Radiator Vents Simplified

Hinman

So I want to change out all of the vents on the actual radiators themselves in the building, 12 units, 3 stories, building is in the shape of a long rectangle with two tiers(6 apartments) towards the back near the boiler and 2 tiers(6 units) toward the front furthest from the boiler. There are 5 radiators per apartment. I’ll be using Gorton vents since they are cheap where I’m at and seem like good quality. I want to simplify the process and choose 2 vent openings and match them according to size of radiator. Was thinking D’s for the larger radiators and C’s for the smaller ones like in the bathroom. Is this a bad idea or should it be ok? I’m in the process of adding bigger vents on the mainlines of which there are two, one long one to the front of the building and one shorter to the back, so the mainlines should be well vented. Any suggestions or concerns? Trying to avoid using 6 different vents if I don’t need to. Right now there are all kinds of various vents on the radiators from super old (found a vent made in 76) to super new to brandless to different brands etc. no thought was put into it as it is right now. No rhyme or reason, however, the heating has been fine but I think it can be better and more efficient. I attached a google map image of the building and mapped out where the boiler is and the 2 main lines. Again, 3 stories, 12 apartments, 2 tiers(6)apartments in the front on one main and same in the back but shorter main.

nicholas bonham-carter

I wouldn’t replace any radiator vents first, apart from ones which fail the blow through test, or those which are of dubious quality.
Put your efforts into the main vents in the basement, as they do all the work of air removal. I like the Big Mouth from Amazon, which ha the biggest bang for the buck.
Later on you may find some radiators need faster or slower vents.—NBC

Hinman

@nicholas bonham-carter I put one Gorton #2 on the short return line last week. It’s made a huge difference, one apartment in the tier that was always 68 and now hovers at 72 now which is great. That was before I discovered this forum and learned about the Big Mouth. I would have preferred to put just Big Mouths on had I known about them but what to do now. I ordered a Big Mouth today from a SupplyHouse.com, Amazon says it’s unavailable. I picked it up for $78 which was cheaper than the $100 Gorton #2 I got at the local hardware store. The Big Mouth will go on the long line to the front of the building. I’m going to wait until I have the Big Mouth on and see how everything is running before I replace other vents on radiators.

KC_Jones

How long and what pipe size are your mains. For a building that large it is quite possible if not likely you need multiple big mouth or Gorton vents on each main.

Hinman

@nicholas bonham-carter attached is a picture of what is on the long line that I’m going to put the Big Mouth on! 😂 I don’t think it’s been changed in DECADES. Doubt it even works. I think putting anything on the line will help compared to that.

ethicalpaul

This part concerns me:

> Was thinking D’s for the larger radiators and C’s for the smaller ones like in the bathroom

It’s not really the size of the radiator, it’s the volume of air between the main and the radiator that are more important (roughly expressed as distance but the pipe size is a factor that can’t be ignored.

I agree with nbc to not change them all at once. Start with the hot rooms and give them each a slightly smaller vent than they have now. Then see what happens.

The hot ones should slow down which will direct more steam to the colder ones. Then re-assess where your hot ones still are. Repeat with slow changes because a couple changes might have a butterfly effect.

I don’t know how good they are, but I like Maid-O-Mist because you can just swap out the orifices and not have to re-seal the vent each time you change it.

See: http://www.maid-o-mist.com/images/jacobus1.jpg

gfrbrookline

Deal with your mains before you make any changes to the radiators.

The main vent you posted is scrap metal.

As others have asked please post the length and diameter of your mains and the wallies can advise on the proper venting.

It is likely you will need more than one Big Mouth on a system your size. I have a total of 5 Big Mouths and 3 G2's on my system and guessing I am smaller than yours as I have 3 floors and 6 units unless of yours are all 1 bedrooms.

