2-Pipe Convector

New England SteamWorks

Ran into a customer yesterday who had 2 baths (at opposite ends of the house) renovated and convectors installed on a 2-pipe system. All is quiet except for these two, which are quite loud with boiling water sounds.

Seems to me that once the trap closes the only place for the condensate to go is down the supply, and this is causing the noise. Can convectors be piped in this manner? Thoughts?

hvacfreak2

I guess if this were an old Victorian radiator the same would be true ( regarding the condensate ) wouldn't it ? The difference is the supply pipe size doesn't look as though it is up to the task of handling condensate and steam. From a contracting standpoint I think you are correct though , those traps are heading down to the basement ( or wrecked out ).

Danny Scully

I don’t know that I’d consider that a convector but rather a recessed cast iron radiator Try pitching the radiator dead flat, and possibly use eccentric bushings. Maybe removing the steam trap and adding an orifice could work too.

New England SteamWorks

> @hvacfreak2 said:
> I guess if this were an old Victorian radiator the same would be true ( regarding the condensate ) wouldn't it ?

Well, normally you’d see the supply piped to the top of the radiator. In which case the condensate can lay at the bottom until it cools, and then exit via the trap.

Maybe this is one of those deals where there needs to be a cooling leg before the trap?

New England SteamWorks

And correct @Danny Scully , not a convector in the traditional sense, but these units do convect.

Paul_87

I would think you need to pitch it pretty heavy towards the return or size the supply as if it were a one pipe supply to handle the condensate.

Ironman

It would seem that the way it's piped is the problem. If I understand Burnham's literature, the supply and return are different sizes and they're reversed. As Danny said, the concentric bushing is causing water to pool in the bottom of the rad.

Chris_L

For what it's worth, I have one of these radiators in my bathroom. It is a one-pipe, is level, with the supply on the right, and it is silent. Even though condensate is certainly pooling on the (left) plugged end.

The Burnham sheet is confusing. One dimension (F) is the pipe size, the other (C) the height above the floor. The two ends are the same.

I would wonder if the trap is working properly.

New England SteamWorks

Trap is working.

I’m on the road, but if someone could find in TLAOS where Dan writes about a cooling leg in such circumstances, it would be greatly appreciated.

ethicalpaul

Page 215 I think you're looking for.

"Since the condensate has to cool about 20 degrees below the saturated temperature of the steam, you'll sometimes see a "cooling leg" before a thermostatic trap when it's used to trap piping.

"The cooling leg gives the condensate a place to cool off so the trap can operate without backing water up into the pipes. Cast-iron radiators have large internal spaces so they don't need cooling legs. There's plenty of room in there for the condensate to spread out and cool.

"You'll more often see a cooling leg when the thermostatic trap serves a radiator without a lot of internal space (baseboard, for instance) or drips the base of a riser. Many older systems used thermostatic traps for dripping risers. They're slow to react, though, and hold water back in the system. Nowadays, you'll more likely see F&T traps on riser drips."

Then it goes more into F&T traps and there's no more about cooling legs, at least for quite awhile...sometimes Dan wanders a bit

Paul_87

If it’s a Burnham Radiant which it looks like it is both tappings are 1 1/4”.

New England SteamWorks

Can one use either tapping? Or is that one of the problems?

Steamhead

I think there is water pooling at the inlet connection, and the steam has to get up through it, causing the noise. The way this thing is constructed, pitching it won't help. Is there any way you can increase the size of the steam connection to allow for some counter-flow?

New England SteamWorks

> @Steamhead said:
> I think there is water pooling at the inlet connection, and the steam has to get up through it, causing the noise. The way this thing is constructed, pitching it won't help. Is there any way you can increase the size of the steam connection to allow for some counter-flow?

No. But I think I could remove the trap and reinstall it in the basement before it tees into the dry return. That should provide for plenty of condensate storage, as they are on the 2nd floor.

Steamhead

Problem is, water at the inlet connection doesn't make its way to the trap.

New England SteamWorks

Because the trap is closed, no?

Steamhead

Because the water has to go UP from the steam connection to get to the level where it can travel horizontally and drop down to the trap. Water is lazy and doesn't like to do that.

clammy

Just a idea how about u make a orifice plate with a top hole that’s acts as the feed orfice and a lower drain notch or cut that allows the condensate to drain down the riser . Hopefully w a small enough supply hole u can lower the velocity entering the raditor and in effect the riser and that would help drain any water pooling not to say that may not cause hammer in the riser at it s horizontal . Not to bust but had to ask is the boiler piped correctly and pipes insulated I can attest to decrease in issues on systems just by them being properly insulated .as heard echoing in space it worked till u showed up lol peace and good luck clammy

New England SteamWorks

Now that I am back at the shop and can see the Burnham stuff on my desktop, -it seems pretty obvious to me that the problem is that the supply and return are reversed. Right?

What's not to understand about "System Flow" with an arrow?

Ironman

That, plus the concentric bushing causing water to pool.

hvacfreak2

Someone mentioned that they have one supplied from the right and it's quiet. Either way moving the trap ( or gutting it ) and drip the spindly riser may be easier at this point depending on the working room in the basement.

Gsmith

Is the front and back of this radiator/convector the same? If so, take it out and reverse it end to end. Can’t tell from the cut sheet.

Paul_87

“Now that I am back at the shop and can see the Burnham stuff on my desktop, -it seems pretty obvious to me that the problem is that the supply and return are reversed. Right?

What's not to understand about "System Flow" with an arrow?”



I think you’re looking at the wrong picture. Look at the one on the top of the specs. There is no difference between the left and right tappings on that radiator. They are identical. The one you are looking at shows side tappings which that radiator does not have.

Chris_L

Yes, the supply/return tappings are identical 1-1/4 inch. (My quiet 1-piper is bushed down to 1 inch).

The only difference between the left and right sections is the locations of the top 1/8" vent tapping (front vs. side).

That System Flow diagram is not specific to these "Radiant Radiators" as Burnham calls them. The diagram is just showing the generic orientation of the supply (and return if there is one) and the vents for all their radiators used for steam and water. Here is link to the whole thing: https://files.gitshare.io/link/rBDNg1g1CSM/Radiator-Baseboard Product Data Sheet.pdf

EBEBRATT-Ed

I am sure plenty are installed that way and they work fine
But

Both supply and return are reduced at the radiator so water is laying in the bottom of the rad all the time.

The big if is if you have basement access and this is the FF (I hope)

Put trap in basement and use a eccentric bushing, coupling or reducing 90 in it's place.

If that's not enough fix change the inlet to a reducing 90