Portable aircon for renters and flats

Renting does not have to mean sweltering. A portable air conditioner is the one form of real air conditioning that needs no installation and no landlord sign-off to own - as long as you solve the window problem the right way. Here is the honest version.

Why portables suit renting

A portable air conditioner is a plug-in appliance. It runs off a normal 13A socket, sits on the floor like a dehumidifier, and the only thing that leaves the room is a flexible exhaust hose through an opening window. There is nothing to install, nothing to fix to the building, and nothing that needs your landlord's permission - the unit itself is yours, the same as a washing machine or a fan.

Compare the alternative: a fixed split system needs a wall-mounted indoor unit, an external condenser, a drilled pipe run and a qualified engineer - an alteration to the property that few landlords will approve and fewer will pay for. A portable moves flat to flat with you, which also means the money you spend on it is never lost to a tenancy you leave.

The window problem, honestly

There is no way around this part: a refrigerant air conditioner works by moving heat, and the heat has to go outside. The exhaust hose needs an opening. Run a portable with the hose venting into the same room and it will heat the room more than it cools it. So before buying, look at your windows and pick your venting route:

Everything above is removable and tool-free. The one rule that protects your deposit: never cut a pane, drill a wall or screw into a frame without your landlord's written permission. A through-wall vent is an alteration to the property, even a neat one.

Window seal kits: your deposit's best friend

A seal kit is a cheap piece of coated fabric or foam that closes the gap around the hose. It matters more than it looks: an unsealed open window lets warm outside air pour straight back in, undoing much of the cooling - especially with single-hose units, which slightly depressurise the room as they exhaust (our size guide explains the single vs dual hose difference). Kits fit with adhesive velcro, come off without marking paint or uPVC, and pack flat to move with you. Many units include one; if not, budget for it.

Storage between summers

A typical portable has roughly the footprint of a bedside table, so the wardrobe floor, an under-stairs cupboard or the corner of a box room will take it. Before it goes away: drain any leftover condensate, run the unit on fan-only for a while so the coil and tank dry out, coil the hose, and throw a cover or bin bag over it against dust. Store it upright - that protects the compressor - and keep the box if you move house often.

Running costs and fairness in shared houses

A portable costs tens of pence per hour to run flat out at 2026 electricity prices, and less once the thermostat starts cycling - our running costs guide has worked figures per unit size. In a shared house the fair approach is a smart plug or plug-in energy monitor on the unit's socket: it logs exactly what the aircon used, so the owner can settle up at the house's unit rate instead of arguing from guesswork. If your rent includes bills, check the tenancy for fair-use or high-consumption clauses before running it all day, and if the unit will live in a bedroom, our quiet aircon for bedrooms guide covers the noise side.

Buying one: the sold-out problem

Here is the catch renters hit hardest: nobody thinks about air conditioning until the first properly hot week, and that is exactly when every retailer sells out at once. Restocks then arrive in small, unpredictable batches rather than one big drop - we wrote up what we see about restock timing as a live tracker.

Two things tilt the odds your way. First, watch a live aircon stock tracker instead of refreshing retailer pages: AirconWatch checks 17 UK retailers every 2 to 5 minutes. Second, remember click & collect - Argos and Screwfix store stock often survives after delivery slots vanish, and collecting today beats a delivery date next week when you are sleeping in a hot flat. Currys and B&Q are also worth watching for delivery restocks.

FAQ

Do I need my landlord's permission for a portable air conditioner?

Not for the unit itself. A portable air conditioner is a plug-in appliance you own, like a washing machine or a fan, so buying and using one is normally your call. Permission matters the moment you alter the property: drilling a vent hole, cutting a window pane or fixing a panel permanently all need your landlord's written consent. Stick to removable window seal kits and there is usually nothing to ask.

How do you vent a portable air conditioner in a rented flat?

Through an opening window, using a removable seal. Casement and tilt-and-turn windows take a fabric zip kit that fixes to the frame with adhesive velcro; sliding sash windows work with a foam or rigid board the sash closes down onto. All of these fit without tools or damage and come with you when you move. Never cut glass or drill through a wall in a rental without written permission.

Where do you store a portable air conditioner in winter?

Somewhere dry and upright: a cupboard, under-stairs space or wardrobe floor usually does it, as the footprint is roughly that of a bedside table. Before storing, drain any leftover condensate, run the unit on fan-only for a while so the inside dries out, then coil the hose and cover the unit against dust. Keeping it upright protects the compressor.