If you are buying an HVAC system such as a window air conditioning unit or a mini split, the heating or cooling capacity is usually in BTUs.
While smaller units use BTUs, big Home air conditioning units will often be rated in Tons, which can be confusing.
Both BTU and TON are used in HVAC to get an idea of how much cooling or heating capacity a unit has.
Example 1: How Many BTU is 1-TON?
12,000 BTU is roughly equal to a 1-TON HVAC unit.
Example 2: How Many BTU is 2-TON?
24,000 BTU is roughly equal to 2 TON HVAC unit.
Example 3: How Many BTU is 3-TON?
36,000 BTU is roughly equal to 3 TON HVAC unit.
HVAC BTU to TON Conversion Table Chart
| BTU | TON |
|---|---|
| 9,000 | 3/4 TON |
| 12,000 | 1 TON |
| 24,000 | 2 TON |
| 36,000 | 3 TON |
| 48,000 | 4 TON |
| 60,000 | 5 TON |
Why is TON Used to Measure HVAC Capacity?
When refrigeration was first introduced, there were several methods for calculating the amount of energy needed to cool a space.
One method which became very popular was the amount of energy needed to melt or freeze 1-Ton of ice over a 24 hour period.
A machine that could freeze 1-Ton of ice over 24 hours was called a 1-TON unit.
The water was weighed to 1-Ton, and then the amount of energy was measured to freeze the ice by the air conditioning machine.
This naming scheme for the amount of power an HVAC unit can output has carried over to today and is still wildly used.
Why is BTU Used to Measure HVAC Capacity?
BTU, or British Thermal Unit, was introduced by Britain as a way to measure heating and cooling capacity and is now commonly used.
A BTU is the amount of heat or cooling power needed to raise or lower the temperature of one pound of water by one degree Fahrenheit.
Since a BTU can measure heating and cooling capacity on a small scale, it is often used for window air conditioners and mini split units.
Summary
If you are thinking about buying an HVAC unit such as a mini split and wonder how the sizes compare to standard home HVAC units, the above conversion table can help.
Most homes have a 2-3 TON unit that heats or cools the entire home.
The square feet of a home dictates how big a unit is needed to heat or cool it.
For example, a 1200 Square Foot home often has 24,000 BTU or 2 TON units.
Of course, the size can also vary depending on the climate and how well insulated a home is.
For example, in a very hot climate, a 1200 Square Foot home may have a 2 1/2 TON unit to give extra cooling capacity on a very hot day.
Both BTU and TON can be used to get an idea of how much cooling or heating capacity is needed for a home.
If you need to convert BTU to TON, it is easy to do using the conversion table above.