Portable air conditioners

A portable air conditioner is a self-contained unit on castors that cools the room and pumps waste heat outside through a flexible hose fitted to a window. There is no fixed installation, no outdoor unit and no F-Gas engineer, so you can buy one today, wheel it in and plug it into a normal socket. That convenience is the whole appeal, and for renters or a quick fix in a heatwave it is hard to beat.

The trade-off is honesty most listings skip. A portable is noisier, thirstier and less effective than a wall-mounted split, and it must vent hot air outside. A "portable air conditioner without a hose" that still chills a room does not exist: those products are evaporative air coolers, which add humidity and only cool the air near you by a few degrees. If you want a genuinely cold room with no install, a portable is the right tool. If you want quiet, efficient, whole-room cooling for years, look at a wall-mounted split.

Size it to the room. Portables are rated in BTU. As a first cut allow about 1kW (roughly 3,500 BTU) per 10m²: 7,000 BTU for a small bedroom or study, 9,000 BTU for a double bedroom or home office, and 12,000 to 14,000 BTU for a living room or open-plan space. Because single-hose units draw warm air back into the room as they work, err towards more BTU or a smaller room rather than undersizing.

Single-hose or dual-hose. Most units are single-hose: cheap and simple, but they create slight negative pressure that pulls warm air in through gaps, so they work harder. Dual-hose models feed separate outside air to the condenser and cool faster and more efficiently. Either way, fit the supplied window seal kit and check it is included.

Noise, water and refrigerant. Expect 50 to 65dB(A); the quietest sit near 53dB(A) on low. Many modern units are self-evaporating and expel most condensate through the exhaust, but in humid conditions you may need to drain a tank. Newer portables mostly use R290 (propane), a low global warming refrigerant sealed inside the unit, so there is nothing for you to service.

Prices and running costs correct as of July 2026. The energy price cap changes quarterly, so check current rates before budgeting.