Where Should an Indoor Air Conditioning Unit Be Positioned?

It's not just about finding an empty wall

It's tempting to think indoor unit position is simply a case of finding a stretch of wall with nothing in the way, but there's more to it than that. Where the unit sits affects how evenly air is distributed around the room, how much noise you notice day to day, how disruptive the pipework route is, and how easy the unit is to service in future. Getting this right at the survey stage avoids compromises later.

High-level wall mounting is the default for good reason

Most indoor units are wall-mounted at high level, typically near the ceiling, because this allows cooled air to spread across the room and settle naturally rather than blowing directly onto anyone below. It also keeps the unit clear of furniture and day-to-day activity in the room, and reduces the risk of it being knocked or obstructed.

This positioning also generally gives the best sensor placement for the unit to read the room's actual temperature, rather than being affected by a nearby heat source like a lamp or a sunny window ledge.

Avoiding direct airflow onto beds, desks and sofas

One of the most common requests we get is to avoid the airflow blowing directly onto a bed or a desk chair, since constant direct airflow can feel uncomfortable even if the room temperature itself is fine. We take this into account by looking at where furniture is, or is planned to be, and choosing a wall position and orientation that distributes air across the room rather than funnelling it at one specific spot.

Most units also have adjustable louvres that direct airflow up, down or side to side, which gives some flexibility even once the unit's fixed position is chosen, but starting with a sensible position makes a bigger difference than relying on louvre adjustment alone.

Wall construction and structural considerations

The unit needs a wall capable of supporting its weight and the vibration of normal operation, so solid walls, or timber-framed walls with adequate noggins, are checked during survey. Stud walls without appropriate backing can sometimes need additional strengthening before an indoor unit can be safely fixed.

The wall also needs to allow a practical route through to the outside for refrigerant pipework and condensate drainage, so position isn't decided purely on airflow grounds; the practicality of getting pipework out to the outdoor unit is considered alongside it.

Distance from the outdoor unit

Because refrigerant pipework runs between the indoor and outdoor units, the indoor unit's position is considered together with where the outdoor unit will sit, rather than in isolation. A position on the wall closest to a viable outdoor unit location generally means a shorter, simpler pipe run, which is more efficient to install and often looks tidier once complete.

Rooms with unusual layouts

Rooms with sloped ceilings, such as loft conversions, or awkward layouts with limited wall space, such as conservatories, need more careful consideration of indoor unit position, sometimes limiting the choice to one or two practical options rather than several. In these cases we prioritise the position that gives the best overall airflow and pipe routing compromise for that specific room.

Servicing access

Indoor units need periodic filter cleaning and servicing, so position also needs to allow safe, practical access for this ongoing maintenance, not just for the initial installation. A unit mounted too close to a ceiling with very limited clearance, or above an obstruction that would need moving every time, isn't ideal even if it seemed like a sensible spot during the initial installation.

Why this is assessed on-site, every time

Because every room's furniture, wall construction, ceiling shape and relationship to the outdoor unit position is different, indoor unit position is always decided during a site visit rather than assumed in advance. This is a routine part of every survey we carry out, and we're happy to talk through the reasoning for your specific room before work begins.