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    A Steam Odyssey (Part 2): Midco Low-NOx Burner (63 Posts)

  • MarkS MarkS @ 10:04 AM
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    A Steam Odyssey (Part 2): Midco Low-NOx Burner

    The first Odyssey thread was getting rather long so I've started another specifically for the Midco burner and controls.

    I'll let JStar comment on any specifics, but from my perspective the burner installation was pretty straightforward. The burner came in four pieces: the Midco controls cabinet, burner, blower, and valve train. I had to make a few modifications to the cabinet wiring to tie in my own controls cabinet, the flame rollout safety, and the solid state relay that acts as the "call for heat".

    The valve train, starting from the blower, consists of a gas orifice, manual ball valve, Dungs FRG6 ratio regulator/zero governor, another gas orifice plate, and a Honeywell redundant combo gas valve. The blower is an ebm-papst RG175 electronically controlled centrifugal fan. Flame safeguard is via a Fenwal DS3565 gas ignition control. The only proprietary part is an RTC electronics board customized for Midco that regulates the blower speed. Except for the RTC board, everything is off-the-shelf parts.

    Here are some photos of the burner installed on my Utica Starfire SFE steamer.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 20, 2013 10:07 AM.
  • MarkS MarkS @ 10:07 AM
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    More Midco photos

    More photos of the installed Midco burner
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 10:16 AM
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    Modulating Control Cabinet

    Here are some pics of the modulating control cabinet and hardware.

    The 12 volt supply powers the single-board computer and sensors.

    The 24 volt supply powers the thermostat and vaporstat lockout circuits. The Midco burner has its own 24 volt power on board, but that's only active when the burner is on, so I needed a separate 24 volt supply for the t-stat and v-stat.

    The 24 volt relays on the left side of the cabinet are for:

    1) Vaporstat high-high pressure interval lockout timer relay,
    2) Thermostat on/off (the computer's digital inputs are 5 vdc so need an isolation relay here),
    3) Midco burner firing status,
    4) Midco burner fault status.

    Didn't really need the last two but I had the sockets and relays lying around and room in the cabinet, so I figured why not?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 12:08 PM
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    Midco Burner Operation and Control

    Here are some details on the controls for the Midco burner.

    A call for heat activates a solid-state relay that puts 120V power to the Midco burner cabinet. A Fenwal HSI (Hot Surface Ignition) control unit in the Midco cabinet handles the ignition and burner management functions. Once the Midco goes through its ignition sequence and low fire is confirmed, my controls take over, modulating the burner firing rate with a 2 to 10 vdc signal, with a minimum output of 100 MBH and a maximum of 500 MBH on the LNB-500 (the LNB-1000 model goes up to 1000 MBH). There's a software-adjustable high limit in my control system that restricts the modulating voltage it to the boiler's max Btu input rating, in this case 280 MBH or about 3 vdc. The modulating control has several modes of controlling the voltage to the burner:

    Modulating Control with Override

    The initial output voltage to the burner is set to the high limit value and begins modulating on pressure from there. Since the pressure at startup is zero, the output will stay at maximum until pressure builds. This should yield the quickest preheat time, and as pressure increases the control will cut back the voltage to maintain the steam pressure setpoint, in this case 0.4 kPa (about 1 oz/in2 or 0.06 psi) . If the stack temperature drops below its setpoint, it will override the pressure control and modulate based on stack temp. This is intended to keep the stack temperature high enough to prevent condensation. It will automatically switch back to the pressure signal when the stack temperature is above setpoint.

    I set up this control anticipating the burner at low fire might have condensing issues with the stack temperature. So far though, stack temperatures have been high enough at low fire that the override may not even be necessary.

    Modulating Control without Override

    Works the same as Modulating With Override, except that the stack temperature is removed from the control strategy and the system controls exclusively on pressure.

