What room sizes can an air purifier clean?

If we are talking about an EcoQuest Fresh Air purifier, they are rated at handling up to 3000 square feet of actual air-space (not to be confused with wall-to-wall size). This means, the less space is available for the air to occupy (empty house -vs- full house) then the larger space can be accommodated.

Remember, a Fresh Air is designed to be a "whole home" purifier unit, because it does not need to pull the air through the machine to clean it.

The performance of all air purifiers is rated AHAM. Look for the AHAM seal on the packaging for room size information. Most air cleaners also have appropriate room size reference on the front of the packaging. All room size recommendations are based on AHAM test results. They can vary from 6? x 9? to 20? x 24?.

Yes, purifiers participate in the AHAM's CADR testing will calculate their suggested room size based on the testing results.  However, some purifiers do not participate in the CADR testing and their suggested floor space calculations are all over the map (very inconsistent).  There is no legal guideline for floor space calculation, thus it is much safer to go with the CADR ratings.

The SUN AIRE purifier comes in two sizes; the 11" X 10" X 8" SUN AIRE purifier with handle built of brushed stainless steel and weighing only 9 lbs. covers up to 2,000 sq. ft. The large commercial size which measures 33" X 14" X 7" and can either be wall-mounted or with a handle- also stainless steel inside and out- covers 4,000+ sq. ft. They are NOT just a one room air filter, but a whole-house point of contact indoor air purifier.