Advanced Venting Q

Steve_175

I live in a 2 family (phily style) in the Boston area. This summer had the house insulated, new windows and a new oil fired boiler installed. Have one pipe steam. Before the new boiler was installed the house heated pretty evenly. When the new boiler was being put in the plumber showed me how clogged up the old pipes coming off the bottom of the old boiler were, at least 2/3 full of crud.



The boiler runs well but I have a few radiators that take awhile to get hot. I have skimmed the boiler a couple of times and drained the hartford loop once until it ran clear. After looking at the piping carefully I saw that there are two loops that supply steam to the radiators. The short loop (aprox 30') feeds the bathroom radiator (small), 1st floor bedroom radiator (large), small 2nd floor bedroom, and kitchen.

The long loop (aprox 84') feeds the other 2nd floor bedroom, the front hall, living room, and dinning room. It is the hall, living room and dining room that take awhile to get hot. They are all large radiators, 12,13 &14 section rads that measure 8"X 20" tall by 28"to 34" long. The thermostat is in the dining room which is open to the living room.



Here is where it gets advanced. I have put a Gorton #1 main on the end of the short loop and Gorton #4's on all the rads coming off that loop. The long loop has a Gorton #2 at the end of the main. The 2nd floor bed room has Gorton #6 and is doing well. The hall, living room and dining room have Gorton D on each radiator. All of this was done after the new boiler was installed in an attempt to balance the system a bit better. It did help but the three rads in question still take at least 20 minutes longer than the rest of the house to get hot.



So what else can I do?



As an aside how often should the boiler be drained and when should I add more water back? Fill it when it's cold, when it starts up or while its running? I know that adding water frequently puts a lot of minerals and oxygen into the system. Are there additives to help reduce corrosion or should I not bother with that on a new boiler.



I have included some pics for clarification.



Thanks

jpf321

you left out critical info ...

what is the current venting on the 3 rads that take longer? 

BobC

and . .

Are they towards the end of one of your mains. that long main may need more venting, what size is the main?



Bob

Steve_175

More info

I mentioned in the original post that the three large rads have Gorton D's on them and the long loop in the basement has a Gorton #2 at the end of the main. The piping is 2" on both loops. The rad in the dining room is the last to get steam, about 70' down the line. When the boiler is running I can hear air coming out of the three large rads a little bit. And I have felt the Gorton #2 and it will be hot about 20 minutes after the boiler started.

Steve_175

More info

I mentioned in the original post that the three large rads have Gorton D's on them and the long loop in the basement has a Gorton #2 at the end of the main. The piping is 2" on both loops. The rad in the dining room is the last to get steam, about 70' down the line. When the boiler is running I can hear air coming out of the three large rads a little bit. And I have felt the Gorton #2 and it will be hot about 20 minutes after the boiler started.

jpf321

what is....

the amount of installed edr? what is the boiler rated for in term of square feet of steam? what is the effective firing rate of your boiler? if you don't know the answers please ask your installer the questions as he MUST know.

Steve_175

More Info

The EDR is about 265. The burner has a .85 nozzle running at 140 psi. The pic should have the rest of the specs you are asking for.

crash2009

Steve,

This is how I visualise what you have, based on, what I see in your pictures, and how I interpeted your words.  So much for the disclaimer!  Did I mention that I am not a steam pro?



As I understand it whats happening with your system is Main1 and all its radiation is filling up first.  Then Main2 fills up 20 minutes later.  I am assuming that all the rooms on Main 1 get too hot.  What do the pro's think about installing TRV's on all the radiation on Main1 and add another G2 to Main2.  Or How else can you deal with 1 riser 2 mains?  The steam is favoring the straight line and going right past the entrance to Main 2.

The Steam Whisperer (Formerly Boilerpro)

Take a look here

This is my approach to venting....basically keep the radiators venting very slow and the mains very quick.  All but the smallest Gortons are way too big to work well in this scheme.



http://www.heatinghelp.com/article/11/Hot-Tech-Tips/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell

Charlie from wmass

The two loops as you call them

Should be brought back to the header separately. While a 2 1/2" header is not called for it would be nice.

Charlie from wmass

What is the pressure set for?

I forgot to ask that. Lower is better.

Charlie from wmass

Also on the drop to the equalizer.

