Venting Risers...Because Why Not??

AdmiralYoda

This has come up multiple times but I am going to put a twist on it. Often the problem is with 3rd story radiators on the cold side of the main. But.....

I'll be replacing the radiator valve and spud on my 2nd floor radiators. It dawned on me that it would be a good time to vent the risers going to these radiators. Between the runout and risers there is probably 15-20ft of 1-1/4 pipe going to these radiators.

My back-of-the-napkin math says that's about 1.5-2.0 cubic feet in the riser/runout to vent.

I have Big Mouth main vents and these radiators heat well....but I want the air out of my mains as quick as possible which made me think maybe getting the air out of the risers would help accomplish this.

I'd use a reducing Tee and a straight radiator valve with its matching spud. The fittings are cheap and I already have some good Gorton #1's lying around so this really wouldn't cost me anything. The Reducing Tee I am referring too looks like this:

ChrisJ

I might have missed it, what's the question?

AdmiralYoda

@ChrisJ
Hahaha....sorry, I tend to elaborate (ramble) TOO much sometimes. While I'm at it replacing the radiator valves I'd like to vent the risers. Do I need to? No. Do I want to? Yes.

The risers/runouts are 15-20ft long.

I'm wondering if this is a good idea or a completely unnecessary idea. I tend to be Captain Overkill most of the time.

Jamie Hall

In my view it's an excellent idea. After all, when you really look at it from the viewpoint of the air or steam, a riser is no different from any other steam main.

ChrisJ

AdmiralYoda said:

@ChrisJ
Hahaha....sorry, I tend to elaborate (ramble) TOO much sometimes. While I'm at it replacing the radiator valves I'd like to vent the risers. Do I need to? No. Do I want to? Yes.

The risers/runouts are 15-20ft long.

I'm wondering if this is a good idea or a completely unnecessary idea. I tend to be Captain Overkill most of the time.

I like it.

AdmiralYoda

@Jamie Hall @ChrisJ
I have seen people vent visors after the fact to correct the lack of steam getting to the 3rd+ floors and it usually involves drilling and tapping to get a vent installed somewhere.

I want to use a reducing Tee and a straight radiator valve to accomplish the same thing. It is good to know this is an option. Thanks!

KC_Jones

I'd agree with doing this, it would be a fascinating experiment honestly. The radiator vent would truly be only for the radiator. The idea of getting steam to every rad simultaneously would be much easier.

cross_skier

I vented my risers 20 years ago and I'm happy with my decision.  Large vents on radiators caused random issues during my first two years.  Double vents worked a little better.  Venting the risers fast and the radiators relatively slow solved everything.

I used Gorton D's 1/4" straight vents

AdmiralYoda

@KC_Jones That was my thought exactly. There is even one radiator on the 1st floor with a rather long runout as well. It is a relatively inexpensive experiment with the only extra cost being a Gorton #1. And if for some reason it turns out to be a bad idea (unlikely) I can just plug the vent hole.

@cross_skier If I'm not mistaken the Gorton D and #1 has the same venting capacity, with the difference being the thread size. Sounds like a great choice either way.

ethicalpaul

I did mine on a second floor riser that I re-ran just for fun. I think it's not necessary for 2nd floor. I'm sure it's faster to get steam, but it's not really noticeable at least for me.

Jells

I did one at the furthest spot on my system, but I put the tee between the spud and the rad. Seems to have improved things, I mean, how could it not?

cross_skier

I also started with the furthest bathroom out.  A hot bathroom radiator in the morning was a "must have" every winter morning.  2" main to 33' of 1-1/2" main with 12' of 1"riser to the tiny bathroom radiator.

PhilKulkarni

I would like to vent two of my 1 1/4" risers feeding the third floor radiators, but these recessed Cast Ray rads don't have the space for a tee with a vent on it since the valves are located below the rads, not on the side. The risers come through the floor with a 6-8" run outs from the valve to the radiator.

The risers are in the walls and only a small section of them- 20-24" where they connect to the main are accessible from my crawl basement crawl space. I have 22' risers feeding the 3rd floor rads which are currently vented with the largest orifice MOM vents but still take a couple of boiler cycles to heat up.

Thanks in advance for any suggestions.

jhewings

@PhilKulkarni You can consider drilling the 6-8" runout and tapping for 1/8" angle vent such as a Gorton D.

cross_skier

I also used a tap, 1/4" npt

cross_skier

Jells

jhewings said:

@PhilKulkarni You can consider drilling the 6-8" runout and tapping for 1/8" angle vent such as a Gorton D.

That's an interesting idea. Is there a reason tapping the rad instead just above the spud wouldn't accomplish the same thing? Seems to me EVERY rad could benefit from 2 vents, a riser vent and a rad vent on opposite sides. Or am I, steam novice, missing something?

jhewings

I did 3 like the one above and 1 on a radiator (on the steam valve side about 6 inches above the steam valve because the above was not convenient). They are all "riser" vents though. I have 4 risers. I don't think my system needs 2 vents on every radiator. These are on the 3rd floor of a 3flat (Chicago). I am happy with these riser vents although an unexpected result was one of them erupts with loud hissing of air going back in after the boiler shuts down (every time). I don't mind it although I have read here a vacuum breaker on the main vent tree will solve this.

EBEBRATT-Ed

@AdmiralYoda

1st floor not necessary
2d floor may or may not help
3rd floor ..do it

If your riser and radiator are both 1 1/4" you can use a 1 1/4 X 1/2 x 1 1/4 tee bush the 1/2" as needed for the vent