Gas Furnace Efficiency Calculator

For example if a furnace has a listed input rating of 90 000 btu s and an efficiency rating of 80 it will produce 90 000 btu input x 80 efficiency 72 000 btu actual output.

Gas furnace efficiency calculator.

The only time you can rely on afue as a sole comparison is when comparing two furnaces with the same fuel type. For this comparison exercise we will assume a 65 afue furnace is getting replaced by a standard efficiency 80 or a high efficiency 95 furnace. House are the following. As quiet as they are efficient lennox furnaces also startup and run perfectly quietly helping to preserve the peace and quiet of your home.

Delivering precise comfort and temperature control lennox furnaces can keep your home to within 0 5 degrees of your ideal temperature. Lennox gas and oil furnaces are engineered to deliver perfect warmth efficiency and energy savings. Furnace information estimated efficiency of present furnace. With a less efficient furnace operating at 80 percent efficiency this would require a 60 000 to 72 000 btu furnace.

This calculator will make an estimate of how long it will take to pay back your investment in a new natural gas furnace. Thus efficiency alone is not an indicator of operating costs. Using an online calculator and considering average gas prices in the us the results for a 1800 sq.