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New steam mini tube system installed in my own house. (Iron Fireman style)

The first steam mini tube system of the 21st

century is in and operational. It was a long twisted road that brought me here.

The concept of the steam mini tube system is not new. Back

in the 1950’s a company called Iron Fireman made a steam mini tube system that

employed little steam turbines that were fed steam via 3’8th inch

diameter tubes. The system is incredibly efficient. Once the steam leaves the

header it rockets around the system. My personal feelings were that Iron

Fireman really struck gold with this design except that by the time they came

up with it steam was already out of vogue with the new construction industry.

Anyways, these systems are still in service and perform very

well. The technique never  caught on and

was pretty much lost to the scrap heap of history. But Steve and me brought

back the concept and I put in a steam mini tube system in my own house to

replace the forced air unit that my wife and I hate so much.

I had plans on installing hot water heat in my house and had

already piped the second floor for hot water so when I decided to go with a

steam mini tube system I left the second floor hot water and utilize a steam to

water heat exchanger fed by a mini tube to create the water zone. What I did

was to arrange the water side to draw its water from a 40 gallon tank, (I’m

using an electric water heater vessel with the electric hook up not installed).

Every time the first floor (steam) thermostat calls for heat, it also turns on

what I call the shuttle pump to shuttle water from the storage tank to the heat

exchanger where the steam can heat it and then it of course returns to the

storage tank.

The first floor I installed two runs of fin tube radiation,

one in the kitchen and one in the living room, and I installed a standard wall

convector unit in the master bedroom. All these are directly fed steam via mini

tube (3/8th) O.D. tube. The return pipes on a mini tube system are ¼’’

O.D. tube.

I know that it sounds incredible that a steam system can be

installed that uses such small tube but it can so long as certain things are

considered. This system by the way defies just about every rule of steam ever

made. I tell you this so that you don’t try to take anything away from this

system and apply  it to the everyday

systems out there. Remember that the rules for steam date way before the mini

tube system was invented.

Steam mini tube is an all copper system. Yes that flies in

the face of us steam throwbacks. Its copper because anything ferrous would rust

and clog up the little tubes. So there is a cathode and anode  trade off that takes place with these

systems. To my knowledge the mini tube system was the only steam system to be

designed from the git go to use copper.

The system works better than I had hoped for. The main is

heated to the end in 50 seconds and the radiators are hot all the way across in

about 3 minutes from the time the steam left the header and entered the

takeoff. Now that’s efficiency. Once all the traps close the system builds up

one and a half pounds of pressure and justs sits there at that pressure. So I set

the pressuretrol at 2 pounds. The steam returns to a condensate tank which is

necessary on mini tube steam and is pumped back overhead so that eliminated the

Hartford loop requirement.

I paid extra special care to anything that that would make

noise. The fin tube doesn’t rest on the brackets but is hung with high tensile strength

stainless wire so that it can move without making any noise, and the steam main’s

hangars are installed on the outside of the insulation to prevent noise. Folks,

the system is the quietest steam system I’ve ever run across.

Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.



  • RodRod Posts: 2,067
    WOW !

    Thanks Gerry, for sharing this with us. It's absolutely fascinating.  I'm now going to download your pictures so I can blow them up and study them more closely. My wife keeps giving me dirty looks as I've been staring intently at my computer screen, looking at your pictures and keep remarking "Wow!"  

      I can't quite figure out how you can get away with such small diameter tubing without having a lot of noise (water hammer) occurring. The idea of suspending the piping on the stainless wire is a really neat idea.  I'm sure we'd all appreciate any other details you could give us.

    - Rod
  • gerry gillgerry gill Posts: 2,611
    It is amazing isn't it..

    I'd love to claim credit for it but all i did was steal the idea form Iron Fireman..controlling the noise has to do with pitch and backpressure on these systems..see as soon as the steam rises up it pressurizes the mains and gets backpressured at the mini tubes..its around 2 or 3 ounces in the beginning on my system, and as soon as the f&t traps close, the pressure shoots right up to about a half pound..its that half pound that drives the steam through the mini tube..once the traps close the pressure rises again..some of these Iron Fireman systems (the originals) run upwards of 5 to 6 pounds and thats normal for those systems..but the pressure increase is almost instantaneous.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Just Wonderful!!!!!

