How to Estimate the BTU Required Per Ton

A BTU stands for a British thermal unit and is a measure of energy and heat. When discussing the output of a heating, ventilation and air conditioning unit (HVAC), a BTU is related to tonnage in that for every ton of conditioned air, the unit can output 12,000 BTU per hour. This measure is used to size HVAC units so that they are adequate for the space requirements. In general, 1 ton of air conditioning is suitable for 500 ft^2 of floor area.

Instructions

1. • 1

     Determine the size of the space to be heated and cooled. Assume a room has dimensions of 25 feet by 30 feet. This equals 750 square feet (25 x 30).

   • 2

     Divide the required square footage to be heated and cooled by the conversion factor for tonnage. Because 1 ton is adequate for 500 square feet, then 750 square feet requires 1.5 tons of cooling (750/500).

   • 3

     Determine the BTUs required for 1.5 tons of capacity. Because 1 ton is equal to 12,000 BTU/hr, the space would require 18,000 BTU/hr (1.5 x 12,000).