Heat exchanger not heating up

jdere31760

I have a design that calls for a 40 plate heat exchanger to be placed between a steam boiler and a hot water circuit for radiant heat.

I installed as per the drawn plans. Steam line circuit to the top right of HE and return line bottom left. Hot water portion on the left side of HE.

No traps or vents. Currently when steam is on, the steam supply pipe getting very hot , but not HE. Do I need a vent or a trap?

Jamie Hall

You have three things...

of which one may be missing here: the air has to get out of the system somehow, somewhere, when the steam tries to come in.  So, for that matter, does the condensate from the steam -- but there is a lot less of that.



Sounds to me as though what is happening is that steam is made, and can make it into the feed line to a certain extent -- but since the air which was in the heat exchanger can't get out of it, the steam can't get into it.



There's got to be an air vent in there somewhere...



But I'm not an expert -- just a building super!

jdere31760

I think your right!

Jamie Hall,

  I think you are right. I just want to make sure I don't need anything else other than a vent.

Mark Eatherton

Also....

I don't remember who it was that said it, but "In order for there to be a difference, you must MAKE a difference". In other words, in addition to getting rid of the air, you will need something to make a pressure difference between the steam and the condensate so that the steam flows. Otherwise, you will be back at ground zero...



ME

nicholas bonham-carter

Making the difference

Would the difference be made by the condensation of the steam in the H/E producing the "abhorred" vacuum, and allowing more steam in?--nbc

Mark Eatherton

Well...

Ive seen HXers with vents, and no traps, and they worked, but not to full capacity until a trap was added, and then they kicked butt. Your milage may vary, but that has been my field experience. This was on city steam though. Not locally generated steam.



ME

Plumdog_2

Exchanger not heating?

You say the steam supply is on top right and return bottom left? But the hot water circuit is on the left? Could it be piped wrong? I'd check the connections against the paper diagram that came with the Exchanger.

jdere31760

Heat exchanger not heating up

Plumdog, I wrote it up wrong, It's defintely piped correct. Steam side is all on the right side, hot water side is on the left. I must have meant that steam suppy on top right and hot water side supply is bottom left.