Installing main vents

sobriquet

This will be my second winter in a steam heated home. My attempts last year at balancing the house through individual rad vents were unsuccessful and this year it's becoming annoying. 2500 sq ft home, downstairs is warm, upstairs is noticeable colder by probably 4 or 5 degrees, if not more in some rooms. 8 radiators downstairs, 5 upstairs, and 2 on the third floor which are unused. Most radiators are baseboard style, basically a large pipe (maybe 3") with heat exchanging fins - seemingly not as efficient as the standard upright radiators. The house was built in 1842, when it was piped for steam is anyone's guess. I've been reading a lot and keep coming back to the importance of venting the mains quickly. My system has 1 main vent, just next to the boiler at the end of the return piping. A main pipe comes off the boiler and splits into 2, it then runs probably 25-30 feet, branching off to smaller pipes with radiators and vertical pipes above. At the end of the two large main pipes there are no main vents. I understand this is inefficiently piped? Is it feasible for me to install mains at the ends of these pipes? Will it fix my uneven heating? If so, is a gorton no. 2 the correct main to use? Gorton website says to install the no. 2 at the end of a long run away from the boiler. All the radiators have hoffman 1a vents. Should I keep these vents or try gortons?

BobC

Post some pictures so we can see what the piping around the boiler is like. make a sketch that shows the mains and how the radiators branch off it, show the length of each main and also the return. Look for a spot after the last radiator takeoff (if possible) where a vent could be mounted.

For optimum venting at very low pressure a Gorton #2 vent would be used for every 20 ft of 2" main, a 20 ft 2-1/2" main would need twice as many #2's. In general the radiators should be vented slowly, larger radiators at the end of long runouts may need faster venting. Hoffman 1A"s are not easy to adjust because the caps are sloppily made, if you can adjust them correctly they could be fine. Gorton radiator vents are good but you have to guess which goes where. You can buy Maid O Mist vents that come with 5 orifices so you can dial them in easily, they make experimenting easy.

Get the mains venting done before messing with the radiator vents.

Bob

sobriquet

here is a picture of the near boiler piping, and a rough sketch of the mains and radiator run offs. All measurements are approximate within a few inches. The main pipes are all 2" and are shaded in the sketch. The condensate return is darkly shaded.

Abracadabra

If it was me, I'd do 2 gorton #2 for each main. Do you have pics where the main drops down into the return?

KC_Jones

More pics in their other post.
http://forum.heatinghelp.com/discussion/148705/first-time-steam-owner#latest

Abracadabra

From this picture:

https://us.v-cdn.net/5021738/uploads/posts/21477/photo 1.JPG

It looks like the mains end in a tee. Looks to me that's where you should have vents. Can you take a closeup of the end of the main/tee/drop to return area on each side?

sobriquet

I have adequate space for vents at the end of one main, but not the other. Can a main vent be installed before the last radiator take off? The last radiator take off goes straight to a second floor bathroom.

Fred

If you put a 6" to 8" nipple on the top of those Tee's, you can mount the vents right on top of the nipples. Ideally you want to be 12" to 15" back from that drop into the return but vents work well right at that spot as long as they are elevated enough to keep dirt and crud out of the vent.

Abracadabra

sobriquet said:

I have adequate space for vents at the end of one main, but not the other. Can a main vent be installed before the last radiator take off? The last radiator take off goes straight to a second floor bathroom.

Not sure why you say you don't have enough room? Looks like plenty of room to me.

sobriquet

I don't have adequate room on one end if I want to mount the main vent 12"-15" back as recommended. Is this only to keep debris out? Or does it affect efficiency of venting? If I can just remove the plug at the top of the tee and mount them there (elevated), it will be much easier than removing and re-piping the end of main sections.

Abracadabra

sobriquet said:

I don't have adequate room on one end if I want to mount the main vent 12"-15" back as recommended. Is this only to keep debris out? Or does it affect efficiency of venting? If I can just remove the plug at the top of the tee and mount them there (elevated), it will be much easier than removing and re-piping the end of main sections.

12"-15" back can also mean 12-15" left/right/front.

Here's a pic from Gerry Gill's website

http://www.gwgillplumbingandheating.com/wahelper/GetImage?id=92975

KC_Jones

The basic idea is to keep the steam and condensate from beating the vent to death. My vents are on a tee at the end just like yours would be but I put an elbow and 10" nipple on them to get them away from the tee. You have some height available there which I would exploit to the fullest. Get it up high.