Calculate Utility Savings for a High Efficiency Furnace

A simple method to estimate savings on a new high efficiency furnace is listed below:

Estimated efficiency of old furnace (usually 75% or lower) 70
Efficiency of new high efficiency furnace 95
Savings with high efficiency furnace 25%

Convert the savings to a percentage. Using your old fuel bills, calculate dollar savings from this. For example, if you spent $2000 on gas last year, savings of 25% would equate to $500 each year. Based on this calculation, a new furnace can be paid off in just a few years. If gas prices increase, your savings will be even more.