    Fixed Output

    In addition to the modulating output, there is a separate power supply that delivers a fixed voltage to the burner. This is intended to be used when the system is in "Thermostat" mode. In this mode, the system operates as if it were a single-stage non-modulating burner.

    Manual Output

    For testing and experimentation purposes, the modulating control can be put into "manual" and the output set anywhere between the low and high operating limits.

    On/Off

    This is left over from my original single-stage oil burner controls and won't be used with the Midco burner.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • SWEI SWEI @ 12:36 PM
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    Fun project

    been watching this one and really look forward to seeing how it performs...
  • LarryC LarryC @ 12:39 PM
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    Electrical question

    MarkS,
    If your thermostat uses a mechanical switch contact for generating the heat call, does the Solid State Relay draw enough current to keep the switch contacts clean?  I have run into issues when driving digital inputs with mechanical switches, I did not draw enough "wetting" current and the switch operation became erratic after several hundred cycles.

    LarryC
  • MarkS MarkS @ 12:46 PM
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    Solid State Relay

    Hi Larry, the solid state relay is driven by a 5 vdc output from the single board computer in my modulating control cabinet that manages the outdoor reset control, DHW (I have a tankless coil), and burner modulation. I also have the wall thermostat as backup; when the system is in "thermostat mode", the thermostat activates a 24 vdc relay that switches 5 vdc to the SSR.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 1:20 PM
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    Videos of the Midco LNB-500

    I've made three videos of the burner and controls in operation. The first and second videos include a look through the viewport while the burner is operating.

    In the first video, the Midco Low-NOx burner goes through its ignition cycle, then maintains low fire at about 120 MBH.

    In the second video, the burner goes through its ignition cycle, then ramps up to high fire at about 275 MBH.

    The third video is of the modulating control. Here I've already raised a head of steam and am modulating the burner to maintain 0.4 kPa (just under 1 ounce per square inch) steam pressure in the boiler.

    Here are the links to the videos on YouTube:

    Low Fire Test

    High Fire Test

    Modulation Test
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • SWEI SWEI @ 1:25 PM
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    modulation test

    Seems to be hovering around what looks like 225 MBTU/hr (am I reading that right)?

    I'm curious what outdoor and indoor temps that rate is associated with.


    thanks~
    This post was edited by an admin on April 20, 2013 1:29 PM.
  • MarkS MarkS @ 1:33 PM
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    Modulation

    That's right, between 225 and 230 MBH seems to be the sweet spot. I haven't finished tuning the pressure controller yet, but it seems to control pretty well seeing how the accuracy of the pressure transmitter is +/- 0.02 kPa. When the video was taken it was between 45 and 50 degrees outside and 70 degrees indoors. It will be interesting to see how it performs in colder weather.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • JStar JStar @ 3:57 PM
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    Midco

    Do you have the new Combustion results?
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
  • MarkS MarkS @ 4:33 PM
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    Combustion results

    About the same as when you were here, Joe. Neil from Midco brought his suitcase analyzer yesterday and spent a lot of time trying to dial it in. We get very good NOx numbers out of the burner, but stack temps are still running hot so efficiency suffers. Neil is taking the results back to his engineers to look over; we'll see what they come up with.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • JStar JStar @ 6:04 PM
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    Midco

    I have a theory...

    The burner runs so damn hot, that you could probably grossly undersize the firing rate. 100K worth of ol is 200K to this burner.

    You are making a hotter flame with less BTUH's.
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
    This post was edited by an admin on April 20, 2013 6:29 PM.
  • ChrisJ ChrisJ @ 7:04 PM
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    Ugh

    This is really making me wish I installed a Mega-steam instead of going super simple like I did with an atmospheric.


    I love the control cabinet and your software!!!

    How does that burner work? It looks like it has a sausage made out of mesh that acts as a burner?
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.


