Rock the Residential HVAC Install Exam 2025 – Chill Out with Top Scores!

The correct formula used to calculate the cfm (infiltration) in an HVAC system is (ACH × HOUSE VOLUME) ÷ 60. This formula takes into account the Air Changes per Hour (ACH) needed for proper ventilation and the volume of the house to determine the airflow required in cubic feet per minute (cfm). By multiplying the ACH by the house volume and dividing by 60 minutes per hour, you can accurately determine the cfm needed for proper ventilation. The other options provide incorrect formula combinations that do not accurately calculate the cfm for infiltration in an HVAC system.