Runtal Charleston Pro with one pipe steam

tobynewman

Hi--I'm renovating my living room and bedroom and I want to replace the old cast iron radiators with Runtal Charleston Pros--brochure here:

https://runtalnorthamerica.com/wp-content/uploads/2021/07/charleston-radiator-1.pdf

I realize many people feel that these newer radiators don't provide as good/consistent of heat as the traditional cast iron ones. I'm willing to live with this--I'm on the first floor and it's always quite hot down here compared to upstairs. I'm insulating both of these rooms as part of the renovation and I've taken all the obvious steps to balance the system. For the purposes of this discussion let's not get into the 'quality' of heat provided by these radiators--I want to use them because they're wall hung and the 16" height will fit between my baseboard and window sill.

That said, I don't want to end up dealing with water hammer issues or anything like that. I've spoken to a couple of plumbers who seem comfortable working with these radiators, but I also spoke to one plumber who said he had a horrible experience with one and that he refused to ever do it again. He said that there was water hammer so bad that he had to pitch the radiator 1/4" per foot to get it to stop. That got me scared, but he wasn't really able to give an explanation for why this would be any more of an issue with these radiators versus traditional cast iron ones. Does anyone have any thoughts on this? I can't imagine this company is able to market these radiators for one-pipe steam if this kind of issue always comes up...

I'm also getting mixed opinions from different plumbers about whether it's okay to pipe the steam up through the wall to have a horizontal stub supplying the radiator. Most are telling me it's fine--and I would prefer to do it this way--but again there's one plumber telling me that for one-pipe steam the stub has to emerge vertically from the floor. Is it crazy to supply steam to a radiator with a horizontal stub coming out of the wall?

Thank you everyone for your help!

EdTheHeaterMan

The radiators were not the reason for the water hammer your plumber friend encountered, it was the way he installed them. Getting the pitch correct is most important. that goes for the supply pipe also. you are better off if you can bring the pipe from the floor into the radiator so the condensate will easily drain back to the boiler. You can use a horizontal from out of the wall but it should be at a sufficient pitch to allow for condensate drainage. Like not actually horizontal but perhaps a 45° or at least a 15° angle so water will not pool in the fittings. This is not a job for just any plumber, you will need steam expert to get it to work correctly. Where are you located?

Jamie Hall

Just to add to @EdTheHeaterMan 's comment -- a quarter inch per foot is about right for ANY one pipe radiator, and is a real minimum for any "horizontal" pipes involved.

delcrossv

The link says: "The radiator should be tilted a minimum of 1/16” per foot toward the condensate return."

Which is really lower than I'd be comfortable with. As Jamie and Ed said, 1/4" per foot is preferred for all horizontal runs.

What's wrong with bringing the riser out of the floor?

Mad Dog_2

Those radiators work well with a correctly working steam system. Mad Dog 🐕 

New England SteamWorks

Be advised that being steel, they will begin to rust after around 5 years on a steam system open to the atmosphere...

tobynewman

Thanks all--I would love to have local steam expert in my corner, it's proven hard to find one so far. I'm in New York City.

One of the radiators I'm replacing was a floor-standing one with the riser coming out of the floor. I think I'm coming around to just leaving it that way and adding a longer nipple to reach up to the new wall-hung radiator. However--in my living room I'm replacing a recessed convector, and this room already has its finished floor. Because I can't cut open the floor here I feel that my only option is to go up through the wall and out 'horizontally' (but really I'll aim for ~15 degree pitch as suggested).

Regarding pitch--I'm really trying to find a balance between the radiator working properly and it not looking glaringly crooked right below my level window sill. I guess I'm just hoping I won't have to go all the way to 1/4" per foot, but we'll see. It seems like the mounting brackets make it pretty easy to adjust the pitch as necessary. For what it's worth, I've thrown a level on all the old radiators in my house and several of them aren't pitched at all, and yet somehow I don't currently experience any water/steam hammer issues. I'm definitely not trying to discount the importance of proper pitch, more just curious if anyone knows why this would be the case?

BobC

A couple of 45's might be easier than trying to achieve a 15 degree slope over such a short distance.

Bob

KC_Jones

I have a 3' long radiator in my dining room and it has 1/4" piece of wood under the feet to slope it. Right above it is a level shelf, it's really not noticeable. I think the amount of slope required is minimal, with a system that is working correctly. That is the key point.

Take my radiator and put it on a system running high pressure, excess water, etc. and it will be a nightmare. Someone will give it a ton of slope and say it's "fixed" when the reality is the system is the problem.

With a properly sized boiler, good piping and low pressure (because the boiler is sized properly) steam is a thing of beauty. Quiet comfort.

As far as the one you have in the finished room. Bring the pipe up in the wall and put 2 90° elbows on it, this allows you to have any slope coming out of the wall you want. 15° seems excessive to me, and would probably make finishing it off with an escutcheon more challenging. A slight slope closer to horizontal will look much better.

jumper

There are methods to pipe terminals with separate supply and exit with one pipe systems.

Long Beach Ed

Mad Dog's words are gold. The system has to be running properly to provide good quality steam if you want these things quiet.

If you have wet steam, they will keep you up at night. They just don't have the cast iron mass necessary to absorb noise.

They also rust.

There are plenty of NYC plumbers who do excellent residential steam work.

Mad Dog_2

You're in Steam Country Central. If you can't find a good steam guy here in NYC, there may be other issues. Mad Dog 🐕 

ethicalpaul

They also rust.

Luckily, cast iron never rusts...hmm

Mad Dog_2

Rust never sleeps 💤 😴. My .Cast Iron Radiator in the Parlor is 150 yrs old...rusting away...and still no leaks.  Mad Dog 🐕 

ethicalpaul

Yeah, my living room one lasted about 100 years but finally started dripping between two middle sections. Bummer!

A little trivia for you @Mad Dog_2 -- "Rust Never Sleeps" became the name of that Neil Young album because Young was working with the band Devo at the time (making his super weird movie "Human Highway"), and the Devo guys were graphic artists who had worked on some ads for Rustoleum and had t-shirts with the phrase on it that Neil saw and liked.

https://www.rollingstone.com/music/music-news/flashback-neil-young-jams-with-devo-on-hey-hey-my-my-74213/

Mad Dog_2

"You must whip it...whip it good."  Flowerpot Hats. Mad Dog