How Much Money Can I Save by Replacing My Furnace?

“How much money can I save if I replace my furnace?” is question people ask me most often.

To figure that out, you need to know your annual fuel cost, the type of heating technology you are currently using and the type you plan to use.

AFUE (annual fuel utilization efficiency)  ratings for common systems are shown below.

Annual savings =  A -B x C

A= Seasonal efficiency of proposed system

B= Seasonal Efficiency of current system

C= annual fuel cost for heating

Example: You have a conventional gas furnace and are converting to a high efficiency gas furnace. The conventional furnace has an AFUE ( annual fuel utilization efficiency) of 60% . The high efficiency furnace has an AFUE of 96%. The annual heating cost id $1200.

Savings =  96 – 60 x 1200   =$450.00

Your annual savings would be $450.00 plus you eliminate the need for a chimney.

Typical Heating System Efficiencies and Energy Savings

Energy Source	Technology	Seasonal Efficiency (AFUE) %	Energy Savings (% of Base’)
Natural Gas	• Conventional furnace boiler	60	Base
	• Standard-efficiency furnace	78-84	23-28
	• Standard-efficiency boiler	80-88	25-32
	• Condensing furnace	90-97	33-38
	• Condensing boiler	89-99	33-39
	• Integrated space/		33-38 space
	tap water condensing	90-96	44-48 water
Propane	• Conventional furnace/boiler<	62	Base
	• Standard-efficiency furnace	79-85	21-27
	• Standard-efficiency boiler	82-90	24-31
	• Condensing furnace	88-95	29-34
	• Condensing boiler	87-97	29-36
Oil	• Cast-iron head burner(old furnace)	60	Base
	• Flame-retention headreplacement burner	70-78	14-23
	• High-staticreplacement burner	74-82	19-27
	• New standard model	78-86	23-30
	• Standard-efficiency	83-89	28-33
	• Integrated space/tap water		28-33 space
	standard-efficiency	83-89	40-44 water
Electricity	• Electric baseboards	100	N/A
	• Electric furnace or boiler	100
	• Air-source heat pump	1.7 COP’
	• Earth-energy system
	(ground-source heat pump)	2.6 COP’
Wood	• Central furnace	45-55	N/A
	• Conventional stove(properly located)	55-70
	• “High-tech” stove’ (properly located)	70-80
	• Advanced combustion	fireplace’	50-70
	• Pellet stove	55-80

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