help with new-to-me steam system

jms1051

I bought a new-to-me house this summer with steam heat and I’m trying to learn about how it works. I bought and read the “We’ve got steam heat” book which was really helpful. The house was built in 1933 and the boiler is new last year, installed by the previous owners. I adjusted the pressure per the book's recommendations.



My house has eight radiators and they all hiss and whistle. They do all deliver heat but the rooms upstairs are cooler than the rooms downstairs. They all have Dole 1933 Vari Valve vents and I took them off to see if they need to be cleaned. Several of them don’t have the top piece that lets you adjust it from 1 – 10 anymore so I guess they are fully open. Several of them didn’t have a tongue when I removed them for cleaning and one that did have a tongue lost it to the radiator when I removed it. There are two main vents by the boiler and air seems to come out of them. They are 40' and 42'. They are both Dole #4.



I think I need to get new vents for the mains and the radiators, at least for the ones that are missing the tongue and probably the ones that can’t be adjusted anymore. I’m not sure if this will resolve the hissing problem though, since I could blow through all of them when I removed them. I ordered the “Balancing Steam Systems” pdf and tried to use it to figure out which vents to get. It seems like Gortons and Hoffmans are both recommended with Gortons in the lead.



The troubles I had in calculating are that I don’t know how to determine the pipe diameter since they are wrapped in encapsulated asbestos. They are all about 10-12” in diameter. I also wasn’t exactly sure how to measure the pipe length. I measured from the main to where I could see it go into the floor and then added 1-2 feet if it was on the first floor and 8-9 feet if it was on the second floor since I have 8’ ceilings.



I think I should get 2 Gorton #2s to replace the main vents. I have enough clearance. I will get some help to remove the existing mains as I can’t turn them so I don’t know the diameter. I think they are ¾” so I would need some sort of ¾” to ½” adapter.



Attached is a screenprint of my calculations. Assuming my calculations were reasonable, my numbers are between the Gorton 5 and the 6 and I wasn’t sure which one to chose. The thermostat is in the dining room; the dining room is open (ie, 4’ opening) to the living room and the living room is open to the sunroom. So when adjusted, 4s for the main living area, 5 for the entry and 6 upstairs. I’m not sure if that’s accurate so then I started to think about getting the Hoffman 1As so I can adjust as needed.



The previous owners installed a new boiler last year. I’m guessing they installed the same size boiler as what was there before. It is a CAC/BDP 187,000 BTU (<span style="color:#000000">bs2aan000187abaa). It has a net ibr rating sq ft radiation of 479. If my calculations are reasonable, I need 283 so it’s way oversized. My house is 1600 square feet.</span>



Here are my questions:

1. Are 2 Gorton #2s enough for main vents? Is the Dole #4 a ¾”? If so, how do I make a Gorton #2 fit a ¾” pipe?

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2. Do you think I should get Hoffman 1As or Gortons? If Gortons, are my calculations right?



3. Is the boiler terribly oversized? Is there anything I can do to improve its efficiency?



Given that the boiler seems oversized and the radiator vents are in bad condition, it seems that they picked a contractor who just replaced the boiler and didn’t look at the whole system. I am in Madison, WI. It seems possible that my next move should be to contact a recommended contractor to come look at my system. There aren’t any in Wisconsin but possible the Illinois contractors travel to Wisconsin.



Much thanks in advance for your help. I appreciate you reading my long post.



Jeanne

Jamie Hall

A few comments...

on the vents, I'm partial to Gortons, but Hoffmans are excellent vents too for the mains.  There is no way that you can oversize the main vents on a system (the ones on the steam mains) -- the only downside to bigger (or more) is better on the mains is the money.



There are bushings or reducers readily available to go from one pipe size to another.  That's no problem at all.



I would prefer the Hoffmans for the radiators, as they are easily adjustable -- and you are going to need to fiddle with the adjustments to get the system balanced to your liking.  Note those last three words: to your liking.  You are the ultimate authority on whether your system is heating the house the way you want it to!  So adjust happily!



Unfortunately there is no good way to really compensate for an oversized boiler.  About the only thing you can do is make sure your pressuretrol is set properly, which you've already done (bravo!), and live with the cycling.  I'll grant you that the result isn't as efficient as a boiler which is really correctly sized and fired, but the difference isn't enough to warrant doing anything about until you need a new boiler -- which may be quite a while.  You'd never get your money back.  You might, though, when you have a real pro. there, ask about downfiring it (putting in a nozzle with a smaller flow) (I'm assuming oil?).  Sometimes it is possible, with some makes of burners and boilers, to downfire quite a bit, and that could make quite a difference in your situation.

BobC

mains

Is this a single pipe steam system?



The steam main vent has to fully vent any air in the boiler, the steam header and the steam main. You said the mains are 40 and 42 feet; if we assume they are 2-1/2 inch pipe then you have about 1.4 cu ft in each main. For that volume you need one gorton #2 on each main.



The doles you have were probably fine for a slow burning coal fire but are no match for a modern boiler. that produces steam much faster than the old boiler did. get the mains venting corrected before trying to balance out the radiators. i assume you are running 1.5PSI as your cutout pressure.



