On Mar 7, 12:07 am, "dean" wrote:
Hello all,

I have a wood furnace in my basement with central forced air, and
right now (all winter so far) I have been leaving the basement door
open so that the cold air return is sucked down the stairs.

I'm considering connecting up the returns to the furnace so as to make
a closed system, and I wanted to know if this makes much of a
difference in fuel usage and/or house temperatures. Right now, the
furnace has a struggle with a 50-degree difference outside vs. inside,
so if its 20F outside, I can almost not reach 70F inside.

Any experiences welcomed here.

Thanks

DeanB

There are so many variables to consider here that I don't think anyone
will be able to answer your question by comparing their own
experiences. How well insulated is your basement from the rest of the
house? How well insulated is your basement from the outside? How far
with the air returns have to run? What size ducting will you use?
How well insulated is your house? What is the level of difficulty in
installing the ducts? What is the air volume of your basement as
compared to the volume of your house? What would be the total cost of
installing the returns?

If the duct is just a straight shot up from the furnace into the floor
above, then that would be both easy and cheap to install. Consider,
however, that the temperature difference at the surface of the floor
and the basement ceiling probably isn't going to be all that much.

Some of these questions can't ever be answered with a high degree of
precision. If you really want an accurate projection on your ROI for
this project, I'd talk to a qualified HVAC consultant who can do an on
site inspection

With that said, also don't forget that if your basement is very poorly
insulated and dips below freezing, you risk rupturing your pipes, or
ruining any stored materials such as latex paint.