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venting question

I have a chimney in my house but no fireplace. There never was a fireplace, only a pot belly stove long ago that vented into the chimney by way of a vent pipe. The chimney is completely enclosed in the wall. Currently, my gas water heater's vent pipe 90s over in the attic and vents into the chimney. I called the codes office recently to find out if this was allowed since I am about to have my roof replaced. Trying to decide whether or not to dismantle the chimney above the roof or not. The chief plumbing inspector said it is allowed. I failed to ask him this, however. I will eventually call him, but thought maybe some of you would know. There is currently no vent hood in my kitchen. I plan to install one. Do you think I would be allowed to vent the piping for the vent hood into the chimney as well along with the gas water heater (which will eventually be replaced with a gas tankless water heater)? Is there any cause for concern in having a gas water heater and a vent hood vent into the same chimney?

Re: venting question

Our code says that "any vent offset angle greater than 45 degrees from the vertical is considered horizontal. The total horizontal run of a vent must not be greater than 75% of the vertical height of the vent".

So here is what we have: if you had a straight up vent fron your stove through the roof with a total length of 20 ft, for example, you could 90 it, in the attic, to the chimney, if the distance is less than 15 ft.

But since you are putting a new roof, why go through all this?
Install individual vents for the range and water heater. They will be shorter and cost less. And what to do with the chimney? dismantle it, unless you want to keep it for looks.

BTW, have you finished your bathroom?

Re: venting question

Not sure about a hood vent but most codes do not allow two different fuel sources to be vented into one chimney. (gas and oil)


Re: venting question

By installing individual vents, as I suggested before, all doubts are eliminated. It's the course of action I would choose.

Re: venting question

This is a layout of the kitchen where the stove and the current water heater are located in proximity to the chimney.......literally right next to each other.

dj1.....A couple of reasons for wanting to vent them both into the chimney. One is that I see the chimney as one roof penetration instead of two (individual vents). Another is that I'd really prefer not to have the two vents coming out on that side of the peak of the roof since that is the side you see when you drive up. A chimney, I don't mind seeing, but I'd prefer the vents to be hidden on the other side of the peak.

No, I'm not even close to finishing my bathroom. That is a huge undertaking on my part. I'm not very efficient when it's work I've never done before. I'm learning as I go, by asking questions here and talking to my dad about it all. Not to mention that I only have Saturdays free to work on the house.

I will definitely call Metro Code again this week and ask him what I should have in the first place......his answer may make my decision for me. :)

Re: venting question

Due to the accumulation of grease at the range hood and into the vent and chimney would create quite a fire hazard, especially due to the water heater and or heater duct vent already being installed into the chimney.
If your cook top, range is located on an exterior wall you can vent out the side of the home. If not, Your safest bet is a seperate vent through the roof, looks wise or not. It would be a bad day for all if you came home to a structure fire.... Hope this helps, Chris

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