Multimple terminations at Chimney

[Eric Roberts In San Jose]

Hello All,

This is my first post so i hope that i am in the right forum.
My project is in Mountain View, CA and I am trying to find any codes
that may apply to my question.

I will have a chimney that serves a Direct Vent Fireplace Vertical Termination. And i am trying to find out if my Chimney can also serve as a termination point for my environmental air duct that is serving a range/oven. I am thinking if i include a divider plate, i should be able to have multiple termination caps in the same chimney.

It's my understanding that neither of the terminations would be considered 'openings' that i need to maintain a 3' clearance from each other.
I couldn't find any reference to clearances between multiple terminations.
Is anyone aware of any reason this would not meet code?

Any input is greatly appreciated
Thanks!

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[H.G. Watson, Sr.]

Yes, several.

Mechanical Code, Residential Code, Fire Resistant construction.

First off, I suspect you do not mean "a chimney" but a common chase or possibly a common shaft, which may or may not be of fire-resistant construction and may or may not be fire stopped.

Your mechanical environmental duct (range hood, micro-hood, etc. fan driven) does not belong anywhere in or too near "a chimney".

Your direct vented mechanical requires a combustion air intake originating within specific proximity to your exhaust vent termination to be "direct vent" (either sep. vents or a concentric vent & term) - that intake shouldn't be anywhere near a mechanically vented exhaust - and certainly not sucking in grease and moisture ladden exhaust from your range hood.

Neither appliance nor mechanical should be vented or exhausted in "a chimney".

The environ. duct most likely required to be metal of specific min. guage depending on metal type. The DV may be special venting which most likely will be a different material.

Both must be appropriately and independantly fire blocked and draft stopped as the California Codes specify. You may not combine fuel-fired venting with environmental air ducting.

Any modification, alteration, change-in-use, or abandonment, of an actual chimney (site built or manufactured) requires inspection and evaluation by a professional.

[Eric Roberts In San Jose]

Hi H.G.,

Thank you for your reply to my question.

I hope i didnt make you feel like you wasted your time with my poor nomenclature, i definitely think my question was not worded correctly. Please forgive me for that. Ive included a little sketch pdf of what i'm proposing.

I am not proposing to share or connect either duct system with any other flue serving the other appliance. And both will maintin the manuf. rec'd clearances to combustibles.

Both the venting for the Direct Vent Fireplace is through a manuf. approved vent system to a termination cap (Simpson Dura-Vent)
The exhaust vent from the range/oven is also through its own seperate vent system to a termination cap.

And, i understand that i would not want to intake exhaust from the environmental air duct. I can maintain the 3' clearance from openings into buildings mentioned at CMC 504.5.

Is there anything preventing me from including both metal ducts in a shaft if i can maintain clearances to combustibles.

FYI, this is for a project that is not built yet, and still needs to go through the city's plan review process. Trying to 'hide' the mushroom terminations in a shaft 'false chimney'

Thanks again for your time