two pipe steam radiator question.

mike from pa.

I want to install air vents into 2 pipe rads, to "speed up" the time it takes to fill the rads with steam. There are new 1 1/4 thermostatic valves on the feeds and new 1/2 inch 17c angle traps on the returns.
The reason for adding the vents is because the system is controlled by a Heat Timer Platinum control. The control only allows a certain amount of time for the steam to stay in the system per cycle. On warmer days the cycles are shorter(as it should). This is in a school and the rads in the classrooms are covered. (not only by wood but also alot of "artwork") The classrooms are cool compared to the rest of the building.
I have already made recommendations to "open up" the radiator covers to allow more heat out. I am considering the vents to help "speed up" the steam in the classroom.

So...my question is...Will there be any negative effect to the system if I add the vents? I can't think of any but I am interested in what you guys think.
I considered f&t traps, but there is piping access concerns below floor (cost).
I did consider ajusting the Heat Timer control but I figured if I could correct these rooms (since the rest of the building is comfortable) I could save this school some fuel.

mike from pa.

2- pipe steam radiator question

I want to install air vents into 2 pipe rads, to "speed up" the time it takes to fill the rads with steam. There are new 1 1/4 thermostatic valves on the feeds and new 1/2 inch 17c angle traps on the returns.
The reason for adding the vents is because the system is controlled by a Heat Timer Platinum control. The control only allows a certain amount of time for the steam to stay in the system per cycle. On warmer days the cycles are shorter(as it should). This is in a school and the rads in the classrooms are covered. (not only by woood but also alot of "artwork") The classrooms are cool compared to the rest of the building.
I have already made recommendations to "open up" the radiator covers to allow more heat out. I am considering the vents to help "speed up" the steam in the classroom.

So...my question is...Will there be any negative affect to the system if I add the vents? I can't think of any but I am interested in what you guys think.

I did consider ajusting the Heat Timer control but I figured if I could correct these rooms (since the rest of the building is comfortable) I could save this school some fuel.

gerry gill

well, first

install faster steam traps..those hoffmans don't pass air worth a darn..if you must add an air vent, put it on the feed pipe prior to the radiator..if you put it on the radiator, and the trap fails, which it will someday, and if it fails closed, the air vent on the radiator would still let the air out, and then the steam in..and the steam will condense, and when you fill the whole radiator up it will either prompt a no heat call for that radiator, and you'll pull the trap cover and discover gallons of water coming at you, and all over the floor, or the water will slowly leak back to the boiler and cause mystery boiler flooding calls..you want the radiator to air lock if the trap goes bad.

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Jamie Hall

a couple of other thoughts to try, too

What is your system pressure? Run it as low as you can (I'm sure you've heard that!). Also, are those TRVs either full open or full closed? It's been my experience that throttling valves on steam feeds can cause the kinds of problems you're seeing (and worse).

mike from pa.

Thanks

Thanks! I didn't think of the traps failing. The system runs only at 3 pounds max.

I was only going to ad the vents if the unblocking of the rad covers doesn't help. I was only trying to figure out my next move if it didn't work out.

Just for my curiosity..What angle traps would pass more air? There is very little room to work here. I know I would love to put some f&t's in ........ but wish in one hand....

+
Thanks for the replies !!!

Christian Egli_2

The local bestseller

You're in luck, the venting chart by our very own Gerry Gill is for sale here and will tell you everything you always wanted to know about the air venting of traps.

The Good Book

http://www.heatinghelp.com/shopcart/product.cfm?category=2-138

The 17c break easily, I have quite a few crumpled up samples, changing those traps will improve things for sure. Add my voice to this camp.

Yet another thought along those of Jamie.

You say thermostatic valves were installed. Two problems pop to mind about them.

1) If they were installed on the wrong vertical body, where the actuator sits on top of the riser heat, you'll never get a call for heat in that particular radiator - the thermostatic head is always nice in warm, and why should it care about anything else. You need the horizontal valve body. I have a hunch you have Honeywell thermostatic valves and I've just seen lots and lots of the Honeywells with the wrong details for steam.

2) Those plastic actuators get cooked, particularly if mounted vertically. Next, the plastic gets brittle and some of the clasping lips break. Then the actuator head becomes lifted off from the valve body and you get no more heat - ever. Are the thermostatic heads well protected from bouncy kids?