AIR CHANGE RATE EQUATIONS

The most generic method used to calculate ventilation air requirements is based on complete changes of air in a structure or room in a given time period. To determine the airflow required to adequately ventilate an area, calculate the Room Volume to be ventilated Width x Length x Height = ft3 (cubic feet) and than calculate the Air Volume requirement by multiplying the Room Volume by the Air Change Rate per hour.

ACH = Cu-ft / min x 60 min/hr / room volume

CFM = ACH x room volume / 60 min/hr

Where

• ACH = Air Change Rate per Hour

• CFM = Air Flow Rate (Cubic Feet per Minute)

• Room volume = Space Volume (Cubic Feet)

The most generic method used to calculate ventilation air requirements is based on complete changes of air in a structure or room in a given time period. To determine the airflow required to adequately ventilate an area, calculate the Room Volume to be ventilated Width x Length x Height = ft3 (cubic feet) and than calculate the Air Volume requirement by multiplying the Room Volume by the Air Change Rate per hour.

ACH = Cu-ft / min x 60 min/hr / room volume

CFM = ACH x room volume / 60 min/hr

Where

• ACH = Air Change Rate per Hour

• CFM = Air Flow Rate (Cubic Feet per Minute)

• Room volume = Space Volume (Cubic Feet)