Airguardian is a newsletter relating to air filtration of particulates, gases, and odors, written to present ideas, comparisons, and new information for buyers and HVAC contractors. It discusses issues, standards, and products related to air filtration within the commercial, industrial, medical, and institutional sectors. Subscriptions are free.

Airguard, Attn: Gary Heilmann, director of marketing, P.O. Box 32578, Louisville, KY 40232; 502-969-2304; 502-961-0930 (fax); gheilmann@airguard.com.