Comment by Daniel Logue, Advisor – Decarbonisation of Commercial Sites, at Energy Systems Catapult 

Heat pumps are changing the way we provide space and central heating and hot water to buildings across the UK. Increasingly, heat pumps are installed in commercial buildings and on public estates to provide an efficient source of heat that only uses electricity to reduce carbon emissions.

Due to heat pump efficiencies and electricity carbon intensity, heat pumps outperform gas boilers in terms of energy use and carbon emissions, making them an ideal solution for decarbonising commercial and public estates and buildings. As the electricity grid decarbonises, this advantage increases. However, effectively selecting and siting your commercial heat pump is not without its challenges.

What are my options?

There are three main types of heat pump: Air Source Heat Pumps (ASHPs), Ground Source Heat Pumps (GSHPs), and Water Source Heat Pumps (WSHPs).

ASHPs are the most commonly deployed; they fall into two broad categories, air-to-water systems and air-to-air systems. The difference between these two common types is that if you have a wet heating system operating in your building (i.e. pipes and radiators with water running through them) you could connect the air-to-water heat pump direct to that system, whereas the air-to-air heat pump would provide you with an air output that could be used in an air conditioning system.

GSHPs benefit from more stable temperatures offered by the thermal mass of the ground. This can be accessed using pipes buried about 1m below the ground or boreholes drilled vertically. The boreholes can contain pipes that form a closed loop, or they can access an underground aquifer. Deeper than about 10m, the ground temperature is fairly constant throughout the year. The temperature depends on the geology and ground conditions but is about the same as local average air temperatures (between 10 and 14ºC in the UK). Additionally, GSHPs can store heating and cooling energy between seasons further improving efficiencies.

WSHPs work on the same principle as GSHPs; however, they use water as a heat source or sink. These can be open or closed loop systems and can use either surface water (rivers, lakes, canals or the sea) or wastewater (sewage or industrial process wastewater).

What should I consider when siting a heat pump?

You may find that different types of heat pump are suitable for a commercial or public sector building and can’t quite settle on the most appropriate. Aside from technical suitability, there are other considerations you should make before jumping in. For instance, when selecting a heat pump, it’s worth considering how disruptive the installation process could be. If you choose an ASHP and it needs to be placed onto the roof, lifting equipment might be required. Likewise, if you choose a GSHP, a lot of external groundwork may be required. This might cause noise on site and be disruptive to day-to-day operations at the building during the build – this may be of concern if the building is a hospital or care facility.

The speed and ease of installation should be a core consideration for any commercial installer or specifier. It’s possible that installing a heat pump will take longer than a fossil fuel heating system owing to the potential need for GSHP or WSHP pipework. You may also need to factor in changes to the configuration of pipework in your plantroom, and the installation of an upgraded Building Management System (BMS). Again, many businesses or buildings delivering vital public sector services might not be able to go long periods without adequate heating and cooling, so a temporary solution may be needed while the installation is progressed.

Supply chain disruption is a concern for specifiers, designers, and installers across the UK. Making sure that any plant or equipment is on order early in any installation is really important. Particularly with Public Sector Decarbonisation Scheme (PSDS) grants, or other budgets that require spend within specific time periods, it’s important to make sure that any equipment is ordered and confirmed delivery dates received before commencing on any project.

How can I find out more?

Selecting and siting an appropriate commercial heat pump doesn’t have to be complicated. To simplify the process we’ve put together Heat Pumps: Which one is right for your site and what else to consider alongside. This guide has been developed to give guidance on what heat pump types may be appropriate for a particular site or situations. You can also reach out to us directly: PSDecarbGuidance@es.catapult.org.uk.