    I've been looking at revamping standard 2 pipe systems with orifices to pressurize the main first just like your system.  The same principles would hold true for using tiny air vents on radiators in one pipe...Move the steam down the main and fill it  then begin building pressure to force the steam into the rads..  Seeing this may revolutionize steam and bring it back into the mainstream.   We can only hope that people begin to start waking up to the advanttages of steam heat. 
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • gerry gillgerry gill Posts: 2,611
    Hi BP- yes, we are hoping

    to be able to market this technique with remodeling guys who currently take a steam heated house and put additions on it then put forced air in the addition..usually the people with steam heat like their steam heat. This gives them an alternative for those jobs than furnaces...i hadn't thought about it, but it is kind of the idea your talking about with orifices isn't it..

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Please...

    you must show/tell us more...
  • RodRod Posts: 2,067
    edited August 2010
    SelecTemp Info.

    A couple of months ago, Gerry mentioned that he was working on a system for his own house . It's really great to see that it came together so well.

    For anyone who is interested there is some info "Off the Wall" on the IronMan SelecTemp System at this link.

    I've also attached below a couple of old SelecTemp brochures I found.

    Gerry- Just as a thought it may be beneficial to look into polysulfone tubing and fittings. I looked into polysulfone a while back as I was thinking about converting my 1 pipe system to a Paul system and possibly using a polysulfone tube for the vacuum hose. Polysulfone is used for steam (270* F) and wouldn't have the galvanic corrosion problems that copper/iron would have. A lot of the pex plastic fittings are now made from polysulfone and there are other fittings available that are full bore compression type.

    Here's some info on it.

    It could be more convenient that using copper for regular installations

    - Rod

  • Thank you

    Thanks for the additional information, Rod.  I'm still trying to get an idea of how this all works.  
  • gerry gillgerry gill Posts: 2,611
    Hi Rod-I had no idea that a polymer was made that could handle steam.

    I wonder how it handles for the long haul..would be an interesting experiment tho..and yes that would get rid of the cathode/anode issue as you stated..interesting.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • gerry gillgerry gill Posts: 2,611
    Well LBE, the mechanics was pretty much straight forward,

    I installed heat emitters to match the heat loss, then looked for a boiler that (no joke) was small enough..since the iron fireman system i work on has a boiler thats downfired  to perhaps 50% i did a little gambling and it worked out. You have to remember that while the sales literature for mini tube still exists we never could find any of the engineering data, so my project was not just for heat but also to relearn the engineering..

    It seems to be a very forgiving steam system. I took one mini tube takeoff and purposely stood it at 90 degrees off the top of the main and my gut said that it should retard the steam because of the hard turn..i wasn't sure with the pressure build up if it would tho..and yes it is the last heat emitter to get steam, so a sideways or 45 degree tap off the main works better..

    There was no piping pick up factor allowed at all..heck there really isn't any the boiler is smaller there..its also down fired to 3'' w.c.,

    I added a second pressuretrol and wired it in series with the MV terminal of the gas valve as these systems will cycle on the pressuretrol more often as you might thought there was this way i don't overwork the automatic ignition and damper motor..though mine turned out not to cycle much..

    We also learned inorder to keep away the flow noise we had to pipe the fin tube sideways with 3/8th and all the original iron fireman systems convectors i've seen were piped into the top even when fed from below so i followed suit there..i figure they had noise issues when piped from below because i've experianced that even with standard piping set ups.

    We also got rid of all expansion noises by lifting the one end of the fins with stainless wire in their housing and giving them significant pitch.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • RodRod Posts: 2,067

    Hi Gerry-   Yes, longevity was something that bothered me too.  While it seems to hold up to well to steam, most of the test info I could find were less than a year long. Watts uses it for fittings so maybe they might be a source for more info. 

    - Rod

  • RodRod Posts: 2,067
    edited August 2010
    Double Posted

  • RodRod Posts: 2,067

    LOL ,ED,  Me too!

