water-baseboard as steam radiators?

Lew

Paul,
I had a 4 foot section of the multipac w/ 1 1/4 steel element installed in my kitchen. Works great once I found the right vent for it. The radiator and element cost less than $100, if I remember correctly.

Paul Reid

Why not?

My house is steam heat and I like it. One-pipe.

But I'm short on radiators. The previous owners must have removed a few; also I'm thinking of adding a room and it will need heat. Of course I grab any radiator I see being thrown out, and have filled a few holes that way. But good recyclable radiators are hard to find, and new or professionally salvaged ones are expensive.

Why can't I use the hot-water baseboard units on steam? Adapt one end to a steam valve, the other to an air vent?

They won't burst: they are rated 100psi, and if I ever have more than 2psi steam then I am doing something wrong. I doubt very much that the copper or aluminum will melt at 212 deg. steam temperature. Baseboard with steam at 212 is more of a burn hazard than baseboard with water at 160, but baseboard has a faceplate while we run steam radiators totally exposed where the dog can burn his nose; nobody's been burned-bad yet.

Dan says I will have trouble venting more than a little baseboard. Of course: a foot of 4" baseboard is 10 square feet of radiation, so more than a few feet will be bigger than the average home radiator. But at 2,400 BTU per running foot (at 212 deg.) I don't need more than a few feet of baseboard in any one spot. Maybe two units, 2 or 3 feet each, to heat a large bedroom.

(I saw Dan's recent article in OHJ about a hybrid steam/water system. Looks complicated, to plumb and especially to recover after any air-leak. And it isn't real steam.)

The killer seems to be: these thin-tin baseboards have lots of warning about air in the water. I guess they rot-out easy. And working steam, they will be full of damp air much of the time.

On the other hand, they are cheap enough to be considered throw-aways. And I don't plan to stay in this house forever (though I should feel a little guilty about leaving a kudge for the next owners).

On the third hand, a burst baseboard in the middle of the night could be very annoying. Open an eye, fumble through the fog, shut the valve, back to sleep to be rested for a repair the next day.

Is this totally stupid or just dumb?

-PRR

Steamhead

Velocity is the killer

when using fin-tube baseboard on steam. The usual 3/4" or 1" fin-tube is too small. Slant/Fin makes baseboard called Multi-Pak-80 which can take several different elements, and they make a 1-1/4" steel-pipe element for steam. But this should still be hooked up as 2-pipe. And fin-tube doesn't hold heat the way cast-iron does.

If you want to use baseboard with your radiators, the best choice is cast-iron baseboard as made by Burnham or Slant/Fin. This will hold heat like an old radiator will. But it should still be hooked up 2-pipe unless you're using a piece 3 feet long or shorter.

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DanHolohan

It's mostly

the amount of space within the pipe. The steam is moving very quickly and the condensate is trying to roll backwards against that and something's got to give. Usually, it's the condensate.

Drod

Cast Iron Base Board

I have a single pipe steam system heating my two story w/ basement residence. 90% are conventional radiators, but in two rooms I have base board units (cast iron). They were here when I bought the house. One is about 6 feet long, the other is about 10 feet long, both piped with the single pipe, traditional vent on far end. They both work great-in my opinion even better than the radiators.

I'm truly a novice, and have seen Stemhead's great responses here before, so I've got to ask-how would a two pipe to a cast iron baseboard be piped and how would it work (on a single pipe sytem)?

Steamhead

Run your return line

to the wet (below the boiler's waterline) return. This way, steam stays in the baseboard where it belongs.

If you can't get to a wet return and have to use a dry return, use a loop seal at least 5-feet deep in the baseboard return. When this is filled with water it will keep the steam in its place. You can even return condensate to the steam main thru a loop seal.

Most cast-iron baseboard is only tapped 3/4-inch so there's a limit to how much steam you can get into it. Using 2-pipe keeps the condensate out of the steam line, so more steam can move thru it. But as long as your baseboards are working properly and not banging............

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George Berkeley

Multi-pac-80

I have one of the Slant-fin baseboard steam units installed in a new room addition. It was piped in just as Steam Head advised, and per the drawing in Dan's book.

It works great in this one pipe system! I had one plumber who saw the 2-pipe unit in the 1-pipe system. Told me that it would never work.

Well, he was a plumber and not a Steam man!

Paul Reid

> Multi-pac-80 ...I have one of the Slant-fin baseboard steam units installed <

Thanks Steamhead for the idea, and JG for the endorsement. It does look like a sweet unit.

Why do they offer both copper and steel- for ease of plumbing or is there a cost/life tradeoff here? (There is a performance difference: 1160BTU copper, 980BTU steel, but this is hardly significant.)

JG or anybody.... what does a Multi-Pak-80 cost? The room addition is a lot of carpentry cost, so if I don't find an affordable way to pipe steam in there it is going to have to be (don't hit me) Electric Baseboard (gasp).

I don't need a to-the-penny price, not trade-price, not list price, but a ballpark to see if it is worth looking into. Say two 4-foot lengths of Slant/Fin 85-A (1 1/4" copper) or 86-A (1 1/4" IPS steel). $50? $500?