    Boiler pictures.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
    This post was edited by an admin on April 20, 2013 7:06 PM.
  • JStar JStar @ 7:35 PM
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    Burner

    It has a cloth burner like most mod/con boilers. It blows the gas/air into the tube and it bleeds out of the cloth. The flame is completely radial. It's a perfect match for wetbased boilers.
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
  • MarkS MarkS @ 7:40 PM
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    Radial burner

    The radial burner is a tube about 20" long and 3" in diameter. It's covered in some sort of fuzzy metal mesh which I think showed up better in the high fire video. The centrifugal fan is bolted onto the end of the tube. Gas goes into the blower on the right side, and the fuel/air mixture is injected (?) into the radial burner.

    Your post reminded me that I forgot to post a photo of the burner before it was installed. Here it is.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • ChrisJ ChrisJ @ 7:46 PM
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    Interesting

    Is there any maintenance needed for that type of burner?


    One thing is for sure. I could not have installed this type of burner my self. I was able to do the atmospheric type fine but this is way beyond that.
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.


    Boiler pictures.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • JStar JStar @ 7:50 PM
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    Burner

    The maintenance is rather simple. Clean the flame sensor and electrodes. Clean the burner as needed. Fire and test. I think this burner is was beyond most of the population. You would need MarkS on every maintenance/service just to go through the controls!
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
  • MarkS MarkS @ 9:29 PM
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    Yeah, but I'm a controls geek

    and my system is designed for flexibility and experimentation. No way you'd put that in the average home.

    But it doesn't have to be that complicated. To set up a basic pressure control scheme, all you'd need is a pressure transmitter and a single loop controller with a 2-10 vdc output, both of which are readily available. The call-for-heat can be a wall thermostat, a Tekmar or other outdoor reset control, or even a Nest thermostat (if their adaptive algorithms for steam actually work). This all assumes that any problems with the steam system itself, main venting and the like, have been corrected. Otherwise a modulating burner probably won't help. As Mr. Scott once said, "I canna change the laws of physics!"
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 8:32 AM
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    Real world conditions

    Overnight temperatures were in the 30's so I got to see the burner perform under real world conditions. Here are the statistics for two runs this morning. The Preheat cycle is the time it takes to heat the mains and see steam at the condensate sensor on the farthest radiator.

    First run
    Preheat: 8:42 / 35.0 MBtu
    Heat On: 31:13 / 122.4 MBtu
    Total Cycle: 39:55 / 157.4 MBtu

    Second run
    Preheat: 7:42 / 31 MBtu
    Heat On: 19:49 / 75.4 MBtu
    Total Cycle: 27:31 / 106.4 MBtu

    Both Runs
    Preheat: 16:24 / 66.6 MBtu
    Heat On: 51:02 / 197.8 MBtu
    Total: 1:07:26 / 264.4 MBtu

    The Beckett oil burner was rated at 245 MBH. For the same total time, that's 273.6 MBtu. There's not enough data yet to tell if the difference is significant.

    I've attached a plot of the two runs. I need to spend some more time tuning the pressure controller to eliminate the oscillation when the pressure first comes up.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 12:49 PM
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    Question

    What is the difference between this burner and what one would typically find mated to  say a Giannoni style heat exchanger or other water tube style mod/con?
    This post was edited by an admin on April 21, 2013 12:50 PM.
  • SWEI SWEI @ 1:22 PM
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    differences

    It's a low volume product, has discrete gas train parts ahead of it, and has a mounting plate like an oil burner.

    Oh, and it costs a bit less than half what a similarly sized mod/con boiler does.
  • Eastman Eastman @ 1:35 PM
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    So nothing a little duct tape won't resolve?

    Does the burner length need to be pretty close to the depth of the boiler?
  • MarkS MarkS @ 6:52 PM
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    This burner

    is right up against the Kaowool liner in the firebox.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 6:05 PM
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    What were...

    the stack temperatures before the conversion?

