Do steam radiators heat a home more than the radiator pipes?

Hey living in a prewar structure so my heating method is of a steam heat radiator system with boiling hot water running inside the radiator. My question is what often heats up a room quickly and how big of a room can it heat up. In my 300 square foot room, there is one radiator on the side of the room which is keeping the room at 81 degrees while it is 50 degrees out. There are other radiators in the other rooms but they are not an actual radiator instead it is a long 9-foot long pipe from ceiling to floor. It's a pole that gets really warm and hot sometimes. It keeps a 150 square foot room as warm as 82 degrees on a 45-degree day. For that 300 square foot room, would putting a radiator cover make the room look aesthetically nicer and cooler temperature-wise? Also, why do supers turn on the radiator heating system when it is 50 degrees out. There is nothing wrong with letting a room cool down to 70-72 degrees. Also, supers should not be allowed to heat a room more than 78 degrees unless it is below 10 degrees out. 81 is a bit too warm for me, lol feel like turning the ac back on. I'd rather wear a sweater in my home rather than be cooking as if it's July. 


The image is the radiator in my 300 square foot room. 81 degrees in room with 50-degree outdoor temperature. The window is 12 inches open so cool air entering though very slow. If it's below 40, the room would not struggle to cool. Yesterday was 72 degrees and today it was raining and 50 degrees all day. New York City in autumn. I had my air conditioner running yesterday but not today though I kinda feel like I want to turn it on. The radiator surface temperature is 234 degrees.

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6 Answers

  • 4 weeks ago

    There are two considerations in heating a space.   How hot it is and how much.   A match is very hot but there is not much of it.    On the other hand radiators that might only get up to 80 degrees are not all that hot but there is a lot too it.   The main consideration is can the heat source compensate for the heat loss thru the walls and windows.   A match would never do it but an 80 degree radiator could.   If you find the room is too hot then you need to either cut down the heat flowing into the room by slowing down the radiator OR increase the heat loss by opening a window.  

  • elhigh
    Lv 7
    4 weeks ago

    Adjust the inlet valve at the lower right of the radiator.  You should be able to control its output to some degree, though I admit it is pretty hard to do.  When I lived with steam heat it felt like the valve was all or nothing except for about 1/4" of turn where you had some kind of modulation, but you had to hold your mouth right and not cross your eyes at it later or else it would flip to the extreme you didn't want.

    You could consider building a radiator cover with operable vents above and below that would prevent the heat escaping except at the rate you want.  You could even equip it with fans and a thermostat so that once the room hit the temperature you wanted, the fans would turn off and the room temperature wouldn't go any higher.

    Dang, now I want to build this thing.

  • Droopy
    Lv 5
    4 weeks ago

    The valve on the right will control the amount of steam allowed into the radiators.   Thus controlling the temperature.  

  • Anonymous
    4 weeks ago

    You use the valves to shut off the radiator. You will get some background heating from the pipework unless it is lagged, and from other apartments if you are on an upper floor.

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  • 4 weeks ago

    If the radiator makes the room too hot, you can turn it down by adjusting the knob at the lower right.  All the way clockwise closes off the steam completely.  Given what you say the surface temperature of the radiator is, it may be all the way open.

    And yes, you should put some kind of cover over the radiator.  Since it's hot enough to injure, and probably not within code.

    As far as the other room, that pipe is probably the line feeding a radiator on the next floor up.  You won't have a knob for that one, and the only way to stop it from getting the room too hot is to wrap it with some pipe insulation.  You can get some for a few bucks at Home Depot.  Just make sure it's the kind rated for hot pipes, rather than cold ones.

  • DW
    Lv 6
    4 weeks ago

    The big limitation of these old systems is that it's very difficult to balance heat throughout the building. Bringing your apartment down from 81 to 71 might bring another apartment down from 70 to 50. There's probably no law against overheating an apartment, but in my city there's a law against underheating a rental apartment.

    You might be tempted to partly close the valve leading in to the radiator, but that can be a problem. That can cause the radiator to fill with water, then it sprays rusty water from the vent valve, which is messy. Plus vent valve is disturbingly close to an overloaded electric outlet.

    Radiator covers look better than a collection of old paint, chipped paint, rust, and dust. I think a radiator that's completely stripped of paint and polished looks great, but it's hard to get that way. Radiator covers are designed to allow heat through. It might block a little, but not much.

    My understanding of single pipe steam systems, which is what yours looks like, is that the boiler sends steam through the pipe to your radiator, that goes back into the pipe as water and returns to the boiler. If something is out of balance the steam and water collide - if you hear clanking noises from the pipes, that's why.

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