Steam baseboard to Radiator

captainHarlow

Hi All, i have a 1 pipe steam system that has cast iron radiators in all rooms of the 2 story house except for the living room. The living room has steam baseboards that i believe are not pitched correctly. 1 of the walls is about 20 feet long and is a single pipe, it has a lot of cold spots within the pipe and doesn’t heat the room well at all. The biggest issue is this room contains the thermostat for the house so the rest of the house gets very hot while the living room slowly heats up.
I would like to replace the baseboards with a radiator.
I have just found this site and hunted for a scenario to match mine but i couldn’t. I did contact a contractor from the site for an in person check but would love to try to figure it out on my own.

Any and all information would be great!

EdTheHeaterMan

The fact that the radiator is not getting hot all the way across may be a result of insufficient venting of the air from the radiator.

Not properly pitched can cause water to trap in the lower push nipples but the upper push nipples should allow the steam to get to the end where the vent is.

Is there any banging noise associated with that radiator?
Is that 20 ft of baseboard one continuous radiator?
Are there hot spots then cold spots then hot spots again across the radiator?

Waher

@captainHarlow See this thread:
https://forum.heatinghelp.com/discussion/153455/baseboard-vent-one-pipe-steam-system

It seems one pipe steam baseboard commonly suffers from venting issues because the manufacturers' don't offer an end piping diagram to allow for use of typical radiator vents. Several of the members of the forum have suggestions for either using a straight section of pipe and drilling the outside cover to allow for use of a typical radiator vent outside the end cap cover (see post dated March 7, 2022 by
Paul3) or creating a venting loop inside the end cap cover to fit a typical radiator vent. (see post dated October 13, 2022 by Larry_52)

captainHarlow

EdTheHeaterMan said:

The fact that the radiator is not getting hot all the way across may be a result of insufficient venting of the air from the radiator.

Not properly pitched can cause water to trap in the lower push nipples but the upper push nipples should allow the steam to get to the end where the vent is.

Is there any banging noise associated with that radiator?
Is that 20 ft of baseboard one continuous radiator?
Are there hot spots then cold spots then hot spots again across the radiator?

There isn’t any banging in the baseboard, and there a multiple warm and cold spots along the 1 continuous radiator with no vents in the middle.

EdTheHeaterMan

After reading @Waher comment, I found this diagram from @Larry_52
I want to thank the IT Dept., Engineering Dept., and the Graphics Dept. at the company where Larry works for the collaborated, detailed, graphics and design that went into the great illustration. The dimensions and attention to detail are phenomenal.

I have had great success with this design

captainHarlow

captainHarlow

It doesn’t look like i have the space for that impressive diagram.

mattmia2

Are the baseboards cast iron or copper or steel fin tube?

Fin tube will never heat remotely the same as the cast iron radiators and you won't be able to balance it. Cast iron baseboard is better but still will heat and cool faster than cast iron radiators so the balance won't be great but could be acceptable.

20 feet is a lot of baseboard to get to work properly as 1 pipe steam. You could set it up as a 2 pipe radiator on a one pipe system and it would heat properly but it still wouldn't heat at the same rate as the cast iron radiators.

If you have the space for it, the cast iron radiator is probably the best bet. It likely will hook up to the current runout for the baseboard, but you will need to have a runout large enough for the size of the radiator and it will have to slope to drain condensate so you might need to adjust the length of the nipple through the floor to the valve that connects to the radiator or otherwise adjust that height.

You will need to figure out the heat loss of that room to size the radiator. Calculating the heat loss of a few other rooms and seeing how the radiator size compares to that would be a good idea, if the other radiators are oversized, you would want to oversize the new radiator a similar amount to balance the system.

captainHarlow

mattmia2 said:

Are the baseboards cast iron or copper or steel fin tube?

Fin tube will never heat remotely the same as the cast iron radiators and you won't be able to balance it. Cast iron baseboard is better but still will heat and cool faster than cast iron radiators so the balance won't be great but could be acceptable.

20 feet is a lot of baseboard to get to work properly as 1 pipe steam. You could set it up as a 2 pipe radiator on a one pipe system and it would heat properly but it still wouldn't heat at the same rate as the cast iron radiators.

If you have the space for it, the cast iron radiator is probably the best bet. It likely will hook up to the current runout for the baseboard, but you will need to have a runout large enough for the size of the radiator and it will have to slope to drain condensate so you might need to adjust the length of the nipple through the floor to the valve that connects to the radiator or otherwise adjust that height.

You will need to figure out the heat loss of that room to size the radiator. Calculating the heat loss of a few other rooms and seeing how the radiator size compares to that would be a good idea, if the other radiators are oversized, you would want to oversize the new radiator a similar amount to balance the system.

It’s steel fin tube, i think the radiator is my plan it’s just above my pay grade of work i can do myself!

Thanks everyone!