    Does gas produce a higher volume of combustion products versus oil at similar temperatures?
  • MarkS MarkS @ 6:57 PM
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    Stack temps

    with the oil burner were between 465 and 500 degF. Note that my thermocouple is in the flue pipe about 30" from the boiler. Combustion analyzers probes are inserted much closer to the boiler and read higher temps..
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 8:25 PM
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    Sounds like it's

    working pretty good.  What is the heat loss for your home?
  • MarkS MarkS @ 9:28 PM
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    Heat Loss

    I used the Slant-Fin Heat Loss Express software to calculate the heat loss for the outdoor reset model. It's 133 MBH if you count the 3rd floor (used for storage; there are two radiators up there, one's turned off), and 106 MBH for just the 1st & 2nd floors. The model has been more accurate at predicting the heat-on time using the lower number.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Bio Bio @ 9:38 PM
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    Wondering

    Wondering if your radiators are fully hot or top half hot in order to satisfy the thermostat, any difference with the change of burners
  • MarkS MarkS @ 10:08 PM
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    Depends

    on how long the system runs. During recovery from setback (4 degF) most of the rads will be hot all the way across. On a normal heat cycle maybe half to 2/3 of the way across. In mild weather it's even less than that.

    It'll be a while before I have enough data to tell what difference the burner makes. What I know right now is that I'm controlling the burner at just under an ounce of pressure and am getting steam to the rads, where with the oil burner it was at 1.75 ounces. That's got to be saving fuel and $$$. But I think that's more a function of the corrected near-boiler piping than the burner.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 10:12 PM
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    What's preventing...

    the burner from dropping to an even lower btu output?  What's the road block in the train of components there?
  • MarkS MarkS @ 10:36 PM
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    Limits

    The low fire output of the burner is 120 MBH (the specs say 100, but we clocked 120 on the gas meter). That's controlled by the RTC electronics in the Midco cabinet. It's probably limited by the ability to maintain a good fuel/air mix at lower blower speeds. I'd guess the limiting factor is the gas regulator; those electronically controlled motors can be driven accurately over virtually their entire range.

    On Thursday we ran at low fire for 45 minutes while we did some initial testing. In that time we raised a head of steam, heated the mains, and started heating a few of the rads. One of the experiments for this fall when the weather is colder is to see just how low I can run the steam pressure while still getting adequate performance from the radiators.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Bio Bio @ 10:35 PM
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    Another thought

    It will be interesting If you could follow Boilerpro's theory, you could under fire and vent very small on the rads, longer fires at lower btu's, confortable heat, no overshooting and efficient just a thought....
  • MarkS MarkS @ 10:41 PM
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    That's a plan

    That's in my plans for the fall, I've been fascinated by Boilerpro's theory and would love to try it for myself.

    JStar had an idea about running the system like a coal boiler; run the burner on "simmer" to keep the mains warm and then ramp up when there's a call for heat.

    I built the controls to be flexible and configurable just so I could do experiments of this sort.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 10:54 PM
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    What did Boilerpro say?

    He was talking about orifices?

    **********************************
    Are there any electrically activated valves that are compatible with one pipe steam?  I was thinking perhaps one could stage the delivery of steam into the rads over the cycle in such a manner as to maintain system balance throughout the range of modulation.
    This post was edited by an admin on April 21, 2013 11:04 PM.
  • MarkS MarkS @ 5:46 AM
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    Boilerpro's article

    Boilerpro wrote an article in 2009 with an interesting perspective on sizing steam boilers and venting. Here's the link:

    http://www.heatinghelp.com/article/323/Boilers/1551/Taking-Another-Look-at-Steam-Boiler-Sizing-Methods-by-Dave-Boilerpro-Bunnell
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Dave in QCA Dave in QCA @ 4:25 PM
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    another article on 2-pipe

    Boiler Pro, aka The Steam Whisperer also did another article on 2 pipe system.  Same ideas as the first paper, but he was proposing the use of orifices to provide even distribution instead of the "slow" vents proposed for 1-pipe.
    I can attest that it has worked for me on my 2 pipe system.   I fire at 75% of the normal recommended rate for the connected EDR.  It works very smooth.
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • ChrisJ ChrisJ @ 10:07 PM
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    Adapt

    Will the software learn and adapt to changes?

