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engineer

Paul S_3
Paul S_3 Member Posts: 1,257
edited April 2016 in THE MAIN WALL
I'm in the beginning stages of a job....im working with the customers engineer...he has to draw out the plans then the building dept approves them. there is an existing 6 inch b vent chimney already there. not exposed....chimney runs about 45 ft to roof....total btus are (3) 40k water heaters and (2) 50k input boilers so total btus are 220k....when I look in my Selkirk manual it says that the existing chimney can handle the load and properly vent.....the engineer is insisting on us running a new 10 " bvent chimney....the engineer says "he does not feel comfortable with a 6 in chimney" am I wrong with my calculations ? this engineer is not budging and gets aggravated when I question this. I really do not want to run an exposed 10 in bvent ..also what happens when one water heater runs is the chimney oversized? he told me he never heard such thing...can that pose an condensation problem down the road?....thank you
ASM Mechanical Company
Located in Staten Island NY
Servicing all 5 boroughs of NYC.
347-692-4777
[email protected]
ASMHVACNYC.COM
https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company

Comments

  • ChrisJ
    ChrisJ Member Posts: 11,974
    Paul S said:

    I'm in the beginning stages of a job....im working with the customers engineer...he has to draw out the plans then the building dept approves them. there is an existing 6 inch b vent chimney already there. not exposed....chimney runs about 45 ft to roof....total btus are (3) 40k water heaters and (2) 50k input boilers so total btus are 220k....when I look in my Selkirk manual it says that the existing chimney can handle the load and properly vent.....the engineer is insisting on us running a new 10 " bvent chimney....the engineer says "he does not feel comfortable with a 6 in chimney" am I wrong with my calculations ? this engineer is not budging and gets aggravated when I question this. I really do not want to run an exposed 10 in bvent ..also what happens when one water heater runs is the chimney oversized? he told me he never heard such thing...can that pose an condensation problem down the road?....thank you

    What does the manufacturer of the B vent say for multiple appliances?

    You'll have to check for yourself, but this is what I just grabbed out of Simpson's Duravent book.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • JUGHNE
    JUGHNE Member Posts: 8,949
    Could he be not considering the height? That should suck your hat off your head with a little wind.
    Delicate feathers to ruffle aren't they?

    Can't believe an engineer would allow such small appliances in the first place ;) .
  • Paul S_3
    Paul S_3 Member Posts: 1,257
    Thank you @ChrisJ ....im at around the same with the btus on the 6 inch on the Selkirk manual....he just insisting on the 10 inch because "he does not feel comfortable with the 6 inch"
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • ChrisJ
    ChrisJ Member Posts: 11,974
    Paul S said:

    Thank you @ChrisJ ....im at around the same with the btus on the 6 inch on the Selkirk manual....he just insisting on the 10 inch because "he does not feel comfortable with the 6 inch"

    I wouldn't feel comfortable with the 10" at 45 feet.
    My 6" 30 foot B vent pulls one hell of a draft when it's cold out, especially near 0F. That's why I left the barometric damper on it even with the drafthood.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Steve Minnich
    Steve Minnich Member Posts: 2,674
    Are the boilers Cat I (Nat) or Cat III (Fan Assist)?
    Steve Minnich
    Minnich Hydronic Consulting & Design, LLC
    [email protected]
  • Paul S_3
    Paul S_3 Member Posts: 1,257
    @Stephen Minnich there CAT I natural draft
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • JUGHNE
    JUGHNE Member Posts: 8,949

    Here is a generic chart from AGA & GAMA of 1991, no brand name or company associated with this info.
    I doubt if these things change with time.

    He is actually arguing with his peers as I would bet there were a lot of ME's involved in all three charts here.

    Perhaps he is looking at vent connector capacity, that always kicks my but as I seldom ever run "B" vent at all.
  • Rich_49
    Rich_49 Member Posts: 2,611
    Cold flues are cool . What is his reasoning for the 6xs larger than necessary vent ?
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • JUGHNE
    JUGHNE Member Posts: 8,949
    edited April 2016
    Somewhere there must be a guide for the maximum oversizing of existing "B" vents for orphan water heaters abandoned when condensing boiler/furnaces are installed.

