is this normal for house radiator?

[luv2liv]

with a thermal camera, i can easily see the radiator is hot near the top. i thought it would be more evenly distributed. so is this normal?

with normal light, it looks something like this:

 

[MagnusTheBrewer]

Yes, that is normal. If they were uniformly hot, the water wouldn't flow.

 

[boomerang]

Heat rises. At some point the steam must cool enough in order to return to the boiler as water. A radiator therefore cannot not be uniformly the same temperature.

 

[luv2liv]

ahhh ok. thanks!

 

[paperfist]

Isn't that kind of a low temp?

 

[Greenman]

Isn't that kind of a low temp?

I never thought about that, but it does seem low. I also don't see an out let pipe, though it has to be there somewhere.

 

[Billb2]

That's a weird (cheep) setup. There's no condensate return line (back to the boiler), and no air vent. The steam (hot) coming into the radiator is cooled by the condensate (cold) returning through the same pipe. And without an air vent the top of the radiator is filled with air. Whatever steam makes it to the radiator just turns into water vapor (warm) at the top of the radiator. It's just wrong. But, it you're getting enough heat for the room and you don't pay the heating bill who cares. It's just very inefficient and expensive to run that way.

 

[hdfxst]

move the cover away from the radiator and then look at it.What your seeing in the pic is the temp of the screen on the cover and not the radiator

 

[paperfist]

That's a weird (cheep) setup. There's no condensate return line (back to the boiler), and no air vent. The steam (hot) coming into the radiator is cooled by the condensate (cold) returning through the same pipe. And without an air vent the top of the radiator is filled with air. Whatever steam makes it to the radiator just turns into water vapor (warm) at the top of the radiator. It's just wrong. But, it you're getting enough heat for the room and you don't pay the heating bill who cares. It's just very inefficient and expensive to run that way.

Air vent is on top left, but it's manual.

That does seem to be an odd setup, I always thought the water had to circulate. Not sure how that's accomplished without a return line. Maybe that's why all the heat is up top.

 

[luv2liv]

yeah, the thermal pict is with a metal cover on top.
let me post something else later

 

[NetWareHead]

Isn't that kind of a low temp?

The camera measures the temperature of the radiator surface, not of the steam inside the radiator. The steam inside is surely > 212 F. It looks like that radiator has just begun heating. It takes a while for that entire mass of cast iron to heat up. You can see in this thermal image the steam entering from the bottom left and rising to the top.

I never thought about that, but it does seem low. I also don't see an out let pipe, though it has to be there somewhere.

This is a 1 pipe steam system. It relies entirely on the buoyant effect of hot steam to move energy throughout the system. Nowadays with electric circulators (hot water hydronic heat systems), steam powered energy transfer systems are a lost art. The radiator itself is slightly pitched down at the steam riser end. When steam cools, water condensate forms on the bottom and the pitch of the radiator allows it to run off and back into the steam riser and ultimately back towards the boiler for reuse.

2 pipe steam systems also exist with dedicated supply and return pipes. The radiator air vent in the room is also eliminated in this type of system.

 

[Greenman]

I've done several split hydronic systems, and one that used radiators, but I've never seen an actual steam heat system. Any idea what pressure they run at?

 

[NetWareHead]

I've done several split hydronic systems, and one that used radiators, but I've never seen an actual steam heat system. Any idea what pressure they run at?

Not more than a few pounds of pressure, if that. Most buildings heat well with 2 PSI of steam pressure. Steam packs far more energy than hot water and wants to actively expand to areas of low pressure as it seeks to equalize. Its a different animal than hydronic; one of my hydronic boilers has a pressure relief valve that blows at 25 PSI. . Read in some old steam manuals once that 1 PSI is enough to move steam upwards 2/3 of a mile.

 

[Meghan54]

I found this site useful for both one pipe systems, like the OP's, and two pipe systems.

https://inspectapedia.com/heat/Cold-Steam-Radiator-Repair.php

Diagram of basically the OP's setup: (from link above)

 

[paperfist]

The camera measures the temperature of the radiator surface, not of the steam inside the radiator. The steam inside is surely > 212 F. It looks like that radiator has just begun heating. It takes a while for that entire mass of cast iron to heat up. You can see in this thermal image the steam entering from the bottom left and rising to the top.

This is a 1 pipe steam system. It relies entirely on the buoyant effect of hot steam to move energy throughout the system. Nowadays with electric circulators (hot water hydronic heat systems), steam powered energy transfer systems are a lost art. The radiator itself is slightly pitched down at the steam riser end. When steam cools, water condensate forms on the bottom and the pitch of the radiator allows it to run off and back into the steam riser and ultimately back towards the boiler for reuse.

2 pipe steam systems also exist with dedicated supply and return pipes. The radiator air vent in the room is also eliminated in this type of system.

So water doesn't really circulate back to the boiler it basically is continually heated? I don't quite understand how it does that with low pressure.

