Steam Radiator Vents

Mark Z_2

Nicholas, how true it is about venting the main lines quickly. Recently, due to home project, expanded one-pipe steam system to accomodate 25x30 rm. Original main line vents were all wrong. Almost the size of a Hoffman 1A plus rust stains present. Current main line 45' long has two Gorton #1s w/ a Hoffman 4A at the 15' point and two Gorton #2s w/ a Hoffman 4A at the end of the line set 1 ft back from the end and up about 10" like the book says. Open port, 3/4", vented in 5:15 min. With the Gorton #2s at the end, a touch over 5min. Don't think it gets closer than that. Best thing thou is that before expansion of the house, orginal was 2300sq, we burnt ~1000gl a season, after adding another 1200sq onto the house w/main line venting set right we're down to ~700gl. Thanks to Dan H's book and the rad venting guide plus some other great profeesionals who answered questions. Luv dat steam.

regards to all, Mark Z

Mark N_2

Steam Radiator Vents

After reading "Balancing Steam Heat Systems" I'm contemplating replacing my radiator vents. What the best way to go Heat Timer varivalves or Gortons.

Thanks

Mark

Supply House Rick

air vents

first make sure the venting on your main lines is as good as possible, then pay atention to the rad vents, if you think they are not working. the main vents do 90% of the air removal, and have a harder life, and are more likely to be "tired". many of my 64 rad vents are still working after decades of use, but my main vents are all new.--nbc

Mark N_2

Main Vents

The main vents are new. I'm using Gorton #1's. I did the test in the book. Without vents the main vents in 2.5mins with the Gorton 3.5 mins. Tapping is 1/2 in.

Mark

Kool Rod

The Heattimer Vari-valves are adjustable so that might be a benefit as it gives you some flexibility. Both are good units.

http://www.heat-timer.com/literature/VariV056082C.pdf

- Rod

movin2gas

The \"balancing\" e-book says...

There's an addendum in the "balancing steam systems" e-book that describes a particularly weird circumstance where the author had to replace some VariValves with Gortons because the VariValves were too fast and a vacuum was created. I don't quite understand why it would be necessary to do this if the VariValves are adjustable across (more or less) the entire range of Gortons. Anyone have an idea?

Supply House Rick

mysterious vacuum

i read that too, and i can't follow that explanation. i could see that if the steam production were less than the total radiation, and you had vacuum vents that you could run at sub-atmospheric pressures but you would still have steam everywhere i would think. just another mystery of the ancients!--nbc

Vinny_4

main vents and rad. vents

Where are the main vents in my system located??
My vents on my one pipe steam radiators are located about 1/2 way up on the opposiite end of the valve. Would it be more effective if it was located at the top of the radiator? there is a location at top of radiator where I could easily install the vent.
Thanks,
Vinny

Supply House Rick

main vent location

follow the pipes out from the boiler, until they come back full circle to the wet returns [if a parallel-flow system]. somewhere there should be openings for main vents-a 1/2 or 3/4 in. hole. if a counter-flow sytem, the vents will be at the far end of the mains after the last rad.

you really need big main line vents, and the system will only work as originally installed, when they are fully functional.

don't move the rad vents up, unless you need to decrease output from the rad.--nbc

Kool Rod

Vinny - As NBC says if the radiator vent were at the top the radiator output would decrease.

To understand this you have to think of steam entering the radiator. Steam enters the bottom and because it is a gas and warm, it flows towards the top of the radiator and then slowly moves across the top of radiator. After it fills the top of the radiator, it starts moving down. Since the vent allows air to escape but shuts when it detects steam, if it was positioned at the top of the radiator it would shut off when the steam reached it and since no more air could escape the radiator no more steam could get in and you'd end up with a radiator only half filled with steam. Less steam = decreased output.

On some really big radiators they have a vent at the top and also have another vent farther down the side. This allows for very fast venting and also gets the majority of the air out and steam in.

- Rod