From inside (document excerpt):
58MEC Performancet Boost 90 4 Way Multipoise 2 Stage Condensing Gas Furnace Input Rates: 60,000 thru 120,000 Btuh Product Data 4-WAY MULTIPOISE DESIGN ALLOWS MORE APPLICATIONS design, the secondary heat exchanger reduces the pressure drop in the furnace resulting in lower electrical usage. The high efficiency achieved by superior heat transfer is made only better–by optimizing the efficient ECM motor speed tap locations.
A standard media filter cabinet accessory is provided with the Performance Boost 90 in order to provide an opportunity to enhance indoor air quality. As with all other Carrier furnaces, this model is designed to work as a part of the total home comfort system which includes elements for cooling, air cleaning, humidification, ventilation and zoning. Boosting the unit’s efficiency with the ECM motor and Carrier’s deluxe features show the Performance Boost 90 has been designed with the homeowner in mind. PERFORMANCETM BOOST 90 FEATURES & BENEFITS ComfortHeatt Technology — The Performancet Boost 90 has a 2-stage gas valve to vary the amount of gas being used from low-heat to high-heat stage. The low-stage operation allows longer running periods, which helps maintain your most comfortable temperature, prevents drafts, reduces noise, and enhances the air quality of your home. During the extreme cold, the high-heat levels will run to ensure that you are still comfortable. ECM Blower Motor — The ECM motor and Carrier’s control logic can help selected 13- and 14-SEER Carrier Air Conditioners achieve added energy efficiency up to 1.5 SEER as compared to the Air Conditioning and Refrigeration Institute’s standard coil-only rating. (A/Cs up to 3.5 tons) when paired with selected Carrier evaporator coils. Serpentufft — Exclusive Serpentuff coating, a patented polypropylene laminate is used on the secondary heat exchanger and greatly reduces maintenance. Power HeatTM Igniter — Carrier’s unique SiN igniter is not only physically robust but it is also electrically robust. It is capable of running at line voltage and does not require complex voltage regulators as do other brands. This unique feature further enhances the reliability of the Performance Boost 90 gas furnace and continues Carrier’s tradition of technology leadership and innovation in providing a reliable and durable product. ComfortFanTM — Improves comfort all year long by allowing the homeowner to select different fan speeds during continuous fan operation to achieve more or less airflow. This is done right at the thermostat. SmartEvapTM — This feature allows your system to reduce summertime humidity levels by nearly 10% over standard systems. A05069 A UNIQUE SEER SOLUTION The Performancet Boost 90 is an exciting addition to your product line. This high-efficiency two-stage 4-way multipoise design furnace allows more applications while the ECM motor and Carrier’s control logic combine to provide a SEER BOOST of up to 1.5 points.* The Performance Boost 90 is available in 5 heat/air-flow combinations and with the 4-way multipoise design can be installed in upflow, downflow, or horizontal positions covering up to 24 applications. Some of Carrier’s best-engineered components contribute to the efficient performance of this condensing furnace. The Performance Boost 90 utilizes Power Heatt hot surface ignition (HSI), which ignites the burners directly. HSI eliminates gas waste that typical continuous-pilot designs can bring. Hot surface ignition has proven to contribute to reliable start-up and operation of Carrier furnaces. Another deluxe feature included with this furnace is Carrier’s trusted Serpentufft secondary heat exchanger; a patented polypropylene laminate that provides exceptional heat transfer and corrosion resistance. Using the exclusive flow-through *as compared to the Air Conditioning, Heating and Refrigeration Institute’s standard coil only rating (A/Cs up to 3.5 tons) when paired with selected Carrier evaporator coils.