Bedrooms, especially upstairs and in loft conversions, can hold onto the day’s heat well into the night. Opening the window helps on some nights and lets in noise and insects on others.
A bedroom is also the room where air conditioning has to be at its quietest and gentlest. This guide covers how hot rooms affect people, why noise is the first thing to check, where the unit should go, sizing, sleep functions and the outdoor unit.
Hot bedrooms and health
The NHS heatwave advice suggests keeping windows, curtains and blinds closed during the day and opening them at night when it’s cooler outside, and checking room temperatures, especially where at-risk people sleep. Babies and young children, older people and people with long-term conditions are among those most affected by heat. For them, a cool bedroom can matter a great deal. See our guides for babies and nurseries and elderly relatives.
Noise comes first
For a bedroom, the most important figure on the data sheet is the sound pressure level at the lowest fan speed. Quality wall units are very quiet on their quiet or night setting, but figures vary between models and ranges, so compare them on the manufacturer’s own data sheets. Our noise guide explains how to read them.
Installation affects noise too. A condensate pump in the wrong place can hum above the bed; we put pumps where they won’t be heard or avoid them with a gravity drain.
Where the unit should go
The unit shouldn’t blow on the bed. The best spot is usually on a wall where the air travels across the ceiling and settles gently, often above the door or on the wall at the foot of the bed. We avoid placing it directly over the headboard. We also plan the pipe route to the outdoor unit and the drain, ideally on an outside wall to keep pipework short.
Sleep modes and timers
Most units have a sleep or night mode that gradually raises the set temperature and drops the fan to its lowest speed. Timers let you cool the room before bed and switch off in the early hours. Many people find a modest setting with sleep mode more comfortable than a low setting all night. Screen-off or light-dimming options are worth asking about if you’re sensitive to the display.
Want it done properly? AirCon Doctor installs, repairs and services air conditioning and heat pumps across London and the South East, from our base in East Grinstead. We’re an F-Gas certified company and NICEIC approved. Get a fixed-price quote.
Sizing a bedroom
Bedrooms are usually small enough for the smallest units in a range, but a loft room under a hot roof or a room with large windows may need more. Oversizing a bedroom unit is a common mistake: it cools in bursts, switches on and off, and handles humidity less well. We work out the load at the survey. See choosing the right size.
The outdoor unit
Keep it away from your bedroom window and your neighbours’. On a wall bracket, anti-vibration mounts reduce noise carried into the house. Avoid corners and narrow passages that reflect sound. Many models have a night mode for the outdoor unit as well. See where to put the outdoor unit.
More than one bedroom?
If you want to cool two or more bedrooms, a multi-split lets them share one outdoor unit, with each room controlled separately. Single splits for each room cost more in outdoor units but keep each room independent.
Prices
A single room split system costs £1,200–£2,200 + VAT, a 2-room multi-split £2,800–£4,500 + VAT and a 3–5 room multi-split £4,500–£8,500 + VAT, including supply, installation, commissioning and F-Gas documentation. Most units heat as well, which is useful in cold bedrooms in winter. We confirm the VAT on your quote.
Quick answers
Is bedroom air conditioning too noisy to sleep with?
A good wall unit on its quietest setting is very quiet. Check the lowest fan speed figure on the data sheet, and make sure the outdoor unit is away from the window.
Where should the unit go in a bedroom?
Usually where air travels across the ceiling, not onto the bed: often above the door or on the wall at the foot of the bed.
What is sleep mode?
A setting that gradually adjusts the temperature and drops the fan to its lowest speed through the night.
Can one outdoor unit cool several bedrooms?
Yes, with a multi-split system. Each bedroom has its own indoor unit and control.
Related services
- Domestic air conditioning
- Wall-mounted air conditioning
- Multi-split air conditioning
- Air conditioning installation
More advice
- Air Conditioning Noise: How Quiet Are Modern Systems?
- Air Conditioning in a Baby’s Nursery
- Air Conditioning for Loft Conversions
- Keeping Elderly Relatives Cool in a Heatwave
- All advice
This guide is general information, checked against the sources linked on 30 October 2026. It isn’t legal, tax or financial advice. Rules, grants and product ranges change, so check the current position before you rely on it.