I make the turn full size and use a 6" nipple to drop, then use a reducing coupling. This helps the condensate get the heck out of the way.

nicholas bonham-carter

switching vents

now that it is getting colder, why don't you measure the time needed to heat up each main with steam, and then switch the main vents, and make the same measurement, because i think that gorton #2 is probably enough for only the smaller line.

while you are at it, you might measure the pressure in ounces as the boiler is steaming, and the vents are letting the air out. i put all my venting money into the 18 gorton #2's, and kept the original hoffman non-adjustable radiator vents [some 40 yrs old!]. after a month or so on the new boiler, i did put a few gorton d's on some radiators on the 3rd floor, as their risers were 35 ft. long. this has resulted in my back-pressure during initial steaming, to remain at about 2 ounces, with no short cycling.--nbc

Dave in QCA

Old Venting Comments

I recall that in the 1970s, I lived in an apartment, a nice 4-plex built in the teens.  It was my first encounter with steam heat.  Being a steam heat fanatic in the making, I spent some time studying the system and trying to understand it.  I remember being puzzed as to why there was a cross connection (the equalizer) between the supply and the return of the boiler.  There were also remnants of early devices that I now recognize as a Paul System.

Having been converted to gas firing, the venting on this system was typical for practices as that time.  There was one Hoffman 75 at the end of the uninsulated main.  (It provided heat to the basement area laundry and storerooms.)  The radiators were all vented with Hoffman #40 vents.  The system had a total of 600 EDR, give or take.  The system was a silent as is possible and the heat was very even.

crash2009

Well so much for the TRV idea

Nobody liked that one at all!  After reading all the replys it looks like you need to start from scratch.  One G2 on main 1, and two or three G2's on main 2.  Plus a round of Hoffman 1A's or Ventrite 1's, for the rads.   

Here is a photo of one way to get 3 main vents into 1 hole.





 

Steve_175

All sorts of suggestions

Let me answer a few Q before I ask some more.

The pressuretrol is set to somewhere between .5 & .8, hard to tell on that vague little gauge. Why don't they make that thing with a digital readout? But I digress.

Both loops have their own drop down to a hartford loop, as can be seen in the pics.

Crashes diagram is correct except of course they both loop back to the boiler and his assessment of what is happening during the heat cycle is mostly correct. The only room that would get to hot on the short loop is the 1st floor bedroom and only if the door is kept shut. Now that I think of it the bathroom would get to hot if the door was kept shut.



I did time the speed at which all the rads got warm then hot. This was done when the long loop rads had Gorton #6 on them.

The short loop rads started getting warm 20-25 min. The long loop rads started getting warm 35-45 min. By that time the short loop was hot. The system was satisfied at 1hr 2 min starting at 65.5F and shutting down at 67.5F with the flywheel effect taking it to 68F.



Boilerpro I read your link and am intrigued by your ideas but it raises a few Q. I have read elsewhere on this forum by Dan I believe, that large radiators or those far away from the boiler need faster venting. You say only the main should be vented fast.

Also it has been suggested that the short loop should have a Gorton #2 on it. It has a Gorton #1 and seems to vent really well.

It has also been suggested that I add more Gorton #2 to the long loop. How many and are you guys certain this will make a big difference? The reason I ask is when the boiler is firing I can hear the air coming out of the rads on the long loop and the Gorton #2. Kind of like someone gently breathing. I am happy to do it if it works but those suckers are pricey and I don't know if I can return them if they turn out not to be needed. And yes I am familiar with the 'antler' and 'menorah' method of adding additional vents.



It was suggested getting a pressure gauge that measures in ounces to see what is happening in the lines. If I did that which one should I get? And where should I put it?

http://www.gaugestore.com/products.asp?dept=1123

BobC

gauge

Steve,



I used a 0-3PSI gauge (33020) but some like the 0-20 oz for real low pressure systems. You might want to add a snubber to even out any pulsating on the gauge http://www.valvestore.com/prodinfo.asp?number=32618; I should have put on on my setup because my vaporstat and gauge tends to bounce around a bit at the 0.7 to 0.8PSI point.



The pic below shows how i mounted my 0-3 gauge but I've got a 1/4' union that I'll mount so I don't have to unwire the vaporstat when I want to take things apart. I decided on the vaporstat after my pressuretrol failed for the second time (in 13 years) because i wanted to lower my pressure below the level I could with a pressuretrol. You can get the fittings you need at a hardware store or one of the big box stores.



Bob

crash2009

Your right

about that "1 here and 2 or 3 there statement" it does sound a little careless.  I was only approximating just to give you a rough idea.  The exact method of calculation is explained in detail, in the following handbook.   

http://www.heatinghelp.com/products/Books/5/146/Balancing-Steam-Systems-Using-a-Vent-Capacity-Chart-by-Gerry-Gill-and-Steve-Pajek

chuckNJ

puddles?

