For a UK bedroom, Mitsubishi Electric MSZ-AY is the indoor many surveys start from because of low fan sound. Fujitsu General's residential wall splits are a credible alternative at the same nominal kW, often at a keener equipment price, with a thinner house-call network than Mitsubishi. Neither badge fixes a condenser on the bedroom wall. Survey the room, compare sound data for the exact codes, and use an F-gas installer.
What you hear at two in the morning
You notice the indoor at the lowest fan speed at two in the morning, and you notice the outdoor unit through an open window or a party wall. AY is specified so often for sleep because its quiet fan settings are the ones bedroom buyers ask to see.
A shut bedroom is not a loft with roof windows
Start with the survey. A small shut bedroom and a loft room with roof windows are different loads even when both are called bedrooms. Do not copy a living-room kW onto a box room, or the reverse. A rarely used spare room may be fine on HR or a Fujitsu value wall at the same kW. The survey should say which.
Same cooling duty, then the sound sheet
Match nominal cooling kW and, if you will heat on cold nights, heating output at a stated outdoor temperature. Energy Saving Trust describes air-to-air heat pumps in that heating role. Ask each firm for the model code, not the logo. Do not borrow a SEER from another size or from a commercial cassette sheet.
- Compare indoor sound at the lowest fan speed, same kW.
- AY is the common UK bedroom starting point.
- Fujitsu often prices as the value Japanese wall split.
Who attends this postcode in January
Mitsubishi's domestic installer base is deeper. Fujitsu accreditation and parts still exist across the UK, especially where commercial fitters also do houses. The practical test is who will attend this postcode in January, and whether the warranty years are in writing.
A cheaper Fujitsu quote that moves the condenser
As a 2026 illustration, both sit in the usual single-split installed band, high hundreds to a few thousand pounds including VAT on a straightforward house. A cheaper Fujitsu quote that moves the condenser onto a fence under the neighbour's window is not a saving.
Drains, isolators and a sleeping room
Drain, isolator and anti-vibration are bedroom essentials on either brand. A missing pump on an internal wall will stain new plaster whichever fascia you liked. Tell the installer it is a sleeping room, which wall the headboard uses, and where the outdoor unit could go that is not under a bedroom window. GOV.UK F-gas rules still apply to the refrigerant circuit, however low the fan sound is. Night use should be on the enquiry so nobody prices a shop unit.
Frequently asked questions
Is Fujitsu quiet enough for a bedroom?
It can be, at the right size and fan setting. Do not assume it matches AY because both are Japanese wall splits. Compare the published sound figures for the exact models, then judge the outdoor position.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.