As summers become hotter, air conditioner sales are booming. If you’re looking to invest, here’s what to consider

When a heatwave struck the UK this week, Jon Connorton, a software developer, began monitoring temperatures inside his east Hampshire terrace house. With some rooms reaching close to 40C, it was time to deploy the air conditioner. “We just wheel it out in emergencies,” he said. “We were having trouble sleeping.”

Connorton and his wife have a portable air conditioner. These plug-in devices cool interior air by removing heat from it and blowing that heat outside, typically via a large hose slung from a window or door.