Strange setup - no main air vents?

Circa1902

This is my first home with steam heat. It's... functional, but as I learn more about steam heat the more I see wrong with the system. Many rads cold, or half cold. Air vents all seem to be working though so, I turn my attention to the basement. This is a one pipe system.

A couple things stand out to me, many pipes are currently uninsulated. Probably 50%. This is of course leading to a toasty basement but a cool first floor and a cold second floor. Another item on my to-do list.

As I was investigating the setup downstairs, I noticed there aren't any main air vents (that I can see anyway?) From my understanding main air vents are much larger than the ones on the sides of the rads. Also most that I've see have a vertical connection. I don't have those. What I have, is two air vents that look like they're sized for radiators - i believe they're both 1/8" side connections. One is mid-way along a main (not at the end) and the other is much closer to the boiler, I'm not sure of the name of the loop but it looks like it's part of the line that returns water to the boiler.

FWIW one says Dole No 1A Vari-Vent, and the other is a Syphon King 102. Neither looks like they've been maintained so it would not surprise me if they didn't work.

Has anyone seen this before, these smaller sized vents, and is it impacting my heating efficiency? (Assuming a big YES here)

Jamie Hall

Yes! Between the lack of main venting and the uninsulated basement mains... you have some work to do. The vent midway along a main is going to be just decoration. You can leave it, take it off and plug it, or whatever -- it isn't doing much. You will need some nice main vents at the ends of the mains. The one on the line near the boiler... if this is one pipe, it isn't doing much for you either. Probably not doing any harm, but...

Fred

It would be good for you to post some pictures of your piping, at the boiler and the mains as well. The vents you have on the mains are way too small to do the job of venting the Mains and need to be replaced. The one that is half way down the main, if that location is after the the very last radiator run-out, that is fine. You really don't need to vent air out of the dry return portion of a main (portion after the last radiator run out that pitches and makes it's way to a drop before or at the boiler.
Do you have one or two mains? The vent near the boiler could be from the end of a second main??? If they are both on the same, single main, then it would be best to locate them together, somewhere after the last radiator run-out but a 1/8" tapping will likely be too small and finding a location that maybe has a larger tapping may be needed. Do post pictures.

Circa1902

As an aside, this was (when the house was brand new) a coal system. From what I understand, there was less need for venting in a coal system because unlike a modern boiler, coal was a constant burn, whereas a modern boiler shuts on and off, and therefore allows air back into the system/pushes it out as part of normal operation.

Is my understanding of that correct?

Fred

Circa1902 said:

As an aside, this was (when the house was brand new) a coal system. From what I understand, there was less need for venting in a coal system because unlike a modern boiler, coal was a constant burn, whereas a modern boiler shuts on and off, and therefore allows air back into the system/pushes it out as part of normal operation.

Is my understanding of that correct?

That is correct!

Danny Scully

Coal systems sometimes used perimeter venting, which might be what you're describing.

MilanD

Post photos and then we'll be able to see what's going on. Also, you may have an oversized boiler. A lot of them out there. This alone will add to headaches.

About venting: I just read one of the posts links to 'Illinois Heating System' from, oh 1928, about 'wasting fuel to push out the air'... they are talking about wasting coal to fight air in pipes. So even then, manufacturers wanted to sell you their newest and coolest to save people coal expense. Today, as a contrast, we waste gas or oil, and vast majority of 'pros' out there seem not to care if we waste it in steam systems. Not guys here, but people coming for advice, just like I was once... boilers go in, installers walk out, and sayonara sucker.

You need to be able to get the air out of the main, and fast. If steam escaping the boiler is going at about 18 ft/sec, it has to push the air out. This will build pressure and pressure will waste fuel.

Post some pics of near boiler piping, vents you have on the mains, and how many mains there are. You may only need some tweaking and this alone will improve operations significantly.

Your 2nd floor being cold, 1st mild and basement warm means that steam is staying in the basement and has a hard time going upstairs. It's not so much about insulating the mains if it's this drastic. It's about removing the air out of the main pipe(s), so steam can go to the radiator. Faster the main vents, lower the op pressure of the system can be, and more fuel you save, and in the process, you'll be much more comfortable in your home.

Most of these venting tweaks can be done by a handy homeowner with some knowledge. Your vents you described are mostly decorative. But, if there is an opening with a reducer or a bushing to which your vent is attached, that means there is hope and it may be only a few turns of a wrench away.

Circa1902

Wonderful posts and thank you all for the writeups. Will take some pics tonight and post them for some more advice.

Very helpful to be able to pull from the knowledge of this group. I'm impressed!