-PRR

Steve Levine

I, as a manufatcurer that sells only to wholesalers

can't quote a price to you. I bet others will.

It is a general rule to use steel with steam. Steam cauyses far more expansion and can subject the system to water hammer. The steel is much more tolerant to this.

Roger Litman

Steam baseboard

Cast iron baseboard works as it holds the heat similarily to the radiators and thus it will give you good balance if on the same zone as the radiators, assuming proper sizing.. If it is on a separate zone, then you can use it pumped as per Dan's book. Piping should be two pipe, but I have seen single pipe systems work.

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George Berkeley

My Cost

I had about 8’ of the steel installed. While I read this site and tinker a lot, I paid my Steam Heat Plumber to put it in. Given that he had to break 90 year old fittings, thread big pipe, and tie the low end of the run into the wet side of the system, it was more work and required more tools that than I am able or willing to do.

Besides, it was worth every penny of the $800 I paid to watch him swear as he did it, and then see the grin when it worked just as the section in “The lost Art…” said it would.

Later we changed the air vent fittings and put a 6”- ½” nipple to raise the Vari-vent as the volume of condensate produced would sometimes be so heavy the vent would sputter.
The nipple solved that.

My only comment backs up something posted above. When the steam is up and the vent is open the heat is awesome. However, unlike a good old 500-pound radiator, when the steam drops, the heat from the unit goes almost stone cold.

Paul Reid

jg> I had about 8’ of the steel installed. ... worth every penny of the $800.. to watch him swear as he did it ... unlike a good old 500-pound radiator, when the steam drops, the heat from the unit goes almost stone cold. <

Neal> I had a 4 foot section of the multipac ... radiator and element cost less than $100

Thanks guys.

I also asked my grandfather's dog. He figured that 4 feet of good-quality finny iron with faceboard would be priced around $100 plus $10 for endcaps. My dog was not clear if that was book-price or real price; at the factory dock or my plumber's cost.... price-fixing is no longer legal and everybody expects discounts for buying in bulk and then justifiably marks-up for penny-ante buyers like me. It's so complicated. (I understand why Steve does not want to guess what his product costs on my wall, several layers down the line.) Your prices suggest my dog knows his prices. (He got it from my grandfather who sold airplanes by the pound.) Not $50, not $500, but lower rather than higher.

Thing is, I've been seeing new "european boutique" radiators for $600-$1000. Some wonderful finishes and colors, but they are charging more for style (and low production or bad distribution) than for BTU. (Some don't even carry BTU ratings. I can guess, but when buying iron at the price of good beef, I shouldn't have to guess.) And there are shops that refurbish old radiators, but to make that chore worth the effort they must charge a bundle, and then there is 500 pounds of shipping. My FedEx guy already hates me, and the Roadway guys hate all home deliveries.

For $100-$200 on my porch or $800-$1000 installed, it sounds worth looking into.

As for the lack of thermal inertia... well, you get what you pay for and what you can carry without throwing-out your back. And I actually don't get a lot of inertia from my 200-pound radiators. They warm the house and the house stays warm. Partly because there is a LOT of mud-plaster in these walls. (I tried to jack a sag in the house and woefully underestimated the weight.)

And I suspect I will still toss some Electric Baseboard in there. Think: in the day the bedroom can be cool, at night the house can be cool but I can't take a cold bed. Likewise the bathroom wants a shot of heat on demand but can be left cool most of the day. So the loads are out of sync; two systems is best. I guess I can Zone steam, but not by breaking up all these 80 year old joints. Reddy Kilowatt doesn't work cheap, but he's always ready to work quick. Thing is to use him for small short jobs where it seems silly to bring a ton of iron to a boil. (Electric is also nice when the boiler quits, as it has done twice.)

jg> one plumber who saw the 2-pipe unit in the 1-pipe system. Told me that it would never work.

Sure it can. There isn't any real difference, 1-pipe or 2-pipe, not for low-pressure home heat. AFAIK, it is always 2-pipe at the mains: upper steam pipe and lower return pipe. You could maybe do one or two rooms with a single pipe from the top of the boiler, but the falling condensed water will knock-down the rising steam. Much better to bring the water back to the bottom of the boiler: 2-pipe. For a run to a single radiator, 1-pipe works especially if you can angle the condensate to stay out of the steam pipe. And 1-pipe is a lot easier and cheaper to bring upstairs. But you can run a radiator 2-pipe on the same mains as a 1-pipe, and for the same radiator it may work better. (For a too-low radiator like baseboard, 2-pipe seems to be almost essential to keep that condensate draining fast.)

He may be confused with high-pressure industrial steam heat. When you have acres of radiation along miles of walls, you can't afford pipes big enough for a gentle drift of steam. You run real pressure to force the steam down to the far end of the building and overwhelm local pressure drops. A system plumbed that way won't work with low-pressure steam: pipes too small for the load. But you never have THAT much load or distance in a home (not ones we can afford). For home-loads, plain 1.25" pipe passes plenty of low-pressure steam for most rooms, and is too cheap to try downsizing.

-PRR