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.

Boiler Header Size and Other Questions

Options
NoelAnderson
NoelAnderson Member Posts: 49
I will be installing a Slant Fin 60,000 Btu input boiler with a Cross four zone manifold. The heat loss for the structure is @ 47,500 Btu's and the four zones of fin tube are plumbed using 3/4" copper pipe. I plan on using a Alpha 2 pump with a magnetic air and dirt separator. My question is would you use 3/4" copper pipe out of the boiler to the manifold, or 1" diameter pipe. The 3/4" pipe would be cheaper for my customer and would still be under the 4 feet per second rule for the air separator, but I don't know if it would be too much a restriction for the 1" diameter Cross manifold.

For my next question, how is every one liking the Cross manifolds since they are still new to the hydronic industry?

Finally, on the Slant Fin Sentry boiler line the circulator appears to be bolted to the return side of the block and not using a NPT. tapped hole from the factory. I would be ditching the factory circulator and mounting the Alpha 2 and expansion tank on the outlet side of the boiler pumping away from the PONPC. Can anybody confirm there is a 1-1/2 NPT. on the return side of the Sentry boiler along with the four bolt holes, or will I need to make some sort of adapter to hook up my return pipe.

Thanks,
Noel

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,153
    edited March 2021
    Options
    You are very close to the tolerance of 3/4" piping used for shared piping.

    All you need to know about near boiler piping is in this text.
    http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

    with a handy reference chart on the last page.

    The answer to your query is in the first few pages of the text and included on the first three items (and 6th chart) in the rules of thumb cheat sheet.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,735
    Options
    @NoelAnderson

    I would use 1" as @EdTheHeaterMan said your right on the edge of the 3/4 capacity. 1" will allow better air separation
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,153
    Options
    The Joy of a lower price is quickly forgotten while the dissatisfaction of inferior workmanship is long-lasting

    I can about guarantee your customer won't care a lick about the cost difference between 1"and 3/4" with velocity noise was driving them crazy. Or they weren't quite getting enough heat.

    I do know what you mean though, the price does jump a bit between the two sizes. 

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?