Single Pipe Steam Heat Balancing

Tim Armacost

Let me first apologies for asking a question that I'm sure many of you have seen time and time again. (I was unable to find my answers when searching through previously posted Q&As.)

For five years my wife and I have lived in a single family house built in 1927 with single pipe steam heating. During that time we lived (with what I am finding to be a typical problem with unbalanced steam systems) a significantly colder upstairs during the heating months. In the past the problem was resolved with very warm PJs and a few extra heavy blankets.

This February our first born can home and I went to work on trying to warm up the upstairs. I started by trying to partially close the shutoff valves on some of the downstairs radiators – I have since learned this is incorrect – and later moved on to installing some pressure adjustable air vents on radiators. At one point in time, I actually had the floors very close, but then my kitchen radiator was reinstalled (our kitchen was in the middle of being renovated when I started my balancing project) and I quickly figured out way the term "balance" is used. I continued trying to adjust my air vents, but even with the downstairs ones as "closed" as possible and the upstairs ones as "open" as possible, I am still unable to get the two floors close.

I have searched the net for as much information as possible, much of it coming from this site, and additionally have ordered the books being offered here.

My continuing education has discovered some answers, but also created almost as many addition questions that I am hoping can be answered here.

1. I have looked for the main's steam vent in the basement with no success. Either I never had one or it became a casualty of a past renovation. There is one capped lead off the main from a past renovation that I have been wondering if it might be able to be refitted with a vent seeing that it is conveniently located at the very end of the main.

2. The new vents that worked for a time do not seem to have the adjustable range needed to balance the system since the addition of the kitchen radiator. I read about temperature controlled vents and thought that placing a few of these on the radiators closest to the downstairs thermostat, when properly adjusted, might slow down the speed at which this room warms, thus giving the upstairs more time to warm up before the boiler shuts off. I have also not ruled out that the adjustable vents I got were maybe not the best. If some combination of the pressure adjustable vents and the temperature control vents seem appropriate, I would love to get some recommended manufacturers.

Thanks in advance to all that replied.

Unknown

First thing I would do

is locate that main steam vent . Chances are , if there is one somewhere in there , its probably clogged shut . If you dont have one , you definitely need it - otherwise your radiators are handling the extra air the main vent is supposed to . If that capped vent is past the last radiator takeoff and is in the header itself - not at the end of the line in a tee pointing up ( bull headed tee ) - its the ideal spot for it . With the main vent working , itll bring steam to the farthest radiator off the header almost as fast as it brings steam to the closest radiator .

Unknown

The usual suspects

That vent, I agree, is the single most important thing to address. No question in my mind.

The other things to look at are also important. If the mains aren't insulated, the steam that they condense takes steam away from the radiators. If all of the supply piping is uninsulated, the pipes are now too small to carry the load that they are connected to. Insulation was figured into it when the sizes were originally selected, and the sizes are two sizes smaller than they would be if they were selected for uninsulated piping.

Does the piping above and around the boiler look like the picture in the installation manual? Are the pipe sizes correct? This is critical. If it isn't correct, water and steam move out into the piping together. That isn't good.

Dirty boiler water can cause that, too.

How much steam are you making? How much steam can you condense? Are those numbers somewhere near each other? Measure up how many square feet of radiation you have, and compare that to the boiler size. This is an important factor.

What steam pressure does your boiler shut off at? A pound or two is more than enough.

The vent on the main is the first thing to address. You need one. Ron's right.

Noel

John@Reliable

What type of heating system?

If this is an oil system,like others have said main vent.
But I also find this often. During yearly service the wrong undersize nozzle gets installed.Now you can't made steam to fill system. I will do 15 to 20 calls like this a season and installing the right nozzle along with main vent and adjustable air vents will do the trick. Hope this helps

Fred Harwood

Steam heat

Install one, or more, large Gorton (or is it Groten) mains vent. I think a number 2. Pay special attention to the last riser to the second floor. Install a second large mains vent near that riser if it heats long after the other vents.

Never partly close a radiator valve.

What size is your main? Vapor systems (low pressure) use big mains and may indicate that you use a Vaprostat for better pressure control

Steamhead

You can get vent sizing charts

by ordering Dan's "Dead Men's Steam School" video and workbook. Plus, you get to watch Dan in action which is not to be missed!

BTW Fred, it's Gorton. That #2 is a heck of a vent, but it's overkill on mains less than about 45 feet of 2-inch pipe. However, it can't be beat on Vapor systems.

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