As heat pumps become more common in UK homes, AND as our Summers are getting hotter, one question often comes up: can they also cool my house in the summer?
Technically, yes — most modern air-to-water and ground-source heat pumps can reverse their cycle and provide cooling. However, at VitoEnergy we’ve found that while it’s possible, it’s rarely practical or cost-effective, especially in retrofit properties. Here’s why.
The Theory Behind Cooling with Heat Pumps
A heat pump works by transferring heat from one place to another. In winter, it extracts warmth from the air or ground and delivers it into your home’s heating system. In summer, that process can be reversed — taking heat out of the home and rejecting it outdoors.
In principle, that sounds ideal: a single system that keeps you warm in winter and cool in summer. But in practice, it’s not quite that simple.
The Practical Challenges
When using an air-to-water or ground-to-water heat pump for cooling, the water circulating through your pipes becomes colder than the surrounding air. That immediately raises an issue: condensation. Any exposed pipework or manifolds must be carefully insulated to prevent moisture forming and dripping — something that’s often impractical or costly in existing homes.
Even if you solve the condensation problem, the emitters (radiators, underfloor heating loops, etc.) are not designed for cooling. Standard underfloor heating can only offer a few degrees of temperature drop before the floor feels uncomfortably cold or slippery, and radiators are simply ineffective for chilled water.
To achieve meaningful cooling performance, you’d need specialist emitters such as Jaga convectors or fan-assisted low-temperature units — and those come with significant additional cost. By the time you’ve upgraded emitters, insulated every pipe, and made sure the system can safely handle condensate drainage, the gains are minimal compared with the effort and expense involved.
When It Can Make Sense
There are some exceptions. For clients who are completely renovating or building a new home — replacing all emitters, pipework, and insulation anyway — it can make sense to integrate a cooling function from the outset. In these cases, we can design the system with suitable emitters, proper condensate management, and high-quality insulation to make it work efficiently and safely.
However, that level of specification comes with a premium price tag. It’s a niche option suited to larger budgets and full refurbishments, rather than something that’s viable for the average retrofit. For most properties, it’s simply not a mass-market solution.
What Works Better
If your main goal is to stay comfortable during the warmer months, a much more practical option is a separate air-to-air heat pump system — in other words, modern air conditioning. We usually recommend air-con in the difficult rooms, the bedrooms and maybe a living space if there is a lot of solar gain.
Air-to-air systems are designed specifically for cooling (and can also provide heating if needed). They deliver fast, efficient temperature control and excellent dehumidification, without affecting your main heating setup. A well-placed wall or ceiling unit can cool a large area for surprisingly little energy.
Meanwhile, your air-to-water or ground-to-water heat pump can continue doing what it does best: providing low-carbon heating and hot water through the colder months, without compromise.
The VitoEnergy View
At VitoEnergy, we’re all for innovation, but we also value practicality and long-term reliability. In most UK homes — particularly retrofit projects — using a water-based heat pump system for cooling simply doesn’t deliver enough benefit to justify the complexity.
Our advice? Use your air-to-water or ground-source heat pump for efficient heating, and pair it with a compact air-to-air system if you want real comfort through the summer. It’s usually cheaper, simpler, and far more effective.
Heat pumps can do many things brilliantly — but in the case of cooling, sometimes two systems really are better than one.
