"Edwin Pawlowski" wrote in message
...

"xanuda" wrote in message
oups.com...
Hi all. We live in IL and looking to replace our old furnace. We
have had a
few
estimates and now we are trying to decide between an 80% and 90%
efficient heaters and 1 stage / 2 stage / variable models. The price
difference between 80% and 90% seems to be about 600-800 for Trane.
The price difference between different stages is also several hundred
$$$. How do we make a decision whether it is worth money to go with a
more expansive model. I'm looking for a dummy-oriented advice as my
knowledge here is pretty mich zero

Take a look at the fuel use from the previous year. How much did it cost
you? If it was $2000, you'd save about 10%, or $200 in a year. Payback
will be about 4 years, then you save that every year after. As the cost
of
fuel goes up (and it will) the savings will be even greater.

You are not taking into consideration the fact that the 80% furnace uses
inside air for combustion and the 90% furnace brings in outside air. The
inside air has already been heated, that has cost you $$$ and you're
throwing it up your chimney . This air has to be replaced and the new air
is coming into your house from the outside--cold air that has to be heated
to room temperature--more $$$$. It gets into your house through cracks,
windows, under doors--so your house gets drafty. All this newly heated air
has to be humidified because it is going to be very dry. My point being
that the $$$ difference between the 80% and the 90% furnaces is more than
the 10-12% in furnace efficiency.
MLD