Steam radiators

[goosegunner]

I found some steam radiators that are being used but will be taken out.

They at

20 wide x 38 tall They have 8- 5 tube sections.

I can get them for $20 each.

Other than pressure difference is there other issues with steam radiators?

More corrosion or less?

They have top and bottom ports on both ends.

gg

 

[tom in maine]

Connections can be an issue, but more importantly, there is apt to be more rust/sludge inside.
There can be weak spots in the lower areas. You should probably pressure test them before installing.

 

[HeatFarmer]

According to the guy I spoke with who refurbs steam radiators, they have less corrosion, etc than cast-iron water units. Are these in sections which can be pulled apart? That is a huge benefit because then you can size the units up or down.

Hydronic Alternatives makes a conversion valve from steam to water. That is a great price. The place here, local to me, sells them starting at $20 per section. A pressure test is a must tho. At $20 each grab them. You can always make your money back selling them for scrap if they're crap.

 

[Clarkbug]

Yeah, for $20 you really cant go wrong.

Once you get them, I would flush them out to get rid of the sludge that Tom in Maine mentioned. The steam systems tend to have the bottom 1/4 or 1/2" of the radiator as an area to collect all sorts of nastyness from the piping system. Some hot water with detergent flushing to get that out is a good step, and then a pressure test is a must. I would say go in that order in case there is some gunk thats plugging up a leak. It would be lousy to pressure test, have them pass, then clean and install only to find a leak once its in your house.

If you do get them up and running, they throw a nice heat, even if they do take up some floor space.

 

[RobC]

There is a difference with the internal piping between steam and water. For water you need to have a tube at the top. Some steam ones don't have anything at the top.
There is a lot of info if you goggle search. Also Craigslist is a good place to locate used.
Here is a hot water radiator that I use for the over heat protection loop. Ideally it should be above the boiler but it does it's job here.

 

[goosegunner]

Here is a picture of one of them.

 

[HeatFarmer]

Those are some pretty high BTU units. The more tubes & fins the more they radiate. Well worth the $20 each. I was going to go with Cast Iron Rads, but the cost from the local guy was ridiculous...albeit for pressure checked & painted...and they are large & heavy when full. I just don't have the floor space. :-S

 

[Jeff S]

That radiator looks similar to the ones I have in my house ,mine are the Corto style by American Radiator and were designed to be used for both steam and hot water.Mine were also previously used for steam and I converted them to hot water.I had the outsides sandblasted and painted but the inside I only power washed to remove any loose debris and been using them for 3 years now.A thin layer of rust on cast iron is no big deal and actually acts to protect the metal in fact cast can be fully covered with rust but if the piece is broken the interior will be just like new,unlike steel that will rot through the whole piece of metal in short order.

I would not try to break down the sections ,these were put together at the factory with either screw type or push type connections that are no longer available besides you stand a good chance of breaking a section in the process.

To convert to hot water use both bottom ports for water flow and use one of the top ports for an air bleeder.You can reduce the bottom ports to 1/2" and use pex for supply and return,I know they probably have 1 1/4" or larger ports now but this was for when heating was done with gravity style flow in mind,if you were to pipe these in with full size connections with a circulator ,water would just just zip across the bottom of the rads with out much therm-cycling in the rad itself so we need to slow the water down by using the smaller connections.

At $20 I would certainly be backing up the truck.In fact after I done my house I found 10 more rads that I purchased at $25 each just so I could use for a future project,with everyone ripping these out of there houses and scraping them,they are going to be hard to find in just a couple of years,which will be about the time people will discover how useful they really are.

The radiator you have pictured is 40 EDR (equivalent direct radiation)which will provide .

50 BTU per EDR at 120* or 2000 BTU

100BTU per EDR at 145* or 4000 BTU

150BTU per EDR at 170* or 6000 BTU

 

[goosegunner]

That radiator looks similar to the ones I have in my house ,mine are the Corto style by American Radiator and were designed to be used for both steam and hot water.Mine were also previously used for steam and I converted them to hot water.I had the outsides sandblasted and painted but the inside I only power washed to remove any loose debris and been using them for 3 years now.A thin layer of rust on cast iron is no big deal and actually acts to protect the metal in fact cast can be fully covered with rust but if the piece is broken the interior will be just like new,unlike steel that will rot through the whole piece of metal in short order.

I would not try to break down the sections ,these were put together at the factory with either screw type or push type connections that are no longer available besides you stand a good chance of breaking a section in the process.

To convert to hot water use both bottom ports for water flow and use one of the top ports for an air bleeder.You can reduce the bottom ports to 1/2" and use pex for supply and return,I know they probably have 1 1/4" or larger ports now but this was for when heating was done with gravity style flow in mind,if you were to pipe these in with full size connections with a circulator ,water would just just zip across the bottom of the rads with out much therm-cycling in the rad itself so we need to slow the water down by using the smaller connections.

At $20 I would certainly be backing up the truck.In fact after I done my house I found 10 more rads that I purchased at $25 each just so I could use for a future project,with everyone ripping these out of there houses and scraping them,they are going to be hard to find in just a couple of years,which will be about the time people will discover how useful they really are.

The radiator you have pictured is 40 EDR (equivalent direct radiation)which will provide .

50 BTU per EDR at 120* or 2000 BTU

100BTU per EDR at 145* or 4000 BTU

150BTU per EDR at 170* or 6000 BTU

I thought with hot water you supplied to the top on one end and return from the bottom on other end?

gg

 

[Jeff S]

You can supply the top and return from bottom like you mentioned as well.I should have said that I prefer the bottom connections.I don't have a automatic water feed on my system so even if the system looses any water through a valve packing or such during the course of a heating system all connections are still below the water line.

Dan Holohan says a trick the Dead Men would use on gravity systems would be to oversize rads on the upper floor of a building and not completely fill them and the air space would be the expansion tank.