Air Source Heat Pumps

Air source heat pumps (ASHPs) are an energy-efficient and environmentally friendly way to heat your home and provide hot water. Rather than generating heat by burning fuel, they extract naturally occurring heat from the outside air — even in low temperatures — and upgrade it into usable heat for your property. This makes them a low-carbon alternative to traditional gas and oil heating systems, with the added benefit of significantly improved efficiency.

Types of Air Source Heat Pumps

There are two main types of air source heat pumps, each suited to different applications.

Air-to-water systems are the most commonly installed in UK homes. These connect to a wet central heating system and provide heat to radiators, underfloor heating, and a hot water cylinder. They are ideal for replacing or upgrading existing boiler systems.

Air-to-air systems distribute warm air directly into rooms using fans. While they can also provide cooling in warmer months, they do not supply hot water, which makes them less common for full home heating in the UK.

How Air Source Heat Pumps Work

Air source heat pumps operate using a refrigeration cycle that allows them to capture and amplify heat from the outside air. A fan draws air into the outdoor unit, where a refrigerant absorbs the heat and evaporates into a gas. This gas is then compressed, which significantly increases its temperature. The heat is transferred into your home’s heating system, and the refrigerant cools back into a liquid, ready to repeat the process.

Because they move heat rather than generate it, heat pumps are highly efficient. For every unit of electricity used, they can typically produce three to four units of heat — making them far more efficient than conventional heating systems.

The Installation Process

Installing an air source heat pump begins with a detailed assessment of the property, which is essential to ensure the system performs correctly. The most important part of this is the heat loss calculation. This involves measuring the size of each room, assessing insulation levels, and evaluating elements such as windows, doors, and construction materials. The purpose is to determine exactly how much heat the property loses, so the system can be accurately sized.

Once this has been completed, the system is carefully designed to suit the home. Because heat pumps operate at lower temperatures than traditional boilers, it is sometimes necessary to upgrade radiators or consider underfloor heating to achieve the best performance.

The installation itself includes fitting the outdoor unit in a suitable location, installing internal components such as the hot water cylinder, and connecting everything to the existing heating system. After installation, the system is fully commissioned, tested, and set up to ensure it runs efficiently and delivers consistent comfort throughout the property.

Government Grant & MCS Certification

Homeowners in England and Wales may be eligible for financial support through the Boiler Upgrade Scheme, which can provide a grant of up to £7,500 towards the cost of installing an air source heat pump. This significantly reduces the upfront investment and makes switching to renewable heating more accessible.

At AC Plumbers Ltd, we are committed to delivering high-quality, energy-efficient air source heat pump installations that meet the latest UK industry standards. To ensure our customers can benefit from government-backed incentives and fully compliant installations, our projects are completed under an MCS umbrella scheme provided through the heat pump manufacturer’s accredited network. This means your installation is carried out in accordance with Microgeneration Certification Scheme (MCS) standards, allowing eligible homeowners to access the Government’s Boiler Upgrade Scheme (BUS), which currently offers grants of up to £7,500 towards the installation of an air source heat pump, subject to eligibility criteria. By working under an approved MCS umbrella scheme, we can provide customers with professionally designed and compliant renewable heating installations that meet recognised industry standards for quality, efficiency, and performance.