Put the indoor unit in the bedroom, not in the en suite. The decision is that a closed bathroom door stops the bedroom unit at the threshold, so the en suite will not hold a setpoint unless you leave that door open or fit a second indoor unit. The wet room is a poor place for the casing: moisture, towels and a short wall. Survey the bedroom wall and the drain. An F-gas certified company fits the refrigerant circuit. Do not confuse the extract fan with cooling.
The bedroom wall, not the shower wall
If you sleep with the en suite door shut, the bathroom is not cooled by the bedroom head. Most people should accept that. You want the bedroom comfortable, and the bathroom is a short visit. Leaving the door ajar takes the edge off the en suite and gives the bedroom unit a little extra volume. Say which habit you actually have, because it changes the duty slightly and it changes whether anyone should price a second head. Say the job is the bedroom, with an en suite next to it. A photo of the bedroom wall, the en suite door and the outdoor elevation, and whether that door stays shut at night, is the survey note. Ask for one bedroom unit, model codes, pipe length and condensate route.
Steam, the extract fan and the bedroom setpoint
Steam, deodorant and a towel on the casing are how filters choke. Electrics and a condensate pump in the splash zone need a competent design, and many en suites have no safe wall left once the shower and the door are drawn. The bedroom side of the same wall is usually the right bracket, drilling out to a lawful outdoor spot. The bathroom extract continues to do the moisture job the split is not there to do. The extract fan stays. The split does not replace it. Size the bedroom with the door positions you agreed. Keep the throw off the pillows. In England the outdoor unit still has to meet Planning Portal conditions.
A drain that is not an improvised shower tie-in
Do not dump air conditioning condensate into the shower tray or the basin waste on a whim. It is a separate pipe to a proper drain or a pumped line, so a blockage does not back up into the indoor unit. As a 2026 illustration, the bedroom pair is often in the low thousands including VAT. A reverse-cycle bedroom unit also covers cool nights, which is the half of the year the en suite never asked for. Ask them not to price an indoor unit inside the en suite unless you have said the door must stay shut and the wall in there is actually usable.
Frequently asked questions
Will the bedroom unit cool the en suite?
Only while the door is open, and only partly. With the door shut, survey the bedroom alone and leave the bathroom to its extract fan.
Can the indoor unit go on the bathroom wall?
Avoid it. Moisture, towels and splash are a bad host. Use the bedroom face of the wall unless a survey shows no other place and a safe mounting. Do not mount the casing over the shower.
Should condensate run into the bathroom waste?
Not as an improvised tie-in to a shower tray. Give it a designed drain or a pump route so a blockage cannot fill the indoor unit.
When is a second indoor unit in the en suite worth pricing?
Rarely. It only makes sense if the door must stay shut and someone is using that room as a dressing room for long stretches. Even then the pipe length and a lawful outdoor spot have to work. A new indoor unit on the bedroom outdoor unit is usually not a mix-and-match unless the combination is listed. It is easy to spend the extra on a room you occupy for ten minutes.
What if the only outside wall is the one the bed sits against?
An internal wall with a surveyed pump route may be quieter at night than a condenser outside the headboard. Keep the throw off the pillows either way.
Core buying guides
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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.