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IPC double wall HXer requirements

Mark Eatherton
Mark Eatherton Member Posts: 5,840
Greetings, has anyone come across the double wall requirements in the new IPC yet? A good friend of mine notified me of it yesterday. If in fact it is true, it's really going to out the kaibosh on indirect and reverse indirect water heater efficiencies... I hope he's mistaken...

It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.


  • jumper
    jumper Member Posts: 2,139
    Do you mean ICC?

    I remember when double wall requirements came out in the seventies for refrigerant desuperheaters and kiboshed that source of free energy. Nobody was previously harmed by DHW becoming contaminated with refrigerant but...

  • hot_rod
    hot_rod Member Posts: 20,790
    Is it just on glycol systems?

    Some areas I visit require all double walled DHW HXers. I think Minneapolis is one.

    Then I heard that Montana dropped the double walled requirement a number of years back?

    If that is true, maybe an external FP double walled would be better efficiency? Tank replacement $$ would drop with external HX.
    Certainly much better heat transfer with two pumped flows with FP.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kcopp
    kcopp Member Posts: 4,305
    edited March 2018
    Why would they do that?
    Has anyone gotten sick from leaking into the DHW tank?
    More than likely it will leak to the boiler and have the relief valve drip.
    I suspect that the indirect water heater manufacturers will try to not let that get adopted at the state level.

  • Rich_49
    Rich_49 Member Posts: 2,763
    Have had several inspectors make the call to forego requirement when non toxic is used or No glycol period .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
    EBEBRATT-Ed Member Posts: 14,534
    Double wall heat exchangers. Used to use them in the old days to heat heavy fuel oil (#4 &#6) to preheat it (with steam or hot water) to burn it.

    If the hx let go you would get oil in the boiler which of curse is a no no.

    Google: Alstrom Energy Group. They have been around for years and make double wall and other hxs
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,369
    Mark That is the code in Allegheny County where I live and has been for a long time. It is the Plumbing Inspectors asking for it
    Ray Wohlfarth
    Boiler Lessons