Air cleaners

Factors to consider

From Joey Fox

Determining the amount of clean air necessary for your space is crucial when selecting an air cleaner. This measurement is commonly referred to as the Clean Air Delivery Rate (CADR), and it is typically quantified in cubic feet per minute (CFM), liters per second (lps), or cubic meters per hour (m³/h).

The industry-standard approach, as recommended by AHAM (Association of Home Appliance Manufacturers), is to use the 2/3 rule. According to this rule, the CADR should be 2/3 of the area measured in square feet. For instance, if your space is 300 square feet, the air cleaner’s CADR should be calculated as 300 x 2/3 = 200 CFM. This provides five air changes per hour in residential spaces with 8-foot ceilings, or 4.4 air changes per hour in most commercial areas with 9-foot ceilings.