Steam newbie with some questions-boiler short cycling/main venting/etc

nicholas bonham-carter

Tekmar limitations

If tekmar would go wireless like the prestige, then I would jump right now -(are you listening daniel@tekmar?)--nbc

a2shutt

.

I'll check those out. Right now I think the cheap Honeywell is keeping things going, so I'll focus on insulation and venting first. Those do sound ideal though, and I like that I can adjust the stat without having to arrange to get into an apartment. I'm tempted to put those in all my units. Now if they could be controlled via an iPhone app...



Ed-in response to your other post, the radiator vents are mostly fine. Someone has maintained them halfway decently.



I do have a nasty steam leak in one of the crawlspaces that I've got a bandage on for now (hasn't completely stopped it, but its a bit better). As soon as I can find someone who can thread 2" pipe for a decent price I think I'm just going to replumb that section...the pipes are badly corroded.

a2shutt

steam controller

Just looked at them on pexsupply. They better be good for $949! They seem to have good reviews. Do they take a lot of work to get everything adjusted correctly?

Long Beach Ed

Tekmar

Shop at a local distributor for your better pricing. 



The Tekmar requires a little trial and error to set up, but on a system like yours, the fuel savings should pay for it pretty quickly.  They are also made in North America, and are extremely reliable.  All their literature and instructions are on line on their site so you can read how they work and see if you are up to the task of installing and configuring.



Most of the Honeywell I've seen recently is Chinese garbage, but I'm anxious to check out their wireless thermostats, if they are made here. 

crash2009

I just figured out something

When you use (...) as the title of your post we are unable to respond to that post and are forced to respond to the entire thread at the bottom of the page instead of directly under what you last said.  So, our discussion of mains and main venting will be continued below.

a2shutt

oops

sorry

crash2009

Main Vents

Steam doesnt know the difference between up, down, left, or right.  All it knows is pressure.  Steam (higher pressure) will always go to the area's of low pressure.  In your case since there are no main vents to force the steam to go where you want it, it will go wherever it wants.  Right now, I think, your areas of low pressure are the leak in the 2" (where is that?)  The main vents in the center of the building that may or may not belong there.  And the radiator vents. 



I used the charts from    http://www.heatinghelp.com/products/Steam-Heating-Books/25/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek   to calculate that you have about 5 cubic feet of air in your mains.  3.75 in the big one and 1.25 in the other.  On paper, to me, the condensate drain/wet return should be up there by old rusty.  Both mains should drop right there and go underground.  All the main vents should be up there too.  Somebody has hacked this one-pipe to pieces.  One-pipe is supposed to be real simple.  Up, over, down, and back.  My second thought, and I like this better, was like this new diagram but I'm not sure if your slopes can make it happen.  Just throwing it out there, this one has me scratching my head.  Not sure what you can get away with.  It would run real sweet like this, but it might be overkill and expensive.

a2shutt

That

does make sense, however I'd like to not replumb the whole basement.



Is there an advantage to the main vents being in the center of the building, or could I replace the rusty vent (maybe put an antler with 2 of them at that spot?) and then just add a vent or vents at the end of the other leg? The vents would both be in the upper left of the diagram then. That may be crude but it would be a whole lot easier/cheaper, as long as it worked.



My steam leak is in the south-west corner (top right in the diagram) about 4 feet into the crawlspace (denoted by the shading on the diagram). Right now I'm trying to find someone who can thread 2" pipe locally so I can replace it.

crash2009

If slope permits

Most of Main 1 is allready done.  If slope permits, all you would have to do is join rusty to its neighbor (at 1) to make the main straight through to the end.  Remove the pipe and vent between 3 and 4.  Then cut in at 2 and extend out to the drop.  Just like the extention you allready have. 



1 to the right is allready low, 1 to the left drains to the existing vent.  1 + 1 = Main 1 done.



Elevation survey needed so you can see where you are at.

a2shutt

EDIT

Ok, I was a little off. There actually IS another vent at the end of the north steam main. It was tucked up between some joists and I didn't notice it before. I've modified the diagram to indicate this.



All of the main vents are Hoffman 75's. The vent on the dry part of the return on the left (looking at the diagram) gets HOT, but the one on the right does not.



The big yellow dot on the diagram is where the steam leak is. I'm going to remove most of the stuff in that area and redo it since its pretty corroded and has several bandages already.



Should I insulate the return, both the dry and wet parts?

a2shutt

We just

posted at the same time. I'll look at the elevation and and see what I can do. Should the boiler be the highest point? Your number one circle, from what I remember, is up pretty high.

crash2009

Look at the side view

The main should be highest at the boiler (6) and lowest at the vent (5)

crash2009

I wouldn't insulate

 anything just yet.  Give yourself some time to get this all figured out. 



Probably after you fix the steam leak the vent between 3-4 will start to get hot.



