What is Ton in AC? How to calculate it for a Room?

When we refer to an AC.

We say oh!!! 

It’s a 1 ton AC. 

It’s a 1.5 ton AC

For noobs like us, we think this is the weight of the AC unit. 

If this was true, a 1 ton AC would weigh 907 kgs then a whole army will be needed to lift the AC unit for installation.

But that’s not the case

The ton refers to the cooling capacity of the AC unit. More the ton, More the cooling capacity.

1 ton AC can remove 12,000 BTUs of heat per hour.

What is BTU?

BTU stands for British Thermal Unit

It is the amount of heat required to raise the temperature of 1 pound of water by 1 Fahrenheit at a constant pressure of 1 atm

Way back in time when there was no ACs and refrigeration cycle, 1 ton can be seen as 1 ton of ice used to give cooling and it takes 24 hours to completely meltdown.

This is equivalent to 288000 BTU in 1 day and 12000 BTU/hr

12000 BTU/hr = 3.5 kW or 3517 Watts

Note – A 1 ton AC will not consume 3517 Watts of electricity, it depends on the star rating and cooling efficiency of the AC

For 1.5 ton AC,

12000 * 1.5 = 18000 BTU/hr or 5.27 kW

For 2 ton AC,

12000 * 2 = 24000 BTU/hr or 7kW

How to calculate AC tonnage?

AC tonnage can be calculated based on various factors. You should get the right tonnage AC for your room. 

If you get higher tonnage AC in your room, it will cool faster and consume more electricity and if you choose lower tonnage AC it will fail to cool the room to the desired temperature even after constant use for hours.

To calculate the AC ton correctly.

There’s a general rule for choosing tonnage based on the size of the room.

Size = length x breadth

For example, if you have 100 square feet room

Size = 10 x 10

You would require 1 ton capacity AC.

The same goes for 150 square feet room = 1.5 ton AC and 200 square feet room = 2 ton AC

But this is a general rule.

Choosing the right tonnage will depend upon other factors like the height of the room, the floor on which the room is, the number of walls the room gets direct sunlight on, the number of people that live inside the room, the number of electrical equipment the room has.

Based on these factors, calculate AC ton from here.

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