    Such as if ts really windy one day and calm the next?
    Weil-McLain EG-45 connected to 392sqft of radiation via two 2" risers into a 3" drop header and 2" equalizer. Using Rectorseal Steamaster water treatment to greatly reduce corrosion in the boiler.


    Boiler pictures.
    https://picasaweb.google.com/thetube0a3/Boiler?authkey=Gv1sRgCImUxIqv9436MQ#
  • MarkS MarkS @ 10:24 PM
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    Sort of

    The outdoor reset model I've developed knows the heat loss of the building and the heating capacity of the boiler. During a cycle, when the system transitions from Preheat (heating the mains) to Heat On, the software fetches the current wind chill temperature from a local WeatherBug station over the internet. The model uses the lower of the wind chill and outdoor sensor values in the equations that calculate the btu input and run time required to achieve setpoint. Lower temperature = greater heat loss = longer heat-on cycle time.

    So while the software adapts to current conditions, it doesn't really learn from one cycle to the next.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 7:02 AM
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    Payback's a

    wonderful thing. I know we don't talk price here, but did want to provide some idea of the expected payback period since the initial outlay is pretty hefty.

    I prepay for 1100 gallons of fuel oil each year. Around these parts, natural gas (including supply, distribution, and other surcharges) is less than 40% of last year's prepaid cost of oil. That'll save me an estimated $2500 a year at current prices. Counting the cost of the burner, installation (excluding the piping rework), and the electronic & hardware components for the modulating control, the payback is less than three years. Maybe even sooner if you figure a modulating burner ought to use less fuel than a single-stage burner under similar conditions.

    Incidentally, this made it a relatively easy sell to She Who Must Be Obeyed, although what really got her attention was the "greener" aspect of lower emissions from the Midco Low-NOx burner.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • SWEI SWEI @ 10:31 AM
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    How's the sound level when the LNB is firing?

    I'm hoping that ECM proves less annoying than a typical induction fan.
  • vaporvac vaporvac @ 12:51 PM
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    71dcbls

    Mark addressed this issue in Part 1 of his steam odyssey near the end of the thread under  "We have ignition". He also then responded to my query  "quieter...but quiet?"
    http://www.heatinghelp.com/forum-thread/145950/A-Steam-Odyssey-Midco-Low-NOx-Burner-Oil-to-Gas-Conversion-Project

    It's near the end of the thread.

    "As for the Midco burner - absolutely smooth install and startup. And
    quiet - at my boiler's rated input I measured 71 dB 18" behind the
    blower, compared to 86 dB for the Beckett oil burner."


    Quieter...but quiet?
    Thank you for posting the decibels. I've been worried about the loudness
    of the power burners, but the  two (2) x Riello  #G400 series #C8554115
    gas power burners I've ordered for the SF TR50s are rated by Riello at
    66dcbls. I didn't have anything to compare that to so it looks like it
    shouldn't be too bad. I know the Becket oil burner was louder, but would
    you consider the 71dcbls to be quiet?

    Fantastic job, Jstar.

    Looking forward to studying the burner install.








    Reply
    Edit





    MarkS
    MarkS
    April 20, 2013
    @ 4:47 PM




    Contact this user





    Quiet
    Of course it's all relative but yes, I'd consider 71 db to be pretty
    quiet for a running motor. You could hear the Beckett running on the
    first floor, and feel it too. Can't hear the Midco on the first floor at
    all, except for the 15 second purge cycle when the blower runs at high
    speed. In fact, when the Midco is at low fire it's hard to tell it's
    running even when you're standing right next to it.
  • Dave in QCA Dave in QCA @ 4:30 PM
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    AMAZING!