Hinman

@gfrbrookline thanks for your response. When you say the “mains” which pipes all fall under that term? All horizontal pipes leading in the various directions and the vertical pipes that carry the steam to the different floors? There are definitely various diameters which I will post tomorrow and add some pics. All original to the building which was made in the early 20’s.

nicholas bonham-carter

Measuring the pipes is just the beginning…………
The development of the antler, for multiple main vents; the Big Mouth vent, and the low pressure gauge, (valworx 0-3 psi) have made it easier to select enough main venting.
Keep adding them on each return, until you can see a backpressure of 2 ounces on the gauge, during the venting phase, as steam is just beginning to rise out of the boiler, and push the air out.—NBC

jb802

@gfrbrookline @Hinman I have a 1920's steam system, my main valve in basement looks like yours. I only have 4 radiators off the system. Should I replace with a similar valve or use the 'Big Mouth?' I am getting a lot of steam hammer and was going to replace all the valves on the radiators until I saw this post. Now, I will start with the one in the basement (photo attached). I have one valve that is spitting a bit of water steam, it's opened to the fastest setting. Should I wait to see how it goes with the main valve before replacing the spitting valve?

Hinman said:

@nicholas bonham-carter attached is a picture of what is on the long line that I’m going to put the Big Mouth on! 😂 I don’t think it’s been changed in DECADES. Doubt it even works. I think putting anything on the line will help compared to that.

Hinman

@gfrbrookline hi! So I have some rough numbers for pipe size and length and attached some pictures. I’d say there is 85ft of 4inch pipe(seems to be the biggest coming out of the boiler and stretches accross the basement. Then another 80ft of 2 1/2 inch that connects to that 4inch pipe in various directions accross the basement before pipes head up. Then some 2 inch and some 1 1/2 pipes connect to that 2 1/2 inch and go directly up to the apartments. 3 floors, 12 apartments. 4 apartments on each floor. Most apartments have 5 radiators, and 3 apartments are two bedroom with 6 radiators. The rough estimates for length are on the conservative side, I’d say there is more. The main that connects to that big fat pipe coming out of the boiler that services the back of the building isn’t as fat, that pipe is 2 1/2 inch. The other main(fat 4 inch) goes to the front of the building on the roughly 85 foot stretch.

Hinman

@gfrbrookline

I have rough numbers and sizes. 4inch pipe 75ft long from boiler to the front of building via the basement. Then some smaller pipes coming from that 4inch that is 2 1/2 inch in various directions, (about 80ft of that), then there are some 2 inch and some 1 1/2 inches that connect to the 2 1/2 inch pipes before they go straight up.

For the back of the building there is a 2 1/2 inch pipe that connects to the 4 inch and that one services the back 6 apartments. 3 stories, 12 apartments, 6 in the front and 6 in the rear. 3 in the front of the building are 2 bedrooms with 6 radiators each. The rest are 1 bedrooms with 5 radiators each. 63 radiators total in the building. Attached are some pictures.

KC_Jones

You are going to need a TON more main venting. A single big mouth isn't even remotely close for all that. I would estimate you need about 4 big mouths just for the 75' of 4" pipe, maybe more.

Hinman

@KC_Jones Yeah, I was afraid of that😂 all of this starts to add up in $$$. Once I get it setup properly, will the savings on gas be noticeable?

Hinman

@jb802 That’s a beautiful artifact! 😂

That definitely needs to go. I’m not an HVAC/steam tech, but I would also check the return lines to see if they are still angled in a downward slope as they head back to the boiler. I’ve read that wood floors/joists can settle and in the process get the pipes out of angle. Also, the pipe holders themselves can even stretch a littl . If the pipes are not nicely angled down at a slope they can start to pool water. You want to avoid any pockets of water in steam piping. I attached some diagrams that can give you an idea of what I’m talking about. More or less all steam systems angle slightly I think. You want to maintain that angle.

neilc

@jb802
maybe start your own thread to get better attention,
but what's your boiler pressure at ?
are all your radiator valves fully open ?

@Hinman that main turns up thru the floor ?
gonna need to vent up top there also.

Hinman

@neilc no, the fat pipes don’t go up, they are just in the basement.

neilc

I'm still thinking you're gonna have to follow some of those not so fat, but still fat, ones up, and vent.
(the one above the boiler, against the brick)

gfrbrookline

I have a similar set up with close to the same size piping. I have a 6" nipple set back 6 " before the 90 degree drop to the wet return with a 90 degree joint and 3 Big Mouths attached. It's not a small investment but paid for itself in a few months on the heating bill and the heat is much more even. Don't use setbacks as any money you think you save you waste reheating the building mass.

