*
I haven’t got much experience with these. My BIL is building a house and wanted to know if you could put elbows in the vent stack. His plumber says yes but the gas man says he doesn’t want to suppy gas to such an appliance.
What say y’all
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
The FHB Podcast crew takes a closer look at an interesting roof.
Featured Video
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
*
Min. 5ft. height from collar
Bends allowed are 45° max. except one of 60°
minimum size = 7sq.in. or 3in. dia
right from the code:
http://www.codecheck.com/mechcode.htm#anchor795525
the length of the flue determines the diameter required. each bend decreases the length of the flue allowed (something like 2' per bend?) at a given diameter. sorry, but i don't have the table available. gas dryer flues allow 16' length at 4" diameter with 2 bends. each additional bend reduces that allowable length by 2'.
stick with your plumber and ask the gas co. to send a supervisor.
technically referred to as flue. vent stacks are for sewer gases.
have a good one bro,
brian
*Can you describe the planned installation with a bit more detail?I rarely see a DHW flue that doesn't have elbows, so I'm thinking there might be something else going on here.What area is the BIL in?
*Brian,Dryer vents are flues, drain and waste vents are not flues. All flues carry products of combustion (it is part of the definition), some vents are flues, some are not.Piffin, as Bob said, more information is required to get a useful response. Something of note, manufacturers installation instructions are an enforceable extension of the code (according to BOCA) and should be followed. Check those for the appliance(s) in question first. Not knowing what type of vent were talking about, nobody can answer you accurately. What Code applies?
*Piffin... sorry I haven't followed up on your e-mail.Job ain't here in CO is it?Lemme know if I can help.Note to others... gas supplier also has final say whether code allows it or not... but the idea to call a supervisor is good.Last job I finished I had designed the gas piping system for what is known as a 2 pound system. When I called for a 2 pound "set" on the regulator the gas company guy came out a day late. I wasn't there and he proceeded to tell the HOMEOWNER and the CONTRACTOR that I didn't know what I was doing, that my system was grossly undersized, etc. I was plenty hot, as GWB would say.I called a super and they sent the same idiot out. He wanted to argue with me. I felt bold for some reason and so this was my reply. "Since you don't know what you are doing, and since I do, why don't you just set the d*** regulator at 2 pounds and get the **** out of my hair and off this place." VERY unlike me but I was ticked a whole lot.He meekly complied. Claimed there was no such thing. Well, why did he have the 2 pound reg on his truck? He didn't know. I explicitly explained my opinion in a professional manner to the supervisor later... found out he was fired the next day.
*WHW: Any thoughts on the legal basis (if any) on the gas company dictating what piping is inside your home? Since the city inspector has already confirmed it is to code, where do they get off insisting on their particular requirements?Locally, they don't want dope and tape. They want dope only. Or nothing! The inspector is happy either way. They also don't like the creative use of a HWH which is something I often do.I've also had trouble specifying anything other than 7" water column service. Seems to me that if you know to ask for 2 psi service (or 5 psi in my case for 1,500,000 BTU/hour toxic waste burners), then you are more likely to know what/why you want it than the homeowner or GC who just calls for a meter without a pressure spec (and therefore gets 1/4 psi service).I've encountered these paternalistic attitudes from gas companies in many areas of several states. They act like they could be liable for some mishap in our house. Yet the electric company is happy with an inspectors sign-off or a licensed electrican's tag. What's the diff? Yeah, "Boom" is more dramatic that "zap", but you can be killed either way. Seems to me they'd be LESS liable if they DIDN'T stick their nose into things beyond the meter. -David
*Intresting, all.I don'tknow all the details since I haven't been on the job. BIL was over for dinner and asked the question.This is an island so no natural gas. It is propane on 100#bottles. This state, Maine, allows the plumber to install under his license. However, a new State code for gas, as I understand it, dictates that the gas man is ultimately responsible for where the gas goes and what it does, who it gases, monoxidizes, and blows up, as a general rule. He has the right to refuse to hook up and install in order to protect his license. I suspect that all these guys with the new licenses have been schooled in LIABILITIES. They also charge about three times as much as they used to a couple years ago. Some of that background came to me a couple of years ago when I called all the way to the State House and the New England council of blah blah because the regs had suddenly gotten so tight that the propane couldn't be hauled to the island via ferry boat.This particular installer is an individual in the business so there is no supervisor to appeal to. His license and the ability of the State to pull it if he messes up makes this a self enforcement issue. We have no building code enforced out here so no govt official. It is a similar situation with electrical in this state. A licensed master electrician signs off on his own work. And unless you are doing your own work, it is a class blah blah felony with possibility of jail time (that'sa right - not a civil offense - it's criminal law here)if you do electrical work for pay.Generally we all work well together to find solutions to design problems but these gas guys are running on the paranoid level 'til every thing shakes out. eg. We finally got the senator to push through an ammendment so the Coast Gaurd would allow us to cook with gas again. So if he can present solid reasoning to the gas guy he is likely to come out ok.I suspect that what has happened here is that the architect didn't allow for gas and the homeowner decided midstride that it is what he wanted. And so my BIL is trying - like all good builder do - to solve the problem.Appreciate you guys. This kind of random asssociation of experience and interchange is where we all learn.
