Which expression represents the BTU formula?

Which expression represents the BTU formula?

• A. Weight x Change in Temperature.
• B. Pressure x Volume.
• C. Mass x Acceleration.
• D. Energy divided by Time.

Answer: (A)

BTU is a unit of heat energy. It is defined as the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. In HVAC terms, using water’s specific heat of 1 BTU per pound per degree Fahrenheit, the energy in BTUs can be represented simply as the weight of the water (in pounds) times the temperature rise (in °F). So the expression becomes weight × change in temperature. This reflects how much heat is added to raise that amount of water by that many degrees. The other expressions don’t describe heat energy in the same way. Pressure × volume corresponds to work done by a gas, not the heat required to raise water’s temperature. Mass × acceleration gives force, not energy. Energy divided by time gives power (rate of energy transfer), which is related to BTU/hour, but the basic BTU energy calculation itself is weight × ΔT.

BTU is a unit of heat energy. It is defined as the amount of heat needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. In HVAC terms, using water’s specific heat of 1 BTU per pound per degree Fahrenheit, the energy in BTUs can be represented simply as the weight of the water (in pounds) times the temperature rise (in °F). So the expression becomes weight × change in temperature. This reflects how much heat is added to raise that amount of water by that many degrees.

The other expressions don’t describe heat energy in the same way. Pressure × volume corresponds to work done by a gas, not the heat required to raise water’s temperature. Mass × acceleration gives force, not energy. Energy divided by time gives power (rate of energy transfer), which is related to BTU/hour, but the basic BTU energy calculation itself is weight × ΔT.