On Tue, 6 Dec 2016 07:42:53 -0600, "Terry Coombs"
wrote:

cln wrote:
I did a quick math on my Furnace. Even when adding the air exchange
vents, the air return is not even close to the same as what is fed in
the floor vents and such. if I'm generous it may be 3:2 ~ out:return

I'd also like your opinion on if this should be replaced for
efficiency?
Furnace is a late 1980 wood/electric Newmac.

Return air surface area should be like 125% of total output surface area -
more if the return path is long .
I've always worked with the goal of 150%