*WHW,Could you expound a bit on why different pressures - what are the factors, why a 2 lb set on the one kjob you mentioned.Or, is the subject to complex for this sort of discussion?
*tim. i think that's what i said. it was only noted because it was described as a "vent stack", not just vent. "vent stacks", as such, is a reference to plumbing. i only noticed it because i read the message after scrolling below the title and got lost about what we were talking about.tim's right. manufacturer's provide recommendations as to the allowable run/diameter/bend combinations. david and whw: i would also appreciate any links pertaining to water heater exhaust.brian
*Wethead,Thanks for the reply and for remembering. I just assumed you were researching the other question at the coffee shop.I've had run ins with building officials out in CO also but remember, a code book and a cool attitude will always win the argument.
*This was a duplicate soooo.....
*My pleasure...When you have a home with a large and scattered gas load the main trunk line is huge and expensive.So by using 2 psi. (or 5 like Mr. thomas mentioned on the REALLY big ones) you can reduce the main trunk line to a tiny line. Like on this job I reduced from 1 1/4" to 1/2". Then at the end of the trunk line I put a special self limiting regulator to reduce it to 8" water column. Instead of the usual 6". If sized correctly I will have the required correct pressure at the appliance.Sometimes the "high" pressure is actually run to each appliance and the regulator is installed at each appliance.This reduces material and labor costs. BTW, 1.5 to 3 million BTU loads are not rare for houses here. Telluride, Aspen, etc.Also the piping immediately after your regulator is no considered your source as opposed to the meter outside allowing for smaller runs to each appliance.In certain circumstances you can vent the regulator to the outside but this is usually not required.Does this answer your question?Go to Gastite.com for more info including a free software program you can download to check sizing if you run acrossed it in the future. You have to be licensed AND certified just to buy their stuff but being a home inspecter you may find this useful.Now Bob, if you'll excuse me I need to mention a couple things for anyone else reading this.NOTE: Unless you are certified, DO NOT EVER ATTEMPT TO USE CSST for gas piping. And unless you are an experienced professional DO NOT EVER try to install one of these 2 psi. systems. They are not for the DIYers. Period!
*At the risk of sounding arrogant, I have never had a problem with a code official. I pour on everything I have ever learned about working with people and it works out. Because I want them to do their job... and I want to do it to code... and I assume that is all they want... so we must understand something diffferently... so let's see if we can learn something together...Feels pretty doggone good to have the head inspecter tell a large group of plumbers that if you need to argue with us try to do it like ******* who you know as WHW! I have been working on them on one piping issue for a year. They announced they were wrong and I was right and from here on they would allow this and this...I am not trying to brag... only trying to show what the way you recommended will get you in most cases. They know I try hard to get along and that gets me on a good foot to start with.Not all inspecters are this way though... I guess???