Maybe you havn't noticed yet, but you have some crosslinked files.  The thumbnail shows the change but the full size shows the picture before the change.  To avoid this in the future, you must change the name of the file before you upload.  This is just a work around that I have come up with working on this particular website.  For example I have your original diagram saved as Jackson0015.jpg everytime You or I makes a change, I save the file as a new name such as Jackson0016.  I think what happens is the website pulls Jackson0015 from its cache rather than from your computer.  This is hard to explain.  Let's not even go there!  This file is Jackson0024



 

a2shutt

Here's a

renamed file.



One problem is that there is an old fieldstone wall between the two main vents in the upper left corner of the diagram. Tying them together would be a chore.

crash2009

It worked

 the file is not crosslinked.  3" pipe contains .053 cubic feet of air per foot.  2.5" =.03 per foot, 2" =.023 per foot.  I get 3.3 cubic feet in the big main.  I have been told to vent the mains using the 1oz scale from the venting chart.  So my suggestion would be 3 Gorton 2's (The Gorton 2 is rated at 1.100 cfm at 1 oz) at the end of Main2.



Up there at old rusty (Main1) I would go one Gorton 2 and one Gorton 1.  (1.100 + .330 = 1.430 cfm @ 1oz)  I got 42 feet of 2.5" plus 9 feet of 2"  (1.467 cubic feet of air) 1.430 of venting. 



It just might work.

a2shutt

Thanks

a lot, crash!



I like your idea for replumbing the system but a) no budget for it right now and b) I can't have the system down for long in the winter. That might be a summer project, along with one of those steam controllers.



Worst case, I'll need those main vents anyway, so even if it doesn't work well I can still re-use them and not be out much.



Couple questions, though-



1: Can you explain why I need those dry return vents? Seems to me that if it's only condensate running down there, they don't need to be vented, or at least not much. A vent like what I've got is just sucking steam down the return and robbing the rest of the system. Am I right?



2: The apartment that I've had the most problems is in the bottom left of the diagram, upstairs (north east corner). Is there an advantage to putting one or two of those three #2's in that corner of the basement, and putting the rest at the end of the main?

crash2009

Venting

1-I don't know if you need them or not.  I would install the vents as suggested up in the top left corner and run it for a couple days.  Then remove the Hoffmans and plug the holes and run it for a couple days.  See what is better.



2-No I wouldn't even try that one.  If you wanted to improve that apartment figure out a way to vent the riser a couple feet before the radiator valve.  Drill and tapp for a Gorton D, or maybe a C.  Would this be riser 1 or 2 that you are having the problem?

a2shutt

I'm not

exactly sure. I think it's riser 1.



I'm going to go ahead and order those air eliminators, and over the next week or so I'll be installing them, replacing that leaky steam pipe, and insulating (I'm meeting up with that guy from Redford in AA this week).



I'll let you know how it goes.



Thanks a lot for all your help...I really do appreciate it.

crash2009

Insulation

I gave Mike a photo of the boiler room, and told him I want to insulate everything.  He figured it all out for me.  He measures tight, no waste.

crash2009

Counterflow?

I finally stumbled into the counterflow diagram that I was looking for.  (thanks Bob) 



A2shutt, are the 2 venting locations in the top left of the diagram, the high points of the system?

a2shutt

YES!

That's exactly what they are. That's why I've been slightly confused about this "boiler is the high point of the system" thing. Everything in my system pitches toward the boiler.

crash2009

Well,

ain't that a major discovery.  You likely want to remove the vents on both of the condensate drains.  What size is the pipe that goes to, the under floor wet return?

crash2009

Counterflow huh?

Could you draw a side view plan of each main?  I started one but ran out of room.  Main 2 will be much longer than Main1.  We need them separate to simplify things that would overlap.

a2shutt

The mystery deepens

I went back over there today, and made some discoveries.



The pipe actually slopes toward the condensate returns. So, it slopes down from the boiler until it reaches the return, then it slopes back up. Pitch on most of it is about 1" per 10 feet. Some of it is flatter and some is a bit more. I can indicate those areas if it matters.



I modified the diagram to indicate pitch, which is the black arrows next to the pipes. I also attempted to make a side profile...not sure how it turned out or how it will view in this website. I'm on a mac and not real familiar with those drawing programs.



The return on the north main is 2", the return on the south main is 1 1/2"

Abracadabra

looks pitched right

If your notations are correct, it looks like the mains are pitched correctly.  The drips to the main now make sense.

crash2009

Abra

You looked at the header right?  Why would the previous installer abandon the second system riser, and combine both mains on one riser?  Wouldnt that increase velocity? 

Abracadabra

plugged riser

yep, that plugged riser has me confused.  I'd think the main that comes off tee branch would not get as much steam as the thru.  Looks like someone tried to make a change to correct some problem. Not sure what tho.

a2shutt

There

seems to be adequate heat off both mains. Could there be a reason why they wanted LESS steam...for instance, is the boiler oversized and this is their way of cutting it back?



It seems odd to me that they would go through the expense of plumbing that riser up, if they were just going to plug it. Again, it's obviously newer pipe that was replaced at the same time as the boiler.



With the mains pitching toward the condensate returns the way I've described, is the main venting strategy the same?