## How to Calculate HVAC Tonnage | Hunker

Jul 17, 2017 · Tonnage: In reference to air conditioning, a ton measures how much heat removed by the system would be needed to melt 2,000 pounds, or one ton, of ice in a 24-hour period. The result is then expressed in Btu per hour. According to the standard calculation, it takes 288,000 Btu to melt a ton of ice in 24 hours, or 12,000 Btu per hour.