Counter-flow system

STEAM DOCTOR

Good afternoon. I am in middle of a very sticky consultation job on a renovation. The homeowner doesn't trust the general contractor the GC doesn't trust the plumbers he is bringing in etc. etc.One of the things that the GC/plumber decided to do was to move the low hanging main. In the processes they turned the parallel flow system into a counter flow system. I have an appointment tomorrow to meet with the homeowner and plumber to try to explain to them why it wont work as is. From reading  Lost Art I know that counter-flow systems need 1) a larger pipe size,2) pitch of one foot/10 feet3)for the steam main to be fed from top of the main and not the bottom. I would intuitively assume that the equalizer should have to be much bigger then normal because besides for its normal job as drain pipe for the header it is now also the drain pipe for the entire system. If I am making any mistakes or if I have left anything out I would appreciate input or advice.Also if anyone knows any sources besides Lost Art I would appreciate it (this way I can tell the plumber that I have multiple sources). Thanks!

Rod

Counterflow System

Hi - I don't know if this will be of any help to you. Attached are some pictures of an very nice counterflow system done by Steve Gronski, a steam pro in Rhode Island http://www.heatinghelp.com/professional/263/Gronski-Plumbing-and-Heating-Inc

It's really good way of dealing with multiple counterflow mains. I've also attached a couple of drawings that might be of help. Using drips would take the excess condensate volume off the equalizer. Just a thought.

- Rod

Steamhead

It's gonna bang

unless the steam main was oversized to begin with. If a main is sized for parallel flow and is turned into counterflow, there won't be enough room for steam and condensate to get out of each other's way. So the water will collide with the steam, bringing on the Anvil Chorus.



A "rise and drip" is a much better solution here. With this method, the main pitches down for some length, but before it gets too low, you install a tee with the continuing main on the bull and the run leading to a drip into a wet return or water seal. This keeps the main from hanging too low, and provides a drain for the condensate so it won't bang. It's also another way to avoid using the equalizer as a condensate drain.



I didn't see a pic of this in Lost Art, but any older ASHVE Guide should have it. You might also check Linhardt's Field Guide.

STEAM DOCTOR

Thanks Rod and Steamhead

I am going there tomorrow and I will try to talk the plumber/GC into one of your ideas. The steam main was definitely not oversized.

STEAM DOCTOR

Dripping counter flow

In the event that they stay with counter flow and don't have proper pitch and pipe size is there any rule of thumb to how may and what sized drips from the main they can use to compensate for main size/slope issues? Thanks

Steamhead

I would say

re-structure all the runouts so they come off the bottom of the main at a 45° angle, then drip each riser into the wet return. This will keep radiator condensate from re-entering the main. See page 87 of Lost Art.



Not sure how well this will handle start-up condensate, though.



With all the runouts installed this way, it is even possible to run the main perfectly level, since each runout becomes a condensate drip and therefore nothing will accumulate in the main. A flat main would probably handle start-up condensate better too.

JStar

...

I don't think that I would ever recommend leveling any piping on a steam system. The real solution is too raise the main back to where it was. That way, the system is back to "normal" and the contractors learn a lesson; they can't just do whatever they want.

Steamhead

Actually, some Dead Men did this

and from what I read, it works well. The key is that EVERY radiator runout connection also serves as a drip from the main.



Yes, it flies in the face of everything we've been taught, but this is one exception that can work if done right.

JStar

Hmm.

I can see that being theoretically okay. What would you do for the end of the main? Just cap it or drain it back?

STEAM DOCTOR

very very interesting

This is very intriguing. The BIG problem is that I am not the one doing the work. I was brought by the homeowner as a consultant because he doesn't trust the people doing the work. I am under the impression that the GC's approach is to make everything pleasing to the eye. Steam pipes too low? Move them! radiators in the wrong place? Move them! I don't think there is any way that I will get the GC to drip every runoff. That just means more of the "ugly" black pipes. O well. But again from a steam stand point I find this all extremely stimulating. THANKS!!

P.S. This GC also want to turn the steam system into hot water and use one "those fancy digital boilers". Never mind that the radiators only connect at the bottom. I think he would of had to drill and tap a few hundred times. At least I was able to talk them out of that "high efficiency" option

Steamhead

JStar, I'd use the last runout as a drip

just like all the others, and put the main vent just before it.



BN, the advantage to dripping in this manner is that all the near-horizontal pipes should be high enough so they won't be in the way- even the runouts, since they pitch DOWN to the risers as shown in Lost Art, using parallel flow, and therefore only need a 1" in 20' pitch.  You do end up with more vertical drips, but they can be painted.



And if those are steam-only rads, they never would have worked on hot-water, possibly landing the GC in court. He apparently has no clue regarding the trouble you've saved him from.

STEAM DOCTOR

update

Had meeting with homeowner and plumber. Meeting went great. Plumber asks "Whats up?" I show him the pipes and tell him that the main wont drain due to the pitch. Plumber says" YOU THINK I DON'T KNOW PLUMBING"!! Plumber storms out of house. Meeting over. HURRAY

Steamhead

So

does this mean you get the job of fixing it? 

