IPC double wall HXer requirements

Mark Eatherton

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...

ME

jumper

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

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.

kcopp

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

Have had several inspectors make the call to forego requirement when non toxic is used or No glycol period .

EBEBRATT-Ed

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

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