Heat Pumps in the UK
Are Heat Pumps the Right Solution?
A heat pump, in simple terms, is a device that transfers heat from a source (such as the heat of the soil in the garden) to another location (like the hot-water system of a house). To do this, heat pumps, as opposed to boilers, use a small amount of electricity but they often achieve a 200-600% efficiency rate, as the amount of heat produced is markedly higher than the energy consumed.
At least to some extent, their efficiency and cost explain why they have become a popular choice in the UK in recent years. They are effective alternatives to fossil fuels and they can significantly reduce your utility bills, or better yet, make you earn money through the Renewable Heat Incentive.
Heat pumps play also an important part in reaching the ambitious UK's 2050 Net Zero target. With an expected 19 million heat pump installations in new homes by 2050, their role in reducing the UK's carbon emissions at a domestic and national level has drastically increased. According to a survey by the Heat Pump Association, it is anticipated that the surge of heat pump demand will almost double in 2021. With the new heat and buildings strategy coming up, it is expected to further increase the installations of various heat pumps as a low carbon heating solution.
However, when considering the purchase of a heat pump, there are numerous factors to take into account, like the location of your home and whether you want them to heat domestic hot water or provide heating. On top of that, other aspects like the heat pump supplier, the size of your garden, and your budget also influence what type of system is the most suitable for your profile: air source, ground source, or water source.
Read on to learn more about the different types or fill in the contact form above, and we will get you up to 4 non-binding quotes on heat pumps that fit your home the best. This service is free of charge and without any obligation.
What Are the Different Types of Heat Pumps?
There are various different types depending on the source of the heat and the use of that heat in your home. While all types of heat pumps are worth the investment in the UK, your choice depends on two things:
- Whether you want the heat to be extracted from the soil (which requires digging up your garden for laying pipes underneath), from the ambient air (which requires little space but a fan will constantly emit a low amount of noise), or from a body of water (if you have such available close to your house).
- Whether you want the heat to be used for domestic hot water and conventional heating using radiators or underfloor heating, or you prefer heating the home by ventilating with heated air (similarly to how an air conditioner would cool the room).
When the heat source is the soil, we talk about ground source heat pumps. Similarly, the ones using the ambient air or a body of water are called air source and water source heat pumps, respectively. These umbrella terms can, then, be broken down based on the application.
Read more about the specific heat pump types below:
Ground source or geothermal heat pumps are, in most cases, used for heating water. With the help of additional system elements, it is possible to use heated air ventilation with geothermal systems, but it is far more common to use it for conventional radiators and underfloor heating.
Both air source and water source heat pumps can be used for heating water as well as indoor air in your home.
When used for heating water, we refer to air-to-water heat pumps and water-to-water heat pumps. Water source, air-heating systems are called liquid-to-air heat pumps which are a kind of speciality products.
Hot air ventilation is usually provided by air-to-air heat pumps. The latter can also be reversed and used for cooling your home — however, it is not eligible for the RHI.
What Is a Ground Source Heat Pump?
There is a variety of ground source heat pump systems (GSHP). GSHPs can be sub-categorised into vertical and horizontal systems, and open- and closed-loop systems. The different choices affect the prices of ground source heat pumps.
The video below explains how a ground source heat pump works:
Despite being called a ground source heat pump, open-loop systems pump up groundwater from deep underneath the soil, then after extracting the heat from it, the water is pumped back. Such a system has higher running costs, as you need to make sure the water is unaffected and need to comply with regulations of using such natural water sources.
Closed-loop ground source heat pump systems are far more common in the UK. These systems circulate an antifreeze liquid through a closed plastic polymer tubing that is buried in the soil.
Vertical ground source heat pump systems: Such a system requires several holes to be drilled into the ground, 5 metres apart from each other. Each hole is 15–120 meters deep. At greater depths, the temperature increases significantly, warming the anti-freeze liquid. This liquid then comes back through an exit hole, where it then heats up the refrigerant that stays in the house within a second system. The system’s main disadvantage is its high initial investment.
- Horizontal ground source heat pump systems: This type of GSHP is less costly than a vertical system, as it is less complex. To install a horizontal geothermal system, the ground has to be dug out just below the frost line. Then, coiled pipes are laid down into the ground, creating spirals. A liquid is sent through the system which heats up the refrigerant in the second pipe system. Although more affordable, this system requires more garden space and is affected by seasonal changes due to the lower depths of the system’s installation.
Radial or Directional Drilling
A radial or directionally drilled system is a great option when the property cannot be reshaped. With this GSHP system, small holes are drilled into the ground at an angle in order to insert the pipes. Radial or directional drilling enables you to install a GSHP system without needing to demolish gardens, yards, buildings, etc. The cost of the system lays somewhere in between the vertical and horizontal systems.