*I thoroughly dislike it. But if I remember right the code book actually says they have the final say so. (left code book on job today by accident)I want to point out this guy was not in compliance with his gas company. I first learned about this method from THIS GAS COMPANY!That along with the fact that he had badmouthed me to the GC and homeowner were what ticked me off and gave me the boldness to talk like I did. I would never talk to an inspecter like that... see my other post in this thread... I didn't need this guy on the job site period!
*Sorry I missed detail about WHO you had in your sights.Sleep good!
*that's cool... here is what did it to you! when I said...Job ain't here in CO is it? sleep good yerself...
*Bob: I need 5-psi gas on occassion because the equipment is designed for it. You are well aware of how home furnaces, stoves, and water heaters are vented to atmospheric pressure. But if, for instance, you need a flame IN FRONT of a catalytic bed, then you need enough gas pressure to overcome back pressure through the cat bed and various piping losses. The alternative would be an acre of platinium honeycomb and a stack 100 feet high to do it all with natural draft. So the equipment comes with a little stamped plate (like voltage requirements on motors) saying 4-7 psig natural gas. So this is nothing you'd ever encounter in residential construction. (Unless maybe the house was on top of a toxic waste site).Whereas Wet's 2 psi trick is a cool one for an easier piping install for large residential heating loads. And I absolutely agree with him, "I am a professional. Do not attempt this at home." Which I actually have on a work T-shirt. -David
*David, that comment was not meant for you. I just wanted to make sure someone reading this didn't say "Cool, I can do that"Like my friend who tested his gas line with 15 psi. right through the equipment gas valve because he had watched me do it one time. Somehow he missed the little point of disconnecting it between the shut off and the equipment! So he got to buy new gas valves the whole way around!I have never worked on equipment like you describe. Sounds very interesting. (BTW, I haven't but you can use a 5 psi set on my type of system) Is there a link I can learn more about it? I have no ned for it but like you I like learning about new stuff even if I will never use it.BTW, have you ever heard of a situation where they wanted to be able to crank the gas valve down so as to create carbon monoxide? Seems this is a standard proceedure in advanced ceramics... very interesting!
*WHW & Dave,Thanks! The range of information and expertise here is fantastic!A couple of follow up quetions,if i may:WHWH said: "Also the piping immediately after your regulator is no considered your source as opposed to the meter outside allowing for smaller runs to each appliance." [Empahsis added]Was that "no" supposed to be "now," which is what would make sense to me, or perhaps "not" (which wouldn't make as much sense, but when I don't know much about an area, I tend to distrust my "intuition."Also, I looked at my residential meter: the label read "MAOP 5psi ANSI Class 250."Am I correct in interpreting that as saying "this baby can take it up to 5 psi." Or "It shouldn't let higher than 5 psi into the structure?"What's the common pressure in the gas co's delivery system? You guys are talking about 2 psi and 5 psi. I assume you can't specify higher than what the system delivers, but, again, distrust assumptions made by an ignoramus in this area such as myself!And: the relationship of water column inches and psi is ...?And finally; I often see the botom section of the gas m,eter buried in soil from relandscaping. Should I consider that an issue? How much of an issue? E.g., if it's ok with the meter reader, can I let it slide?Thanks again
*I meant to say NOW considered the source! Sorry and thanks!They can actually just change the spring to change it to 2 or 5 psi so they can use the same regualtor for all of them. I would guess that is what your tag refers to. (that it can take up to 5 psi.)I honestly do not know the incoming pressure. I'll ask a gas company guy the next time I see one. Interesting question.I don't know of any charts comparing the 2. My guages have both scales on them. Do not know why the wci is used but it is impler and easier to remember, etc. They are both just a way to measure the same thing.I would condider this an issue but cannot back that up. My responsibilities stop where I hook to the meter. For sure do not depend on the meter reader! They are usually very ignorant on such issues. Ask the gas company's planner. They will know.Hope I helped you.
*BTW, thanks for the compliment.Also the water column inches is used for ranges under 1 psi. It gets impractical for over 1 psi. It is just a more acurate way to read it I think.(I just looked at my guage to come up with that last comment)
*Piffin,So did anyone answer you in wether or not you can have bends in a flue/vent?