From inside (document excerpt):
58CTA/CTX PERFORMANCE 80 TWO-STAGE 4-WAY MULTIPOISE INDUCED-COMBUSTION FURNACE Input Capacities: 45,000 thru 155,000 Btuh Product Data THE PERFORMANCE 80 GAS FURNACE The 58CTA/CTX Two-Stage, 4-way Multipoise Gas Furnaces offer unmatched comfort in their class with ComfortHeatTM technology in an 80% AFUE gas furnace. You get the benefits of a ComfortHeatTM technology furnace: reduced drafts, reduced sound levels, longer cycles, less temperature swings between cycles, and less temperature differences between rooms.
Its exclusive, intelligent microprocessor control adapts to the heating needs of the home by automatically adjusting high and low heat times to maximize comfort. The 58CTA/CTX furnaces are approved for use with natural or propane gas, and the 58CTX is approved for use in Low NOx Air Quality Management Districts. STANDARD FEATURES Performance · · A04041 · · ComfortHeatTM Technology Intelligent microprocessor control Two-stage heating with single-stage thermostat with patented Adaptive Control Technology Very low operating sound through low-stage operation and QuieTechTM system SmartEvapTMHumidity control when using a Thermidistat/Infinity control Comfort FanTM adjustable constant fan speed from the thermostat High-Efficiency Media Filtration Cabinet included Microprocessor based control center LED diagnostics and self test feature Stores fault codes during power outages Adjustable heating air temperature rise Adjustable cooling airflow 4-way Multipoise furnace, 13 vent applications Compact design – only 33-1/3 in. tall Power HeatTM Igniter Draft Safeguard switch to ensure proper furnace venting Insulated blower compartment Inner door for tighter sealing Hybrid HeatTM compatible All models are Chimney Friendly when used with accessory vent kit ISO 9001:2000 EFFICIENCY RATING CERTIFIED REGISTERED CERTIFIED MEETS DOE RESIDENTIAL CONSERVATION SERVICES PROGRAM STANDARDS. Before purchasing this appliance, read important energy cost and efficiency information available from your retailer. · · Twinning in Upflow, Downflow and Horizontal Residential installations eligible for consumer financing through the Retail Credit Program LIMITED WARRANTY · · 20-year warranty on “Super STM ” heat exchanger 5-year parts warranty on all other components LED EAC-2 BHI/LOR HI HEAT A02169 A02169 HEAT EXCHANGER Model number nomenclature 58CTA 045 100 58CTA Two-Stage 4-Way Multipoise 58CTX Low NOx version 08 Nominal Cooling Size (Airflow at .5 e.s.p.) (400 CFM per 12,000 Btuh) 08 — 800 CFM 12 — 1200 CFM 14 — 1400 CFM 16 — 1600 CFM 20 — 2000 CFM 22