Mike O. wrote:
About two years ago we moved into a 35 year old house. The furnace
was replace by the previous owners and is about 10 years old (92+
Rheem). The ductwork appears to be original (except for a few pieces
around the furnace)
A problem we've had last year (and this year too), is that when the
weather cools down, the upstairs is about 5-7 degrees cooler than the
downstairs. Partially closing the downstairs registers helps some,
but I don't want to close too much and reduce the airflow through the
furnace to a level that will cause problems. I'm looking for a
solution to help the heat make it to the upstairs, without causing
problems with the furnace.

....

Mike O.

I don't think insulating ducts is going to be the answer.

You have a distribution or second floor insulation problem.

In that house I would say you almost certainly have a distribution
problem and the only way you are going to get that fixed is to have someone
with professional knowledge see your home, measure as needed, and run the
numbers.

You may be able to gain some by checking insulation. There may be non
in the attic and you may be able to fix that. It should be fixed before
doing the changes to the distribution system.

It is rather unusual that the upstairs would be too cool. I might also
suggest that the distribution problem may be more of a return problem than
supply.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math