What Are Air Source Heat Pumps?

What are air source heat pumps?

Air source heat pumps use heat from the outside air to heat your home through radiators, underfloor heating or warm air heating and they can also heat your hot water.

Air source heat pumps are not carbon neutral, since they do require electricity to run, however because they use renewable heat from the environment, their output is greater than their input. This means that air source heat pumps have a lower carbon footprint and offer a cost-effective and energy-efficient alternative to other heating systems such as electrical or coal heating.

How do air source heat pumps work?

Air source heat pumps work by drawing heat from the air outside your home, which is then absorbed into a fluid at low temperature before being passed through a compressor, increasing the temperature ready for use to heat your home or water.

They are capable of absorbing heat from the air even when outdoor temperatures are as low as minus 15 degrees celsius, so are suitable for year-round use.

There are two types of air source heat pump:

An air-to-water pump

This absorbs heat from the air outside and transfers it to water. The water can then be used to heat the water and radiators in your home via your central heating.

An air-to-air pump

This type of air source heat pump transfers heat from the outside air into warm air, so requires a warm air circulation system in your home in order to work. It won’t provide you with hot water and isn’t eligible for the government Renewable Heat Incentive (RHI) scheme.

How much space do I need for an air source heat pump?

Air source heat pumps don’t require as much outdoor space as a ground source heat pump does but you will need a suitable space outside your home for a unit to be fitted and a space inside your home for it to be connected. The internal unit for an air source heat pump is typically smaller than an average gas boiler.

What are the benefits of an air source heat pump?

There are many benefits to an air source heat pump, both for yourself, your home and the environment.

Air source heat pumps can-

• Lower your home fuel bills
• Reduce your carbon emissions
• Heat both your home and water from a renewable energy source
• Provide an income through the government’s Renewable Heat Incentive (RHI) scheme

Air source heat pumps also remove the need for fuel deliveries. They are easier to install than a ground source heat pump and installation is typically quicker and less disruptive.

Air source heat pumps offer a low-carbon heating solution that is energy-efficient and cost-effective in comparison to other heating systems such as electric heating.

Are there any drawbacks to air source heat pumps?

Air source heat pumps do have some drawbacks. Unlike traditional gas and oil boilers, an air source heat pump is designed to deliver heat to your home at a lower temperature over a longer period. This means they’re better suited to home heating systems such as underfloor heating or large radiators.

It’s also important, when considering fitting an air source heat pump to ensure your home is properly insulated to maximise on the effectiveness of the pump.

In winter, your air source heat pump will have to work harder to produce heat so will be less economical as a result.

Air source heat pumps can be costly to instal but they are eligible for green energy grants to assist with the upfront and ongoing running costs.

Is an air source heat pump the right choice for my home?

There are several factors to consider when deciding if an air source heat pump is the right choice for your home.

Location of the pump

Air source heat pumps don’t require as much outdoor space as a ground source heat pump but you do need to ensure that you have an outside space that is suitable for the pump to be fitted either to a wall or the ground. It will need plenty of space around it for airflow. The external unit will be connected to an internal unit inside your home (similar in size to a boiler) so this is also a consideration.

The size of air source heat pump you need will depend on your house size. It’s important to note that unlike a ground source heat pump, an air source heat pump will be visible outside your property after installation and will emit a noise similar to that of an air-conditioning unit. Therefore you may need to consider if this will be an issue for you or cause friction with neighbours.

Your heating system

Air source heat pumps require a central heating system, so if you don’t already have one, that will be an additional consideration and expense. They work best with home heating systems such as underfloor heating or with larger radiators.

An air source heat pump is an ideal replacement for inefficient heating systems such as electric heating where savings will quickly be seen. Savings are likely to be far less if switching to an air source heat pump from a mains gas supply.

Installation time and costs

Air source heat pumps require specialist installation but the installation process is less disruptive than installing a ground source heat pump and doesn’t require any digging outside of your property or access for heavy machinery, making it a more straightforward process.

The initial installation cost of an air source heat pump is typically between £9,000 and £11,000 on average. Running costs are significantly less than other heating systems, since electric use is minimal but given the upfront cost, it may take time to see savings. Don’t forget that there are grants available to put towards the cost of installing an air source heat pump as well as to help with ongoing running costs.