STEAM DOCTOR

Dont think so

The GC came in a few minutes after the plumber walked out. I told him about the first idea that you posted and I think that he will try to get the plumber to go that route. That was actually what they tried but they ended up with the main slopped the wrong way. I also noticed that one of the radiator runoffs that the plumber had redone was slopped the wrong way. That radiator might have worked the first time but after that the radiator either would have stayed cold,would have banged like crazy or would have spit water halfway across the room. Word to the wise! DON'T GO CHEAP! IT IS VERY EXPENSIVE! So far the homeowner has paid me to size the boiler, has paid me to fix a leak that occured when the plumber take out the old boiler and left the water supply valve open,has paid me to oversee the boiler installation and paid me to oversee the correction of this steam main problem.

STEAM DOCTOR

update

I went back today to look at the actual boiler install(i originally advised the plumber and the GC how to properly install the boiler) This is a burnham IN7. The header was 2" instead of 3". The steam main takeoffs were between the boiler risers. The equalizer was 1 1/4" instead of 1 1/2". Thankfully the plumber was not there. The homeowner and GC were there. I showed them the manual which was black and white. I told the homeowner that he should  not pay the plumber. Holding my breath!

Steamhead

Hopefully

another knucklehead will bite the dust. How hard is it to follow instructions? 

STEAM DOCTOR

score

Maybe its time for a scorecard section on the wall. The scorecard section can include near boiler piping and boiler sizing.

Rod

Graphical Backup

If you need something graphical to back you up on the no steam riser between the boiler risers, I've attached the following from the Peerless "Pre - Installation Survey and Check List for Steam Systems.

- Rod

STEAM DOCTOR

thanks rod

Not sure if the plumber will care for the diagram but  I will try to show it to the homeowner and GC. The GC told me that the plumber said that the system will work fine because the header is pitched toward the equalizer. I also have a bridge to sell. CHEAP!

Rod

Another Source

You probably already have this but thought I'd mention it anyway just in case.

There is also a good diagram and article of page 51 of The Lost Art of Steam Heating which explains it even  better than the graphic I posted.  If Dan and a boiler manufacturer aren't a good source I don't know who is. Since you can provide written material which backs your opinion up,  I would think it was up to him to come up with a written source to back up his opinion.  If he fails to do so, his credibility with the GC and Homeowner has to suffer.

j a_2

re

As a heating guy/plumber I would never let a G C tell me how to do my job, especially when it comes to the installation of a steam boiler...It has been my experience that G C guys will go with the cheapest price they get...and charge the owner for the highest price they get...I am sorry but If I were the owner I would demand it be corrected, correctly....If your going into someones home to sell them a 5 or 6 k job you best know what your doing, no head scratching and trying hard to figure it out..There is so much training available, Dan offers the best steam training ever...Get trained and ask questions prior to going into that persons home....J A

Steamhead

"As a heating guy/plumber I would never let a G C tell me how to do my job"

Well, that guy didn't know how, so someone had to tell him......

STEAM DOCTOR

update

1. I had the plumber pitch the main away from the boiler then he ran a vertical pipe up then a horizontal pipe across the ceiling of the basement then back down and then horizontal again until it meet up with the return.At the end of the first horizontal run I had him put in a return to carry back the condensate from the first horizontal run and from the vertical part.I hope that I am describing this coherently. It's similar to the diagram on page 95 in Lost Art just in my case there in no "U" on the bottom. Instead there is a vertical pipe connecting the main on the left side to a new wet return.The plumber was prepared to not have anything to drain the condensate at all. Somehow he was hoping that the condensate would go up and over.

2. The plumber replaced the the 2" risers and headers with 3" and he replaced the 1 1/4" equalizer with 1 1/2".

The homeowner (per my advice) told the plumber the he would not get paid unless he maid these corrections.

STEAM DOCTOR

update

I was called back a few days ago to look at an attic radiator that was not getting any heat. I took off the air vent. Nothing. I took out the handle to the radiator shutoff valve. Nothing. I told the homeowner and the GC (who happened to be there) that someone probably disconnected the pipe leading to the radiator(keep in mind that the homeowner bought this house a few months ago and did major renovating). Without missing a beat the GC said that the previous homeowner must have disconnected the pipe when they did some renovations. Whatever. Anyway as we were sitting there trying to figure out the options the GC came up with this GREAT idea. "Lets run new pipes along the outside of the house and bring it in through the attic wall." I gave him a look and told him that you cant do that. He looked at me as if I was some sort of ignoramus and said" We will use galvanized. This way it wont rust." I told him that that still won't work because number one, you cant use galvanized on steam and number two if you run a steam pipe from basement to attic in New York you will have ice cold condensate in the pipe and not steam. In the end I think they are planning on putting electric baseboard in(this room is only used as a guest room at the present time so cost of operation is not much of an issue).