Almost every week someone comes to the counter and asks for “a 1.5 ton AC”. When we ask how big the room is, the answer is often a guess. That guess decides whether the room gets properly cold in May, and how big the electricity bill is in August.
So before you look at brands or prices, measure the room.
A rough size guide
Multiply the length and width of the room in feet. That is your floor area in square feet. Then use this as a starting point:
| Room size | Suggested AC |
|---|---|
| Up to about 120 sq ft | 1 ton |
| About 120 to 180 sq ft | 1.5 ton |
| About 180 to 250 sq ft | 2 ton |
A typical Dhaka master bedroom of 12 x 14 ft (168 sq ft) lands in the 1.5 ton range. A small 10 x 11 ft room is fine with 1 ton.
When to go one size up
The table assumes an ordinary room. Go half a ton higher if any of these apply:
- The flat is on the top floor and the roof heats up in the afternoon.
- The room faces west or has a big glass window that gets direct sun.
- Four or more people usually sit in the room, or it doubles as a TV or drawing room.
- The ceiling is higher than normal.
An undersized AC runs flat out all day and still struggles. An oversized one cools quickly but switches on and off a lot, which leaves the room feeling damp. In our humid weather, that matters.
Inverter or non-inverter?
A non-inverter AC works at full power until the room hits the set temperature, then stops, then starts again. An inverter AC slows its compressor down instead of stopping, so it holds the temperature more evenly and uses noticeably less electricity over a long night.
If the AC will run for many hours a day, inverter usually pays back the higher price within a few summers. For a guest room used a few times a month, a non-inverter model is a fair choice.
Three things people forget
- Voltage. If your area has frequent voltage drops, ask whether the model has a wide voltage range or whether you need a stabilizer.
- Outdoor unit space. The outdoor unit needs air around it. Squeezing it into a closed balcony corner hurts cooling.
- Pipe length. Installation includes a standard pipe length. If the outdoor unit has to sit far from the room, ask about extra pipe before installation day.
Still not sure? Send us the room size and which floor you live on, and we will suggest a model. You can also browse our air conditioners and compare tonnage side by side.