Jamie's comments are all applicable I would advise following them. Post some pictures of your boiler and the near boiler piping from a couple of different angles. Also some pictures of the steam mains and there vents would help.



Bob

AlexR

spare vents can be a good idea

Radiator vents aren't that expensive, so it may make sense to order an extra 5 and an extra 6 so you can move them around to see what works well.  You'll also have the extra for when a vent dies.



Your spreadsheet says it's assuming 1 1/4" pipe, but some of your radiators are big and may have larger pipe, so that may bump some vents up a size.  I use 6s and Cs on most of my radiators and haven't had problems with them being too big; I think you can just drill a slightly larger hole on the Gorton vents if you find yourself wishing you'd bought a bigger vent.



Reducing the pressure can make the hissing and whistling less.  My vents got much quieter when I got a vaporstat and turned the pressure down from 2psi to 8oz.



You can't easily do much about your boiler being oversized (I have the same problem).  The best you can do is to make sure you have enough venting that your boiler doesn't cycle on pressure while the pipes are first filling with steam.  You should watch it from the basement a few times to make sure that it's not cycling early.  If it is, more venting (that is, more than the spreadsheet suggests) may help.

The Steam Whisperer (Formerly Boilerpro)

Venting, et el

Your difficulties are typical.  Take a look here http://www.heatinghelp.com/article/11/Hot-Tech-Tips/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell

for an article I wrote on venting sizing.  The book you have by Gerry and Steve provides the foundation, but I take a bit of a different appoach.  Since your boiler is so big, I would suggest starting out sizing the main vents and radiator vents according to thier methods.  What you need to be very careful with, howver,  is that the main vents need to be several times larger in capacity than the total capacity of the radiator vents to make sure the steam races to the ends of the mains before it begins filling any of the radiators.  The problem with most radiator vents today is that they have much to much capacity allowing the steam to begin filling the closer to the boielr radiators before the steam gets to the ends of the mains.  This is better explained in the above article.

I may be making a trip up to the Madison area, as I have a couple of potential clients up there with steam difficulties.  One is trying to get together other owners so I can do some group consulting.  This helps spread the travel costs so the expense is less for everyone.  This will probably be taking place this spring if things come together.  We'll see.

jms1051

thanks!

Thank you all for your responses. I am going to order the Hoffman 1As and 2 Gorton #2s to start.



Now that I understand better how the radiators connect, I realize that the loudest ones are on the same main. I think it's not venting well.



Boilerpro, please let me know if you plan a trip to Madison. It would be great to have you look at my system.



I will post photos tomorrow. I appreciate your willingness to look at my system to see if there is something wrong.



Much thanks,

jeanne



 

jms1051

I forgot to ask my question

Do you think I can get the 3/4 to 1/2 adapter at a local hardware store? What material does it need to be?



One of the vents is directly below a beam with 8 1/2" to the floor beam. Since the Gorton #2 is 6", is that ok? I wonder if shooting steam at one of the board is bad for its longevity. Or is there a connector that will let me move it over?



thanks!

jeanne

AlexR

adapters and antlers

You can get small size (eg 1/2", 3/4", 1", 1 1/2") fittings and nipples (short pieces of pipe) at Home Depot or similar.  You'll also need two large wrenches or pipe wrenches or pliers (something that opens wide enough to grab the fittings and gives you 10-14" of lever arm) and teflon pipe tape and/or pipe dope.   It all fits together just like it looks like it should- look around for examples of "antlers" for how to move a vent out from under a beam.



For the main vent, you should ideally have it raised above the dry return and back a foot or so from the end so that condensate doesn't splash up into your vent (again, there are lots of example pictures around on The Wall).  Just make sure that it slopes slightly down away from the vent (or at least not down towards the vent such that water will collect and block the pipe).

BobC

Reducer

You should be able to get a 3/4 to 1/2" female reducer at a hardware store or Home depot / Lowes.



The additional height of the reducer plus the Gorton #2 might be to much to slip under rthat beam. Try it to see if it will fit, but with a couple of 90 degree elbows and a 6 or 8" pipe nipple you can move the vent over away from the beam. Make sure the nipple has a slight slope back to the steam main so any water can find it's way back.



Bob

nicholas bonham-carter

new-to-me-steam-help

you had excellent suggestions in these replies, but i will make one more:

get a good low-pressure gauge from gaugestore.com [0-3 psi] so you are certain what the back-pressure is, as the main vents are letting the air out. if the budget is very tight, theexisting  radiator vents can be left in place for a while, until you have had some experience with the new main vents.

check your thermostat to make sure that it is set for steam.

maybe you could ask around at the wholesale plumbing supply house to find the name of a retired pipe-fitter to help you put those vents on. he would not necessarily need any knowledge of steam [coming to this site will make you the steam expert!], as long as he can turn pipe.

you will take great satisfaction from your new improved system after these corrections to its deferred maintainance are made!--nbc

jpf321

no shooting steam ...

most people are raised thinking that vents are made to shoot steam .. when working properly, they ONLY "SHOOT" AIR .. if you are steaming your board/wall/ceiling etc .. get a new vent .