You mention a "breathing" at the main vent and those rads that seem unduly slow. This can be a symptom on puddling condensate in that section of main. One thing to check is the pitch of that main, especially beyond the take off to the 2nd floor rad which you say heats well. It does not take much to disturb pitch, changing the boiler can certainly do it. Old piping can also come with some strange little wiggles when you look closely..It only takes a little bit of puddling in a long main to create major speed bumps for steam heading that way. Also, realize that once the short main gets a good head start heating it will tend to draw more steam with the vacuum created, further disadvantaging the laggard elements.

The Steam Whisperer (Formerly Boilerpro)

Venting....

Yes only the main should be vented fast.  And yes larger radiators still should be vented faster than smaller, but not at the rates you typically see with modern radiator vents.  The problem is balance.  Too big of radiator vents will cause the steam to favor the radiators over getting to the end of the mains.  When you fire up your system on the typical heating cycle (pipes warm from previous cycles) The steam should hit the end of the mains within  2 minutes or so and should not be filling any of the radiators. The vents at the end of the mains should also allow the steam to reach the ends of all the mains about the same time.  Its sounds like you need a larger main vent on your longer main.   Then the radiators will begin filling at the same time and to the same percentage full as the boiler continues to run.  All should be 1/4 full together, then 1/2 full together, etc.  Once you get to this point in balancing the system, then you can take a tweak up a little a room that is cool, or down a room that is too hot.  This way you can get very balanced heating even when the boiler cycles off on the thermostat before all the radiators fill completely. 

Steve_175

Pipe Pitch

Puddling is something I had never considered. I checked the long loop with a 4' level and found one spot that reads level, all other areas looked ok. This spot is tied to a hall rad that I shut off because it is not needed. It is also after that second floor rad. This area also has some sagging in the floor framing do to improper construction when the house was built. I am going to try and lift the rad off the floor and put some thick shims under the feet. This should pull up the loop to put a little pitch back in it.

Thanks.

Steve_175

Vaporstat

Form what others have said on this thread and elsewhere on this forum I am thinking of replacing my preasurtrol with a Vaporsat. Do you know if this is the best model for my system?



http://www.macwilliamsupply.com/honeywell-pressure-control-l408j1017-vaporstat-controls-vapor-l408j-controllers-l408-controller-1017.html

jpf321

nope .. that's the 0-4psi model ...

you want the 0-16 OZ model .. I think it's the 1009 or 1025 .. I've posted it here before ..



This one .. 1009 .. http://www.patriot-supply.com/products/showitem.cfm/HONEYWELL_L408J1009



(next time someone please remind me to remember 1009 or come up with some pneumonic thanks) ..

Steve_175

Snubber Q

Would you put that snubber under the gauge or under the T fitting?

BobC

T

I'd place it under the T so both the gauge and pressuretrol (or vaporstat) would see the benefit.



Bob

crash2009

Heres the pitch Steve.

When your boiler was installed, the Y that your mains come down to was not broken up to form 2 separate mains.  These 2 separate mains could have come down to as Charlie suggested (a 2 1/2" header).  If it was you could have vented everything pretty much any way you want.  Nobody is going to tell you that the way you have it is wrong, because it's not.  It's just that because of the way it is, you need to use a different venting strategy.

You have 5 or 6 guys here all telling you that you need more main venting, and 2 professionals Charlie and Boilerpro.  



I am going to give you the numbers from the venting chart to show you with math the way things are right now.  And maybe you can convince yourself of what you need to do.  All these numbers are in CFM @ 2oz

Main 1     four Gorton 4's @ 0.040 each = 0.160

                one Gorton 1  @ 0.540 each = 0.540

Main 2    one Gorton 6  @ 0.235 each = 0.235

          three Gorton D's @ 0.540 each = 1.620

                                                    total 1.855

                                  one Gorton 2  @ 1.650

As you can see Main 1 is vented about 3 to 1, Main 2 has more venting on the radiators than the main line itself.  What Boilerpro is suggesting for you to make it work is to slow all the radiators to 0.026 Hoffman 1A, (Charlie's Vent-rite's are 0.020) and MAX your mains with G2's. 

I know you think you have 2 separate mains but your steam disagrees.  You need to treat venting the mains and venting the radiators as 2 separate problems.  Get the mains correct, once the mains are correct, the radiators become easy.  Hope this helps.

Steve_175

Vaporstat Settings

I got the Vaporstat, snubber, and low pressure gauge that were recommended. What should I set the Diff and Main to?



BTW any body want to buy a Pressuretrol. Practically new, I am in the Boston area.