Air Changes per Hour, a metric quantifying the rate at which air within a defined space is replaced, is determined by dividing the volumetric flow rate of air entering or exiting the space by the volume of that space. For instance, if a room with a volume of 500 cubic feet receives 1000 cubic feet of fresh air per hour, the rate is two. This indicates the air within the room is replaced twice every hour.
This calculation is vital in various applications, impacting indoor air quality, energy efficiency, and the control of airborne contaminants. Correct calculation and implementation can lead to improved ventilation, reduced energy consumption for heating and cooling, and a healthier indoor environment. Historically, its significance has grown in parallel with increased awareness of the effects of poor indoor air on human health and productivity.
