These new makeup air systems have air volumes ranging from 2,000 to 150,000 scfm. Features include direct- and indirect-fired systems using natural gas, propane, or No. 2 fuel oil. Options include recirculation, variable-volume control, direct evaporative cooling, indoor and outdoor mounting, roof curbs, and filters. Vertical and horizontal unit mounting configurations are available. The systems are ETL listed.

Des Champs Laboratories Inc., Route 130, Natural Bridge Station, VA 24579; 540-291-1112; 540-291-3333 (fax); (e-mail); (website).