Cooling is the conversation our industry hasn't had yet - by John Felgate
The UK has just experienced its third heatwave of the year, with temperatures reaching 35C on 9 and 10 July and parts of the country still seeing highs above 30C. And while the UK is not accustomed to such frequent high temperatures, the Met Office has warned that ‘climate extremes are becoming the new normal’ across the country.
Despite rising temperatures, our industry's conversation around heat pumps is still mostly a winter one: how they perform in the cold and how the running costs stack up against a gas boiler. This is where most of the value gets proven, however the recent heatwaves are a reminder that it isn't the whole picture.
More households are asking installers about air conditioning during these heatwaves, often without realising the heat pump already sitting in their garage or plant room do the job. Cooling has become something customers assume they need to buy separately, and something a lot of installers aren't yet used to selling.
A heat pump normally collects heat energy from the outside air, raises it to a useful temperature and releases it into the heating water that warms a home's rooms. Run in reverse, that same water can be sent through the rooms cold. It picks up heat from inside, the heat pump draws that energy back out and pumps it up to a temperature it can release outdoors, and the cooled water goes round again to collect more.
Comfort cooling, essentially, rather than air conditioning as most people picture it. But for a household in the middle of a heatwave, that difference doesn't matter much. What matters is the room getting cooler.
STIEBEL ELTRON’s current range is built for this. The reversible circuit needed for cooling is standard on our air-to-water heat pumps, including the HPA-O Plus and Trend series. Getting the rest of the system ready takes a bit more thought.
The hydraulic module, buffer tank and connection lines need vapour diffusion-tight insulation, because they're carrying relatively cold water, and without it condensation forms on the surfaces. At least one room, usually the living room, needs a controller that measures temperature and humidity, calculates the dew point and adjusts the cooling water temperature so condensation doesn't occur there either. That same controller switches the function on and off.
Cooling is simplest to install alongside underfloor, ceiling or wall heating, because the large surface area means the system doesn't need a big temperature difference to have an effect. The control valves need to be cooling-compatible, but that's a modest addition rather than a redesign.
Even without underfloor heating or other surface heating systems, cooling can still be achieved. However, this typically requires specialist radiators, fan coil units, or additional equipment, and may involve structural alterations on renovation projects. For this reason, it is always advisable to highlight these requirements to the customer as early as possible.
When paired with the correct emitters, STIEBEL ELTRON heat pumps can also provide active cooling. Active cooling means the heat pump cools the distribution circuit below the dew point, allowing chilled water to be delivered to fan coil units or purpose-designed cooling radiators.
These emitters can be accurately sized to meet the cooling demand of individual rooms, providing a genuine and effective cooling solution. As with any heating or cooling system, careful specification and design are essential to ensure optimum performance, comfort, and efficiency.
For installers, the opportunity here is retrofit as much as new build. Plenty of households already running one of our heat pumps could add the cooling function without replacing the system. We're working with our partner network so that conversation gets raised with every customer, not just the ones who ask.
That's the shift I'd like to see this summer - cooling as a standard line in the sales conversation.
We've got the technology sitting in customers' homes already. It just needs to be part of what installers offer as a matter of course.