As the UK and the rest of the world seeks to move away from using fossil fuels to warm homes, talk about heat pumps is increasing. Even though they are seen as the future of heating in the UK, there are still a large number of questions about their costs and benefits. In this guide, we will take you through everything you need to know about heat pumps and what their usage means for you in the future.
What are Heat Pumps?
A heat pump uses electricity to move warmth from the exterior of your home to the interior. As heat pumps operate by moving heat already present, they do not burn fuel or emit any carbon dioxide.
Types of Heat pump
There are two main types of heat pump you can install. Air source heat pumps and ground source heat pumps.
Air Source Heat Pumps
Air source heat pumps extract heat from the air outside your home and use it to warm the inside, usually through the heating of water like a traditional boiler. Air source heat pumps are able to extract warmth from the air even when temperatures outside are freezing. They aren't as efficient as ground source pumps but as pipes don't need to be dug underground, initial installation costs are usually lower.
Ground Source Heat Pumps
Ground source heat pumps use pipes buried outside your home to extract heat stored underground. Whatever the outside air temperature is, the temperature of the ground is generally stable between 8 and 12 degrees. This means ground source pumps can still extract heat in winter when air temperatures are cold. Ground source heat pumps are considered more efficient than air source pumps, but the initial installation cost is usually higher. As pipes need to be dug underground, installation can also be disruptive and they may not be suitable for homes with a small or no garden.
Can You Use a Heat Pump with Standard Radiators?
Yes, you can use a heat pump with standard radiators and heated towel rails. However, as heat pumps are generally most efficient when running at lower temperatures, you may need to install larger radiators to accommodate this.
Standard gas boilers are designed to work efficiently at temperatures between 60-65 degrees. Heat pumps are able to reach these temperatures, however, their most efficient temperature is around 40-45 degrees. This means to sufficiently warm your home, you'll need a larger surface area to radiate heat. For this reason it's often recommended that you install underfloor heating if you're using a heat pump.
If you do want to use a heat pump with your current radiators, an engineer will be able to tell you if your radiators are large enough. In many UK homes, correct sizes weren't calculated when radiators were installed so it's common for people to already have 'oversized' radiators.
How Much do Heat Pumps Cost?
The cost of heat pumps will vary wildly depending on the type of heat pump you want to install and the type of home you live in. Air source pumps are generally cheaper to install than ground source pumps which need pipes buried underground. A typical cost for an air source pump will be from £6000 to £8000 on the lower end and a ground source pump can cost between £10,000 and £18,000.
As heat pumps work most efficiently at lower temperatures, homes need to be well insulated to ensure heat loss is minimised before heat pumps are installed. Much like a lack of off-street parking is seen as a stumbling block for the uptake of electric cars, the generally poor insulation of many British homes is likely to increase costs and be a barrier to people in the UK installing heat pumps.
These costs are likely to come down as heat pumps become more popular and even though the cost of electricity to run a heat pump is higher than gas, you can offset these costs through the installation of solar panels.
Are Heat Pumps Good for the Environment?
Home energy usage, including gas boilers, contributes to 15% of the UK's total greenhouse gas emissions, so heat pumps are an important step for the UK's target to reach net zero emissions by 2050. Heat pumps, unlike gas boilers, release no greenhouse gases. They also have high levels of efficiency and use a source of heat which isn't going to run out. However, much of the environmental benefit of heat pumps will only be realised as the UK moves towards renewable energy for its electricity production. Heat pumps require electricity to run and in the UK, only 35% of this is currently generated through renewable sources.
Should I Install a Heat Pump?
The government is banning the installation of gas boilers in new build homes in 2025 and they will not be sold in the UK by 2035. This means, at some point we'll all need to find a new way to heat our homes. The cost of heat pumps is high relative to gas boilers as the market is currently a lot smaller. With an increase in demand and competition, these prices will likely drop so it could be argued you should wait. However, from April 2022 the government will be offering grants of £5000 to help homeowners upgrade to a heat pump. It's unlikely this grant will be around forever so you might want to take advantage while you still can.
What are the Alternatives?
One of the potential alternatives to gas boilers is the use of hydrogen. This is attractive as hydrogen could be fed into homes using the same pipes as natural gas, making the switch easy for homeowners. However, producing low carbon hydrogen isn't easy and it could be a few years before this technology is available.
There are some places in the UK, such as Cornwall, that could use geothermal energy to heat homes. However, this is likely to stay a niche option and won't be available to the vast majority of us.
Can I Still Install a Gas Boiler?
There's currently no legislation stopping you installing a new gas boiler. It's been proposed that new gas boilers will be banned in 2035. However, similar to the ban on fossil fuel cars, gas boilers will still be allowed to operate past this date. Boilers can last from between 10 to 20 years so depending on the quality of the boiler you choose, if you were to install a gas boiler now it could still be operational by the time the ban comes in.
Heat pumps are a promising technology which should help the UK reach it's target of net zero emissions by 2050. Whether or not you install one in your home now will largely come down to budget and circumstances.