Baffled by heat pumps? We take a look at the key considerations for installing a heat pump in your home.
How do heat pumps work?
Heat pumps use the free supply of natural heat from the air or ground to generate domestic heating and hot water. An efficient heat pump transfers significantly more energy into a property as heat than it uses to extract it from the ground or air, helping to lower fuel bills and reduce environmental impact.
A buffer tank holds water heated by the heat pump which supplies the heating system. Rather than switching on and off, like radiators on a schedule, heat pumps maintain a constant, pre-set temperature in each room. The heat pump only increases the temperature of the water in the buffer tank when additional heat is required, and holds a minimum pre-set temperature when extra heat is not needed.
Domestic hot water (DHW) is stored in a cylinder in much the same way as with a traditional central heating system. The water in the cylinder is heated by the heat pump and held at a pre-set temperature.
What are the benefits of a heat pump?
A heat pump typically transfers three times the amount of energy into a property as heat than it uses to extract it from the air or ground, so has the potential to significantly lower your fuel bills. If you meet the Government’s Renewable Heat Incentive (RHI) scheme criteria, you can also receive additional payments to offset the initial cost of installation.
Is my property suitable for a heat pump?
A heat pump (whether air source or ground source) is a great eco-solution for any property, but is particularly beneficial to those without access to mains gas. Your property will need to be well-insulated in order for the heat pump to operate efficiently. If your property meets current building regulations it should be suitable for heat pumps without any alterations. Older properties may require additional insulation – check your Energy Performance Certificate to find out your property’s current insulation levels and any recommendations for their improvement.
Are heat pumps compatible with underfloor heating?
Yes! Heat pumps are at their most efficient when operating at lower temperatures, making this technology a perfect partner for underfloor heating (UFH), which operates at a much lower flow temperature than radiators. Heat pumps can still be used in conjunction with radiators, but the radiators would need to be oversized in order to heat the property adequately.
What floor coverings should I choose?
Heat pump powered UFH works best with high heat output floor coverings such as stone or ceramic tiles, vinyl or lino. If the floor covering has good thermal conductivity, the heat pump and UFH can operate at a lower flow temperature for optimum efficiency.
How much room do I need for a heat pump?
The amount of space you will need is different for a ground source or air source heat pump.
A ground source heat pump (GSHP) will generally require an area of up to three times the total floor area of the property (ground and upper floors) for the installation of ground loops. If you don’t have sufficient land to accommodate ground loops, a bore hole is an effective – but more costly – alternative. The GSHP itself is installed indoors, along with a buffer tank and cylinder. The combination of these elements will provide all of the property’s heating and domestic hot water requirements, without the need for boiler back up.
Air source heat pumps (ASHP) need to be positioned outside. Whilst less space is required for an ASHP than a GSHP, it is best practice to consider your neighbours and locate the heat pump at least 1m away from your neighbour’s boundary (3m if your property is in Wales). Bear in mind that your heat pump will need to work harder if it is situated in a cooler, north-facing, shady position, than if it is located in a southern-facing, sunny spot. The cylinder and buffer tank will need to be accommodated within the property. The cylinder is designed to sit on top of the buffer tank for a compact installation, and can often be housed in an area no larger than an oversized airing cupboard.
Will I need planning permission?
Heat pump installations generally fall under permitted development rights, and planning permission is generally not needed unless the property is listed or located in an Area of Outstanding Natural Beauty. You will need to seek approval from your electricity supplier before your heat pump is installed.