Main vent like Gorton 1 on a radiator?

steamobsessed

I have a 100-year-old house. I have two main runs, one is 50 feet and the other 40 feet. On the 50' run I am using a combination of one Gorton 1 and one Gorton 2. On the 40 foot run I am using just a Gorton 2. Every radiator in the house has a varivalve on it. For the sake of completeness I am running 10 ounces of pressure. Every radiator in the house is getting hot within 10 to 15 minutes from start except however my sons room which is furthest from the boiler on the second floor is just starting to get hot when the thermostat is satisfied. The system is completely silent - no hammer at all. I did a simple test by removing the valve completely and my son's radiator got hot almost instantly. I concluded it was simply a venting issue. I have since put TWO varivalves on his radiator in tandem using a 1/8 inch T and elbow. This has made things much better but the radiator could still use a little more venting. My question is this: has anyone ever used a main vent to vent a radiator? Is there any reason why I cannot do this? Should I just put 3 varivalves or is that crazy? Thanks in advance.

KC_Jones

You don't have enough main venting. On the 40' you should have 2 Gorton#2 vents and on the 50 2 #2 and 1 or 2 #1 vents. You are trying to make up for the inadequate main vents by over venting the radiator. The reason it isn't getting to that rad is because the main isn't full of steam when you are starting to heat the rads. You should be able to fill those mains in 5 minutes or less after the boiler is steaming.

BobC

depending on the size pipe used on your mains you really need at least twice as much venting on them. What have you got the varivalves set to? They are very aggressive if not set very low and can make it difficult to balance a system.

Getting everything to heat up at the same time is a matter of balance, judging by the lengths of your mains it sounds like your radiator runouts are pretty short so the radiator vents on the first floor really only have to handle the radiators as long as the mains fill with steam quickly. Have you ever tried something like the Gortons or Maid O Mists on the radiators? Most find slow venting works best. Maybe a #4or 5 on the first floor and #6's on the second for a start.

Of course if your happy with what you have, leave it be.

Bob

Fred

I'm with the others that have commented on this issue. If you put the correct amount of venting on the mains, I'm pretty sure that radiator will get steam before the thermostat is satisfied.

STEAM DOCTOR

Get rid of all the vari vents. Replace with Gorton #4's on the smaller rads and Gorton#5's on the larger rads. Vari vents cause balance problems. They don't solve balance problems. Tried and tested.

steamobsessed

Thanks for all the responses. It seems that the consensus is that my mains are not vented sufficiently. Isn't a Gorton 2 equivalent to about 3-4 Gorton 1s? If I put 2 Gorton 2s and a Gorton 1 on the 50' isn't that excessive? I just struggle to imagine that when this house was built 100+ years ago that much venting on the mains was ever contemplated. Regarding the varivalves, originally I did have all Gorton valves throughout the house. I had 4 and 5 on the first floor as appropriate and 6, C and D upstairs according to Gortons chart. The problem that I had with these valves was that I had very loud vacuum sounds after the cycle was completed. Is that normal? I don't have that with the varivalves except for one radiator upstairs. The varivalves are much quieter than the Gortons were. Thus, my wife insisted that I get rid of the Gortons. Is it normal to have vacuum loud vacuum coming from the radiator vents once the pressure drops down and the cycle is completed ?

steamobsessed

Hatter: that seems to make perfect sense. And as I was writing my last post I was starting to put this together in my mind. Off to the supply house tomorrow to get more main vents! If all of this plays out as planned i imagine I will want to go back to Gortons on the rads. Oh well. Sigh. I will just lower down my varivalves to slow the rads down. Thanks everybody.

ChrisJ

How well is the boiler matched to the load?

All of my radiators heat evenly within seconds of each other, but more importantly the rooms all stay the temperatures I want all year.

My system also never sees more than 1 ounce because if it hits that, it shuts down for 5 minutes.

I'm using all Gorton vents. I had four varivalve vents back in 2011 but I gave them to a friend to use as main vents. As others have said beef up your main venting and then play with the radiator vents.

jbmoff

And remember,100 plus years ago, the system was coal fired which allowed for totally different venting tactics on the mains than what we need today. Coal fires burned long and often all day, so the venting in the mains was quite different. Keep us posted.

BobC

If you want to make balancing the rads easier after increasing the mains venting look at the Maid O mist 5L's. A vent gets packaged with 5 different orifices so you can select the venting rate you need.

Some say the Gorton is a better vent but I've had them for 3 years without any problems. Don't know why Gorton doesn't make their orifices swapable.