Hinman

@gfrbrookline hi! I have a few questions, sorry if they have simple answers:)

1) What is a setback? Post a pic please if you have one, or the answer alone will be simple enough to understand.

2) The only two vents I have currently on the lines seem to be at the end of the 2 returns only(1 vent will be removed and the other was removed and replaced by a gorton #2) I had a problem with one apartment in the back of the building where it would never get past 68 and when I replaced the old busted vent and added the Gorton #2 the temp now reaches 72 in the apartment which is great, I’m guessing I’m heading in the right direction. There is nothing connected to the fat pipe that leaves boiler and goes to the front of the building, however the vent for that side of the building is on a smaller return line(that vent is not working). Do I need vents on the lines that go out from the boiler too or just on the returns?

3) This is going to be a bigger project for me in general. For now, is it ok to just add as many vents as I need on the 2 return lines since those are the only tapped pipes I see, say on antlers and just go from there and see how the system is functioning? If I need vents on the big pipe that will have to wait until next year.

4) Can these pipes be drilled with a hand drill and tapped? If yes, where are the ideal points on the lines to do this? Or is there some other way to add the points where I would add more vents if I have to?

Attached is a few pictures of where I have the one Gorton #2 which is the return line from the back of the building. I’m going to add more vents on an antler, but am I going in the right direction with my thinking?

gfrbrookline

1. A set back is when you turn the Tstat down for a period of time. 1 pipe steam is usually most efficient when the temp remains constant in the building.

2. You need a ton more venting than you have now. You can start by putting a 90 degree joint where you have the G2 and add 2 Big Mouths, that will max out the 1/2" tapping. If that pipe is 3/4" you should use 3 Big Mouths as that will max out the vents. Can't tell the size of the pipe from the pic.

All of my vents are on the "small" pipes which are called returns, that is fine. I would also replace the G1 with a 90 degree elbow and install another 3 Big Mouths, assuming the vertical pipe is 3/4".

It sounds like a huge investment but mine was paid back in under a year and the difference in comfort and balance was immediate.

3. Just use the taps you currently have and invest in a good set of 14" pipe wrenches and a 5/8" allen wrench. Make your antler with a 90 degree and not T's.

4. Start with the above and see where you wind up before you tap anything.

Venting is always trial and error but your mains give you the biggest bang for your buck.

Hinman

@gfrbrookline Thanks! That all makes sense. Im super good with tools and figuring things out, just need the proper directions and instructions and I can make it happen. This website is awesome! I’ve found Bug Mouths for $78 online which isn’t bad. I bought the Gorton #2 before I discovered this website for $100 at a local hardware store considered the best in Chicago. Clark and Devon hardware, they have everything. Seems like I over payed and could have gotten the Big Mouths which vent more and are cheaper...oh well. Now I know. I’m sure the Gorton #2 is fine, it’s definitely helped the heating in the one apartment that wouldn’t break 68. I can only imagine how much better things will run once I get the Big Mouths on and in the desired numbers. The one I ordered yesterday arrived today and it’s a sweet piece of brass!

When you say antler, you mean 90 degrees in one direction? T meaning it branches off with vents on both sides? I made a rudimentary drawing of it. If it’s what you mean just say yes:) the circles are the vents. pics attached

jb802

@neilc Thanks, yes, I sort of jumped in there! Sorry about that. PSI 1.5, valves are open, I think. @Hinman thanks for the diagrams, makes sense. I am finding out they are not angled correctly, gotta fix that!

Hinman

@gfrbrookline I attached pics of the old school boiler in case you were curious. I’ve posted it in a few other posts. Sounds like a jet engine when it’s firing😂 says manufactured in 1924.

gfrbrookline

Picture 2 is what you want to do and make sure they are pitched so the condensate flows away from the vent.

The G2 is a good vent, hold onto it. You may find one of your mains heats too fast so you may need to swap one of the Big Mouths out with the G2 to slow it down. Like I said balancing is trial and error but, you need a ton more but once you ramp it up you may need to dial it in especially since since you are venting one main on the end of the main and the other on the end of the return. I am guessing the one that is vented on the return will vent slower so depending on the load connected load.

gfrbrookline

That is a work of art.