Outside exhausting damper

[Joe Shinall]

I'm probably going to ask about 12 more questions by the time I finish this dust collection setup so bear with me....


For those of you that exhaust outside, do you have any sort of damper on your pipe so bugs or rain doesn't get in? I'm not as much worried about the rain because I'm up high near the eave, but more worried about the bugs or birds or such because it's by the woods.

Was thinking about some sort of spring return damper or something but wasn't sure if that would work well.

Thoughts?

[George Werner]

Subscribing to this thread, I too am facing the exact same question with my install.

[Lee Schierer]

My DC doesn't go outside, but I would think you would want at least a screen to keep flying critters out. In colder climates I would think you would want an exhaust damper to limit heat loss and back drafts from the wind. I recently helped my son put in a ne range vent and he purchased a 6" spring loaded damper (https://www.amazon.com/Broan-641-Round-Range-Ventilation/dp/B00QW2BDYW/ref=sr_1_10?ie=UTF8&qid=1489102687&sr=8-10&keywords=exhaust+vent+damper) from amazon that works for his range hood. I've seen similar ones at 8" and 4" size.

[Joe Shinall]

My biggest concern with a damper is restricting the flow of the exhaust. Most dampers vent down under the cover and to me that is just shoving the exhaust against a wall basically. I would think I would have to find one where there is no outside cover, just the flaps opening straight out. It's a 5" exhaust pipe.

[Alan Schaffter]

Remember, SP anywhere in the "system" whether it be at a drop, in the DC or cyclone, or at the discharge affects the entire system, meaning it decreases CFM everywhere. If the discharge duct/hose is really long, is smaller than the outlet of the DC/cyclone, has an opening with smaller cross-sectional area than the duct, or has any obstruction (wire screen, spring-loaded flapper, transition- round to square/rectangular, etc.) it will add SP and reduce CFM everywhere in the system. The best recommendation is to have an unrestricted opening that aims downward (to prevent rain from entering). If you want a flapper, make it so gravity closes it and so it is nearly neutrally balanced.

[Joe Shinall]

Alan, there's not much I can do about the exhaust size. It's 5 inches and I'm not sure I can change that. The inlet is 6" but the exhaust is 5. Kind of weird to me, but I don't think I can change that besides reinventing the wheel and becoming a sheet metal worker haha!

[Alan Schaffter]

Alan, there's not much I can do about the exhaust size. It's 5 inches and I'm not sure I can change that. The inlet is 6" but the exhaust is 5. Kind of weird to me, but I don't think I can change that besides reinventing the wheel and becoming a sheet metal worker haha!

Inlet of 6" and outlet of 5"! That's bassackwards for sure!!!!! I can not see any reason for that??? Is this just a motor/blower unit or a cyclone? If it is a cyclone, what brand?

[Dan Friedrichs]

There's no reason you need to stay with the 5" exhaust, and you also don't need to use rigid pipe (because the exhaust is at pressure relative to the atmosphere). You could just go get some of that ~16" diameter insulated HVAC duct and use that for the exhaust - probably deadens noise and would drastically reduce SP loss (relative to 5" pipe). You also don't need to do any sheetmetal work to attach it - use a zip tie to clamp it down to whatever exhaust fitting you have :)

[Jim Andrew]

I have an 8" exhaust, and found no available fitting, so built my own. Used a piece of 3/4" ply with an 8" hole, caulked the pipe inside the hole and used flat head screws to attach the metal to the plywood. Then I used a piece of 1/4" plywood and a door hinge to make the damper. Had to make a shim to allow for the offset. The plywood damper closes pretty tight to the plywood, so I cut the hole in the wall between studs and attached it with screws, then cut some plywood to make a box to protect from moisture and ran it up to the soffit. Cut the plywood box to fit the siding, and used screws to attach it and caulk to seal around it.

[andy bessette]

Instead of installing an exhaust damper, which is sure to decrease air flow, how about installing a large blast gate to completely close off the exhaust whenever the DC is not being used? It could even operate on a solenoid that opens whenever the DC is powered up.

[Alan Schaffter]

Instead of installing an exhaust damper, which is sure to decrease air flow, how about installing a large blast gate to completely close off the exhaust whenever the DC is not being used? It could even operate on a solenoid that opens whenever the DC is powered up.

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[William C Rogers]

Instead of installing an exhaust damper, which is sure to decrease air flow, how about installing a large blast gate to completely close off the exhaust whenever the DC is not being used? It could even operate on a solenoid that opens whenever the DC is powered up.


That is is what I did. Also have a vent over the outside port. It was some type of dryer vent covering from big box store. Note the small amount of dust on the trailer fender was after running my drum sander about 4 hours making cutting boards.




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[Joe Shinall]

I don't know why my reply with quote won't work. But Alan, this is a Grizzly 2HP dust collector that I am adding a Super Dust Deputy XL to. I'm sure I can fashion something but that's going to take some time that I don't have right now. It seemed odd to me as well that the exhaust was smaller than the inlet. It's pictured below. I can probably take the adapter off the end and fashion some sort of square piping for it I guess. But I am very new to this "making parts" deal so I want to get the DC in place first and up and running so I can work then I'll tackle that issue. But any advice in the meantime would be welcome.

William, I like that idea.

I also thought about a blast gate with selanoid but I'm also not that smart so I'll have to figure that option out.

[Robert Delhommer Sr]

All I have on mine is a screen. So far no problems.