Walling off a furnace?

[supton]

I'm starting to use my basement more; and it stays kinda cold in the winter. I put up some 1" thick foam insulation onto the cinderblocks; that raised the temp about a degree. I think the big problem is the breeze coming through a horizontal flue on the furnance. Ergo, I am thinking about making a removable wall around the furnace. [Due to space constraints I can't just make it into its own room.]

I'm guessing I need an air intake, preferably with a one-way flapper (ala dryer vent). Would a 4" hole be good enough? Or should I use two of those? It's not a big furnace, I don't know size off hand but it's a typical Beckett burner, heating a small house. The flue does have an fan in it, to ensure draft, so it does pull a good amount of air.

 

[Rob_Roy]

Horizonal flue? Are you talking about the barometric damper on the flue pipe? a.k.a. "draft control"?

Fan in the flue? Are you talking about a draft inducer??

If you do wish to wall off the furnace, you will need to bring combustion air into that space by another means. There are rules to guide you with the duct sizing, and plenty of info online: http://www.nationalboard.org/index.aspx?pageID=164&ID=191

Lastly, don't expect miracles by bringing outside air to the burner. An unheated basement will still be cool. My preference would be to add a zone/duct to the basement and enjoy a warmer spare, and more comfortable floors.

 

[supton]

Err, sure... All I know is that it has a squirrel cage for draft, and a damper which, when the furnance is not running, will move about as the breeze blows. The exhaust from the furnace goes through the exterior wall in a horizontal fashion, hence the blower.

After looking that link, I now have to wonder if part of the problem is that the furnace has to pull air through every air leak in the basement. Which of course will cool the basement. I did block off the chimney (woodstove), as I had a backdraft from that, which by itself raised the basement temp by a couple of degrees (if not more). I wonder if I could get a cold air intake, somehow, with another fan to feed the intake side.

Seems like I would need a huge opening, as I think the burner is 8 gallon per hour. Two openings, actually, which would defeat the purpose. Ok, sounds unworkable, will forget the idea.

Thanks!