    I just buried my copy of The Lost Art.... in the back yard hoping that would clear my mind. It's sort of like suddenly finding out the world is really flat! :)

    - Rod
  • gerry gillgerry gill Posts: 2,611
    this is probably a good point to say be careful about dwelling on this to much.

    This type of steam system has its own rules, and its own logic that apply only to for those viewing this thread, don't try to take away to much info from this, and apply it to a standard steam just won't work..this is a ''stand alone'' system and cannot be added to an existing system..the physics of both systems wont mix..just wanted to make sure that is clear to everyone.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • OK Gerry,

    ... so then why doesn't this thing hammer like mad?  Must everything be pitched on the steam side to keep water pockets from forming, or does the steam just blast any standing water through the thin tubing? 

    This looks amazingly simple.  Am I missing something, or did I cut and thread a million feet of iron pipe over this lifetime for nothing? 

    The brochures appear to show a basic two pipe system with thin tubing.  Is that it? 

    Darn!  And all these years I thought may Paul system was cool.  
  • Applications....

    I've been dwelling on some of the issues of supply sizes to typical 2 pipe  radiation and had begun to question them based on the size of the orifices required to supply that radiation.....typically under 1/4 inch diameter sizable radiators for only a few ounces of pressure drop across the fitting. If you are driving the system at 1/2 pound then the orifices would get much smaller... so why not downsize the supply piping to the rads.  Increasing pressure drop at the supply to each emitter would inherently improve system balance by making the steam head to the end of the main.   

    I think seeing this gives us all a good idea how sloppy the engineering was on most two pipe steam.  Two pipe steam was going in mostly after the war when faster and cheaper was the chief goal.

    It will be interesting to see how the mini tube concept would work on a larger scale.  The pressure drop across the long small main will probably start being a factor and may need balancing.  If I remember correctly the larger orifice systems used orifices in the branch mains also to ensure similiar supply pressures at the supply valve orifices, making it easier to achieve very even heating. 

    I'd love to see if you can use supply orifices on that minitube system to eliminate the traps and institute a pressure reset system (outdoor reset or indoor modulating thermostat)  to eliminate cycles altogether most of the winter.  That would probably really even out the heating on those low mass emitters.
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • gerry gillgerry gill Posts: 2,611
    thats theory is

    that the sudden buildup of back pressure pushes any water thru the tube..the tubes are pitched tho..altho the nature of tubing is shall we say 'wavey' does boggle the mind tho doesn't it...i'm not being elusive..i work on these and i installed this one but i'm still trying to wrap my head around the physics also...i know on two story upfeed systems you can hear the water rush thru the tube ahead of the quietness of the steam if its quiet and you listen closely..i figure that some water gets hung up by surface tension and the next cycle pushes it thru..but it only lasts a second or two and is much quieter than one pipe air escaping sound..i don't hear that in my house..but a customers has that but its hard to say if thats normal because an electrician pulled down a bunch of his tubes and made loops that hold water as he ran this big conduit thru..guess he thought they were water i say i pitch my tubes and hear nothing..its a mind bending system tho isn't it?

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Long Beach EdLong Beach Ed Posts: 686
    edited August 2010
    New Quest

    Gerry, you've started me on a new quest.  I would love to find engineering data on this beast.  The funny thing is I'm beginning to believe that when we find it they'll be no surprises.  Many of the problems induced by pitch and water pockets are probably related to the larger pipe diameters and amounts of water standing in bigger, conventionally piped systems. 

    As you surmised,  steam pressure probably blows right through a small slug of water laying in a quarter-inch tube.  

    These guys were geniuses.  Talk about thinking outside of the box! 

    Can you imagine one of those convectors with the steam turbine in it? 

    I'm gonna find me one.  I promise. 

    So you sized the boiler for the standard heating load.  I see no need for much pickup factor.  Their edge was the forced air convectors.  See how tiny they are?  They probably got more BTUs out of less EDRs.  That permitted them to further downsize their boiler.   If that's the case, we can do with electric fans what they did with steam turbines.  After all, those kick space heaters are available for hot water and could easily be converted to steam. 

