump dimensions are 100-150 centimetres height and 50-100 centimetres width. These may vary depending on manufacturer, heating power, and various other factors.
Benefits of a Properly Sized Heat Pump
If the heat pump is the right size, the homeowner will receive several advantages. It will ensure that you enjoy the same levels of comfort in all the rooms of your house. It will also mean lower electricity bills because less power will be consumed.
A heat pump that is correctly sized is more durable and has fewer breakdowns. In the same way, it is eco-friendly, allowing you to maintain a small carbon footprint. Appreciate the warm winters and hot summers with a correctly sized Air Source Heat Pump.
Mistakes to Avoid When Sizing a Heat Pump
Take sensible steps to determine heat pump size for your home. These are not the only sources of information that should be placed any faith in – estimates as well can be laboured. In any case, carry out heat loss evaluation.
Never think that purchasing a bigger heat pump is better. One will not save on usage with an oversized equipment and even costs more. And do not forget about the help of governing bodies. Installers have the experience to help you make the right choice. Even if you follow these precautions and tips, your average heat pump.
Choose a Right Size for a Cosy Home
Choosing the right size of an air-source heat pump is paramount when it comes to ensuring comfort and efficiency in the residence. Take into account the dimensions of your house, the extent of insulation and the degree of heat loss in making your selection. Seek the help of experts for proper calculations.
Ensure that you enhance your home’s insulation in order to minimise heat loss. Spending effort on the selection of the correct size will result in lower bills and higher comfort levels. Reap the advantages of a cosy house by purchasing a heat pump of the right size!
Frequently Asked Questions
The right size of heat pump depends on various factors including number of bedrooms, home size, and heating requirements. Moreover, the condition of your home insulation also determines what size of air source heat pump is suitable for your home.
A 6kW heat pump is usually recommended for a 40 – 45 square metre living room. But that’s not the yardstick, there are various other things that should be counted when deciding the right size for choosing air source heat pumps.
