The short answer
Point the airflow level or slightly up when cooling, because cool air sinks, and down when heating, because warm air rises. Avoid aiming it straight at people, and use swing if the air isn't reaching the whole room.
On this page
A wall-mounted unit can only make a room comfortable if its air reaches the parts of the room you use. The flap across the front and the vanes behind it steer that air, and the fan speed decides how far it travels. What these controls are called, and how many directions they cover, varies between models, so check your manual.
The flap and the vanes
Most wall-mounted units have a wide flap along the bottom edge, sometimes two, that tilts up and down. It's motorised and set from the remote. When the unit switches off, the flap usually closes.
Behind the flap are narrower vanes that steer the air left and right. On some models these are motorised too; on others you move them by hand. Check the manual before doing so, as many say to switch the unit off first. Never push the motorised flap by hand, because that can damage the mechanism that drives it.
Many units also go to a default flap position for each mode, or remember the last one you chose.
Which way to point it
| Mode | Flap position | Why |
|---|---|---|
| Cool | Level or slightly up | Cool air sinks, so it spreads and falls |
| Heat | Down | Warm air rises, so aim it at the floor |
| Dry | Level or slightly up | Keeps cool air off people |
| Fan | Wherever feels best | There's no heating or cooling to spread |
When cooling, aiming the air across the ceiling lets it spread out and settle through the room. Pointed straight down, it lands on whoever is underneath as a cold draught. In humid weather, a flap left pointing down for long periods in cool or dry mode can also collect condensation, which then drips; see water dripping from the indoor unit.
When heating, warm air tends to stay up near the ceiling. Pointing the flap down pushes it towards the floor and the places you sit, so the room warms more evenly.
Wherever you point it, avoid aiming it straight at a bed, sofa or desk. Even air at a pleasant temperature can feel uncomfortable when it blows on you for hours.
Swing and sensors
Swing moves the flap continuously up and down, and on some models the vanes from side to side, to spread the air around. It's useful in large or awkwardly shaped rooms, and when the air isn't reaching one end. Some people find the constantly changing airflow distracting, and a fixed position often suits a bedroom better.
Some models have a sensor that detects where people are and steers air towards or away from them, or a setting designed to stop the air blowing directly on anyone. Names vary, so look for them in your manual.
Fan speed
Fan speed settings usually include auto, several fixed speeds and a quiet setting, and some models add a powerful setting.
- Higher speeds move more air, so the room responds more quickly and the air reaches further, but the unit is louder.
- Lower speeds are quieter. When cooling, they tend to take more moisture out of the air, because it spends longer passing the cold coil, but the temperature falls more slowly.
- Auto speeds the fan up when the room is far from your setting and slows it down as it gets close, which suits most situations.
Keeping the airflow clear
A wall-mounted unit usually draws air in through the top and blows it out at the bottom. Keep the space above it clear, and don't put shelves right above it or tall furniture in front of it. Curtains, a pelmet or a tall cupboard can get in the way too.
If the air hits something nearby and bounces straight back, the unit can take in its own cooled or heated air and decide the room has reached your setting before it has. Dusty filters also restrict the airflow, so keep them clean; how to clean the filters shows how.
If you've tried every setting and the air still can't reach part of the room, the unit may be in the wrong place for how you use the room. Where to put the indoor unit covers what makes a good position. In the meantime, a pedestal fan can help carry air to a spot the unit doesn't reach, such as a desk around a corner.
Related guides
- Where to put the indoor unitA wall-mounted indoor unit usually goes high on a wall with clear space around it, where its airflow can reach the whole room without blowing straight at people. The best spot also depends on the route for the pipes and where the condensate can drain.
- The modes explained: cool, heat, dry, fan and autoCool lowers the temperature and takes out some moisture, heat warms the room, dry mainly removes moisture with gentle cooling, fan only moves air, and auto chooses between cooling and heating for you.
- Doors, windows and blindsKeep doors and windows shut while the system runs, and close blinds or curtains on sunny windows in warm weather. In winter, let the sun in by day and close curtains at dusk.