Damper for add on

[mattinpa]

I wanted to put a damper in the pipe between my add on furnace and my oil furnace plenum. When I went to go
order one at my furnace supplier, they said one typically is not used and that I should just run the heat pipe
at a 45 degree into the plenum. They said a damper would not give me the effect that I would think it would give.
Does this make sense??

 

[smokinj]

I wanted to put a damper in the pipe between my add on furnace and my oil furnace plenum. When I went to go
order one at my furnace supplier, they said one typically is not used and that I should just run the heat pipe
at a 45 degree into the plenum. They said a damper would not give me the effect that I would think it would give.
Does this make sense??

ok what effect you wanting?

 

[mattinpa]

I just thought one would control backflow. When I run the oil furnace, I really don't want the air from it
flowing to the wood furnace, do I?

 

[smokinj]

I just thought one would control backflow. When I run the oil furnace, I really don't want the air from it
flowing to the wood furnace, do I?

yes i would use one if nothing else the manual one so you can cut the wood furance out of the loop in the summer

 

[jdew1920]

I'm installing a Daka furnace and manual states to place a manual damper on the wood furnace side for the reason smokinj said. For the Daka they use 2 8" ducts going form the wood furnace into the plenum of the main furnace - they say to use 90 degree elbows pointing up in the plenum (in the direction of air flow) to avoid back flow into the wood furnace. They also have a couple of other alternatives in their manual you may want to look at. You can find it at dakacorp.com. I have also seen in the US Stove manuals that they show the duct intersecting the main furnace plenum at a 45 deg angle like you mentioned.

 

[laynes69]

Yes you need one despite what they say. That way you don't lose pressure through the plenum of the oil furnace.