Let's talk about oven venting!

[Livinincolor]

As much as I hate to do it, I am convinced a vent is needed on our 38 cubic foot oven. I would like to hear from everyone that has installed a vent on their unit. If you have seen a commercial oven and noticed the vent, details about that would be cool too!
I am thinking about a 3" pipe, with some sort of flu cap on it. Can't vent it to the outside, but both big doors are open when in use, so air is always refreshed in the shop.....there is always a breeze blowing thru here!
If I could find the right circulation fan, I would think about maybe installing a fresh air vent on that....haven't had any luck at all locating a fan that can withstand heat though (and that doesn't cost an arm and leg).

Mike & Johnny
Sho Me Coatings

[Popeye]

Ours is 37 cubic' and it has a 5" vent at the top, the vent goes out through the wall and is terminated into a tee with a Breidert style cap. The vent is double wall B-vent pipe and is also insulated with high temp insulation. The vent has a very good sealing damper right where it exits the oven. That allows us to regulate the amount vent and retain heat when possible.

The air inlet is on the very bottom of the oven floor, there are a series of 2" holes covering the floor under the heating element.
You could probably accomplish the same thing with another 5" pipe near the bottom... and add a damper to help regulate the inlet air.

Our shop is 60 x 66 x 16, before we vented the oven to the great outdoors larger parts being cured would drive us out. That is with the hanger door open which is 45' wide x 14' high. Basically a wall removed...cough, cough

If you mount the fan OUTSIDE of the oven and run the shaft through the wall you can add a blade inside the oven. Be sure to add a blade outside the oven as well. The second blade acts as a heat sling and keeps the heat away from the motor. Make sure and blade shrouds... those blades make an excellent meat slicer as well..
IMHO

[Banditperformance]

Are we talking a vent for the fumes, or for cooling the oven down to cure temp after flow out has occured? I have a home built 16 CuFt oven w/7000W heat. Should I be thinking of venting that?

[Popeye]

Fumes mainly but it also works well for cooling down the oven once done.