From inside (document excerpt):
Product Data HEATING & COOLING 58TUA Weathermaker® 8000 2-Speed High-Efficiency Upflow Furnace Input Capacities: 40,000 thru 135,000 Btuh Two-Speed Heating for High-Efficiency Gas Furnaces Carrier leads the industry with our new Weathermaker® 8000 Two-Speed Induced-Draft Gas Furnace. This furnace can operate at 2 different speed settings which provide outstanding home comfort. The Weathermaker 8000 furnace is built with the most advanced manufacturing equipment, processes, and technology available in order to ensure top quality.
Packed into the cabinet are the industry’s foremost dealer and homeowner features. The 58TUA Upflow Furnace is the latest addition to Carrier’s list of product leadership in the gas furnace industry. These 2-speed induced-combustion, gas-fired furnaces offer not only low installation costs, but fuel economy as well–delivering an Annual Fuel Utilization Efficiency (AFUE) rating of 80.0%. The Carrier Weathermaker 8000 two-speed utilizes a hot surface, silicon carbide ignition system to save energy and increase reliability. Our design uses the patented S-shaped 4-pass heat exchanger, a soft mount 2-speed inducer assembly, and a 2-stage slow-opening gas valve to minimize sound level. The Super-S heat exchanger provides better heat transfer while enabling us to make a compact furnace. This provides more room in closet, utility room, and short basement installations. The heat exchanger is constructed of aluminized steel and is backed by a 20-year Limited Warranty. The Carrier Weathermaker 8000 Two-Speed Gas Furnace will meet your 1994 Carrier Corporation Form 58TUA-4PD This document was created with FrameMaker 4.0.4 home heating requirements. This furnace family provides the widest range of heating capacities available. The superior attention to cabinet detail is obvious. The Carrier Weathermaker 8000 two-speed features 1-piece, seamless, wrap-around construction. There are no spot welds on the exterior surfaces of the Weathermaker 8000 Two-Speed Furnace. There is also double protection for the cabinet. First, a galvanized steel substrate provides resistance to rusting. Then the cabinet is constructed of prepainted steel–the same high-quality finish found on refrigerators and dishwashers. Perhaps the most advanced feature of the Weathermaker 8000 two-speed is the state-of-the-art microprocessor control center which shows true leadership in furnace technology. The simplified electronics in this control provide high reliability while performing many of the functions of older, electro-mechanical devices in other furnaces. Advanced features of the control show Carrier’s true leadership in furnace technology.