"Tony Hwang" wrote in message
news:XSVub.437257$pl3.49018@pd7tw3no...


CBHvac wrote:

"j j" wrote in message
...

our furnace is probably 50 years old. it's a big cast iron thing.

everyone we asked told us not to change it because new furnaces have
crappier construction.


Then you are asking the wrong people.
Granted, they dont make tanks anymore.

Hi,
Big cast iron thingy alright but at what efficiency?

50% or 60% maybe? Seen a few old oil units that MIGHT make it to the 50%
range...and have seen more than one Chrysler Airtemp gas unit that was
feeling frisky if it saw 65%....

Maybe your dollar
is going up the chimney more than heating your house.

Bingo...

How about doing some cost anaysis?

With AFUE ratings, its simple..
Figure, just on fuel, that if you have a 60% unit, 60 cents of the heat
generated, goes into the home, with 40 cents going off to heat the world...
now, with a 95% unit, only 5 cents goes away...not including the savings on
more energy friendly motors and controls.

Tony