I don't remember reading any rules about replying to old threads... if there is one, please let me know and I won't do it again.
Anyway, I remember reading this post a couple years back when I was considering a stoker instead of the hand-fired furnace. Noise was one of my concerns, so I planned a similar setup for when I purchased my stoker, a Leisure Line Pioneer. My suspicions were confirmed when I fired the stoker up a week ago. Don't get me wrong, I'm VERY pleased with the unit; it works beautifully! But why not try to quiet it a little more? I have the stove right in the middle of my living room so it couldn't hurt.
My other concern was fresh air for the stove. I have a fairly tight house, and when I ran the furnace, I had to keep a window open near the furnace, or the fire would actually go out! So this mod kills two birds with one stone for me!
Anyway, after about $20 of supplies, I performed a similar mod to what av8r did with the combustion fan, and since his pictures aren't loading for me anymore, I wanted to post a few pictures I took, and cover how I did it, for anyone else stumbling on this post. I bought a galvanized 4" (I think!) round pipe takeoff (crimped on one side, and a bunch of tabs on the other side) -- can't remember exactly the size -- and bent all but one tab on each "side" of the take off in to all more air flow. I drilled the remaining two tabs to line up with the bolt holes on the combustion fan and attached it. I then took a length of dryer duct and attached it. Now for the rest of the setup. In my case, I couldn't use the plenum in the wall to just attach the pipe to, as it's sealed at the top in the attic, I assume as a fire guard. Also I have no basement. So I used 3" thin-wall PVC pipe, ran through the wall into a 90 degree elbow, and ran up to the ceiling. I have about 2 feet of pipe sticking up in the attic to make sure I don't pull in any insulation or anything else that may be up there. I used 3" thin wall since it's cheap, and larger ID than the intake to the combustion fan. I ran through the wall since I didn't want the PVC in the living room, and the other side of the wall is just a hallway leading to the laundry room and mud room... who cares about the pipe in there?
With it all said and done, I estimate I have quieted the combustion fan noise down to maybe half of what it was beforehand. Well worth the $20 and the hour of measuring and cutting PVC and sheet rock. The total list of supplies for anyone looking to try is:
- 4" duct takeoff
- 4" flexible dryer duct
- 2 clamps
- PVC reducer: 4" schedule 40 pipe to 3" thin-wall pipe
- length of 3" thin-wall PVC
- 90 degree thin-wall PVC adapters as needed
Pictures are below. I suppose if I really wanted to quiet it down more, I could move the fan, but this seemed like the simplest method, and I don't mind a little white noise. I suppose I could also add a gasket between the duct take-off and the fan, but again the noise gain here is minimal for me. Thanks again av8r for the original idea!!