Much of the arithmetic on HVAC exams comes down to a small set of conversions and two heat formulas, and the questions are often lost on units: a kilowatt fed into a Btu formula, a temperature rise applied to the wrong airflow, a “ton” treated as a weight.

This guide gives you those constants with their sources, the formulas with their assumptions, and original worked problems that show the unit check at every line. Your exam’s content outline says what else it covers; this guide is about getting these particular calculations right.

View the HVAC Exam Math guide