Determining HVAC System

Determining HVAC System Cleanliness  HVAC system cleanliness should be evaluated by visual inspection or an approved vacuum test method as outlined in appropriate NADCA standards. An HVAC interior surface is considered visibly clean when it is free of non-adhered debris. Vacuum test methods include visual surface comparison of “clean” areas before and after vacuuming as well as sampling a known surface area to determine the net weight of debris per area sampled to compare to an acceptable NADCA level