"Rick" wrote in message
news:Xezrd.223872$df2.143177@edtnps89...

"HeatMan" wrote in message
.. .

"HL" wrote in message
news:tNurd.223772$df2.120623@edtnps89...
Compared to a 20 year old furnace how much does each design
improvement
increase AFUE:

Draft inducer fan
Ignitor vs pilot
Faster fan startup (is this due to the draft inducer)
Hx design chages?
Anything else?



Yes.

The biggest improvement, IMO, is the ignition vs. the standing pilot.


So my 60% 20 year old furnace will achieve 80% by eliminating the pilot?

Why doesn't everyone just replace their pilots with an ignition system?

Doesn't quite add-up



It's also the amount of gas being burned and used to warm up the house. The
ofrices are smaller and the HX is more efficient.