Slantfin &TraneVaporvac

vaporvac

Hello,

I'm currently in discussion with the people at Slantfin regarding the installation the their Intrepid model. This will be a modular installation although it is not clear if it will be a 50/50 or 70/30 split.   Any thoughts on that?



The major question is whether these systems draw a vacuum in the header or not. On page 16-17 of the 1918May pdf downloaded from heatinghelp.com , it says it does not. Does anyone know differently. I'm also attachingh the steam apps from Slantfin which specifies that there cannot be a vacuum in the header. It is my understanding that the vacuum (I'm sure quite slight in my case) in only in the mains. The folks at Slantfin are gems. We have discussed posting this question to get the best possible input.



Thirdly, It has been suggested not to use a drop header as it isn't necessary. Does anyone see a problem with doing so even if it isn't in the specs?

Thank you in advance for any help. Maybe I'll get heat sometime this Winter. I'm still counting my blessings when I see all the destruction of Sandy!

gerry gill

what do you mean,

by draw a vacuum in the header? do you still have a mercury pot on your vapor/vacuum system?

vaporvac

Pressure in header

Thanks for the reply. The question to me was actually," Will the header maintain pressure?", as mentioned in the 1918 article mentioned. I just interpreted that to mean dos it pull a vacuum.

I do still have the mercury pot which also acts as the vent.

gerry gill

There will only be

positive pressure in the header when the boiler is steaming..or shortly after that..your set up was originally designed for a coal fire that didn't turn off so as the coals died down, the system would still steam because of the mercury pot..not sure how well that would actually work with a gas/oil boiler that actually turns completely off..would be interesting to do though.

Dave in QCA

Slantfin Document?

Vapor-vac, could you post the Slantfin document that states the requirement you reference so that we could better understand what it is saying and the context of the requirement that they are stating?



Gerry, I apologize in advance for speaking as though I have a great deal of actual experience with vapor and vacuum systems.  I do not.  I know that you have experience and knowledge that would run circles around me, so please understand that I mean no disrespect by being a doubter of the current wisdom that vacuum is only for coal.   I am working on restoring my own vapor/vacuum system and will report my findings in the next 30 days or so.  Over the last year or so I have been studying every Dunham document that I can get my hands on.  I have a few Dunham handbooks that I will scan and send to Dan for the Library.  But, what I find consistently in the Dunham literature is that while they say that the vapor and self induced vacuum was helpful in a coal fired situation, it was also helpful in on/off firing such as oil or gas.  In fact, they indicated that it was even more helpful in those situations because it assisted in evening out the temperature fluctuations normally seen with on/off firing.   How effective was it?  Was it all a bunch of hooey that the steam industry was using in a pointless attempt to compete with the hot-water systems?  I must say that I really don't know.  But, the logic that they used seems to make sense and I will let you all know how it turns out.  I am sure that Vaporvac is going to do the same also. 

vaporvac

SF Document...Ooops

Well, I thought I'd already attached that so I apologize. Sometimes It erases all I've written and other times double posts. They both happened this time!



I think I touched on this subject a month ago in a question concerning compatabilty of wb boilers and vaporvac. Dan H wrote that he didn't see why a wet-based boiler wouldn't work and in fact thought it would be the perfect thing for my system. The person I'm talking to at SF just wanted to be sure as he is not so familiar with the Vaporvac systems.



Concerning Dave's comment about coal vs. gas. I really don't know anything except my 1914 system was built for gasfrom the get-go. I have all the original specs, piping diagrams, boiler type, etc.  (This house only had 2 prior families and the original one lived here for over 65 yrs. they kept everything)If it worked as well as coal is anyone's guess, but I think they thought it would when they installed it. .It does work very well and evenly since I cranked down the pressures. I still have a lot of small leaks in the system, mainly where an air vent was put in and around the valves, but it still pulls a small vacuum of a few inches.

I'm hoping after the install to start a thread concerning modulating the burner/outdoor reset or something like that. I have to get SFs input on that...they're very busy due to Sandy so one thing at a time.

