Correct Venting for faster Radiator heat up??

Jamie Hall

As long as everything is sloped to drain…

edplu

https://forum.heatinghelp.com/discussion/comment/1817693#Comment_1817693

Looks like those 90's will be harazonal and not much slope…i don't think i have room for 45's..maybe I can bend the 1/2 pipe some??

bburd

You may not want to use a C on the attic radiator. The radiator takeoff and riser, at 3/4", are below the 1" minimum size for one pipe steam. If you vent that quickly, the steam and condensate may interfere with each other, causing gurgling and spitting from the air vent. Slower venting may be needed to prevent this.

I believe the attic radiator is not heating because of water trapped in the sagging pipe, not because of a venting issue.

edplu

https://forum.heatinghelp.com/discussion/comment/1817693#Comment_1817693

https://forum.heatinghelp.com/discussion/comment/1817726#Comment_1817726

OK … Im going to fix the slope on the attic pipe and use a 5 or 6 vent. I was thinking about pluging it off if it will speed up the cycle. A hour+ is really long to fill all the rada. Also I was thinking b 4 I spend 200 for a new #2 will that really make a big difference then the #75 ? I was hoping to cut the system cycle to 1/2 run time to fill all rads.

bburd

Do not worry so much about the length of time to fill all the radiators with steam. Most of the time a partial fill will satisfy the thermostat and avoid overheating the house. The important thing is that the system heat evenly most of the time, though this may vary in unusual weather conditions.

Regarding the Gorton #2 main vent, you have 90 feet of 2 inch main, right? @steamhead says that's what you need, and you will not find better advice on steam heat.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1817711#Comment_1817711

You can take 45s and have tons of room if you take it to the right of the copper pipe (between the copper and the pvc drain)

Steamhead

https://forum.heatinghelp.com/discussion/comment/1817730#Comment_1817730

The #2 vents about four times as fast as the #75. It's a no-brainer.

109A_5

Hello edplu,

With boiler cold starts, the run time will always be extra long, and not typical of mid winter performance. Changing the venting won't make the water boil faster. I would base the venting / steam distribution performance by monitoring the time from when boiler's header gets hot (boiler actually steaming) to when the farthest radiator's inlet side gets hot.

With adjustable vents usually the top unscrews and the metering plate (holes or incline plane looking tapered slot) will lift off, make sure they are free of debris. They are usually indexed in some way and/or pick the hole size that meets your venting needs.

edplu

https://forum.heatinghelp.com/discussion/comment/1817742#Comment_1817742

Regarding the Gorton #2 main vent, you have 90 feet of 2 inch main, right? @steamhead says that's what you need, and you will not find better advice on steam heat.

—

The piping is like a squre around the boiler, first 20' then 90, then 20' feeds first 2 rads 3in pipe, then 90 reduces to 2 in pipe for 25' feeding rad 3,4, then 90 for 15' fending the attic and rad 5, then 90 for 10' feeding rad 6 at the end b 4 it going sown into the boiler is the main vent ..

https://forum.heatinghelp.com/discussion/comment/1817742#Comment_1817742

I was thinking to the left .. cuz if I go to the right that puts the vent right over the boiler. Wouldnt the heat effect the #2 to close to soon ??

delcrossv

Wouldnt the heat effect the #2 to close to soon.

Nope.

I can guarantee the air above your boiler isn't 212 degrees.

edplu

I'm not done yet but I want to sincerly THANK everyone who responed to my thread !! I learned a hell of alot and can not Thank you enough !!! now if I can get the QB-180 down … I'm good … lol

edplu

I fired the heater up this morning..fix the attic pipe pitch and got heat in the attic. Took a little while...all the rads got hot but 5 was slow ...6 got hot b4 5 not sure why .. shouldn't 5 get hot 1st??? Maybe the old vents not working right??