Chris_L

Can you post the same picture for the other end of that baseboard? I've never heard of anyone using fin tube for steam without an outlet at the other end.

EdTheHeaterMan

That is not Cast iron Baseboard. Sorry for assuming it was. my comments do not make sense cased on that picture.

Where is that vent located?
Is that the supply pipe coming up thru the floor?
If yes then there needs to be another vent at the other end.
And the tube with the fins needs to be supported properly in order for the condensation to flow back to the riser. I believe the rule on counter flow one pipe is 1" every 10 ft. Although the last 6 to 8 ft may not be as critical.

EdTheHeaterMan

If this is the 20 ft Steel tube with fin baseboard, all you may need to do is replace the vent(s) and make sure the tube is properly supported inside the enclosure. Like this
Caution the floor may not be level but the pipe in the enclosure can be supported at the proper pitch to allow the condensate to leave and also let the steam in, all the way to the end.

captainHarlow

EdTheHeaterMan said:

That is not Cast iron Baseboard. Sorry for assuming it was. my comments do not make sense cased on that picture.

Where is that vent located?
Is that the supply pipe coming up thru the floor?
If yes then there needs to be another vent at the other end.
And the tube with the fins needs to be supported properly in order for the condensation to flow back to the riser. I believe the rule on counter flow one pipe is 1" every 10 ft. Although the last 6 to 8 ft may not be as critical.

That vent is from the supply through the floor from the basement. The other end looks like this …

That also goes back to the boiler in the basement

captainHarlow

There are no vents between the 2 pictures and its 18’ in length

captainHarlow

EdTheHeaterMan said:

If this is the 20 ft Steel tube with fin baseboard, all you may need to do is replace the vent(s) and make sure the tube is properly supported inside the enclosure. Like this
Caution the floor may not be level but the pipe in the enclosure can be supported at the proper pitch to allow the condensate to leave and also let the steam in, all the way to the end.

There is only one vent on the supply side, and it drops back down to the basement

Chris_L

OK, so what does the return side look like in the basement? It should drop down below the water line before it goes back to the boiler.

mattmia2

We need to see what is going on in the basement, they may have set it up as 2 pipe on a 1 pipe system which if done properly will heat properly but still is unlikely to balance with the cast iron.

captainHarlow

captainHarlow

captainHarlow

captainHarlow

So those 3 pictures are the path the return takes back to the boiler … the white pipe on the wall brings it all the way back 

captainHarlow

captainHarlow said:

So those 3 pictures are the path the return takes back to the boiler … the white pipe on the wall brings it all the way back 

Correct! 

Chris_L

Can you also post some basement pictures of how the supply side of that radiator is fed from the steam main? And is the gate valve in the second picture on the return line from the same radiator?

neilc

are you sure that vent is on the supply elbow, and not the return elbow?
does that fintube pitch down hill to the vent ?

mattmia2

Where does the end with the vent go? I think it should go in to a return.

EdTheHeaterMan

Here is the redesign of the diagram based on your additional information. The condensate and the steam are going the same direction. So the pitch is 1" every 20 ft of run.

Still need to make sure the pipe inside the enclosure has no low spots.

mattmia2

EdTheHeaterMan said:

Here is the redesign of the diagram based on your additional information. The condensate and the steam are going the same direction. So the pitch is 1" every 20 ft of run.

Still need to make sure the pipe inside the enclosure has no low spots.

Why doesn't the return need to connect below the water line? If it is connected to a main or a "return" that is effectively part of the main, won't steam also come in through the return and probably close the vent before the steam from the supply side fills the entire element with steam?

Chris_L

mattmia2 said:

Why doesn't the return need to connect below the water line? If it is connected to a main or a "return" that is effectively part of the main, won't steam also come in through the return and probably close the vent before the steam from the supply side fills the entire element with steam?

That is what I thought.

But I have to wonder if the OP hasn't confused the supply and return lines. We haven't seen a basement photo of the pipe that connects to the end of the baseboard with the air vent. If that end drops down below the water line, it seems like this should work, assuming the gate valve is open.

mattmia2

Or thinking about it more, you could make a u bend out of fittings in the return to make a water seal trap to keep the steam out of the return.

ethicalpaul

captainHarlow said:

It’s steel fin tube, i think the radiator is my plan it’s just above my pay grade of work i can do myself! Thanks everyone!

If I can do it, you can do it

Long Beach Ed

We put water traps on them as Mattmia suggests. We drop the return down below the boiler water line then back up to the bottom of the main. They work fine, even with 3/4" baseboard. That's how we add a two-pipe radiator to a one-pipe system. Vent it too.

As was mentioned, the problem will then be with balance. The boiler will shut down and the baseboard will instantly go cold while the cast radiators will continue expelling heat. Not a good plan here. Just replace it with an iron radiator sized as has been mentioned above.