On Oct 19, 5:32 pm, wrote:
On Oct 19, 1:22 pm, Caesar Romano wrote:

On Fri, 19 Oct 2007 16:10:27 GMT, PaPaPeng wrote
Re Furnace install Questions:

Look at the labels inside your current furnace. There should be a BTU
rating somewhere. A close BTU match for your new furnace is what you
atre looking for.

Bingo! The OP never said anything about the replacement being
motivated by over/under capacity of his old unit.

Yes, but he did say the old one is 90,000 BTU's and 50 years old.
And he said absolutely nothing about what the duty cycle of it has
been in typical winters. If he has one that's already over size, and
he's getting a new one that's maybe 25% more efficient, why should he
over size it even more by going with the same BTU?

Size it by a load calculation , you may only need 40000 BTU, who
knows, who cares,. New high efficency units waste less and give more
heat . I cut my btu from 110, 000 to 47000 and its still to high, a
new load calc put it at 35000 , R 110 attic helped............