In 2019, the UK government committed to reaching a target of net-zero greenhouse gas emissions by 2050. Part of the push to reach net-zero will be a switch from gas central heating systems to clean, low carbon options for heating our homes, such as ground source air pumps.
In this article we’ll take a look at the pros and cons of choosing a ground source heat pump when deciding how to provide energy for your home.
How Do Ground Source Heat Pumps Work?
Ground source heat pump systems are a network of water pipes buried underground, which are attached to a heat pump at ground level. Water and anti-freeze is pumped into the network, also known as a ‘ground loop’, and absorbs the heat that naturally occurs and is stored in the ground. The water and anti-freeze mix is compressed and passed through a heat exchanger, which extracts the heat and transfers it to the heat pump. The heat is then transferred to your home heating system to warm your radiators and underfloor heating system.
As the ground outside always contains some warmth, a ground source heat pump can supply heat to your home, even when it’s cold. However, it’s vital to have your house properly insulated so that the heat that is produced is retained for as long as possible. Proper insulation also keeps your home cool during the warmer months of the year.
What are the Pros of Having a Ground Source Heat Pump?
There are some very real benefits to having a ground source heat pump installed in your home, beyond helping the UK reach its net-zero 2050 target. These include:
- Financial aid. The upfront cost of having a ground source heat pump installed makes it difficult for people to afford them. However, if you do get one in your home, you can make some impressive savings on energy bills, and the Energy Savings Trust estimates that a ground source heat pump could save you up to £1,400 a year. To bridge the gap between the initial outlay and the savings you can make, the government offers financial help towards the cost of a heat pump. The Renewable Heat Incentive (RHI) scheme gives payments to householders who have a heat pump, which are usually between £2,335 and £2,750 for an average four-bedroom detached home.
- Efficiency. For every unit of electricity used by a heat pump, between three to four units of heat are captured and transferred to your home. This makes a well-installed heat pump between 300 to 400% efficient in terms of its use of electricity. Due to this impressive efficiency, it creates 70% fewer carbon dioxide emissions compared to a traditional gas boiler system. If the electricity used to power the pump is provided by renewable energy, carbon emissions can be reduced to zero.
- Safety. Heat pump systems are safer than combustion-based heating systems, such as gas-fired or oil-fired boilers. They are safe to operate and because they rely on electricity rather and don’t need to burn fuel to generate heat, they come with fewer safety concerns.
- Less maintenance. A well-installed ground source heat pump requires a small amount of maintenance in the form of an annual check which can be done by the owner, without the need to call in an engineer. The installer can give you details of maintenance requirements and advice on how to optimise your system’s performance. Heat pumps have fewer moving parts than traditional heating systems, which reduces the risk of breakdown, and they don’t pose the potential risk of a carbon monoxide leak.
- Longevity. Ground source heat pumps have a longer life than most combustion-based heating systems. The average lifespan is usually around 15 years, though they can last up to 50 years. The ground heat exchanger element of the heat pump installation has a design life of over 100 years, which isn’t something you will find in any other heating system.
What are the Cons of Having a Ground Source Heat Pump?
As with most things in life, there are some downsides to having a ground source heat pump fitted. They aren’t suitable for every home and require a lot of work to install. The main disadvantages are:
- Expensive to install. Installing a ground source heat pump requires a large upfront payment. This is typically between £10,000 and £18,000 depending on the size of the system. You may also need to install underfloor heating, if you don’t already have it, to get the most out of your heat pump.
- May incur costs beyond the initial installation. To feel the full benefits of a heat pump, your home must be properly insulated, including cavity wall insulation, roof insulation and double glazing. This may incur further expense if you don’t already have these in place.
- Disruptive installation. Having a heat pump system installed is a bog job, which will require having your garden dug up. You may need to have underfloor heating and new radiators installed too, which will add to the disruption.
- Not suited to small gardens. If your home doesn’t have a reasonably sized outdoor space where the pipes can be buried, you cannot have a heat pump installed. Ground source heat pumps can be used in flats but all owners will have to agree to the expense and disruption that comes with having one fitted.
Having a ground source heat pump installed comes with both positives and negatives, but the long term benefits are likely to outweigh the initial expense and short-term disruption. As the UK moves to a net-zero future, more and more people will be changing the way they heat their home. Ground source heat pumps will become a mainstream choice, both saving you money and helping to create a cleaner, greener environment for everyone.
