1. Induced draft venting quietly draws hot gases through the heat exchanger, maximizing the heat transfer efficiencies of the exchanger design.

2. Multi-port in-shot burners perfectly shape the flame cone for the maximum heat possible while using less fuel.

3. Adaptive silicon nitride hot surface ignitor starts burning electically for safe, efficient operation. There's no pilot light constantly burning fuel.

4. Aluminized steel heat exchanger is crimped, not welded, to prevent cracks from heat stress. Stamped serpentine channel offers the greatest efficiency in less space. Backed by our 20-year non-prorated, limited warranty.

5. Heavy steel insulated cabinet holds more heat in the furnace to better warm your home. Also assures greater durability and quieter operation.

6. Self-diagnostic controls are the solid-state brain of the Freedom® 80 and manage every function with digital accuracy. Includes safety features and a built-in troubleshooting system.

7. Dual door latches allow easy access to the filter for cleaning or changing (on upflow models only).

8. Sound insulated blower compartment assures the quietest possible operation.

9. Cleanable filter

10. Spring-loaded filter rack automatically adjusts for standard size off-the-shelf filters (on upflow models only).

11. Automotive grade gaskets and insulated blower door reduce operating sound and air infiltration.

12. Two-stage gas valve works efficiently with the multi-speed motor, providing only as much fuel as each stage requires.

13. Multi-speed blower motor operates quietly and efficiently, gently warming and maintaining comfort. Handles all central air conditioning needs, too.