Independent UK guides on what AC actually costs, which type fits your home, and free quotes from F-Gas certified installers. No pushy sales, no upfront fees.
Quick estimate for an average UK room. Sun exposure, ceiling height and occupancy change this.
Get my exact size →Undersized units run flat out and never cool the room. Oversized ones short-cycle and waste money. Our calculator sizes it properly in 30 seconds.
Cost guideReal installed prices for every system type — and try the installation cost calculator for a fitted price range for your rooms.
Buying guidePortables cost £300 up front; splits cost £2,000+ but a third as much to run and double as heaters in winter. Which one actually suits you?
Room sizes, property type, and what you want to cool. Two minutes, no phone number games.
Split-system installation legally requires an F-Gas certified engineer in the UK. We only pass your details to certified local firms.
Installers contact you directly with fixed quotes. No obligation, and your details are never sold beyond the firms quoting.
Most disappointing air conditioning purchases in the UK trace back to sizing, not quality. An undersized unit runs flat out on a hot day and never reaches temperature — while an oversized one short-cycles, chilling the air before it's properly dehumidified and leaving the room cold but clammy. The fix is knowing your room's actual cooling load before you look at a single product: floor area, sun exposure, ceiling height and occupancy set the kW/BTU figure, and everything else follows from it. That's why every comparison on this site starts with the sizing calculator rather than a product list.
We're an independent comparison site, not a retailer or installer. First, work out what your room needs with the size calculator, then compare the two routes: a portable unit you can buy today, or a wall-mounted split system fitted by an F-Gas certified engineer. Our cost guide and installation cost calculator benchmark what a fair fitted price looks like for your home — so when you request free quotes, you can judge them with confidence. We earn a commission from some retailer links and quote referrals; it never changes our advice or your price.
Ten-minute fixes vs F-Gas engineer jobs — and the one habit that prevents nearly everything.
HealthSore throats, "AC colds" and Legionella worries — which are real, which are myths.
Data hubHeat records, overheating homes and the cooling divide — every key number, fully sourced.
Running costsPence-per-hour at the current price cap, plus a free running-cost calculator.
Usually not for houses since the May 2025 rule change — a reversible heat/cool unit typically falls under permitted development, though conditions apply. Flats, listed buildings and conservation areas are different — see our planning permission guide and flats guide.
No. Split systems contain F-Gas refrigerants and UK law requires an F-Gas certified engineer to install them. DIY installation is unsafe, illegal to gas up yourself, and voids the manufacturer warranty. Portable units need no installation at all.
A modern inverter split system typically costs around 10–50p per hour depending on size and your tariff. Portables are less efficient — usually 25–35p per hour for an 8,000 BTU unit. Full breakdown and a running-cost calculator in our running costs guide.
Most modern split systems are reversible air-to-air heat pumps, so yes — and heating a single room this way is often cheaper than plug-in electric heaters. It's one of the strongest arguments for a fixed system over a portable.