Air source heat pumps work differently compared to other more conventional forms of heating such as gas or oil because no fossil fuels are combusted.
Instead, air source heat pumps move heat energy stored naturally within the outside air for use in a home in heating and hot water.
Air source heat pumps can be classified as a form of renewable energy and move heat stored naturally within the outside air. However, air source heat pumps still require electricity as power, which may not come from a renewable energy source.
When paired with other renewable technology like solar panels, air source heat pumps can more fully optimize carbon emissions and energy consumption.
Our own air source heat pump that we use for both heating and hot water extracts heat from the outside by using fans to force air over a series of coils.
We discuss in more detail below why air source heat pumps can still be considered renewable technology despite using electricity.
Air source heat pumps transfer heat from outside homes to regulate indoor temperatures. Depending on the type, they can perform heating and hot water functions, or both heating and cooling. The pumps work by using the same technology as a refrigerator but in reverse.
Air source heat pumps use a refrigeration system, which is composed of two coils and a compressor.
Refrigerants in the coils transfer heat and release it into water or air inside the home. If the system has a reversing valve, the pump can also be used for cooling.
Our air source heat pump (ASHP) uses a central heating and hot water system inside our home. After extracting heat from the air using refrigerant and a compressor, heat energy is sent indoors to be used within these systems.
See our article on air source heat pump explained for more information on air source heat pumps and what our own heat pump system looks like.
Renewable energy is energy that can be naturally and continuously replenished. Sources of renewable energy won’t be depleted over time, unlike fossil fuels. Common examples of renewable energy are solar, geothermal, biomass, hydropower, and wind.
Although we might perceive renewable energy as an infinite energy source, we can only use some of this energy at a time. We are still limited by many things, like our present state of technology; for example, we can’t all use the solar energy available.
Air source heat pumps can be considered renewable technology because the heat extracted is from a renewable source, as solar energy from the sun. That is, the heat is natural and can be replenished.
Air source heat pumps work by forcing air over refrigerant flowing within coils to capture heat.
A compressor helps to maximize the heat gains and the heat is delivered indoors for use in heating or hot water.
While it can be harder for a heat pump to extract heat at lower outdoor temperatures, there’s still enough heat energy to efficiently extract even down to freezing temperatures. For example, our heat pump can still work in winter down to -20°C (-4°F).
Outdoor air will always gain heat energy during the day when the sun is out.
However, air source heat pumps still need to be powered and so some may disagree that an air source heat pump is not a renewable energy source.
Air source heat pumps are electrical appliances and are solely powered by electricity in order to work. For example, our ASHP takes power from inside our home.
The Centre For Sustainable Energy (CSE) explains:
“Because the air is heated by the sun, the energy that heat pumps produce is still classed as ‘renewable’, even though the pump itself is powered by electricity which may or may not have a renewable source.”Centre For Sustainable Energy (CSE)
Although air source heat pumps can be considered renewable technology, the environmental benefits also depend on the optimization of the system. For instance, carbon emissions can be lower if the system uses less energy.
Air source heat pumps use only one part of energy or electricity to generate up to three or four parts of heat energy (see our article on air source heat pump efficiency for more information). Thus, fewer carbon emissions can be produced compared to conventional systems that use more electricity.
Although the electricity used to power an air source heat pump may not always come a renewable energy source itself, a heat pump could be paired with solar panels for a more sustainable system.
Types Of Air Source Heat Pump
Heat gathered by an air source heat pump as a renewable energy source can be delivered into a home in a variety of ways.
- Air to water. Used with radiators and underfloor heating as part of a central heating system
- Air to air. Used with space heating appliances such as air handling units.
- Split. One coil inside, the other outside.
- Packaged. Both coils are outside.
- Ductless. The heat pump is connected to the internal apparatus via pipes.
- Ducted. Suitable for homes with duct ventilation systems to distribute air around a home.
- Single-zone. Ideal for one room only.
- Multi-zone. Can be used for multiple, individual rooms.
See our article comparing air to water and air to air heating pump systems for more information.
Benefits Of Air Source Heat Pumps
While being able to generate heat from a renewable energy source is a major upside, air source heat pumps have gained traction because of the many other benefits their technology offers, which include:
- Savings. Air source heat pumps have been shown to save households hundreds of dollars. However, the actual savings depends on how optimized your home and system are for this technology.
- Energy-friendly. Carbon emissions and energy consumption can be much lower when using air source heat pumps. These levels may even be improved when the electricity used for the pump is renewable, such as solar.
- Government incentives or support. Depending on where you live, green technology like air source heat pumps may qualify for government incentives or support, like the UK’s Boiler Upgrade Scheme.
- Versatile. Certain types of heat pumps can perform multiple functions. For example air to air heat pumps can both heat and cool, while air to water heat pump systems can provide both heating and hot water (when used with the right setups respectively).
- Low-maintenance. Air source heat pumps can last up to twenty years with minimal maintenance requirements when looked after properly.
See all the pros and cons or air source heat pumps here.