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  1. #40
    Join Date
    Aug 2003
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    Ft Worth Tx ( North Richland Hills)
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    2,143
    It was 1979 when my bosses at Honeywell said "Look at this screen ....The information being displayed are temperatures of different office areas of the Mountain Bell building in Rock Springs" (200 miles away) ....we can turn pumps on and off from here or the lights". I thought I was witnessing science fiction.

    A few years later (1984) I was calling up contract customers from home on my (believe it or don't)Commodore 64 talking to Tracer 10's (glorified time clocks)and doing the science fiction my ownself.
    How can you have any pudding if you don't eat your meat?

  2. #41
    Join Date
    Nov 2001
    Location
    Seattle, WA
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    7,744
    Originally posted by ozone drone
    It was 1979 when my bosses at Honeywell said "Look at this screen ....The information being displayed are temperatures of different office areas of the Mountain Bell building in Rock Springs" (200 miles away) ....we can turn pumps on and off from here or the lights". I thought I was witnessing science fiction.
    We had buildings in N.J. or Delaware hooked up and I could read the temperatures 500 miles away. We also had them in a number of office building all around DC and I could go from building to building checking temps, etc.

    The displays were the old vacuum tubes with the numbers inside that would light up. Really looked cool. The main control/display panel looked exactly like something you would see in Star Wars.

    We even did security on the Honeywell building located in Tyson Corner, Va, which is where our main terminal was.

    We also got into lightning, all kinds of pumps including shutting off decoration pumps at night for large complexes including colleges.

    We even got into lighting control and worked with the in-house maintenance crew to turn off lights as they finished the floors. Man, did that cut down on the power bill.

    A guy in Richmond, VA and myself even worked on a rain sensor so we could tie it into the automatic water systems for a college lawn system. Never did get it to work though.

    Nothing personal but you got to be old to remember this stuff!
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  3. #42
    Join Date
    Jul 2001
    Location
    Canada
    Posts
    1,806
    Was great to see the BIRTH of DIGITAL AUTOMATION today its all revised , updated , improved back then it was HOPE this WORKS.

    Had 1 job that the guy could not understand how the 1st Fax machines worked , told him its like photo copier only it spits it out 200 miles away. If he was still around todays technology would really baffle him.

    DELTA T

    Ran across some old HONEYWELL controllers you might remember

    HONEYWELL MD7900 A1K3 Electric Control System big old grey box 8 knobs and vacumn tubes sharing an outdoor air sensor for 4 controllers controlling 4 large supply valves. It still WORKS but being 40 years old they want it updated.

  4. #43
    Join Date
    Nov 2001
    Location
    Seattle, WA
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    Originally posted by Control Man
    Ran across some old HONEYWELL controllers you might remember

    HONEYWELL MD7900 A1K3 Electric Control System big old grey box 8 knobs and vacumn tubes sharing an outdoor air sensor for 4 controllers controlling 4 large supply valves. It still WORKS but being 40 years old they want it updated.
    A big black painted box with ripple effect paint if I remember correctly. And the knobs were black with indentations in them for a better grip, right?

    Ironic cause I just got two different chruches and their associated schools all with a combo of pneumatic and/or electric/electronic (by that I mean the old vacuum tubes or the 7 or 9 series controllers) which I am rebuilding or replacing. I have two really old day/night electric 3 wire stats I'm pulling off the wall on one church which I am going to save for my collection and take a picture of. I'll post it in controls for your enjoyment. I have never seen these types of room stats before and they are like brand new. One even still is in control of the church.

    The other church has boiler hot water reset and a temperature discharge controller on the main A/H all operated by vacuum tube controllers. I'll probably switch those over to Teckmar as soon as the church runs their budget.

    It's really amazing, isn't it, that these controls, at least the ones I run into, still work almost as if they were brand new. We have a duty to keep some of them to show others, as they come along, what we started with and how good they were. I just hope they care.

    Later
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  5. #44
    Join Date
    Jul 2001
    Location
    Canada
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    1,806
    Have a Church with BARBER COLMAN electric controls installed in 1965. With the exception of 2 valve actuators all of the system is original, they have a office / residence next door that was built in 1962 and has the original BARBER COLMAN Pneumatics , compressor pump has been changed twice.

