No.9 snug baseboard piping

jpoops

Hello,
I am about to install Weil McClain snug no.9 baseboard(cast iron) on a concrete basement floor. The supply and return pipes are already stubbed out next to each other on the supply side. I know the supply will be entering the bottom. My question is; can I exit the bottom on the opposite end and return to the top of the baseboard? I fear I have to run my return piping above the radiator to the return that is stubbed out of the wall next to the supply.

Jamie Hall

This is, I presume, hot water? If so, you may have a little more than the usual problems getting the air out, but otherwise the water doesn't care.

jpoops

Thanks for the input. Yes it is hot water heat I am worried the water after it enters the radiator it will take the path of least resistance and not mix properly throughout the entire length of the radiation ( 24 feet ).

Mike

You're correct about the path of least resistance. You need to bring the water in one side, and out the opposite side.

Jamie Hall

As I understand your description, you are coming into the bottom of this thing at one end, and exiting from the bottom of the other end, some 24 feet away? I very much doubt that there will be short circuiting problem in that long a radiator -- if only because unless your velocities in there are truly outrageous, the warmer water will tend to migrate to the top as it goes along.

jpoops

Thanks so much for your help! I didn't want to have the return exposed above the radiator

Jamie Hall

jpoops said:

Thanks so much for your help! I didn't want to have the return exposed above the radiator

Eh? How do you get back to that stubout? Maybe I'm misreading something here? Are you thinking of running the return water back through the radiator? That would short circuit. I'm slightly confused.

jpoops

I had a reputable heating contractor say I could return to the stub out through the top opening on the opposite end in the radiator instead of running a return pipe over the top of the radiator back to the stub out . I was skeptical. My skepticism has been affirmed. Thanks for the help.

woobagooba

Bumping this thread. I am similarly getting conflicting professional views re: hydronic piping supply and return at the same end of cast baseboard (to accommodate inability to get a return pipe from the end opposite the supply).

I've been looking at the WM and BaseRay docs ... recommended piping and internal water paths are not obvious.

To be completely clear, the diagram I attach here is not recommended install?

I am also being told this is a simple as plugging both ports at the left end of the diagram?




Thanks a bunch.

EdTheHeaterMan

Have you considered running the pipe under the WM Snug 9?

Jamie Hall

woobagooba said:

Bumping this thread. I am similarly getting conflicting professional views re: hydronic piping supply and return at the same end of cast baseboard (to accommodate inability to get a return pipe from the end opposite the supply).

I've been looking at the WM and BaseRay docs ... recommended piping and internal water paths are not obvious.

To be completely clear, the diagram I attach here is not recommended install?

I am also being told this is a simple as plugging both ports at the left end of the diagram?



Thanks a bunch.

That piping -- with the opposite end plugged -- won't work. Think about it. The water comes in at one end. The easiest thing for it to do is to go right back out again. It won't circulate down the length of the unit at all.

An arrangement like that would work if the top half and the bottom half of the unit were physically separated -- but they aren't.

woobagooba

@Ed, thanks but not an option.

@Jamie. I am confused. I do not understand the internal structure of these baseboards, nor the need for top and bottom tapping on the ends.

EBEBRATT-Ed

@woobagooba

So you want to connect the supply to one end of the baseboard and return to the return stub which is on the same end as the supply?

It's done every day of the week. Check the baseboard enclosure. They all have a place to run the return line through above the heating element. Use a street 90 degree elbow and a regular elbow (or a baseboard tee) to make the 180 degree return at the far end.

The baseboard MFG makes "return line hangers" it's just a little clip to support the return line inside the enclosure

Jamie Hall

woobagooba said:

@Ed, thanks but not an option.

@Jamie. I am confused. I do not understand the internal structure of these baseboards, nor the need for top and bottom tapping on the ends.

The top and bottom openings are there mostly for convenience, although it is a little easier to purge the units of air if at least one of the top openings is used for connection. Internally, they are hollow -- there is no top pipe and bottom pipe; the whole thing is just one open space inside (well, with fins and things, but that's the general idea). If there were a separate top pipe and bottom pipe, then one could pipe them with a return fitting at one end and the feed and return pipes at the other -- but that's not so; you only need one pipe going in -- at one end --- in either the top or bottom fitting, and one pipe going out -- at the other end -- again, in either the top or the bottom fitting.

At @EBEBRATT-Ed 's suggestion may be "not an option", but you are going to have to run a return from the opposite end of the feed one way or another if you want the baseboard to work. Some things you just can't avoid, and that's one of them. Sorry.

woobagooba

@EBEBRATT-Ed is such a thing available for cast baseboard? AFAIK it is not. It is an option for fin-tube.

@Jamie Helps a lot thanks. This may drive us to fin-tube for this room, which can accommodate a supply / return at the same end (return hangers). Which in turn might drive this entire zone to fin-tube (back of the house ... we will reinstall all the cast in the front zone).

EBEBRATT-Ed

@woobagooba

Mys mistake thought you had fin tube

mattmia2

You could also figure out how to make an adapter or reducer be threaded on the outside and have a length of 3/8" copper sweated to the inside and stick it most of the way through the basebaord as a lance to effectively move the supply or return to the other end. It is sometimes done to feed a conventional radiator from a single tapping.

EBEBRATT-Ed

@mattmia2

A double tapped bushing maybe if they make them that small

mattmia2

I'm thinking a male adapter and a sweat bushing or maybe even a male adapter with the stop filed off depending on what size the tappings are and what the clearance inside the baseboard is. Danfoss makes an all in one supply and return fitting with a lance but that is probably overkill for this.

How long is this baseboard section?

EdTheHeaterMan

Switching to copper w/ aluminum fin baseboard may be your only other option, however, you can’t mix the two different types of radiation in the same zone.   Make sure you use all CI or all copper pipe on a zone.  You will find it to be problematic if you design a system with different emitter types on the same loop.   

But it looks like you already know that 

metrorental

the Snug manufacturer's drawing shows a spot for a return pipe to be run through the area above the fins. i did the same thing with burnham baseray.

woobagooba

I called Weil MClean tech support (they were very helpful). They confirmed recommended best practice for Snug 9 is to supply at one end, return at the other.

@metrorental. I took 1/2 inch copper pipe to the back of the snug 9 and it does indeed fit. See pics.



Remaining concern with this approach is blockage of the convection path by the copper and maybe expansion noise, but AFAIK the snug 9 is predominately radiant.

mattmia2

It doesn't take up enough space to be a concern.

mattmia2

The one thing I might do is cut a few inch or so long pieces of plastic or rubber tubing that slip over the copper and use them to space the copper away from the CI so you don't have dissimilar metals touching, so you don't have the copper chaffing on the CI and so the copper can expand and contract freely without making noise.

woobagooba

An update. We decided to shim the Snug 9 out an inch from the wall to create a space for the return line to run behind the baseboard back to the supply end. We will cover the gap at the top with a piece of wood trim.