If you’ve been looking into getting a heat pump for your home, you’ll probably be aware you have a decision to make. Air source vs Ground source heat pumps is the question you need to answer.
When weighing up the pros and cons of each system, you’ll need to consider several factors, for example, the practicality of installing one system over the other and the differences in efficiency, noise and if you require planning permission.
We’ve put together this piece to highlight the key differences and help you make an informed decision by considering each option’s benefits.
In addition, we will consider any possible complexities that may make one system more suitable than the other for certain consumers:
Why would you get a heat pump installed?
If you ask most consumers, the main reason they would consider getting a heat pump installed is to lower their heating bills. This is the number one reason that domestic customers consider installing energy efficiency upgrades within their homes.
In fact, there are several benefits of installing a heat pump, including:
- They generate renewal energy, making them a fantastic option for anyone looking to reduce their carbon footprint.
- Reduce energy bills. On average, a heat pump is around four times more efficient than a regular boiler making the running costs significantly lower.
- Eligible for Renewable Heat Incentive scheme. If your system is MCS certified by a qualified installer, you could qualify for regular payments under the scheme providing you with a supplementary income for installing a renewable energy source.
- They are more efficient. Generally, heat pumps generate more energy than they use within your home, making them up to 400% more efficient than alternative heating sources.
What is an air source heat pump?
An air-source heat pump is a carbon-free way to heat your home. The pump works by absorbing heat from the outside air. This air then heats your home and hot water.
Air Source Heat Pumps are very efficient and also eco-friendly. For every unit of energy it uses, it will generate three times as much heat on average. An air-source heat pump also requires very little maintenance in the long run and are unlikely to need any significant parts replacing during its lifetime.
What is a ground source heat pump?
A ground source pump is to transfer the heat from the ground and pump it into a home. Using a sequence of pipes buried underground on your property, either horizontally or vertically. They extract heat from the earth.
The heat the ground source heat pump generates can then be used to heat water, radiators, underfloor heating and warm air heating systems in your home.
A ground source heat pump could save you money on your heating bills. This is particularly true if you switch from an electric or old oil or LPG boiler system. Being a renewable energy source, they are also extremely eco-friendly and will help towards reducing your carbon footprint.
Air source vs ground source: requirements for installation
Let’s take a look at these individually to understand the differences in installation requirements.
Air Source Heat Pumps
In most cases, Air source heat pumps are a more straightforward installation than ground source heat pumps. This is because there is no need to dig up your land if you opt for the air sourced option. The units resemble an air conditioning unit and will often be wall-mounted onto an external wall outside your property. Your home heating demand will determine what size air source heat pump you need. As you might expect, a bigger home will require a larger unit. When an installer inspects your property, they will be able to advise what you need.
The air source heat pump will not take up a lot of space. However, it will be visible from your property. So you’ll need to check if you need any additional planning permission with your local authority before going ahead. In addition, the noise from an air source heat pump is comparable to an air conditioning system. You may want to consider how your neighbours may feel about this as the continuous noise could bother them – as well as you.
If you have an existing flue outside your property, it’s possible to get an air source heat pump up and running in a couple of days.
Ground Source Heat Pumps
To install a ground source heat pump, you’ll need enough outside space to install a ground loop. Because the ground loop can be installed horizontally or vertically, so having a small garden isn’t an automatic deal-breaker. However, you’ll need to check with an experienced installer to discuss your options, as there will always be a minimum space requirement. In addition, the ground will need to be suitable for digging.
For vertical installations, specialist digging equipment will be needed to drill boreholes. This inevitably will increase the cost of installation. Laying the ground loop and pipework horizontally is the most cost-effective option. However, you will need a lot more space, for example, a large garden. You will also need space inside for the heat pump unit. This is about the size of a fridge freezer. The unit will make a low level humming noise, comparable to an air con unit.
Installing a ground source heat pump can take some planning and time to install. It’s certainly a messy job. However, once it’s done, none of the pipework will be visible, and it will not affect the look of your property or the use of your garden.
Air source vs ground source heat pumps: energy efficiency
Regardless of if you use a ground or air source heat pump, they both work in a similar way. They extract air from their surroundings and turn it into valuable energy for the home that can keep you warm. You’ll need an electricity source for both systems to run. However, with both systems, the energy output is significantly greater than the input. Therefore, they are one of the most energy-efficient ways to heat your home.
Air source vs ground source: costs
There is a significant difference between the upfront cost of installing an air source heat pump. In comparison to a ground source heat pump, despite their similarities in functionally. The cost of an air source heat pump is between ££3000-£11,000s.
By comparison, a ground source heat pump typically costs £14,000-£19,000. A large amount of the additional costs of installing a ground source heat pump comes down to the added work involved in digging up the ground or drilling boreholes.
When we look at the ongoing costs of the two systems, however, there is very little difference. Both require very little maintenance, and no major parts are likely to need replacing over the life of the units. Your equipment manufacturer will recommend that you have an annual inspection to check the systems are working as efficiently as possible.
Air source vs ground source heat pumps: savings
In both cases, it’s highly likely you will save money on your energy bills by switching to a heat pump. How much you will save will heavily depend on what system you are switching from. When directly compared, Ground source heat pumps are more efficient than air-source heat pumps because the heat is transferred through the ground and water movement. Water has a greater capacity to hold heat compared to air. So if you were to directly compare the energy bills for the same household ground source, heat pumps would save you slightly more per year on energy bills. However, the initial outlay is significantly more expensive.
Air source vs ground source heat pumps: key differences
We’ve summarised the key differences for you:
- Air source heat pumps are installed above ground, making installation easier and quicker.
- You need to install a ground source heat pump vertically or horizontally underground, making a much more complex installation.
- Air source heat pumps can be noisy and disturbing to you and your neighbours.
- A ground source heat pump is significantly more expensive than an air source heat pump.
- You may require planning permission to install an air source heat pump because it will be visible outside after installation.
- You can install an Air source heat pump in any size garden. However, ground source heat pumps need ample outdoor space.
- Ground source heat pumps are slightly more efficient because of the way they transfer heat.
Air source vs ground source: which one is right for you?
While there are many similarities in their operation, these two heat pump choices have some very different requirements when it comes to choosing them for your home. However, both offer excellent energy-saving and eco-friendly benefits and qualify for Renewable Heat Incentive Scheme payments if installed by a certified professional.
Which one you should choose will depend on your budget and available space at your property. If both are an option for you practically, you should consider the needs of your household to determine which would be better for you in the long term. With either option, you’ll be generating renewable energy and doing your bit for the environment as well as saving money on your bills.