    Mark, I am somewhat at a loss for words.   This is an excellent groundbreaking project!  The first application of the new Midco that we have seen!  It seems to be everything that everyone has been anticipating.   And, your AMAZING modulating, weather based control panel.  

    WOW!!!!
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • MarkS MarkS @ 7:46 PM
    Contact this user

    Thanks Dave!

    This has been an incredibly rewarding project, though not without risk. I usually prefer to avoid the "bleeding edge" and let somebody else prove a new technology first, but as a controls guy this was too good an opportunity to pass up. Heck, even coal boilers a hundred or more years ago had mechanical mechanisms to regulate them.

    As with any new applied technology there are a few kinks to work out of the system, both the Midco and my controls.

    Stack temps are still too high, and the Midco folks are working on that. I'm told they have several boilers in their lab, and I'm trying to find out what they're using that's closest to the firing rate of mine. Incidentally, the guys at Midco have been great to work with and are committed to see this succeed.

    On the controls side, it really looks like the temperature override control won't be needed at all given the stack temps we're seeing. It's an opportunity to revisit the current control strategy and add new features that will allow even more flexibility for experimentation.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Stack temps?????

    Are you running a chamber liner?  With that burner, it's probably unneccesary and removing it would probably help radiant transfer really improve.    The radiant output for that burner is supposed to be very high compared to standard gas burners.
    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert


    Noisy Radiators are a Cry for Help
  • MarkS MarkS @ 6:05 AM
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    Chamber liner

    Yes, there's a liner in the firebox. Isn't it supposed to protect the castings from flame impingement?

    I'm willing to try removing it, but what's the risk? How do I know if we've done the right thing?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • JStar JStar @ 6:19 AM
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    Liner

    I thought about leaving the bottom blanket out. I thought that the small casting space at the bottom would cause too much bubbling and turbulence if it heated a lot faster than the rest of the boiler. It's worth experimenting with, though.
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
  • MarkS MarkS @ 6:53 AM
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    Liner

    The liner is just on the back wall and the bottom, correct? Nothing on the sides?
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Liner

    Yep, it there for flame imingement, but the flame is so tight on that burner it is probably not a problem. I don't know how big the chamber is, but it relatively easy to find out if it will work. In the Slantfins Iv'e put in, I don't run a chamber with the burners I've used, (Heatwise and PF XM) and haven't had a problem.  Thier flame is nice and tight. 
    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert


    Noisy Radiators are a Cry for Help
  • JStar JStar @ 8:52 PM
    Contact this user

    Flame

    This burner is all radiation. Really no flame at all.
    - Joe Starosielec
    http://thatcherhvac
    http://facebook.com/thatcherhvac



    Guaranteed performance. Guaranteed energy savings.


    Serving all of NJ, NYC, Southern NY State, and eastern PA.

    Consultation anywhere.

    (Formerly "ecuacool")
  • Eastman Eastman @ 12:29 PM
    Contact this user

    cheating

    Don't you want to do a fair comparison?
  • Noise

    A nice thing about the noise is that it is mostly from the air intake fan.  You can connect the fan to an intake pipe from outdoors to really quiet the burner down.  You could probably build a sound absorbing box and connect the intake to that with an intake opening to the box appropriately placed.
    The Steam Whisperer (Formerly Boilerpro)
    Chicago's Steam Heating Expert


    Noisy Radiators are a Cry for Help
  • Eastman Eastman @ 8:47 PM
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    combustion pressure

    What kind of chamber pressures do these boilers run at?  Is it acceptable to have a significantly higher level than ambient?
  • MarkS MarkS @ 6:40 AM
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    Control Software Features

    Here are some of the key features of the control software:

