With up to 80 percent AFUE, the Performance™ 80 58CTW is a two-stage, var-iable-speed gas furnace. ComfortHeat™ technology offers decreased sound levels, longer cycles, fewer temperature swings between cycles, and a consistent temperature between rooms. Its intelligent control adapts to the heating needs of the home by automatically adjusting high- and low-heat times to maximize comfort. The QuietTech™ system provides low operating sound. Features include Adaptive Control Technology, SmartEvap™ technology moisture-control function, and ComfortFan™ technology, which allows homeowners to adjust the constant fan speed from the thermostat. The Performance 80 has a four-way multipoise design with 13 vent applications. Its variable-speed electronically commutated motor (ECM) allows for efficient operation all year long in heating, cooling, and continuous fan operation.