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**cobblerdave** · 01-24-2013, 12:09 AM

Re: Oven vent

Gudday
Well put mick.....I agree totally except the bit about smoke in the eyes. My mates got a tunnel oven internal chimney which you cap off after flashing up the fire. The heat coming out that entrance is real hot. More than one person has lost their eyebrows putting wood in that oven!!!!

Regards dave

**patiostone** · 01-24-2013, 05:29 AM

Re: Oven vent

Thanks very much! My yard is rarely calm so I will include one in my plans.

Cheers

**Mario Borja** · 01-29-2013, 11:42 AM

Re: Oven vent

I have a vent question for the group. I am designing my WFO to look like a fish with the entry being its mouth, the oven hump being its body and the tail at the rear to be added. I would like to vent my WFO via the usual location behind the entry. I would like to route the vent using 6" round stainless steel flex tubes over the oven hump and exit toward to rear via a fin as a cosmetic. The fin-vent exit is 12" above the top of the completed dome and 18" above the vent opening. Question: Would this design work? How much rise would I need to get a good draft given a 36" diameter floor, 19" dome height (using catenary curve equation), and 12" high entry. I have looked at the flow equation that many are using but it does not allow this variation. Thanks for your interest and response.

**Mario Borja** · 01-29-2013, 03:21 PM

Re: Oven vent

Thanks for the response. No, i have yet to purchase the hardware. I am just a few dollars short and three miles from getting it from a specialty shop here in SD. I came across a thread ref the ratio of vent opening area to door opening area should be greater than 10 percent. With a 6" round vent to a 12" hemispherical door door, my ratio comes out to 36 pi / 72 pi equalling .5. I thought sufficient, but I may have misunderstood what the ratio should be. I can go 8" round. This will give me a .89 ratio. Comment?

**Mario Borja** · 01-29-2013, 08:14 PM

Re: Oven vent

I agree. If I go from a large vent area to a smaller vent area the flow velocity does increase ... per aerodynamic theory. There will be flow with both 6" or 8" diameter pipes with the 6" at much higher rate of flow, Q dot. I am ready to go either way given empirical data from completed WFOs. I could also use a single walled vent piping from Home Depot to test the flow parameters at different diameters and at various venting angles before I finalize the vent system. Hope more responsescome in timely enough. Thanks for your response.