Why A.C measures in Ton not in kw or kva ?

Explanation

Why is air conditioner capacity measured in tons? You may have wondered this, especially since you know 4 ton  capacity air conditioner doesn't actually weight 4 tons. Here's what that 4 ton designation really means and why air conditioner capacity measured this way.

We know that the air conditioner's number of tons doesn't refer to its weight. In fact, this number refers to the amount of heat the air conditioner can remove from house within one hour. For example, a 4 ton air conditioner is able to remove 48,000 British thermal unit (BTU) from house per hour. One BTU is roughly equivalent to the heat that would be produced if you lit one match and burnt it all the way. One  ton of A/C capacity is equivalent to 12,000 BTU per hour.

Now we know what a ton means, but we still haven't answered the question of why the ton is the unit of measure for air conditioner capacity. Before the invention of the air conditioner . people who could afford it used large blocks of ice to cool their homes in the summer and refrigerate food. The ice was harvested during winter from frozen lakes and rivers.

But how did the use of ice to cool buildings lead to them "ton"?
It takes 143 BTU to; melt one pound block of ice at 32 degrees. Accordingly . if you have one - ton (2000 pound ) block of ice.It takes 286,000 BTU to melt completely . If that block of ice melt evenly over the course of the day, it absorbs heat at the rate of 11,917  BTU/hour. Rounded up we get 12,000 BTU/hour, or one ton of AC capacity.