 

[NetWareHead]

So water doesn't really circulate back to the boiler it basically is continually heated? I don't quite understand how it does that with low pressure.

Meghan54 posted a good diagram of a 1 pipe steam system. Steam is pushed to all boundaries of the system by pressure, even uphill. Leaves the boiler via the steam header and reaches different rooms by branch piping. Condensate is created when steam has given up it's heat in the radiator and flows back to the boiler via gravity. The piping system is a 2 way street if you think about it. Steam flows one way pushed uphill by pressure. Condensate flows in the opposite direction via gravity and every pipe is pitched to allow condensate to drain back towards the boiler for reheating back into steam. One pipe steam systems use larger piping than 2 pipe systems since the piping needs to allow for this 2 way traffic. 2 pipe systems have dedicated steam feeds and condensate returns for each radiator and the pipe sizes are smaller as a result.

This is why piping pitch, pipe size and any obstructions interfere with steam delivery/condensate return and create issues like noisy water hammer, excess fuel consumption and rooms that get no heat. IMO these systems are works of art that function entirely without moving parts; no circulators needed. Just steam pressure and gravity work to provide a reliable circulatory effect. Much like a mechanic that can tune a carburetor, the long dead plumbers who installed these systems knew their craft well. That's why I called it a lost art.

 

[luv2liv]

as promised, here are the photos without the cover: https://imgur.com/a/FJnL8
so it looks like my radiator is probably working well after all because heat is evenly distributed as i thought!

left side is where hot water enters the 1 pipe into the radiator. cooler water (20 degrees difference) exits on the right pipe, with a valve on top. i have no idea what the valve does!
a nuisance i have is the 1st floor being cold, around 68F. while the second floor is really hot, 79F. the 2nd floor is hotter because the rooms are smaller with at least 2 radiators per room! i've turned the valve clockwise to close but the radiator is still hot as before. i tried counter clockwise too but no dice. any idea on how to reduce the heat on the 2nd floor without the 1st floor being colder? would be nice if the 1st and 2nd come close to each other at 73F.

 

[paperfist]

I'm not familiar with steam, mine is hot water, so not sure this translates to your system but bleeding is key. I used to have to do all mine manually, but now there's an auto bleeder off the boiler and each radiator has an auto bleeder. Keeps it all balanced, air out of the system, even heat.

https://www.hunker.com/13415682/how-to-bleed-cast-iron-steam-radiators

 

[NetWareHead]

You have a 2 pipe steam system which is great for you because they are supposed to be configurable and easier to balance (balance as in adjust each room) than 1 pipe systems. The valve on the radiator is supposed to to allow you to adjust the flow of steam. If nothing happens when closing the valve, you may need to replace.

Also, give the radiator some time to shed its heat after you try closing the valve. That radiator needs like 30+ minutes to return to normal. If the valve is not letting you close the steam off, you might want to get a plumber in there to replace it.

I'm also surprised to see the valve on the return side. Usually the valve is on the supply side in 2 pipe systems. If my suspicion is correct, closing the valve will still allow steam to enter the radiator.

Lets make sure for a second. You have steam and not hot water system, correct? Does your boiler have a sight glass that shows you the boiler water level? Do you have any circulators near the boiler?

 

[luv2liv]

Lets make sure for a second. You have steam and not hot water system, correct? Does your boiler have a sight glass that shows you the boiler water level? Do you have any circulators near the boiler?

i believe it is hot water. fthere is no glass anywhere near radiator.
each bedroom has 2 radiators connected serial. im thinking of removing 1 of the radiator. since it is serial, i cant just remove 1 and cap the pipes. im thinking of removing a radiator and just connect a copper pipe straight through. then build a bookshelf of the hot pipe to prevent kids touching that copper pipe. good idea?

 

[Greenman]

i believe it is hot water. fthere is no glass anywhere near radiator.
each bedroom has 2 radiators connected serial. im thinking of removing 1 of the radiator. since it is serial, i cant just remove 1 and cap the pipes. im thinking of removing a radiator and just connect a copper pipe straight through. then build a bookshelf of the hot pipe to prevent kids touching that copper pipe. good idea?

You could also put a thermostat in the room and a valve at the supply end, have a zoned system.
The only hot water/radiator system I ever installed was done that way. I put a stat in every room that had a radiator, each stat controlled the valve for that loop. The owner loved the system.

 

[NetWareHead]

i believe it is hot water. fthere is no glass anywhere near radiator.
each bedroom has 2 radiators connected serial. im thinking of removing 1 of the radiator. since it is serial, i cant just remove 1 and cap the pipes. im thinking of removing a radiator and just connect a copper pipe straight through. then build a bookshelf of the hot pipe to prevent kids touching that copper pipe. good idea?

Radiators connected in serial are almost always hot water. Steam radiators are connected in parallel (bad installs are the exception).

The sight glass would be on the boiler, not in the room. The circulators would be on the boiler.

Re your bookshelf idea, better idea would be to wrap pipe insulation around it before building a shelf.