    Maybe you can heat the place with a teapot after all. 
  • gerry gillgerry gill Posts: 2,611
    Ed- I think you have it pretty well figured out.

    My customer still has some original select temp heaters at his house..most have at some point failed and were replaced just as you say with Beacon Morris heaters and an electrician hooks runs 120 volt to them..they work just fine..don't laugh at this, but i sized the INPUT of the boiler to the heat loss of the well..thats another thing that defies the rules.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • gerry gillgerry gill Posts: 2,611
    Bp-- i don't think we can go any smaller on the orifice,

    without the boiler just shutting down on pressure..Steve and me were wondering tho, (since you brought it up) if one could hybrid this with at two pipe system by using mini tube on the supply and cast iron radiators and regular sized return pipes on the return and just slap in a condensate tank to handle any B-dimension issues..?? i'll leave that experiment to you though..sounds like what you were talking about..sort of..

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Thanks

    Thanks for the information, Gerry. 

    It's quite amazing that the turbine convectors had modulating speeds.  I didn't read over the patents yet, but I supposed a temperature responsive element varied the "pitch" of the steam "nozzle" changing the bower speed.   Fantastic!

    I think you're right when you say it's hard to find a small enough boiler...   When you put all the cost-saving components of the system together you'll probably have very, very  low steam requirements. 

    Now the puzzle is to find out just how low they can be!
  • SteamheadSteamhead Posts: 11,159
    Gerry, I'm proud of you

    and I think that speaks for most of us. Nice Work!
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • Good idea, I bet...

    Sometimes you run into systems were the piping is really shot.  This way you could just pull out the old supply piping, replace it with minitube and then use conventional on the return so dirt can pass through.  3/8 supply tubing should be big enough to deal with any debris that might get thrown into the system when the boiler is dirty. HMMM.

    I just wish I had more steam systems to try these things out on.  I probably will soon, because I am really targeting the market in Chicago for steam work and making connections.

    We'll see
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • gerry gillgerry gill Posts: 2,611
    Thanks Frank.

    That means alot!

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • More on polysulfone

    First off, this is amazing!

    An aside on polysufone that may be encouraging- polysulfone fittings are sometimes used in food service. In particular,they're sometimes used in brewing setups to transfer boiling liquid under modest pressure.It it's approved for use with food, I'll bet there's ample research

  • ttekushanttekushan Posts: 901
    micro steam

    Nice work, Gerry!

    To everyone else out there, Gerry was nice enough to invite me on a field trip to the home with the SelecTemp system last year. I couldn't get over how FAST the system heats. And quietly. Like Gerry said, the boiler at that home is downfired. If the proper boiler were in there, it sure would look small for a boiler that is supposed to heat that home!

    I think part of the magic is that the refrigeration copper gives such a smooth route for the steam. Those lines are like peashooters so the water gets jettisoned out of the way of the steam- it can't flow back to create hammer and the lines don't have elbows.

    BoilerPro's comment about the orifices is a good one. I think the original SelecTemp impulse turbine nozzle must have acted as an orifice. If you look at the dimensions of those original unit heaters, they had truly mind-bending output for their small size. along with the modulating thermostat, the whole thing, blower and all would modulate.

    By also modulating Pressure (rather than Temperature) based on outdoor temperature, you could really get tight control over the amount of heat delivered- and still have petal-to-the-metal heat output available for setback recovery.

    My mind has gone wild ever since seeing the system that Gerry showed me. You have no idea, really, how impressive the heat output of a convector or kickspace heater is when fed this way. What comes to mind is the amazing speed with which a room can recover temperature.

    It seems to me that individual valves and occupancy-sensing room thermostats could be integrated into the system to provide a genuinely "green" approach to heating --where room temperature is dependent on occupancy but has a fast enough recovery to make it practical to have deep temperature setbacks. Energy savings would be quite good, I would think. In this way, we can use steam to advantage for all of its characteristics, both its high heat content per unit of mass and its high temperature.

    So Gerry- it looks like I should plan another field trip!

