Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Double wall smoke pipe?

MCarp
MCarp Member Posts: 8
I have to install a Biasi B10-5 boiler this week. I am all ready to go.....only problem, a very tight space.I have no option but to come out of the back of the boiler with the smoke pipe, which happens to be smack up against the sheet rock wall. I know, simple solution, use another boiler but for the money and efficiency.....it's a good deal. MPO is a liitle smaller but the same deal. System 2000 too expensive. Can I use double wall smoke pipe and be alright??

Comments

  • Tim McElwain
    Tim McElwain Member Posts: 4,642
    Double wall "B" vent for

    gas requires a 1/2" clearance from combustibles. If the boiler allows for its use then go ahead.
  • kcopp
    kcopp Member Posts: 4,472
    Can you ...

    Change the wall? Whats behind the wall? How thick?  Can you insulate the cavity w/ Roxul and add cement board and an air space of sheet metal?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    1/2" clearance?

    I've always thought it was 1" of clearance. Has something changed?



    ME

    There was an error rendering this rich post.

  • MCarp
    MCarp Member Posts: 8
    Oil fired

    I am putting a Beckett NX.....does that make a difference?
  • Tim McElwain
    Tim McElwain Member Posts: 4,642
    Thanks Mark you are

    correct, I stand corrected it is 1" for "B" vent which by the way can only be used on gas not oil.



    Too many vent materials today it is hard to keep up with all the requirements, or maybe I am having too many senior moments. Now where are the keys to my car?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,858
    No problem Tim...

    we ALL have those moments, and that it why we are here. To keep an eye out for each other and everyone reading these posts.



    You've forgotten MORE than I will ever know...



    Thanks for your ongoing involvement.



    ME

    There was an error rendering this rich post.

  • Jack
    Jack Member Posts: 1,049
    Clearances will be greater

    B-vent is 1" as noted. Clearances on class A all fuel is 2", but you cannot use it as a vent connector and its thickness is so great that you would loose there anyway. You could use Selkirk's DS or Dura-vents DVL. Check those model numbers. It has been a while since I used them. They are 6" id and are outstanding for oil vent connectors. Type L, btw. Both are close to 7"od, but do have T's, 45 &90's. Perhaps, with authorization in writing from the manuf of the appliance and AHJ you could possibly use 4" pellet vent. It is L vent and again is an excellent liner for oil or vent connector, if you can use it. Check appendix E in NFPA 31 for sizes. These sizes in E are good. Problem is they are still an appendix and therefore not a part of the code. Remember, the only way you can do this is with approvals up and down. Oh, the pellet vent clearance is 3" I believe. DS &DVL is 6" as it is typically used on wood stoves. I don't know if there is a reduced clearance when used with oil. With no room, I think you are in a jam. I am pretty sure of these numbers, but again, it has been a while so please confirm the clearances.



    Whenever i get a call to look at a system that is shoe-horned into a space where no one can get at it to service it, I cannot help but refer to my old adage. "Just because it fits doesn't mean that is where it goes".
This discussion has been closed.