    1. Outdoor Reset Control using either time-proportional or heat loss mathematical models.
    2. Supports simple on/off burner control and the following types of modulating control: Fixed Voltage, Modulating on pressure only, Modulating with low temperature override. (Based on early results with the Midco burner I will be revising the control algorithms to allow more flexiblity in the modulating control modes)
    3. 7 day, 4 period-per-day temperature setback scheduling.
    4. 7 day, 4 period-per-day Domestic Hot Water heating schedule.
    5. Redundant indoor and outdoor temperature sensors, with configurable sensor selection (High/Low/Average/First Good).
    6. Automatic switchover to a good sensor if one of the indoor or outdoor sensors fails.
    7. Optionally retrieves current local wind-chill temperature over the Internet, and uses it as the outdoor temperature in outdoor reset calculations.
    8. In non-modulating mode, eliminates short-cycling on pressure by entering a pressure lockout mode if an adjustable high pressure limit is reached.
    9. On-demand DHW by pushbutton or when hot water flow is detected.
    10. Highly configurable – many parameters can be adjusted to tune the system to its environment.
    11. Logging of continuous analog data and heating cycle events, with trend charting for analog data.
    12. Logging of fuel consumption data for the preheat, heat-on, and DHW cycles.
    13. Automatically reverts to wall thermostat control in the event of a critical failure, or if selected by the user via a switch on the control panel. With the Midco burner, switching to "Thermostat" mode changes the burner control to a fixed voltage.
    14. The user interface is written in Java and will run on any Java-enabled computer - Windows, Mac, or Linux.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Eastman Eastman @ 9:50 PM
    Contact this user

    What is the address for the

    webcam?  I want audio with that too.  Have you heard anything more from Midco?
    This post was edited by an admin on April 24, 2013 9:50 PM.
  • MarkS MarkS @ 10:21 PM
    Contact this user

    No webcam

    Sorry Eastman, no webcam. Not much to see on the outside anyway, all the action is in the firebox and inside the boiler. Neither of which are conditions that the average Best Buy webcam would survive for long. Would be great to see, though.

    No word yet from the Midco folks.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
    This post was edited by an admin on April 24, 2013 10:22 PM.
  • MarkS MarkS @ 8:48 PM
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    Instrumentation and Controls

    The control system has two outdoor and two indoor temperature sensors. The pairs can be configured to use the first good sensor, a specific sensor, or the highest, lowest, or average of the two values. The system also fetches the wind-chill temperature from a local WeatherBug.com weather station over the internet; if the wind-chill temp is lower than the outdoor sensor value, the system will use the wind-chill temp in the outdoor reset equations.

    On the boiler there are temperature sensors for the tankless coil and the DHW temperature after the mixing valve, a type K thermocouple in the stack, and a 0-3 PSI, 4-20 ma pressure transmitter on the pigtail.

    Off-boiler there is a temperature sensor on the riser to the farthest radiator, and temperature switches on the steam header and the (newly divided thanks to JStar) large and small mains. There's also a flow switch in the DHW line that will heat water on demand (with a 3-4 minute heatup delay if the boiler's cold) during scheduled DHW "off" periods.

    I had good results with the Phidgets line of sensors on the previous version of this system, and selected their PhidgetSBC2 single-board computer as the platform to host the boiler control software. The SBC2 has an ARM processor and runs Debian Linux as the operating system. The sensors, control outputs, and control software are all on or interfaced directly with the SBC2; the system does not rely on a PC connection as was the case with the previous version. The user interface communicates with the the SBC2 over Ethernet on the home's local area network. While the SBC2 supports wireless, for this application I felt a wired Ethernet connection would be more reliable.

    Safety & Backup Controls

    The boiler is equipped with the usual safety features. On the 120 VAC side there's the Pressuretrol, LWCO, auto-feeder, and emergency stop switches at the boiler & in the cellar stairwell. During the conversion, JStar installed a flame rollout safety in the 24 VAC circuit to the Fenwal ignition control unit in the Midco cabinet.