Thanks for taking the time the time to reply., especially at such a busy period. Love seeing your new boiler going in, Dave. Beautiful drop headers and just in time!

C

gerry gill

No problem Dave-

i'd be very interested to know how its worked out for you when you get 'er done..we havent tried doing that on purpose have have achieved it by accident..we had one job where the gorton vents would close even tho no steam was in the return due to high ambient temps in the ceiling area of the boiler room..when that happened the boiler would shut off on the vaporstat and drop into vacuum..the gauge spun the opposite way, and all (as in every bit) of water disappeared from the sight glass..was kind of scary actually..thats when we kind of started thinking that maybe the vacuum drop on a vapor vacuum was more for coal, as the coal fire even tho it would have been dying down would still be attempting to counteract some of that vacuum by still steaming..i guess what i'm seeing in my minds eye is less of a vacuum with coal still burning, than the complete vacuum caused by the shutting down of the gas boiler..but thats based on my hunch only..so hopefully your experiments will prove my concerns unfounded as it would be nice to restore some of these systems all the way..

SteamCoffee

Post your results/info!

There are more than just a couple interested followers of the Vapor/Vac quest! Seems that hand-fired coal boilers and Vapor Vac was a match made in heaven. What I haven't seen was anything written of stoker boilers and Vapor Vac. Anyone seen or head of any such documentation? I would think that a stoker firing cycle would be relatively close to that of a gas boiler? Seems to be the missing info link in all this. Also, I would love to see a way to use gas boilers to maintain steam once under vacuum. A program to run a boiler a short time per hour to keep the heat going would be a great step. Especially for those of us that live in milder climates and would benefit the most from VaporVac....Keep it coming! The solution can't be far off! Blessed to have so many experienced folks, all gracious enough to share the info! THANKS! BTW This attachment is cut fro a Dunham Publication that says their system works on coal, gas or oil....



DUNHAM VAPOR HEATING

SYSTEM

This is economical in operation because of the low pressure

used, usually less than 8 ounces. In extremely mild weather

or any time on a declining fire, a self-induced vacuum of as

much as ten to twenty inches is established, Tho piping aud

control equipment are so arranged that, even under this self-

induced vacuum, cilculation may be maintained for some time

after reducing or cutting off the heat supply. When required,

pressures above €ight ounces can be carried.

In its physical part the vapor system consists of a boiler

which may be coal, oil, or gas-filed and temperatule control

equipmeut a system of properly dripped steam piping to the

tadiators, with legulatilrg plates of cast-iron radiators or

Dunham Adjustable Regulating Fittings (page 51) on concealed

radiatois, and Dunham Radiator Traps (page 9), a system of

leturn piping to the boiler in which are installed a Dunham

Return Trap (page 12) and Dunham Air Eliminator (page 61)

with Dunham Air Check (page 61), For pipe sizing tables see

pages 13 and 14.

vaporvac

Iron fireman

I'm at risk of going off-topic on my own thread,  but I have to comment on Steamcoffee's question! As mentioned, my system was designed and set-up for use with a gas boiler. However, a coal boiler was also installed at the owner's expense as a "back-up" boiler in case of gas interruption. (I guess gas was more iffy when first used?) This was an Ideal sectional boiler similar to those shown in the HH literature. It was stoked with an Iron Fireman self-stoker and there was a remote on-off switch and a little red light that lit when on and stoking. It took us YEARS to figure out what that light and switch went to. It's all still in place.



The original owner and his kids, all of whom were still living when I first moved in, said they mainly used the coal during the oil embargo of the 1970s! I just found it interesting that the coal part was designed to be self-stoking. One of the installers looking to bid a replacement (who never gave me a quote), said those IF were the Cadillac system for coal. I've never seen them referred here, except as a later steam system.



Has anyone had a chance to read the above attachments.?I'm supposed to talk to the fellow at SF tomorrow pm so we can move ahead.

Any thought on any of the questions?

I see all of these beautiful installations and can't believe I can't find anyone here to even give me an estimate. Oh well.I intend to have the plumber/installer do a dry run and post here for feedback.