109A_5

Try radiator 5 with the orifice plate removed from the vent, see if the steam gets to the radiator faster. If those holes are not lined up correctly with the port underneath or have debris in them it may not vent correctly.

edplu

https://forum.heatinghelp.com/discussion/comment/1818208#Comment_1818208

Thx … That vent is so OLD … I just order a #6 to replace. When I feel the pipe from the main its the last one that gets hot, rad 6 id hot b 4 rad 5 but it eventully gets hot. should Rad 5 should get hot b4 rad 6 ?? 6 is the last one on the main…

ethicalpaul

ideally, the order of the radiators on the main should not matter. This is because there should be enough main venting that the whole main fills up with steam before very much steam starts heading to any radiator

edplu

https://forum.heatinghelp.com/discussion/comment/1818230#Comment_1818230

It does but what confuses me is that the last radiator and pipe off the main gets hot b4 the one b4 it. which i think could b cuz of the vent on that radiiator not working correctly but it will eventully get hot. The vent is old and i order a #6. Hopefully this will speed it up. My whole goal is to get those radiators cooking ASAP (upgrade the main 75 to #2) to satisfy the Thermo setting for less load on the old QB-180.. lol …. thx

ethicalpaul

Yes, balance/timing problems are almost always due to the venting. That vent in the picture is certainly old.

There can be cases where bad pitch of pipes causes a water trap to form that partially or totally kills steam to the affected downstream radiators.

edplu

Can someone please explain the way the system works to get the radiators hot at the same time Does the entire main get hot first then the steam feeds the radiators one at a time starting with radiator 1 closest ECT??? I'm trying to get all my radiators hot at the same time.

dabrakeman

Think of it this way. Steam takes the path of least resistance. The resistance is the air already in the pipes that needs to be pushed out through vents. Theoretically a well operating system should have adequate main venting such that when steam starts being produced in the boiler the air gets pushed out of the main first because the main venting at its end is vastly greater than the venting at any single radiator. So, steam will travel through the main pushing the air out ahead of it through the main vents. When steam reaches the main vents it/they close so now the path the steam can start pushing air out of the takeoffs and risers going to the radiators. How much goes to any particular radiator vs the others depends upon their relative venting amount. Time to fill any particular radiator depends upon the volume of air in the takeoff leading to it, the volume or air in the radiator and the venting rate of that radiator vs the others. Your control over this whole process for getting steam to radiators evenly includes starting with enough venting on the main to get it to completely vent and fill with steam within about a minute of when steam first reaches the header. It takes longer with a cold system than with pipes because the cold condenses the steam quickly. Next access how long each radiator takeoff to the main is and how big the radiator is to decide relatively how fast of a radiator vent is needed on each radiator.

ethicalpaul

The steam will go wherever it's easiest to go.

So you put a lot of venting on the main, yes, to get the main to fill with steam first.

This sets up the scenario where from that point (when the main vent closes) steam will then start to flow up to the radiators at about the same time.

Then you will use various sized radiator vents to make your rooms comfortable.

You don't actually care precisely when the steam gets to each radiator, you care about the comfort of each room. For the same reason, you don't really care which radiator is closest. It will play into the equation of course, but the goal is the comfort of the rooms.

So you start out with your radiators with smallish vents, then you increase any where the rooms are too cold. That should let those radiators get heat quicker than the others, creating more warmth where it's needed.

edplu

TY..IM going to draw a pic of my system with venting numbers and get your thoughts / advice.

edplu

Here is my venting setup...I haven't changed all the radiators yet..please advise..TY

17314130788987763442965906084573.jpg

delcrossv

Did you replace the main vent?

Do that first and then see if you need to slow down or speed up individual rads.

edplu

https://forum.heatinghelp.com/discussion/comment/1819644#Comment_1819644

Not yet … its $150 .. i was trying to get away with the 75 ..till i get the extra cash …

ethicalpaul

No one can look at your drawing and tell you which rooms are going to be too cold.

