With today’s complex IAQ challenges, how do you select the best air filtration for a building? A new standard known as ANSI/ASHRAE 52.2-1999, Method of Testing General Ventilation Air Cleaning Devices for Removal Efficiency by Particle Size, should help to pave the way. This standard allows hvac contractors, building operators, and others to evaluate filters based on controlled and repeatable laboratory testing, providing much more reliable comparisons. It establishes minimum efficiencies for filters, a more stringent and conservative measure than the previously used average efficiency. And, for the first time, it allows filter selection based on offending contaminants and their particle sizes – making the selection process much more specific and targeted than ever before.