Tri-Stack roof exhaust fans are designed for furnace/boiler exhaust, diesel generator exhaust, and other high-temperature applications. The fans operate at temperatures up to 750°F. Benefits of the units include variable air volume control, low maintenance, low stack height, vibration-free operation at lower operating costs, lower noise levels, and safe, efficient exhaust removal without re-entrainment into supply intakes, says the manufacturer. Accessories include scrubbers and acoustical equipment such as inlet/outlet silencers.

Strobic Air Corp., a subsidiary of Met-Pro Corp., 160 Cassell Rd., Box 144, Harleysville, PA 19438; 800-722-3267 or 215-723-4700; 215-723-7401 (fax); or (Web sites).