Heat pumps – how much money can they save you?

Do you want to save money and help the environment? Well installing a heat pump will do just that – but which type is best for you; a ground, water or air source heat pump?

Ground source heat pumps
require space to install

Despite worries about global warming, the recession and spiralling energy costs, the UK has been slow in taking up renewable energy alternatives like heat pumps. Only around 0.6% of heat is produced by renewable sources in the UK and 69% of household heating comes from gas boilers, says the Department of Energy and Climate Change (DECC).

Installing the right kind of heat pump for your home may cost more initially but will cut your carbon footprint and save you money in the long run by reducing fuel bills. So find out what kind of heat pump best suits your home and how much money you can save by installing a heat pump here:

Ground source heat pumps

Ground source heat pumps work by extracting heat from the earth, which maintains a constant year round temperature of around 11-12 degrees. Ground loops (lengths of pipes which circulate an antifreeze mixture to extract heat) are laid in trenches or inserted by drilling boreholes in the garden. The extracted heat is pumped into the household heating system and distributed via radiators, air ducts or underfloor heating.

Tim Bartlett, from Eco-Hometec Ltd in Doncaster says: “You need around two and a half times the footprint of your property as a rule for installing ground source heat pump loops.” According to the Energy Saving Trust (EST), replacing gas heating with a heat pump would save you around £190 per year, swapping from electric would save £840 and replacing solid fuel heating with a ground pump would save £600. The EST reports that a ground source heat pump will cost between £7,000 and £13,000 to install, however trench systems are cheaper.

The most common kind is air
source heat pumps

Air source heat pumps

According to the Heat Pump Association (HPA), there are two types of air source heat pump: air to water models which produce warm water for heating and air to air pumps which circulate warm air through fans and are the most common option. Tim suggests that: “I think air source heat pumps will become the next trend in renewables, as it has done in France.” In fact, according to a report ‘Sustainable energy without the hot air’ by Prof David Mackay from the DECC, air source heat pumps are the best heating choice for most homes in the UK.

Air source heat pumps are so much easier to install than other kinds, no digging work is required and they don’t take up as much space. “An air source heat pump just fits on the back of your house and is about the size of a fridge,” explains Helen Durose from Evergreen Renewables in Derbyshire. You just need a suitable outdoor space to install an air source heat pump - a south facing, sunny wall is ideal. The only drawback is that in extremely cold temperatures the pump may become less efficient as it spends more time thawing the outside parts of the pump.

Air source heat pumps can save around £700 when replacing electric heating, £50 when exchanging with gas and £460 when replacing solid fuel heating, says the EST, who put prices of air source heat pumps at around £5,000 to £9,000.

Water source heat pumps are good
if you live near a river or the sea

Water source heat pumps

Water source heat pumps can be installed in homes near rivers, streams or lakes where the water is ideally around 5-8 degrees. These pumps come in water to water or water to air models, however the quality of the water source needs to be good; lots of particles for instance can decrease the pumps performance. Tim explains: “The wetter the ground the better, you need a moving water source otherwise it may freeze the water. Living near the Thames or the sea is ideal.” The property should also be close to the water so that it doesn’t need to be pumped great distances. Frank Harris, from H.D Services in Bucks, says: “If you live in the south east you shouldn’t have a problem with water supply.”

This type of heat pump is the least common and there are also restrictions regarding where you can install one and what kinds of refrigerants you can use. “You need to have a licence to take more than 20 cubic meters of ground water per day, so we install water source pumps mainly in residential properties,” Frank explains. In some systems you can use waste water for garden irrigation. Figures for how much money water source heat pumps aren’t yet available.

Benefits of heat pumps

All types of heat pumps:

• Are energy efficient – according to the HPA, heat pumps produce 2-5 kilowatts of heat for every one kilowatt of electricity that they take to run.
• Work best with underfloor heating – Mark O’Brien, from Terra Therma in Essex explains: “Heat pumps are optimised and most efficient when heating water to around 35 degrees, which is perfect for underfloor heating.”
• Are best installed in new builds – this keeps installation costs down and limits the disruption of pulling up floor boards and connecting the pump to the indoor heating system.
• Cost less to run – according to the Refrigeration and Air Conditioning Magazine, heat pumps are on average 56% cheaper to run than gas boilers.

Heat pumps work best with
underfloor heating


• Can be completely cost free – if you use a renewable electricity source, such as solar PV to power your heat pump it could be completely carbon neutral and cost-free (depending on whether you need a back up heat system).
• Save the most when replacing electric, oil or solid fuel heating – replacing gas heating with a pump results in the least amount of fuel and CO2 savings but are the best heating option if you don’t live on a gas main.
• Are low maintenance
• Have a long life-span – most heat pumps last at least 25 years.
• May be cheaper to install with a grant – check with your local authority to see if there are any grants available to subsidise installing a heat pump in your area.
• Can be used for cooling – most heat pumps can be reversed in winter to provide air conditioning for your home.

The Renewable Heat Incentive (RHI)

This scheme is due to be launched in April 2011 and will provide cash back for renewable heat generated by systems like heat pumps in the home. Details of the RHI are yet to be finalised, however it’s likely that tariff levels will vary depending on the heat pump size and payments will be made on a metered system, valid for 20 years. The DECC suggest that under the scheme, a medium sized ground source heat pump (of around 45kw – 500kw) could earn about £1,000 per year.

At a glance – how much can heat pumps save you?

*All figures are approximate and come from the EST; no figures are yet available for water source heat pumps

AB