The Model 583B high efficiency packaged gas/electric unit uses Puron refrigerant, which does not deplete the ozone in the atmosphere. Aimed at the residential and commercial markets, it is available in two- to five-ton capacities. It delivers up to 81% AFUE heating and 12-SEER cooling and carries the Energy Star logo. The 583B has a Turbo Tubular heat exchanger, constructed of aluminized steel that resists corrosion and transfers heat well. Hot gases make multiple passes across the path of indoor air, giving the heat exchanger more opportunities to pull heat from the indoor air. The design is also quiet, as low as 7.4 decibels. The base pan is made of a composite that the company says will never rust and the pan is sloped to guarantee proper water drainage.

ACLS, Dept. 8583-00, 108 Metropolitan Drive, Liverpool, NY 13088; 888/999-BRYANT.