Air source heat pumps
Frequently
asked
questions
What is an Air Source Heat Pump?
Air source heat pumps (ASHPs) are innovative heating systems that absorb heat from the outside air. They work similarly to air conditioning units but in reverse. There are two main types:
Air to Air Heat Pump: These pumps absorb heat energy from the outside air and directly transfer it into your home through a cassette fan, similar to an air conditioning unit. They are suitable for heating individual rooms or small indoor spaces but not entire homes. It’s important to note that you cannot apply for Renewable Heat Incentive (RHI) payments with this type of pump.
Air to Water Heat Pump: This type of pump also absorbs heat energy from the outside air, but it transfers it through a traditional central heating system with radiators and a hot water cylinder, providing both heating and hot water for your entire home. With Air to Water heat pumps, you can claim the RHI incentive, as it heats your entire home.
How does an Air Source Heat Pump work?
An ASHP works by extracting heat energy from the air and transferring it into your home. This process involves several key steps:
Heat energy is absorbed from the air and transferred to a refrigerant with a low boiling point in the evaporator.
The refrigerant changes from a liquid to a gas and passes through a compressor, where it is pressurized, increasing its temperature.
The heated refrigerant then delivers heat to water at the condenser, which is distributed to your hot water tank, radiators, or underfloor heating.
The refrigerant passes through an expansion valve, where it drops in temperature, returning to a liquid state and restarting the process.
How efficient is an air source heat pump?
Air source heat pumps are highly efficient, with some models exceeding 350% efficiency. They achieve this by transferring heat rather than generating it. Compared to other heating systems, such as electric heaters or traditional boilers, ASHPs offer significant savings on energy costs.
How is the heat pump efficiency measured?
The efficiency of an ASHP is measured by the Coefficient of Performance (COP), which indicates the ratio of output heat energy to input electricity. A higher COP means greater efficiency. Additionally, the Seasonal Performance Factor (SPF) considers the system’s performance over the entire year.
How noisy is a heat pump?
Modern ASHPs are designed to operate quietly, typically ranging from 50 to 70 decibels. This level of noise is comparable to everyday sounds like conversation at home or background noise in a rural area.
How long does installation take?
On average, installation takes between 3 and 4 days, depending on the number of radiators being installed or replaced. Minimal disruption is expected, with hot water supply ensured throughout the process.
Do I pay VAT?
Currently, heat pumps are subject to a reduced VAT rate of 5%. However, the government plans to increase this to 20%. Homeowners can benefit from the reduced rate if the system is fully fitted before any changes take effect.
What is the Renewable Heat Incentive (RHI) and is it Means Tested?
The Domestic RHI is a government incentive aimed at promoting renewable heat usage. It is not means-tested and is available to all homeowners. Payments are made quarterly for a seven-year period based on the heat and hot water demand indicated by an Energy Performance Certificate (EPC).
How much income will I receive with the RHI?
RHI income is determined by the heat and hot water demand identified in the EPC. Currently, the maximum annual income is around £1,600, with payments linked to inflation and increasing yearly.
Will the RHI income decrease over time?
It is likely that the government will reduce and eventually end the RHI scheme for new applicants, similar to what occurred with the Solar Feed-in Tariff. Homeowners are encouraged to take advantage of the high payouts currently available, as participants are “locked in” for seven years, with payments increasing with inflation.