Can I use air conditioning in a rented flat?

Yes — a portable air conditioner needs no installation or landlord permission. It vents through a window using a removable seal kit, leaves no marks, and goes with you when you move.

Do portable air conditioners damage window frames?

No. A cloth window-seal kit attaches with removable adhesive and zips around the exhaust hose, so nothing is drilled or screwed. It peels off cleanly.

Is there an air conditioner that needs no window?

Not a real one. Units sold as "no window" portable ACs are usually evaporative air coolers, which do not remove heat. A genuine portable AC must vent hot air out of a window.

Home › Guides › Cooling a rented flat

Air conditioning for rented flats: cooling without permanent installation

You can’t drill a hole in a wall you don’t own. Here’s how to cool a rented UK flat without risking your deposit.

Most air-conditioning advice assumes you own the place and can fit a wall unit. If you rent, that's off the table — you need cooling that leaves no marks and goes with you when you move. The good news: the best option for renters is also the most effective.

Portable air conditioners — the renter's best bet

A portable AC needs no installation and no landlord permission. It sits on the floor and vents hot air out of a window through a hose, using a window-seal kit that fits without screws or drilling. When you move, you unplug it and take it with you. It's the only no-install option that genuinely lowers the temperature (8–10°C), which is why it's the default answer for flats. The two things to check: you need a window that opens (sash or casement both work with the right kit), and the unit is heavy, so think about storage over winter.

Window-seal kits — the bit renters care about

The exhaust hose has to reach an open window, and you don't want hot air (or insects) pouring back in around it. A cloth/zip window-seal kit solves this without any permanent fixing — it sticks to the window frame with removable adhesive and zips around the hose. This is the part that makes a portable AC truly renter-friendly: nothing is drilled, nothing is damaged, and it peels off cleanly when you leave.

What about the no-hose "portable" units?

Be wary of cheap units advertised as portable air conditioners that have no exhaust hose — those are almost always evaporative air coolers, not real ACs. They don't remove heat and barely work in the humid UK (see our AC vs fan vs cooler guide). If it doesn't vent out of a window, it isn't cooling the room.

If you want something more permanent

Some landlords will allow a fixed split system, especially if you offer to leave it behind or cover reinstatement. It's worth asking — a proper system is quieter and cools better. If that's a route you'd consider, you can register for installer quotes and we'll line up local options. But for most renters, a portable AC plus a good window-seal kit is the pragmatic, deposit-safe answer.

Whichever portable you choose, it'll sell out fast in a heatwave — set a free alert for your model so you can grab one the moment it's back.

Get told the second your model is back

AirconAlert watches AO, Currys, John Lewis, Screwfix, B&Q and more, and emails you the instant a sold-out unit is back in stock. Free, one email when it lands.

Set a free stock alert →

Figures are approximate and change with energy prices, stock and season. This guide contains affiliate links — we may earn a small commission at no cost to you, and it never affects what we recommend.