5.3.8	Major Residential HVAC Equipment Lifetimes, Ages, and Replacement Picture
					Typical Service			Average			2005 Average			Units to be Replaced
Equipment Type					Lifetime Range			Lifetime			Stock Age			During 2010 (1,000s)
Central Air Conditioners						8 - 14			11			8			5,354
Heat Pumps						9 - 15			12			8			1,260
Furnaces
Electric						10 - 20			15			11			N.A.
Gas-Fired						12 - 17			15			11			2,601
Oil-Fired						15 - 19			17			N.A.			149
Gas-Fired Boilers (1)						17 - 24			20			17			204
Note(s):	Lifetimes based on use by the first owner of the product, and do not necessarily indicate that the product stops working after this period. A replaced unit may be discarded or used elsewhere. 1) 2005 average stock age is for gas- and oil-fired steam and hot water boilers.