damper for plenum

Hi everyone, been awhile since I posted but love this site. I am halfway complete installing my propane furnace. I've had my hotblast for 3 years now with no backup heat source. Propane is in the middle of the heat and cold air trunks and hotblast is at one end. Problem is I have hot air from the hotblast going through the propane furnace and spilling out, heat that could be used for the upstairs. How could I change this?
John

Can you install a shutter that would stay closed until the propane furnace turned on and then it would open to let the air through?

That's what im thinking. Has anyone made one? Or where could I purchase one, or do they even exist???

Only need to look as far as your manual...

I don't have a problem with the hotblast. Dampers are in place for that. Its on my 16 by 21 plenum on the propane furnace

gitrdonecoal wrote:I don't have a problem with the hotblast. Dampers are in place for that. Its on my 16 by 21 plenum on the propane furnace

Yes, but the principle is the same for either.

gitrdonecoal wrote:That's what im thinking. Has anyone made one? Or where could I purchase one, or do they even exist???

Yes, shop around, something like this,

http://www.homedepot.com/buy/building-m ... 23807.html


http://www.alanmfg.com/products/Shutter ... Start.html

Been asked about previously...
where to buy a 8x16 backdraft damper

Before I switched to a boiler I had a similar set-up. What I did was make a "sliding door" in each plenum. This allowed me to isolate either furnace. LOw tech but it worked great.