Dave in QCA

your questions

Colleen, I wish i could be of more help, but the staged boilers are a little bit confusing for me.  I you could correspond with Steamwhisperer, he has done quite a few of these and understands the ins and outs.



As far as my understandings of the quesitons you posed, I will do my best.  Regarding 30/70 or 50/50, there are many control situations where the staging is set up with 30% first, but I think that will be to small to get circulation, even with your orificed valves.  I think I recall that is what you have, right?  I would go with 50/50.



As far as the dropped header, the diagrams in the SF book show a main header that the individual boilers connect to.  Actually, the boilers drop into this header, so it is actually a dropped header but the individual boilers are not, and I don't think they need to be.



The diagrams also indicate that the system of boilers is fead by a feed pump.  If that is what you are doing, you will not be able to pull a vacuum.  I don't believe that Steamwhisperer used a feed pump, did gravity return because it works fine on low pressure.  However, the water content of these boilers is very low and you may need a return reservoir, depends on how fast the condensate starts coming back on your system.



Regarding vacuum in the header....   I have looked and looked in the SF publication and I cannot find the referance to vacuum that you speak of.  At any rate, if your system draws a vacuum, it will be in ALL parts of the system.  Yes, in the radiator which are connected to the steam mains, which are connected to the header, which are connected to the boiler.  Vacuum, is not normally a problem but it seems to me that it might be if the differential was excessive, as if the vacuum is high enough in the returns and low in the steam mains, it would mostly likely draw the water out of the boiler down to the level of the Hartford loop.  Remember, at atmospheric pressure, 32" of water equals one pound of pressure, (difference)  So, even if the boiler is at 0 psi, if the return is at 2 psi of vacuum, it pull the condensate up 60" in the returns.  I know we alwasy talk of vacuum in inches of mercury, but there is a conversion to PSI, I just don't have it handy at the moment, just trying to illustrate what could happen.  I think it is the phenomena that Gerry referred to in an earlier post on this thread.  Which brings me to the point of sayting, I don't know what Slant Fin is saying regarding vacuum, and I don't understand why it would not work, if connected properly in the manner of your Trane system. 

SWEI

Slant/Fin Caravan

Just wanted to say that Slant/Fin did an exemplary job on that manual.

vaporvac

DropHeader;Vaccuum'feed-pump;70/30

This is the 3rd time I'm trying to post this UGGGGH!

Yes, SWEI, Slantfin did a great job on that manual and they are an

outstanding company to deal with. They are intent on helping me install

the best system possible as opposed to just selling me a boiler. I'm

mainly dealing with their technical support so they are well informed

about the intricacies of  the boiler.



The idea with the 70/30

split is to use both boilers to bring the system up to steam and heat

the pipes at which point the 30 drops out. The 30 is the pick-up factor.

You are correct, Dave that it wouldn't make enough steam on its own to

fill the radiators, but the 70 could keep them filled. That's the idea,

anyway.I'm just not sure if there's some advantage in going 50/50 and both boiler would have to be in play at all times.



Thanks for the insight into the drop-header. I see what you mean after re-reading the manual. I had just received it when I first posted.



Slantfin

just wants to be sure there's positive pressure in the header as the

1st page of the 1918pdf states. I think the manual is correct, but

again, I may be misunderstanding something.I think the situation you and gerry describe is what SF worries about. this could happen on any boile? I think the pipe height specified in the 1918 manual are meant to deal with this and in any case the headers maintain positive pressure when steaming. Perhaps a modulating boiler would mimic  a dying coal boiler better.



 We will not be using a pump-feed which was a conern of mine. The tech I'm speaking to actually developed the specs for the feed-pum and reservoirs for the Intrepid. I will foloow his advice on thes. He suggests a gravity return reservoir. I'll get more information on that tomorrow so maybe I'll understand it better. He's using the water volume of my current boiler to calculate the size reservoir necessary. I would have like to avoile this complication, but it seems to come with the smaller boilers.



