Choosing the right air conditioner capacity for your home, the room volume is a concern that not every consumer grasps, especially those buying an air conditioner for the first time. In this article, Mytour Supermarket will guide you on how to calculate the air conditioner capacity to match the area of your room.
Before delving into the main issue, let's explore the basic area calculation for square or rectangular spaces. Before installing the air conditioner, it's essential to measure the height from the floor to the ceiling.
- Area S = Length 4m x Width 3m = 12 m2
- Volume V = Area 12m2 x Height 3m = 36m3
Calculating the capacity of the air conditioner
1 HP (electrical power, compressor power) = 750 W (electrical power) = 9000 BTU/h (cooling capacity). Cooling capacity = W.
What we often see or hear most is Cooling capacity in Btu/h, the section below will guide you on how to calculate the required cooling capacity for the room in this unit Btu/h.
We can apply the formula: 1 m2 x 600 BTU. In which, BTU is the British thermal unit, used to measure the power of heating or cooling devices.
For example, for a room with an area of 15m2, you will calculate: 15 m2 x 600 BTU = 9,000 BTU, equivalent to an air conditioner with a capacity of 1 HP (1 HP = 1 horsepower equivalent to 9,000 BTU).
Details as follows:
- Room dimensions: 3 x 4 x 3m = 36 m3. Choose a 1 HP air conditioner
- Room dimensions: 4 x 5 x 3m = 60 m3. Choose a 1.5 HP air conditioner
- Room dimensions: 4 x 6 x 3.5m = 84 m3. Choose a 2 HP air conditioner
- Rooms from 30 m2 to 40 m2 (under 120 m3). Choose a 2.5 HP air conditioner
Considerations when choosing an air conditioner with excess or insufficient capacity

Considerations when choosing an air conditioner with excess or insufficient capacity
When buying an air conditioner, it's advisable to choose a slightly higher capacity. It may cost a bit more initially, but in the long run, it proves to be more effective than an air conditioner with just the right capacity. An air conditioner with excess capacity operates strongly, cools quickly, allows the machine more rest time, extending its durability and consuming less energy. It runs for a short time, achieving the desired room temperature and automatically turning off, while units with just enough or insufficient capacity will have to run continuously to maintain the room's coolness.
Choosing an air conditioner for the household

Choosing an air conditioner for the household
Air conditioners for households usually have lower capacity as they don't need to cool excessively. However, for the living room and kitchen, you should add 0.5Hp.
- Volume approximately 40 m3 (cubic) = 1.0 Hp
- Volume approximately 60 m3 (cubic) = 1.5 Hp
- Volume approximately 80 m3 (cubic) = 2.0 Hp
Installing air conditioners for the living room, office, and restaurant

Installing air conditioners for the living room, office, and restaurant...
Installing air conditioners for the room. The loss of cold air is relatively significant due to many heat-emitting devices such as TV, computer, fax machine, and frequent people coming in and out. So, at this point, we will take the volume divided by 35…
- Volume approximately 35 m3 (cubic) = 1.0 Hp
- Volume approximately 55 m3 (cubic) = 1.5 Hp
- Volume approximately 70 m3 (cubic) = 2.0 Hp
Hoping that Mytour's article above will help you understand the concept of air conditioner capacity for suitable installation based on the usage area for your family.