Sensory pollution from a conventional bag-type fiberglass ventilation filter and fiberglass bag filters containing various amounts of activated carbon

Used ventilation filters can significantly contribute to the deterioration of indoor air quality. The present study evaluated the sensory pollution from four filters: i) conventional F7 fiberglass filter, ii) commercially available bag-type stand-alone fiberglass "combination filter" with activated carbon (AC), iii) filter prototype similar to the commercially available combination filter with only half of its carbon content and iv) filter prototype similar to the commercially available combination filter with only quarter of its carbon content. After 6 months of continuous service, the air downstream of each of the combination filters containing AC was judged to be significantly better than the air downstream of the 6-month old F7 filter and was approximately the same as the air quality from a new F7 filter. Additionally, the combination filters containing AC removed more ozone from the air than the F7 filter.