Thank you everyone who took time on their week-end to read and respond to this post. I'll keep it updated when I have some to add or ask. Thank you.  Colleen

Dave in QCA

Pressure "Usually" maintained...

Ah, I was reading the wrong manual, looking for the phrase relating to the pressure being maintained.   I found it now!  But, it says, "pressure is usually maintained."   At the end of the publication it talks about how the system can be run in a vacuum condition as well. 



This is a somewhat helpful overview of vapor heating, but it is not specifically applicable to the vapor systems that operate at 8oz or less.  It talks about pressure of 3 psi or more and how gravity return to the boiler is accomplishedy by very high heads in the return lines.   This characteristic does not apply to your Trane system.



From all of my ready and understanding regarding vacuum, if the system goes into a vacuum after firing, the vacuum will exist throughout the system.  If you have 10" Hg vacuum, it will be in the radiators, return lines, steam mains, header, and boiler.  This vacuum is what allows the boiler to start boiling and for vapor to begin circulating to your radiators in a vacuum, at a temperature that is less than 212.   I think the big issue iin vacuum is that a very strong vacuum in one area of the system can cause the water to move or temporarily hang up in returns.  This should only occur when the vacuum is being formed, and once the vacuum and dispersed, or equalized to all areas of the system, it should have no effect.  At any rate, with a proper Hartford loop, it cannot pull the water out of the boiler below that point.  A delay in the water feeder should help avoid overfilling. 



The approach of using the 70/30% as you describe it makes sense.  However, running the 70% matches heating the radiators to 100% of their capacity and you may not need to do that most of the time.  Also, do I recall your system correctly that you have an orifice type valve on the inlets to your radiators, or some type of orificing setup?  It seems to me that your system is very early and that you do not have traps on the radiator outlets, correct?



That leads me to the description that Dave Bunnell gave me on a set up that he installed.   He used to Slantfin Intrepids, sized 50/50.  He controlled off of a 2 stage thermostat.  Only one boiler operated under almost all conditions.  Even distribution of steam was established by slightly throttling down the valve, partially simulating the behavior of an orificed system.  When the boiler was steaming, even distribution was established, all radiators parially heated.  This was enough heat to maintain space temperatures and only occaisionally in very cold weather did the second boiler fire and cause the system to fully heat the rads.   This would seem to be more economical than firing both boilers every time there is a call for heat, and then shutting down the 30% as soon as steam is established, as with orifices, a slight back pressure in the mains will be present as soon as the air is driven from the steam mains.   IF you have orifice type valves, the normal pickup factor can be ignored, but rather 10-15% piping loss used instead.  Of course, if you go 50/50, than you might have the pickup factor in the total---  Not sure how Dave figured his.  I could see if I can find the email that he sent.  It was well over a year ago.

vaporvac

Food for thought 70/30vs50/50

Thank you, David, for your thoughtful reply. I now understand what you're talking about with the vacuum and I think It should be a go for my system. Too bad we don't have the follow up issue of that May pdf where it deals with all of the specific types of vaporvacuum systems!



You remember correctly in that I do not have traps. My inlet valves (some of them) have the original handles that can only be turned so far. Exactly what is shown in the first picture in the Trane manual. I'm not sure what the others have, but I will address that after the install to restore the original functionality.

I understand what you mean by the 50/50, I believe with either case we would somehow modulate the burners to the load. I'll let you know what SF intends. Frankly, it's cheaper at the outset for the 70/30 set-up (who knows why the larger boiler is less than the smaller), but I'm obviously in it for the long haul so I don't want to be penny-wise, but pound-foolish. I would be most interested in Dave Bunnel's discussion with you on the sizing issue if you can manage. I know you're pretty busy with the install and life in general, I'm sure.

Thank you again. Colleen

SWEI

70/30 vs 50/50

How many square feet is the connected load?  I'm thinking a single boiler with a high-low burner might be a better fit here.

vaporvac

1460edr

thanks for the response, SWEI. I have 1460EDR which puts me above any single  Intrepid which I prefer over the Galaxy. I had considered a single boiler, but combined with the (hopefully) added efficiency of the modular approach and extra expense of the single boilers suggested in prior posts I'm probably going with two. I was very surprised that it worked out that way.