Bob

steamobsessed

Fast venting rads

Everyone on this forum seems to dislike varivalves because they are contrary to the premise that you vent mains fast and rads slow. That said, if I can adjust my 15 existing varivalves to create a (near) balanced system once I increase my mains, is there any downside to keeping them? In other words if the house is heating evenly and all is right in the world, is it really so bad to vent the rad more aggressively varivalve style? It would seem to me that the faster everything is hot (assuming it's balanced) the more efficient the system is.

steamobsessed

Btw This is my 50' run as it exists now.

BobC

"Of course if your happy with what you have, leave it be."

Bob

steamobsessed

That makes perfect sense. So far so good as I have not experienced overheating. I rarely if ever see my thermostat exceed the desired temp. Probably a product of a drafty house together with the fact that the house was expanded and I think we have the bare minimum rads for the space. That said We never have a problem getting the house up to the dialed temp. So I guess we are good. Hopefully additional mains will solve the problem with my sons room - the only "problem" I perceive with the system. I'll let everyone know.

ChrisJ

If they are performing well my only two concerns with varivalves would be spitting (if they're not, they won't) and early failure. There's been rumors on the streets that they fail often but I have not personally seen it.

steamobsessed

Venting mains - why didn't they need as much venting 100 years ago but do today?

I found this great explanation which echos the explanation above provided by JB

Every time the boiler turns on it has to drive out this air. It’s the on/off firing that is the nature of gas boilers that makes this more of an issue than the original constant firing coal boilers that were installed in most homes. The old timers didn’t screw up by putting in minimal venting capacity, they designed for a constant firing coal boiler that didn’t shut off often and didn’t allow the air to keep coming back in like today’s gas & oil boilers do.

SWEI

Two words: Modulating Burners.

ChrisJ

SWEI said:

Two words: Modulating Burners.

Three words.
Americans are cheap and if given the choice would choose cheap up front cost over comfort and long term savings every time.

Ok, so I planned on three words but got caught in the moment.

steamobsessed

Increased main vent - update

I now have 2 x Gorton 2 and 1 x Gorton 1 on the 50' main and 2 x Gorton 2 on the 40'. The steam is reaching the main vents very quickly now and it is also reaching my son's room much faster. I still feel that I need the double vents on his radiator though to vent the radiator at the same speed as the rest on the second floor. It's the largest and the furthest from the boiler. I lowered my pressure down to .5 psi as well. The vacuum issue I was having on several of the radiator vents is much better but not completely gone. I do hear the mains sucking in air now when the boiler stops and the pressure drops to zero which is great I'm guessing. The system seems to be almost perfectly balanced. I'm happy. Thanks again for the advice.

Fred

Great! I suspect when the temps really drop so that the boiler runs longer, you may decide that the double vents on that large radiator makes your son's room too hot and you may want to take the second vent off and plug that opening.

KC_Jones

Did you turn the vents all the way down on the other radiators? Sometimes it's not a matter of increasing the venting on one, but decreasing it on others. Remember steam is "lazy".

steamobsessed

Too much main venting?

I can't stop obsessing over whether I went overboard on the main vents. I know there have been discussions in the past regarding whether you can 'overvent' your mains but the comments are somewhat inconsistent. When I do the math, a single Gorton 2 on each main should be sufficient to vent the mains in 1 minute (1.1 cubic ft/minute). Now I am venting at more than twice that speed. Thoughts?

BobC

You can't have too much venting on steam mains but you can reach a point of diminishing returns. You can over vent radiators, that can result in banging because of excessive condensate and radiators not heating fully because the steam shoots across and closes the radiator vent.

Bob

KC_Jones

steamobsessed said:

Too much main venting?



I can't stop obsessing over whether I went overboard on the main vents. I know there have been discussions in the past regarding whether you can 'overvent' your mains but the comments are somewhat inconsistent. When I do the math, a single Gorton 2 on each main should be sufficient to vent the mains in 1 minute (1.1 cubic ft/minute). Now I am venting at more than twice that speed. Thoughts?

Sure you could vent slower and you burn more fuel to do it. It's about pressure. Do you have a good low pressure gauge on the boiler? 0-3PSI at most? I have a 15 OUNCE gauge on mine and it never goes above an ounce and that's only after the mains are full. I vent the mains below 1 ounce. The lower the pressure (set by your venting) the faster the steam moves, the faster you heat the house, the less fuel you burn to do it all. The diminishing return is putting more vents on than the pipe they are connected to can vent. Once you get equal to an open pipe that's the best you can ever do. Pressure=wasted fuel.