    I also have to wonder if this isn't a pretty good solution to single pipe system conversions as well, where you could run 3/8" OD to a single pipe radiator's vent tapping (drilled & retapped if necessary) and use the existing supply piping for return. No traps. Resize that boiler for the heat loss and away you go! Just a thought, since we're breaking the rules as it is.
  • ttekushanttekushan Posts: 901
    steam to water

    and the steam to water heat exchanger is a really cool set up.
  • ttekushanttekushan Posts: 901
    Iron Fireman

    Iron Fireman was in my back yard (sort of). They were in Cleveland 11, which is where I am.

    Interestingly, I mentioned this to my octogenarian mother in the context of Cleveland's manufacturing heyday and some of the cool stuff that was made here. Turns out, her father (my grandfather, who died in 1951) worked for Iron Fireman before he fell ill. Apparently, working in foundries throughout the 20's, 30's, and 40's along with the unfiltered cigarettes, eventually caught up with him.

    And one more factoid: Rumor has it that all the tech info regarding the SelecTemp system is in the hands of Turbonics, Inc., which makes hydronic heaters.
  • gerry gillgerry gill Posts: 2,611
    Hi Terry--glad you like it!

    Stop over anytime and i'll fire her up for you..thats an interesting thought with the one pipe idea.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • And you didn't think we should apply these ideas to other systems.. HUH

    A refreshing explosion of ideas.....The Wall at its best.
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • GordoGordo Posts: 506
    Amen Boilerpro!

    If the same spirit of inventiveness that has been applied to hot water/radiant/mod-coms etc. had been applied to steam, I have a sneaking suspicion that hot water heat and maybe even forced hot air "heating" would be the "red headed stepchildren" instead of steam heat.

    Gerry's willingness to do this work and show us his wonderful results with this system gives us a window on that world of possibilities of what might have been and what may be still. 

    It ain't over yet!

    Forward into the past!
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • SteamheadSteamhead Posts: 11,159
    edited August 2010
    Gerry & BP, I had a thought on that

    An existing system run this way might not work as well, because it was designed for the lower pressures we've come to love. Even with orifices, the piping would take longer to fill with steam since it is so much larger. Of course if you're repiping the whole thing or reversing the rad's flow as Terry suggests, that's a different story.

    But in a case where we're putting mini-tube steam into an addition that's almost as big as the house, and the original house has an existing steam system, the boiler could run at the minitube pressure and we could put an orifice into the steam main that feeds the original system. This way we could balance the two without extensively modifying the original system.

    Question, guys: if it's possible to keep the minitube system's pressure below 2 PSI and you have at least a 60" "B" Dimension, do you still need a condensate tank and pump?

    I'm really looking forward to seeing this thing.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
  • gerry gillgerry gill Posts: 2,611
    it can run under 2psi.

    But its tough to keep it there..two stage firing might do it..but it would probably be real hard to accurately keep it under 2 psi at all times.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Put your feet up.

    Mr. Gill,

    I respectfully submit this ebay find as a fitting addition to your mini tube steam system. Just upholster this thing and voila- a heated ottoman.

    Beats a heated towel rack in my book.


  • Maybe my mod steamer would do

    Probably could use a Power Flame X4M burner with a pressure control set at 2 psi to mod the burner accordingly.
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • gerry gillgerry gill Posts: 2,611

    that would probably work fine.

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • gerry gillgerry gill Posts: 2,611
    thats pretty neat.

    i wonder who came up with that idea?

    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Could be...

    Looks strangely like a cooling coil from an old ammonia refrigerator.  That might be what it really is. 
  • HitzkupHitzkup Posts: 59
    edited August 2010

    Thanks Gerry for teaching us something new [old] in steam heating.

    The endless possibilities of steam heating! Amazing!
  • Performance updates now that February's ending?

    Hi Gerry!

    You have certainly had some time with the new steam system-- and I've been wondering how it has worked out in the cold temperatures. Do tell-- how has the comfort level been? Has it heated well in zero degree temperatures without going above 2 psi? What is the firing rate on the boiler now? Do you think you could have done without the condensate tank in this instance?

    Enquiring minds want to know. . .
  • i wanna know too

    tell us more master.....
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