 I like the Intrepid because it's designed to be use modularly and SF has it all worked out in terms of the piping, burners, etc. It's a very inclusive package which is important to me since I'm the one helping to run the ship on this , unfortunately.  I have had so much  help from SF thus far so, I'd like to stick with them.



I am interested it a hi-lo burner with the Intrepid, but I'll have to see what they suggest. Thanks you for the suggestion.

SWEI

You've been at this for awhile

and have no doubt done your research, but I think I'd be looking at something like a Smith 19HE with that new modulating Midco Low NOx burner.

vaporvac

sounds interesting!

Thanks for that specific model, SWEI. That was not suggested before when I had posted for best boiler for my edr situationm etc. I originally wanted a single boiler just for the ease and simplicity. I will check it out today. I had called Smith, but it was much harder to get infor from them as a homeowner. Maybe I need to speak with the technical support there as well. The Midco burner sounds interesting and I do like the modulation.

It does seem like I've been at this forever, but it's more starts and spurts. I was more depending on the installer to help with the choice, but that didn't work out. I had some folks that installed Smith come over, but they suggested just replacing what I had (Dunkirk atmospheric). They were not familiar with wb boilers, at all and were the only firm installing Smith in my locale. In the end, they never even gave me a quote for anything.

Colleen

SWEI

sizing

I'm going to defer to the real steam pros here (don't shoot me) but it seems to me that you might be able to get away with a 19HE-4, even though it's nameplate rating is only 1316 square feet.  That would allow you to use the 500k version of the Midco and get maximum turndown capability.  Pickup factor should almost fall out of the equation with full modulation over a 5:1 turndown.  Even with simple two stage firing on Vaporstats, you would have fine-grained control over both firing rates.



Wish you were closer to our little corner of the country -- I'd love to do the controls for this.

vaporvac

Why single boiler?

Thanks for the quick reply. Actually that boiler had been suggested, but when the Smith installer came and didn't give an estimate and didn't know about the WB boilers, I think I just put it out of my mind. Is this Medco burner that cool round  wand-looking one someone posted about recently? I had thought that was just for huge boilers...that sounded so interesting.



May I ask why you don't suggest going with the modular approach...is it all the duplication in the install which I supposed doubles the risk of getting something wrong? Is the general feeling that the efficiencies are the same?

 I do feel totally confident I could replace what I have, but these newer boiler are a bit daunting. I'm planning on getting one of the companies that does a lot of mod/con installs to help with the settings, but none of them gave me a steam quote either. I just feel they probably have experience with these burners.

Where are you located? This is such an old city with so much HW and steam, I wouldn't have thought it would be so difficult. I guess they are pushing for conversions or want to stick with what worked in the past.

SWEI

single boiler

Will be much simpler to pipe and should reduce the cost of installation for both labor and materials.  If this were a multi-million BTU setup the math could be different.  Troubleshooting will also be simpler with a single boiler -- if you need help sometime down the road, a twinned setup would require skills that are not widely available.  When I read some of the horror stories here with simple residential systems...



The fully modulating burner should be able maximize efficiency in a way that would simply not be possible with other configs. http://www.midcointernational.com/products/low_nox/index.htm



I'm in southwest New Mexico, but I'd be happy to collaborate with the right installer on something like this.

vaporvac

Modulating burner!

Yes, that's the one. I'll have to check into that. I fully understand the effiiciency and uses of such a burner. My old Chambers stove has a modulating burner in the oven and it keeps the temp spot on!

I do agree about the ease of install and trouble  with-shooting with a single boiler. I will give Smith another call, but I'll have to make up my mind quickly. The installers are myself, the other owner who is a ME with loads of practical experience (he really understands the mechanics very well) and two certified plumber friends, one of whom used to work on steam. My dad, who's also an ME was going to help, but after fixing his plumbing and the gaskets on his own HW boiler, I think he's had enough of that sort of work for the time being.