Split air conditioner for a bedroom
Updated: October 2026
A split air conditioner for a bedroom has to solve two noise problems, not one. The indoor section must stay tolerable at the setting you use overnight, and the outdoor section must sit where it does not disturb you or a neighbour. Figures in our [split air conditioner comparison](/hub/cooling/split-air-conditioner) are not a quietness league table: some name silent mode, others omit the measurement position, and one field says 1 dB. Read those conditions before you decide a unit is fit for sleep. Listings were checked on amazon.co.uk on 15 October 2026. We did not run a lab test. A purchase through our links may earn a commission at no extra cost to you.
A split air conditioner for a bedroom has to solve two noise problems, not one.
A split air conditioner for a bedroom has to solve two noise problems, not one. The indoor section must stay tolerable at the setting you use overnight, and the outdoor section must sit where it does not disturb you or a neighbour. Figures in our split air conditioner comparison are not a quietness league table: some name silent mode, others omit the measurement position, and one field says 1 dB. Read those conditions before you decide a unit is fit for sleep. Listings were checked on amazon.co.uk on 15 October 2026. We did not run a lab test. A purchase through our links may earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Noise claim | Stated room | Outdoor siting | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Generic Generic 9,000 BTU wall split | 22 dB, named as indoor unit | Up to 22 m², bedroom | Wall kit, installer needed | 7.3 | about £599.99 | View offer |
 Midea Midea PortaSplit 12,000 BTU | 39 dB(A) silent mode at 1 m | n/a | About 2 m, no drilled hole | 9.2 | about £1,099.99 | View offer | |
| Alternative |  Generic Generic 5,000 BTU portable split | Bullets: 40 dB indoor | Bedroom, no square metres | 2 m tube, no drilling | 5.8 | about £403.99 | View offer |
On this page
The number on the listing is not the night
A decibel value is useful only when it names what was measured. Indoor or outdoor section, sound power or sound pressure, distance, fan speed and mode can all change the result. A listing that says 22 dB without those conditions cannot fairly be ranked against 39 dB(A) at 1 metre in silent mode.
Regulation (EU) No 206/2012 caps sound power at 60 dB(A) indoors and 65 dB(A) outdoors for units up to 6 kW. Those caps are not overnight comfort targets. Fields here include 22, 27, 39, 48 and 54 dB, plus an unusable 1 dB entry, and several do not say which section was measured. If the conditions are missing, treat quietness as unknown. Other conflicts are in the split air conditioner buying guide.
Silent mode, named properly
The Midea PortaSplit has the most specific claim in this set. Its UK page states 39 dB(A) in silent mode at 1 metre. That names the mode and the distance. It does not promise 39 dB(A) during full-output cooling, and one reviewer says full cooling is louder. On a very hot night the unit may spend longer away from its quietest setting. Closing blinds and cooling before bedtime may cut overnight work. Neither step makes a product inaudible.
Do not import a 19 dB(A) figure from a Daikin, Mitsubishi or Panasonic table. Those models are not these listings, and the generic 22 dB field is not a winner without the same documentation. The outdoor section still has to fit within about 2 m, and the product weighs 45.5 kg. Those limits are on the best split air conditioner page.
The outdoor unit and the neighbour
Moving the condenser outside takes machinery out of the room. It does not remove sound from the property. Fujitsu’s UK guidance is a sensible principle: put the outdoor unit somewhere secure, dry and ventilated, as far as practicable from your bedrooms and your neighbours. That is not a fixed setback. The installation manual still sets clearances.
Do not default to the nearest wall, especially beneath a neighbour’s bedroom window. The unit needs support, drainage and access. Councils can investigate a statutory nuisance: unreasonable and substantial interference with a home, or noise likely to injure health. These sources give no single domestic decibel cap. If the only position faces a neighbour, stop and seek advice before you buy. Planning is separate in the split air conditioner installation guide.
Skip the biggest title
A 24,000 BTU headline does not make a better bedroom unit. Capacity should match the heat load, and sleep depends on part-load behaviour, sound, airflow and position. The two 24,000 BTU wall listings cost about £799.95 and £849.99. One is rated 1.0 from a single customer. The other has no customer rating.
At 45.5 kg the Midea is awkward between floors, and the connection constrains the bed and the window. The 5,000 BTU portable splits are lighter and cooling only, and their listings do not give dependable night-noise evidence. For a campervan, weight and hose reach matter. This page does not establish a safe vehicle installation. Buy on verified noise conditions and a viable outdoor position, not on the biggest title.
Common questions
Will a split air conditioner keep me awake?
It depends on indoor sound at the setting you actually use, on changes in output, on airflow and on your sensitivity. A silent-mode claim does not describe full cooling. Ask for identified measurement conditions, and think about the outdoor unit if it will sit near your bedroom or a neighbour’s. An unlabelled marketplace decibel cell cannot answer the question on its own.
What does silent mode measure?
There is no universal answer in the product name. For the Midea PortaSplit, 39 dB(A) is specified in silent mode at 1 metre. That does not describe full cooling, and a reviewer says full cooling is louder. Other listings may use different conditions, or none at all. Treat an unnamed figure as unknown rather than as a night-time result.
Can I compare the Amazon decibel numbers directly?
No. The fields may refer to different sections, modes, distances or measurement types, and some are plainly malformed, including a 1 dB entry. Compare only figures that identify indoor or outdoor sound, sound power or sound pressure, the operating mode and the distance. Otherwise record the noise evidence as unavailable.
Is there a UK domestic decibel limit for outdoor units?
The sources used here do not give one universal domestic decibel cap. Councils can investigate noise as a statutory nuisance when it unreasonably and substantially interferes with a home, or when it is likely to injure health. Time, duration and circumstances matter. Planning is a separate question, so ask the relevant authority when the siting is doubtful.
Is a 24,000 BTU split right for a bedroom?
Not merely because it has the biggest title. A bedroom needs capacity matched to its heat load. An oversized or poorly documented product can add cost and make siting harder. In this set, one 24,000 BTU listing is 1.0 from a single customer and the other has no customer rating. Neither has the noise and review evidence for a bedroom recommendation.
Where should the outdoor unit go?
Follow that model’s installation manual, and use a secure, dry, ventilated position as far as practicable from bedrooms and neighbours. Do not invent a universal boundary distance. The unit also needs support, drainage and access for maintenance. If the only position faces a neighbour’s window, seek planning and acoustic advice before you buy.
Related pages
Sources
Public UK sources and the manufacturer page below. amazon.co.uk listings checked on 15 October 2026.
- GOV.UK: qualifications required to work on equipment containing F gas (retrieved 15 October 2026)
- GOV.UK: selling F gas or equipment (retrieved 15 October 2026)
- Planning Portal: planning permission to add air conditioning (retrieved 15 October 2026)
- legislation.gov.uk: England GPDO Class G (retrieved 15 October 2026)
- GOV.UK: building work, replacements and repairs to your home (retrieved 15 October 2026)
- legislation.gov.uk: Regulation (EU) No 206/2012 (retrieved 15 October 2026)
- legislation.gov.uk: Regulation (EU) No 626/2011 Annex III (retrieved 15 October 2026)
- GOV.UK: noise nuisances and how councils deal with complaints (retrieved 15 October 2026)
- Midea UK: PortaSplit air conditioner (retrieved 15 October 2026)