For a typical UK double bedroom (12–16m²) you want a 2.0–2.5kW inverter split with an indoor noise rating of 19–22 dB(A). Installed, expect £1,800–£2,500. The wrong size or a non-inverter unit is what makes bedroom AC noisy and expensive to run.
Sizing the right kW for your room
Rule of thumb: 0.15kW per m² for a well-insulated room, 0.2kW for poorly insulated or south-facing. A 14m² double bedroom needs roughly 2.1kW. Oversizing causes short-cycling and humidity issues; undersizing means the unit never reaches setpoint.
How quiet is quiet enough?
Bedroom whisper-mode targets are 19–22 dB(A); quieter than a library. Daikin Perfera (19 dB), Mitsubishi MSZ-LN (19 dB) and Panasonic Etherea (20 dB) are the benchmarks. Anything over 26 dB on low fan is too loud for sensitive sleepers.
Best bedroom-specific features
Look for night mode (auto temperature ramp + fan reduction), wide-angle Coanda louvres that avoid blowing directly on the bed, and Wi-Fi schedules so the room is pre-cooled before you go up.
Installed price for a bedroom
£1,800–£2,500 for a single 2.5kW split fitted with a 3m pipe run. Add £200–£400 if the outdoor unit needs to be mounted at high level or routed through an upper-floor wall cavity.
See what installers in your area would actually charge.
Get matched quotesFrequently asked questions
Will bedroom AC wake me up?+
Not if the indoor unit is rated 22 dB(A) or below and is correctly sized. Avoid portable AC; they're typically 50+ dB and unusable in bedrooms.
Can I install AC in just one bedroom?+
Yes. A single split is the most cost-effective option for one room and avoids the overhead of a multi-split system.
Does bedroom AC dry out the air?+
Slightly; it dehumidifies as it cools. Most users find it more comfortable, but you can run in dry mode if humidity drops below 40%.