The system uses Lennox’s proprietary SilentComfort technology, and sound-absorbing insulation further quietens operation. With two-stage heating and a variable-speed motor, this model provides efficient heating. This popular furnace has an AFUE rating of 80 percent. The system runs on natural gas and is compatible with the Lennox smart thermostat. The modulating valve and a variable-speed blower improve performance, and according to Lennox, the unit’s silicone nitride ignitor increases its durability and reliability. This quiet unit has two heat exchangers and condensing technology, which provides effective heat dispersement. This heating system was named one of the most efficient Energy Star-certified products of 2019. This energy-efficient Lennox furnace is the company’s flagship gas furnace and has an industry-leading AFUE rating of 98.7 percent. Below are the top 10 Lennox furnace models. Lennox offers furnace options to fit various budgets, heating requirements, and energy-efficiency preferences. Furnaces with constant torque motors offer improved efficiency while delivering greater comfort and cost savings. Two-stage furnaces offer both high and low output settings that calibrate furnace heat flow to thermostat settings.

Ultra-low emission Lennox furnaces burn away more NOx gases and result in cleaner emissions, healthier for you and the environment. Variable speed furnaces prevent large temperature fluctuations and reduce operating costs while providing consistent heating with lower humidity. Different models include variable speed, ultra-low emission, and two-stage furnaces. Within those two fuel types, different furnace models offer different features. Most Lennox furnaces run on gas, but some use oil instead.

Lennox furnace parts diagram