I honestly would just forget about worrying about anything until you can get your new main vent.

dabrakeman

Your diagram shows that some of the length of your main is 3" then reducing to 2"? Depending on how much of the 90' total length is 3" you may need more than just one Gorton #2. I'd probably plan on putting your #75 on an antler with the new Gorton #2.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1819665#Comment_1819665

@dabrakeman excellent idea!

edplu

https://forum.heatinghelp.com/discussion/comment/1819665#Comment_1819665

3" runs abt 16' then 90's, 16' then 90's, reduces 2" for 22' then 90's, 16' then 90's,10' 90's down to the boiler. Hoffman 75 at that 90.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1819675#Comment_1819675

You need more venting.

edplu

https://forum.heatinghelp.com/discussion/comment/1819687#Comment_1819687

Would just the Gorton #2 be good ?? or antler with the hoffman 75 ??

ethicalpaul

• Run your system until the main fills with steam
• Let the system rest for 15 minutes
• Run it again until the steam again gets to the 75 (verify the 75 is operating). Time how long this takes.
• Let the system rest for 15 minutes
• Remove the 75
• Run it again until the steam gets to the open pipe. Time how long that takes.
• Install the #2 within 15 minutes, allow 15 minutes to elapse
• Run it again until the steam gets to the #2. Time how long that takes.

Now you will have a series of times that your system took to fill with a variety of vents and even an open pipe. If the #2 took very much longer than the open pipe, then you can consider to add the 75 to it.

dabrakeman

2.8cuft to vent. I would suggest adding the 75 to the Gorton 2 particularly since you already have it.

edplu

https://forum.heatinghelp.com/discussion/comment/1819737#Comment_1819737

Do you have a pic of a good way to do it with both vents.. current setup

ethicalpaul

You'll have to use a two nipples and two 45 degree elbows to get it moved away from the joist or beam on the left. A gorton #2 is stupidly massive and won't twist on if it's that close.

I would try just the #2 for simplicity's sake, see how that does (by timing it), then think about adding another vent to an antler if necessary.

109A_5

Hopefully the 3" to 2" transition was done correctly and the 3" does not have a bunch of water trapped in it.

delcrossv

Do this

edplu

https://forum.heatinghelp.com/discussion/comment/1820048#Comment_1820048

Here is a pic of the 3' to 2' 90 .. it been like that forever…

3-2 90jpg.jpg

Pic of Rad 1 .. should I be concerned with the pitch ??

Rad1jpg.jpg

THX

edplu

https://forum.heatinghelp.com/discussion/comment/1820057#Comment_1820057

Hopefully the # 2 will be good enough, but i do have the 75 I might as well use too , or is that overkill ??

mattmich

It has been suggested that larger mains need more venting, which is undoubtedly the case when everything is sized proportionally.

But I believe this is only true if your boiler can supply steam fast enough to overwhelm the venting capacity.

Any boiler will produce enough "gas" to fill any main in a minute or less. But since the steam collapses as it heats the main, "heat" moves along much more slowly. This is also dependent on insulation, and time between calls for heat, and of course on the size of the boiler.

My system has 80 feet of main in a loop, most of it 2.5 inches. When cold, it takes about ten minutes from the time the boiler supplies steam to the time the end of the main gets hot, and that did not change measurably when I used the one inch tap as a "vent." This is with a properly sized boiler for our 320 square feet of radiation, but the house was designed for an EDR of 475 originally. So the main is rather large.

My radiators are vented tightly (MoM #4). I'll be doing some tests over the next week — starting by plugging all radiator vents — to see how venting affects the heating up of the main. The results will be posted on my DIY Installation thread.

cheers -m

ethicalpaul

I like that test and look forward to it. I expect it won't affect the timing very much. A #4 is extremely slow. I can tell you that when all the vents are size D, it has a dramatic effect on the speed of the main filling with steam.

What you said (which I completely agree with, and is completely backed by evidence) about "speed" of steam through the main at the start of a call for heat, is why the idea that "steam travels at 35 mph" is certainly not true at the start of a call for heat (where we care about the speed), and should be ignored as any kind of useful metric.