From inside (document excerpt):
Product Data ® 58ZAV WeatherMaker® 8000 Deluxe High-Efficiency Downflow/Horizontal Gas Furnace Input Capacities: 50,000 thru 135,000 Btuh Advanced Technology for Mid-Efficiency Gas Furnaces Carrier leads the industry with our new WeatherMaker® 8000 InducedDraft Gas Furnace. This 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 58ZAV Downflow/Horizontal Furnace is the newest addition to Carrier’s list of product leadership in the gas furnace industry. These induced-combustion, gasfired 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 utilizes a hot surface, silicon carbide ignition system to save energy and increase reliability. Our engineers have incorporated the patented S-shaped 4-pass heat exchanger, a new soft mount inducer assembly, and a slow opening gas valve to improve 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 Gas Furnace will meet your home heating requirements. This furnace family provides the widest range of heating capacities available. Form No. 58ZAV-4PD DOWNFLOW HORIZONTAL 1996 Carrier Corporation The superior attention to cabinet detail is obvious. The Carrier WeatherMaker 8000 features 1-piece, seamless, wrap-around construction. There are no spot welds on the exterior surfaces of the 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 Carrier WeatherMaker 8000 is the microprocessor control board which shows true leadership in furnace technology. The simplified electronics in this control board provide high reliability while performing many of the functions of older, electro-mechanical devices in other furnaces. The control board provides blower delay at start-up and shutdown, while monitoring furnace operations and functions. In the unlikely event of a service call, in less than a minute, the technician can use the self-test feature to determine if a major component has failed. The control board will check itself, then the inducer, silicon carbide ignition, low- and high-speed blower, and the humidifier connections. The control board also features a 3-amp fuse that protects the transformer and control board. Another feature on the control board is a LED status indicator light to ensure top furnace performance.