Heat pumps

Around 31% of a household’s carbon dioxide emissions come from space and water heating. To meet the governments target of net zero carbon emissions by 2050 new technologies such as heat pumps will be needed to reduce these emissions while providing comfortable living conditions.

A heat pump is a device that can replace traditional heating systems such as boilers to provide space and water heating within both domestic and commercial settings. Rather than burning a fuel to produce heat, they move heat from a low-temperature heat source and ‘pump’ it to a higher temperature where it can be used to provide space heating or produce hot water. The source is normally heat in the ground or the outside air. 

The higher the temperature in the source location relative to the desired location, the more efficient heat pumps are. Their efficiency is expressed as a coefficient of performance where a higher figure indicates a more efficient system and therefore less energy is required for the same output. Heat pumps are powered by electricity and decarbonisation of the national grid further helps to reduce the environmental impact of the already efficient technology. Where homes have solar panels even greater carbon savings can be made. 

The average efficiency or coefficient of performance (CoP) for a typical domestic heat pump is 3 to 4 CoP but this will vary throughout the year due to seasonal changes and may vary by property due to differences in system size or layout.

Heat pump process

The diagram below shows the flow of hot and cold water and refrigerant around a typical heat pump installation. It shows how heat from air or the ground warms the refrigerant in the evaporator, how the refrigerant is compressed to increase its pressure and temperature before transferring its heat to your home via the condenser. The process then begins again with the refrigerant cooling at the expansion valve ready to collect more heat.

Typically, the output temperature of heat pump into your home is between 28℃ and 45℃ depending on the heating system and heat pump installation. This means that it can be necessary to upgrade your current radiators to ensure that your home is heated to a cosy temperature.

Heat pump process

Key advantages

  • Lower greenhouse gas emissions from heating your home
  • A more balanced supply of heat helping to improve control over your heating system
  • Potential for lower fuel bills
  • Where hybrid systems are installed there is a reduced need for LPG or oil deliveries

Financial support

As with many new technologies the purchase price can be high can therefore, there are some financial support mechanisms to support the roll out of heat pumps.

Green Homes Grant provides vouchers that will cover two-thirds of the cost of heat pumps (and other carbon saving measures), up to a maximum government contribution of £5,000. For more information see: Simple Energy Advice's - Green Homes Grant

Renewable Heat Incentive is a subsidy scheme to promote the use of renewable heat, where quarterly payments are made for seven years and are based on the amount of renewable heat made by your heating system- for more information see: OFGEM - Domestic Renewable Heat Incentive

Suffolk Greener Homes Interest Free Loan loans of up to £5,000 at 0% APR to help homes cut their energy use. Loans are available for energy saving measures such heat pumps (and other carbon saving measures). Loans are only available for the installation of approved materials and technologies by accredited installers. For more information see: Green Suffolk - Loans for energy efficiency

Hybrid heat pump offer

One alternative to completely replacing your existing boiler and radiators is to use a hybrid heat pump system. A new heat pump can be installed to provide the majority of the heat required to heat your home but is supported by your existing boiler for particularly cold days or where your heating demand is high. This approach avoids you needing to replace any radiators and is supplied with a sophisticated control system to automatically switch between systems.

The village of Gazeley was originally selected to be part of a trial of the hybrid heat pump systems where many people heat their home using LPG or oil. It is anticipated that a greater roll out of the scheme to other areas of West Suffolk will follow shortly after. Gazeley looks at going green on renewable energy for residents - press release 30 September 2020

The diagram below shows the flow of hot and cold water around a typical hybrid heat pump installation, where the heat pump and boiler work together to produce hot water for direct use and space heating.

Hybrid heat pump process diagram

More information