Published on
Before you install a new AC, three decisions shape your comfort and power bill for years: the right capacity for the room, and where the indoor and outdoor units sit. As a rule of thumb, each square meter needs about 600 to 700 BTU with standard ceilings, and unit placement affects air distribution and energy use as much as the machine's power. This guide covers what to decide before installation day: capacity, placement, and the mistakes whose bills arrive months later.
Choosing the Right Capacity (BTU)
The working rule used in Saudi Arabia: about 600 to 700 BTU per square meter of floor area, assuming a standard ceiling (around 2.8 to 3 meters) and reasonable insulation. Multiply the room's area by this figure for an approximate size, then weigh the notes below:
- A 12 m² room: about 12,000 BTU, a 1-ton unit.
- An 18 m² room: about 18,000 BTU, a 1.5-ton unit.
- A 24 m² room: about 24,000 BTU, a 2-ton unit.
These numbers are a starting point, not a final decision. Top-floor rooms with sun-baked roofs and large west-facing windows need more; good insulation and double glazing reduce the load. Oversizing is no luxury either: an oversized AC cycles off before removing humidity, leaving you cold and clammy, while an undersized one runs nonstop without reaching the set temperature. The technician confirms the final size during a site visit, since he sees the ceiling height, windows, insulation, and occupancy.
Where to Place the Indoor Unit
The indoor unit's position decides how cool air spreads, and machine power cannot fix a bad position later. Before the bracket goes up, check these points:
- Balanced air distribution: push air toward the seating and living area, and avoid mounting the unit directly above the bed; direct airflow on sleepers causes headaches and forces you to switch the unit off at night.
- Away from heat sources: keep clear of strong lamps, televisions, and frequently opened doors, or the sensor reads higher than the real room temperature and over-runs the compressor.
- Clear of curtains: a long curtain blocks air circulation and confuses the sensor; leave enough distance or shorten the curtain.
- Proper height: mount 2.2 to 2.5 meters from the floor, with at least 15 cm of clearance above and beside the unit.