    Just a gut feeling that the 3 standing pilots of WH's would be overwhelmed trying to warm an outside exposed 10" vent.
    Then one of the boiler fires and backdrafts thru WH hoods until draft is established. Just a thought.
    Rich_49
  • Paul48
    Paul48 Member Posts: 4,470
    Maybe there's an up side...It could be used as a cell tower :smile:
  • Paul S_3
    Paul S_3 Member Posts: 1,257
    edited April 2016
    Thank you guys i appreciate it.... @Rich he says it will not vent...im meeting him at job in a couple days...im showing him the NYC fuel gas code sizing
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
  • ChrisJ
    ChrisJ Member Posts: 11,974
    edited April 2016
    Paul S said:

    Thank you guys i appreciate it.... @Rich he says it will not vent...im meeting him at job in a couple days...im showing him the NYC fuel gas code sizing

    Well,
    I'd say his rear end is venting, that's for sure.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    JohnNY
  • Steamhead
    Steamhead Member Posts: 14,840
    :D:D:D
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Brewbeer
    Brewbeer Member Posts: 616
    Paul S said:

    Thank you @ChrisJ .....he just insisting on the 10 inch because "he does not feel comfortable with the 6 inch"

    Ask him to show you his calculations that are making him uncomfortable.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • rick in Alaska
    rick in Alaska Member Posts: 1,242
    Too bad you can't get a new engineer. Any engineer that says he "does not feel comfortable with it", apparently can't back up his engineering. Or he would just say, "this won't work, and here is why". Is he a civil engineer?
    Show him the charts and hopefully he will agree with them.
    Rick
  • jumper
    jumper Member Posts: 1,710
    Few engineers understand over&under pressure. I confess that I may fail qualifying for the few.
  • Jamie Hall
    Jamie Hall Member Posts: 17,080
    If I may... if you can educate this individual, that will be a plus -- for both him and your client. However, may I point out that if he (or she?) doesn't feel comfortable, he (or she) won't and indeed shouldn't put his or her stamp on it. It must be remembered that it is one thing to say "well, it's up to code"; that will usually serve as a good defense if things go pear shaped -- but not for an engineer. His or her stamp says, to put it simply, that he or she has examined whatever it is, has evaluated it, and personally guarantees that it will work as intended.

    This is not intended to excuse ignorance on the part of the engineer (although if that is the case, he or she should not be in that particular area of practice -- but that's another story) but only to suggest why some engineers may be seen as rather stuffy or overly conservative.

    For what it's worth, that italicized phrase is why I no longer practice as an engineer -- as an individual, there is no way that I could generate enough billing to afford the errors and omissions insurance (and I've never had a claim). I would need to raise over half a million dollars per year just to hang out my shingle -- and then fork over 20 to 30 percent of my gross fees on top of that. Not happening...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JohnNY
    JohnNY Member Posts: 2,755
    Tell him if you're signing the job off, it's got to be your way with this. You've got documentation and know accepted industry practices for which begin and end with manufacturer's testing and published tolerances, and Fuel Gas Code. Not the opinion of an engineer who doesn't care a lick about what a job is costing.
    Is this a Staten Island job? Nothing good happens on Staten Island. I know. I lived there for 32 years.
    Contact John "JohnNY" Cataneo, Master Plumber
    in New York
    in New Jersey
    for Consulting Work
    or take his class.
    jonny88Paul S_3
  • Brewbeer
    Brewbeer Member Posts: 616


    For what it's worth, that italicized phrase is why I no longer practice as an engineer -- as an individual, there is no way that I could generate enough billing to afford the errors and omissions insurance (and I've never had a claim). I would need to raise over half a million dollars per year just to hang out my shingle -- and then fork over 20 to 30 percent of my gross fees on top of that. Not happening...

    Really? My firm does engineering (geotechnical) and other consulting disciplines (industrial hygiene, regulatory permitting, environmental compliance) and our errors and omissions insurance is about 0.5% of gross billings.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • Paul S_3
    Paul S_3 Member Posts: 1,257
    @JohnNY ...no job is in Brooklyn....and i usually use my engineer
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
    [email protected]
    ASMHVACNYC.COM
    https://heatinghelp.com/find-a-contractor/detail/asm-mechanical-company
    JohnNY
  • Jamie Hall
    Jamie Hall Member Posts: 17,080
    Brewbeer said:


    For what it's worth, that italicized phrase is why I no longer practice as an engineer -- as an individual, there is no way that I could generate enough billing to afford the errors and omissions insurance (and I've never had a claim). I would need to raise over half a million dollars per year just to hang out my shingle -- and then fork over 20 to 30 percent of my gross fees on top of that. Not happening...

    Really? My firm does engineering (geotechnical) and other consulting disciplines (industrial hygiene, regulatory permitting, environmental compliance) and our errors and omissions insurance is about 0.5% of gross billings.
    Yeah... the percent of gross goes down as the gross goes up. A one-man firm gets really truly hammered. Worse, I would be working in hazmat (not compliance -- remediation)... where the potential liability for a screwup is unbelievable!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • jumper
    jumper Member Posts: 1,710
    Courts and discipline authorities have become unfair to professional engineers. Used to be that if you documented concerns properly then your professional judgement ruled. Now you can get whacked no matter what. If you state a code exemption you can be guilty because you substituted your judgement for the consensus of some code writing committee. Who's never held liable. Or if you state that you decided to follow code then you're still liable. Engineers are paid extra just for their bird stamp.