Exhaust DC outside need a makeup air solution

[dennis davidson]

I exhaust my Oneida V3000 outside and am very happy with it. However for makeup air I either open a door or a window. Looking for something permanent/automatic. All the Louvered vents seem to be made for exhaust air and smaller ones all seem to cheaply made and the well made ones all seem to be too large. If you exhaust outside what do you use?

[joe milana]

Google make up air damper

[Mike Heidrick]

Run pipe outside, put on two 90s, run pipe back inside. Done.

[Jim Becker]

Run pipe outside, put on two 90s, run pipe back inside. Done.

LOL

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OP, perhaps you can use the same idea as some folks do with automatic blast gates....when the DC turns on, an air valve is triggered that sends air to an actuator that opens a the gate to allow fresh air in from outside. When the power drops to the DC, the air valve closes which retracts the actuator and closes the gate. Do a search on automated blast gates and see if you think you can work with that. A similar idea could likely be used with a motor-operated louver. Perhaps some of the more industrial suppliers might have something like that. Perhaps a surplus electric "skylight" opening/closing setup could be found, too, and adapted for something on the wall.

[Jim Andrew]

If you have an overhead garage door in your shop, you already have a source of make up air, because as the door is on the inside of your shop, your door automatically allows air into your shop.

[Bill Dufour]

Use one of those automatic fan vents louvers. just install it backwards. You may want to make something so it can be locked closed so high winds do not blow it open in winter. You may want to add a counter balance so it opens at a lower pressure differential.
Bill D.

[Robert Engel]

Are you worried about heat or AC loss? Don't. Its more myth than fact.

You would have to be running a large DC almost constantly to have an issue with it.

The very slight negative pressure created will be made up through door jambs or just opening the door once for a few seconds.

[Rick Potter]

Well....that slight negative pressure almost knocked my teeth out when, after running my DC for about 10 minutes in my 1600' shop, I opened the man door to go outside and it slammed into my foot HARD. Luckily, I had real shoes on, and they saved my face from getting hit.

About that overhead door. I have one and it certainly does not leak enough to provide make up air. (see above)

I have a 3 HP Oneida gorilla, 1600' shop, outside vent. I can notice reduced efficiency after 5 minutes of the DC running with no window open.

I played around with making a homemade vent that would open by itself, but gave it up. My 'temporary' solution for the last two years has been to leave a window at the rear of the shop open and cover it with a towel fastened at the top. When I turn on the DC the towel moves. I have left the window open all year long, living in SoCal.

I have not noticed a problem with heat or AC loss doing it this way.

[dennis davidson]

That’s clever with the towel - I like that🤔

[Julie Moriarty]

If you have an overhead garage door in your shop, you already have a source of make up air, because as the door is on the inside of your shop, your door automatically allows air into your shop.

Not with my garage door...

[dennis davidson]

Stand alone shop, no garage door, and tight windows and door.

[Alex Zeller]

Can you use something like a motorized louvered intake vent? You would have to cut a hole in the wall but you could wire it up so when you turn on the DC the vent opened.

https://www.amazon.com/Motorized-Exh...01D5MTF46?th=1