What Is an Air Source Heat Pump?
Air source heat pumps (ASHP) use the principles of vapour compression to generate heat. It's a popular low carbon heating system, and there are many benefits to using air source heat pumps.
They use outdoor air to produce heat to your home. ASHPs consist of 4 major elements that allow the refrigerant to pass from the liquid form to gas: a compressor, a condenser, an expansion valve, and an evaporator.
When the refrigerant passes through the system, it absorbs the heat from the outside air. Then, the compressor increases the heat by increasing the pressure. In the condenser, this higher temperature heat is transferred to the heating and hot-water circuits of your home. After that, the medium-temperature liquid flows into the expansion valve where upon the release of pressure, its temperature also drops. Finally, the now cooled down liquid is returned to absorb more heat from the air and repeat the process.
ASHPs can be used for heating water for domestic use, radiators, and underfloor heating. Such systems are called air-to-water heat pumps (A2W). If suddenly a large amount of hot water is needed, they are also equipped with an electrical resistance heating element that would supply additional heated water (at a lower efficiency rate, though).
Alternatively, air source systems can be used for heating and cooling the indoors air using air-to-air heat pumps (A2A). These work similarly to an air conditioning unit but can both heat and cool the house efficiently, adding to the list of benefits of air-to-air systems.
What Is a Water Source Heat Pump?
Water source heat pumps (WSHP) extract energy from a body of surface water. While WSHPs are really efficient, not all homes have a sufficiently large body of water close by.
An open-loop WSHP system is deployed in a well or a pond. The water from the pond is pumped through the pipes; once the heat of the water is spread through the system and the heat is absorbed, it is returned back to the pond or recharges the well.
Closed-loop WSHPs can be considered by anyone living near a larger body of water. The water should be at least 8 feet deep in order to avoid freezing. Closed-loop WSHPs work similarly to GSHPs: a special liquid is pumped through the pipe system laid in the water that picks up the heat of the water and transfers it to the compressor to generate usable heat. Closed-loop systems are one of the most effective options, keeping water source heat pump costs low.
What Are the Pros and Cons of Heat Pumps?
Heat pumps extract free heat from the soil, ambient air, or a body of water. This heat is then transferred for domestic use with the help of an electric compressor. This compressor, however, consumes significantly less energy than a boiler. As a result, a heat pump provides close to free heating for your home.
While they may be a significant investment for many households, the benefits of heat pumps are numerous:
- The government helps homeowners who would like to use an environmentally friendly heating solution with the Renewable Heat Incentive (RHI), under which you may be eligible for receiving payments for each kWh of energy generated.
- Thanks to their low running costs, you can save up to £1,350 per year with heat pumps compared to conventional heating options. Consequently, within years, your investment is returned and you start earning money.
- They require little maintenance: all that is needed is a yearly check-up that can also be done by you, and an inspection by a certified professional every 3 to 5 years.
- The lifespan of heat pumps is, on average, between 14 to 15 years. However, high-quality devices can last for up to 50 years.
- They are not only better for the environment thanks to their low energy consumption, but they also make your home safer by eliminating the need for gas pipes and oil tanks.
- Last but certainly not least, many heat pumps are able to reverse the heat collection process, thus providing cooling for your home during summer.
However, there are also certain disadvantages associated with heat pumps:
- The upfront costs are rather high. However, you should see it as an investment: thanks to the low operating costs and the RHI, heat pumps are easily profitable in the long run.
- They might be difficult to install — especially ground source heat pumps, for which installation depends on the local geology and your garden becomes a construction site.
- Heat pumps are the most efficient when used in combination with underfloor heating, or alternatively, with large radiators. If your house has an older radiator system, you might find it costly to replace the heat emitters.
- There are also environmental concerns regarding the refrigerant fluid used in the pipe system. However, under regular conditions, the special liquid should never exit the piping.
Heat Pump Costs and Financial Benefits in the UK
Heat pumps are not a cheap investment for your home in the short run, but they have plenty of long-term benefits. The running costs of heat pumps are fairly low, especially when compared to various electric, oil, and bottled gas boilers.
What is more, not only do you save month by month on your energy bills, but such sustainable solutions are also financially supported by the British government. If you apply for the Renewable Heat Incentive (RHI), you will get paid for every unit of energy generated for a total of 7 years.
