Prioritise sound and airflow
Manufacturer sound data helps compare indoor units, but position matters too. Equipment should not create an uncomfortable draught across the bed, and the route for pipework and drainage should be planned before the final position is agreed.
A correctly sized unit can maintain the room temperature without unnecessary output. Bedrooms often need much less capacity than sunny living spaces, so choosing by the largest available model can be counterproductive.
Consider how the room is used
Night-time cooling is different from quickly cooling an empty room before bed. Sleep modes, fan control, timers and app controls may be useful, but the household should understand what each feature actually does. Blackout blinds and reducing daytime heat gain can also improve results.
If the room is used for daytime work, heating and cooling requirements may differ. Computers, roof construction and afternoon sunlight should be included in the survey rather than treating the room only as a sleeping space.
Plan the outside as carefully as the inside
The outdoor unit needs a suitable position with access for airflow and future servicing. Sound, neighbours, leasehold rules and the appearance of the building may influence the location. Condensate must also have a reliable route.
For several bedrooms, compare separate systems with a multi-room arrangement. The right choice depends on simultaneous use, available capacity, routes and how much independent control the household wants.