  6. #45
    rubobornot Guest
    There are alot of 50 year old pneumatic systems still in operation, I wonder how many DDC systems will last for a third of that time.

  7. #46
    Join Date
    Sep 2004
    Location
    SoCal
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    446

    Like many of you, I learned control theory back in the day when pneumatics were the standard for open & interoperable control systems. Back when energy was cheap, we maintained a 50 deg cold deck and a 95 hot deck mixing a constant volume of hot & cold air to satisfy the zone. Everyone was happy. Enter the energy crisis in the 70's which changed everything. However as well as they could work, pneumatics were basically dumb and didn't easily understand PID, optimimum start, PLC logic, demand control, or how to provide a web based user-interface to monitor and adjust everything. And, few technicians actually understood how to implement a reset schedule or calculate a controllers proportional band unless they worked for or were taught by Johnson or Honeywell - sysint excepted.

    Consider too that in almost every commercial HVAC application, pneumatics had a single point of failure - the air compressor - usually the least maintained and understood component of the mechanical system. I'm sure many of you have heard war stories that included water leaking out of that 2 pipe stat. These were the days of pressure based control systems which I'll also lump in 4-20ma and 0-10V. Today however, we're transitioning to information based control devices which communicate with each other by sending message packets containing all kinds of control information.

    OK, so what's my point. Well, DDC in it's many forms is a control technology that will be here for many years to come. Look around you. You're reading this on a PC and chances are you have more than one. You check your email religiously for posts to hvac-talk. You probably have a cellphone with GPS and your boss knows where their phone is. You've got a housefull of appliances that contain microprocessors. You pay your bills via online banking - blah, blah, blah. We're surrounded by digital technology and there will be no going back to the good old days!

    The good control techs today are part tin knocker, part freon jockey, part sparky, part radioshack hack, and part computer geek. These are the people and the companies who assemble all the parts and deliver the solution to the end user - I think the term for this job today is Network Integrator. And, this is where the true value of control systems lies today - the integrator - their ability, creativity, and the power of the tools they use.

    Besides, the 4th law of thermodynamics states:
    "Everything gets worse under pressure"

    Just my 2 cents...









    A hundred million nodes - it's a LON story.

  8. #47
    Join Date
    Aug 2003
    Location
    Ft Worth Tx ( North Richland Hills)
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    Originally posted by DeltaT

    Nothing personal but you got to be old to remember this stuff! [/B]
    Yeah, I'll be 56 in April ...don't feel old. It's been a fun ride.
    How can you have any pudding if you don't eat your meat?

  9. #48
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453

    Learned alot

    I have thouroughly enjoyed this post. Would love to work in controls.
    One question though, many discussions on which is best, pneumatics or DDC. But which system would actually cost less to operate for a period of ten years. Repairs, maintanence, installation costs, VS savings ? Considering the same systems, which would generally give you good performance for the money spent?

  10. #49
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,744
    bornriding
    In my experience and opinion DDC controls would be more economical over a longer period of time and control better with more capabalities for event timing.

    BUT in my experience and opinion the majority of DDC controls are not HVAC oriented and not installed or designed by HVAC people (some on this board are exceptions from what I see) so the DDC controls end up costing much more, work less, fail more including many erratic events, are controlled, installed and worked on (?) by primadona's who prove their worth by keeping operation, programs, hardware, software, etc to themselves and make the customer pay and pay over and over again for the priveledge of having them involved in their HVAC systems.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  11. #50
    Join Date
    Jul 2001
    Location
    Canada
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    DELTA T your response was very true. Sad part is when you think of all the UPGRADES we never had the chance to sell a PNEUMATICS customer compared to what has been sold to DDC customers in the past 25 years.

  12. #51
    Join Date
    May 2002
    Posts
    9,564
    "Upgrades" and "restrictions" pushed me into Lonworks.

    With some manufacturers putting out 5 year warranties on hardware you would think that DDC wins out over time. Theoretically speaking there should be less maintenance. The more ASC stuff out there the easier and less expensive it gets.

  13. #52
    Join Date
    Nov 2003
    Location
    Mississippi
    Posts
    181
    Im doing one now. Still installing some in south Ms. area but most is DDC.

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