Your choice of heat pump doesn't only depend on your property but your budget might also influence your decision. Certain types are cheaper than others, and the RHI payments also differ, as presented in the table below.
|Type||Price Range||RHI Payments*(p/kWh)|
|Ground Source Heat Pump||£20,000–£40,000||21.29p|
|Air Source Heat Pump||£8,000–£18,000||10.92p|
|Water Source Heat Pump||£20,000–£32,000||21.29p|
* The specified RHI tariffs were specified by Ofgem in Q1 of 2021.
Disclaimer: The price ranges mentioned above are a reflection of unbiased research from our heat pump suppliers. GreenMatch cannot guarantee that these are the lowest possible prices you can find. However, we are confident that you will get a pleasant purchasing experience using our trustworthy, certified heat pump installers.
Currently, air source heat pumps are the most popular in the UK and account for roughly 87% of all sold units, while ground and water source heat pumps account for 9%.
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What Government Incentive Schemes Are Available?
The UK government provides programmes to support the installation of sustainable heating systems. One of the most widely known is the Renewable Heat Incentive, which is categorised into the following:
- Domestic Renewable Heat Incentive (RHI) which is open to homeowners, social landlords, private landlords, and self-builders, with the tariffs as presented in the table above.
- Non-domestic Renewable Heat Incentive which is open to the public sector, organisations, and businesses.
Concerning the domestic RHI tariffs, these incentives guarantee certain prices for the heat generated for 7 years after application. For the non-domestic RHI scheme, the benefits differ greatly, which should, therefore, be subject to extensive research for each individual case.
The RHI is expected to close in March 2022, and a new grant called the Clean Homes Grant is expected to replace it by April 2022. The Clean Homes Grant is an installation grant, unlike the RHI.
There are also Scotland-specific grants, such as the Home Energy Scotland Loan and the Warmer Homes Fund.
Those residing in Wales can make use of the Arbed am Byth Scheme (Warm Homes Scheme).
Factors to Consider Before Buying a Heat Pump
Warranty Periods of Heat Pumps
Heat pump systems normally have a warranty of 2 to 3 years but extended warranty can also be purchased. For example, a warranty for the workmanship of the system usually lasts for about 10 years. The so-called Quality Assured National Warranties also provides different kinds of protection. Moreover, producers and installers may additionally offer various kinds of auxiliary warranties.
Planning Permissions for Heat Pumps
As heat pumps usually fall into the category of favourable renewable energy, often there is no need for planning permissions. However, there are some exceptions to this rule.
Permissions for GSHPs
If you live in a conservation area or a listed building, contact your local council to make sure that all requirements are met before installing a GSHP.
Permissions for ASHPs
There are different rules for ASHPs in England, Wales, and Scotland.
Rules for England
- The heat pump must be built according to MCS planning standards.
- Any additional ASHPs, wind turbines, etc. on the property require additional planning permission.
- The device has to be more than 1 meter from the property boundary.
- The device cannot be installed on a pitched roof. Also, it should not be near the edge of a flat roof.
- Conservation areas, world heritage sites, etc. require additional criteria to be met. Contact your local council for further details.
Rules for Scotland
- Only one heat pump is permitted on one piece of land.
- The device has to be at least 100 meters away from any other dwelling.
- If to be built in a conservation area, the device should not be visible from the road.
- It cannot be built on a world heritage site or a listed building.
Rules for Wales
- All air source heat pump installations require planning permission.
Permissions for WSHPs
Closed-loop WSHPs usually don't require planning permission unless you live in a conservation area.
As an open-loop system alters the natural water temperature and thermal plumes affect the bacteriology and hydrochemistry of the body of water, depending on the type of system, licenses may be required to divert the surface or groundwater, obtainable from the Environment Authority.
Maintenance of Heat Pumps
A heat pump's lifespan is approximately 15 years or more. With proper maintenance, their life can be extended to up to 50 years.
They do require regular maintenance: once a year, you should check certain details of the system yourself, while a professional installer needs to pay the system a look every 3 to 5 years. In the wintertime you may also need to defrost the heat pump manually.
After the check-up, the installer should leave written details of the system’s condition and any indications for possible future issues.
According to the Ground Source Heat Pump Association, maintenance requirements are quite low, as there is no need for crucial safety checks. Usual parts to inspect before starting the system are the pump itself, the external pipes, as well as the electronics and parts of the fittings.
Find the Best Suppliers of Heat Pumps in the UK
Heat pumps, whether ground source, air source, or water source, present excellent opportunities for upgrading your home, as they not only provide you with a solid return on investment but they also improve the quality and value of your home.
If reading this has sparked your interest in heat pumps, fill in the form at the top of the page and get up to 4 personalised quotes from our trusted suppliers in the UK, saving you hours of research. This service is totally free and without any obligations.
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