Air Conditioning Repair Certification (ETI) 2025 – 400 Free Practice Questions to Pass the Exam

The formula CFM = BTU / (1.08 X T) is essential for calculating the airflow in an air conditioning system. In this formula, CFM (Cubic Feet per Minute) represents the volume of air that an air conditioning system needs to deliver to effectively cool a space.

The variable BTU stands for British Thermal Units, which is a measure of thermal energy. When analyzing an air conditioning system, it's important to understand how much BTU is needed to cool a given area. The 'T' in the formula refers to the temperature difference between the supply air and the return air.

The factor of 1.08 in the equation accounts for the density of air and the specific heat of air, adjusting the calculations to provide a more accurate measurement of airflow needed to circulate enough cooled air to meet the BTU requirement for a specified temperature drop.

Utilizing this formula allows technicians to ensure that an air conditioning system is adequately sized and operating efficiently, which is crucial for both performance and energy consumption. Understanding this calculation is integral to effective system design and troubleshooting in HVAC applications.