Steam venting

[Jason Howe]

Hi all,

I have a single pipe steam system in my house. We moved in in the sprint and are now getting a taste of how well the heating system actually works. The issue is this: The first floor heats up fine, but the 2nd floor stays chilly, about 5 degrees cooler than the 1st floor.

I have adjusted all the vents on the 2nd floor to be full open to get them to vent quicker and make the 2nd floor warmer. I was going to turn down the 1st floor vents, but found that they are non-adjustable.

I also noticed that when the things really get going, the 2nd floor vents are loud, they really go for it. This prompted me to go into the basement to check the vents on the mains...

I found 3. Two of them are on risers, about 8 inches above the main, that go up to radiators, none are at the end of the mains. One is of the same adjustable type as on the 2nd floor heaters, which appear to be Hoffman 1A type vents. One is on the return line right above the furnace. The 2nd main that goes to the other side of the house has none. (although only 2 heaters are on it, while the other side has 8.

The insulation on the pipes in the basement is intact and mostly in good shape, although I'm going have a firm come in to remove the old asbestos wrapping and put new stuff on. The only place where there is missing insulation are the pipes that were replaced with the furnace about 10 yrs ago. Those are from the furnace, about 5 feet out, until the brass connects into the old iron asbestos wrapped pipes.

So my question is this: What can I do to improve the evenness of heat in my house?

My thoughts are this:

1) Get insulation on the 1st 5 feet of pipe (even if only temporary) 2) Replace 1st floor vents with the adjustable kind to force more steam upstairs so that 2nd floor heaters get warm first. 3) Get some sort of real venting on the mains so that the now full open vents upstairs don't have to vent as much.

Anyone care to offer corrections or suggestions?

Thanks, Jason

[Mikepier]

The problem could lie in where yout T-stat is located. If it's on the first floor, then obviously its not going to care what the second floor temp is. It's only interested in the first floor. If you can somehow relocate the T-stat to the second floor, or some other location which can monitor both floors mutually, then you should notice better management of your heat.

[Jason Howe]

Well, regardless of where the t-stat is, there is a 5 degree differential between the two floors.

If I set the t-stat to 68, the first floor is 68 and the 2nd is 64. I can get the 2nd floor to 68 by setting the t-stat to 72.

It follows that if I put the t-stat on the 2nd floor and set it to 68, the first floor will get to be 72.

If I put it between the two so that it splits the difference, it'll be

66 on 2nd, 68 at the tstat and 70 on the 1st.

It's a matter of uneven distribution that I'm trying to figure out, and has little to do with t-stat placement.

[Edwin Pawlowski]

The insulation may keep the basement a bit cooler, but it will help overall efficiency if you don't need the heat.

I'd check the second floor vents before replacing the first floor ones to be sure they are working properly. My experience is with two pipe systems so I'm not completely familiar with your setup. As long as there is air in the radiators, steam cannot enter. You are on the right track.

As for the asbestos, do some checking on what you can or cannot do yourself and you may save a bundle of money. Keep in mind, that asbestos is perfectly safe if left intact. I have no idea what people get frightened by it.

[RicodJour]

The tuning of steam systems is a lost art. The old timers would tweak the installation to deliver balanced heat. They's drill, tap and install an additional vent on a radiator if required.

Look into thermostatic actuator valves to replace the existing steam vents. Honeywell, Danfoss, et al, make them. Here's one example:

has a steam vent, a valve and a thermostatic actuator and it operates as a thermostatic control for an individual radiator. When the actuator shuts the valve no more steam will come into the radiator and it will start to cool down (slowly) - no more heat will be added. One caveat - you can't put one in the room with the actual house thermostat - they'll fight each other.

Replacing the existing steam vent couldn't be easier. It will take you all of fifteen minutes to assemble the unit and install it. The Honeywell ones I have cost about $75 each for the setup. Cheapest and easiest way to create zones in a steam system and balance out the heating.

R

[Jason Howe]

As far as the vents go, I have heard that after a while they can get gummed up, so perhaps removing and cleaning all the vents would be a good first step.

As far as the asbestos goes, while I'd be perfectly willing to leave it in place, the fact of the matter is that people do freak out about it, and selling a house with visible asbestos can be a real issue. When buying this place in the spring, I didn't care, because I know it's safe if intact and in good shape, however; I'm sure when I go to sell (don't have plans to currently, mind you) I won't be so lucky as to get someone as understanding as myself .

[Heathcliff]

As I understand it, the vents are on the radiators to allow the air out when the steam first comes on, and allow air in when the steam stops. I think you do not want the vents to be venting a whole lot of steam once the system has heated up as this will fog/ice up your windows when the weather gets really cold. (If that is applicable to your location.) A little steam though is nice to add humidity.

A simple alternative might be to do something to impede the transfer of heat from the downstairs radiators, such as laying a big towel over them. You could try that and if it works OK then come up with a more decorative alternative. Would that reduce the efficiency of the system? I don't think so, I think it would just mean that less steam condenses in those radiators. But that is one for the engineers. -- H