Combined Annual Efficiency (CAE) is a measure of the amount of heat produced for every dollar of fuel used to heat your home’s air and water. It is used to compare efficiencies of integrated water and space heaters.
CAE ratings take into account the AFUE of the space heating component, which is a measure of furnace heating efficiency. Lennox offers residential furnaces with AFUE ratings ranging from the federal minimum of 80% all the way up to an industry-leading 98.7%*. The most efficient models can save you hundreds of dollars a year, compared to an older or less-efficient furnace.
Use our Energy Savings Calculator to find how much you can save
*Based on sound pressure levels during steady-state, high-fire and low-fire operation of Lennox SLP98UH070XV36B and leading competitive units as of July 2013 at mid-point temperature rise and minimum external static pressure when set up per Section 4.4.4 of AHRI 260-2012. Based on AFUE efficiency rating of Lennox SLP98UH090XV60C and leading competitive units listed in AHRI directory as of March 2015. Efficiency ratings established per test standard ANSI/ASHRAE 103-1993.