    Because this is still in the experimental stages, I've included some additional backup features.

    There's a "Control Mode" switch on the front panel that selects between the Outdoor Reset/Modulating control, and the wall thermostat. In the "Thermostat" mode, a fixed voltage is supplied to the LNB burner. The control mode can also be selected from the user interface. And in the (hopefully unlikely) event of a computer or program failure, all of the control outputs are automatically set and held at their OFF state; this forces the system into Thermostat mode, and power must be cycled on the control box to return the system to modulating control.

    A vaporstat is installed on the pigtail, wired to make on cut-out and break on cut-in. It is set to cut out at about 3 ounces of pressure and to cut in at slight negative pressure. On cut-out, an interval time delay relay is activated that cuts power to the burner for 30 minutes. This was added in the previous version of the control software to eliminate end-of-cycle short cycling on pressure, the idea being that if you're building pressure in the boiler then the radiators are probably full of steam and continuing to run the boiler is just a waste of fuel. Now that the new system is controlling on pressure, in theory the vaporstat should never activate, but I opted to keep it in for when the system is running in the fixed-output "Thermostat" mode. This limit control is always active and operates independently of the boiler control software.

    There's also an emergency stop switch at the control box that removes power from the solid state relay that switches 120 VAC to the burner.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • LarryC LarryC @ 3:02 PM
    Contact this user

    Electrical surge suppressor and UPS included?

    Mark,

    Is the whole system protected by a decent surge suppressor.  I would be concerned about the solid state relays being taken out by a decent lightning strike in the area.  This is where I prefer mechanical relays for the additional isolation.

    Larry C
  • MarkS MarkS @ 5:14 PM
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    Surge protection & UPS

    No surge suppressor yet, but will be adding one soon. No plans at this time for a UPS.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • MarkS MarkS @ 6:10 AM
    Contact this user

    User Interface

    I'll close this part of the saga with some pictures of the user interface.

    If you're ever in the Philadelphia area and would like to see the system in operation, send me a message through the forums or to mstayton (at) ieee.org, and we'll see if we can set something up.
    Homeowner, Royersford PA | 1890 one-pipe steam system | 3009 sf | 3 floors | 14 radiators | Utica SFE5200S boiler
    NEW Midco LNB-250 Modulating Gas Burner | EcoSteam modulating controls | 70 to 300 MBH |
    607 sf EDR connected load | Operating pressure: 0.5 oz/in2
    Four main runs (insulated) totaling 135 ft in length | All Gorton vents on mains & rads |
    A Steam Odyssey | Odyssey 2 | A Steam Enthusiast's Outdoor Reset Control
  • Maine Vent Maine Vent @ 8:44 PM
    Contact this user

    This is the Best Part of this Web Site

    Hi Mark,
    I want to thank you for such a fun and interesting thread. I have been following this project, and your web site and your software. I love this stuff, computer science programming, along with steam heating technology. You are a very smart and talented engineer. I have gotten so many great tips from the pros on here over the years, and your expertise is right up there with these Pros. My heating season is over here in Maine, I will take your advise and change out my cycle guard for a safe guard LWCO. My biggest complaint, is the same as yours. I have a backup safe guard LWCO.
    Thanks again for your great work.
  • Eastman Eastman @ 9:55 PM
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    Thank you for sharing this project.

    Is anyone else considering this?
  • tim smith tim smith @ 11:07 AM
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    Re: your project and sharing

    Mark, this project is just too cool. I really appreciate your time in this and the sharing of your process and the results you are getting. If I had the time I would be a mad scientist all the time rather than just when the circumstances allow it.  Kudos to you and also thanks to Midco for this design and their involvement.   Ps, I would lose the blanket with this burner design as you should not see any impingement. Will be interested is if you see any stack temp drop if you do so. 
     The other boiler I would love to see this tried on is the Mega steam from Burnham, I know Steamhead would like that too.  Thanks again. Tim
  •  
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