Pump up the volume

Donna-Marie Evans of LG Electronics explains why heat pumps are the right choice for UK housebuilders and homeowners to comply with the Future Homes Standard, and tackles some myths

With recent announcements from the Government about the decarbonisation of heating in the UK, the arrival of the Future Homes Standard and the decision by the Government that after 2025 no new build homes can have fossil fuel heating systems, the spotlight has been trained on proven renewable technologies to provide our heating and hot water here in the UK. Heat pumps have seen a huge take up in northern Europe, Scandinavia and Canada – all of which experience far worse winters and lower temperatures than we do in the UK – and now it seems inevitable they will at last grow in importance here too.

Air to water (AWHP) systems (‘monoblocs’ or ‘splits’) present a variety of energy-saving options for a home’s heating and hot water. By replacing a traditional gas, oil, or solid fuel system, or specified as the means of providing heating and hot water in a new property, an AWHP can significantly reduce carbon emissions and energy usage. These devices’ absorption of natural energy from external air makes them consume less energy than conventional heating systems. They can operate successfully at low temperatures – as low as -7°C – and it’s very rare for temperatures in most of the UK to drop that low. We’re looking at between three and four times the energy efficiency you can obtain from the most efficient condensing gas boiler.

The terms ‘split’ and ‘monobloc’ refer to how the system is required to be set up in a home. A Monobloc is a bit like a combi boiler and is literally a ‘single block’ system, where the heat pump has all of its components – apart from the hot water cylinder which is installed inside the property – located inside a heat pump unit situated outside the home. Because a monobloc does not require someone with F Gas qualifications to get involved in the use of refrigerants, they are an excellent additional string to the bow of most professional heating installers. After attending an appropriate training course, they will be well placed to join the growing band of installers capable of fitting these heating systems in homes.

A split heat pump unit has both an outside unit which incorporates the heat exchanger and refrigerant and an internal unit that sits inside the property, usually in a utility or boiler room.

Most homes in the UK are suited to a monobloc air to water heat pump. A split system is an option generally for more complex installations; it can be installed up to 30 metres away from the home, which gives far more installation flexibility.

The financial incentive to use heat pumps is changing in 2022. The Government has announced that the Clean Heat Grant will replace the Renewable Heat Incentive (RHI) scheme in 2022. The flat-rate grant is intended for households and small non-domestic buildings across the UK. It has been proposed to help with the upfront cost of installing heat pumps to deliver space heating and hot water, and will move the UK away from the RHI’s tariff-based system for consumers.

There are a number of options for AWHPs. According to the MCS Installation Standard, low temperature air to water heat pumps produce an indoor heat exchanger outlet temperature of 35°C, medium temperature an outlet temperature of 55°C and high temperature air to water heat pumps an outlet temperature of 65°C. These systems don’t produce water as hot as a traditional boiler will, as they generally only reach around 50°C at a maximum. They are perfectly suited to new build homes and self-build properties – which tend to be well insulated. To be at their most effective, they operate well with either larger capacity (possibly K3 design) radiators or a higher number of radiators and/or underfloor heating.

High temperature air to water heat pumps are designed for poorly insulated or particularly large properties, and those where replacing existing radiators or improving the insulation in the home isn’t possible. These high temperature heat pumps, which are offered by a few manufacturers, can heat water up to 80°C.

Donna-Marie Evans is marketing manager at LG Electronics