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  1. #14
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    Originally posted by DeltaT
    Don't have time to get into this but whoever previously compared lack of maintainance on pneumatic to where DDC controls need no maintenance is so full of themselves it's sick.
    Hmmm. Did someone claim DDC controls did not require maintenance? I must've missed that post.

    Originally posted by DeltaT
    I can take you to plants with faily new DDC controls that have not worked since the day they were installed. I can take you to buildings that are over 40 years old and still have the original pneumatic controls working just as well as they did when they were installed.
    Chuckle. Very true, I've seen numerous buildings that're over 40 years old with still working pneumatics. I won't say that they're working as well as they were when they were first installed. But, they're still working well enough.

    And, DeltaT, I could take you to several buildings that're less than 8 years old. Which were built using pneumatic controls. Which have had the pneumatic controls completely reworked and redone 2 to 3 times; and in one case completely ripped out and replaced with new pneumatics ... where the pneumatics have NEVER worked correctly. I know about those buildings, 3 of which are in this state, and one in the next state over, as we were finally hired in a last desparate attempt by the owners to get a control system which worked correctly. We offered to do the controls in pneumatics, or in DDC. Their pick. However, in either case, we wouldn't do it and offer any warranty or guarantee unless we ripped the whole existing mess out and started over again. As it turned out, they opted for DDC.

    And liked the results ... a LOT.

    But, as I pointed out to them. Their real problem had not been the original choice to go pneumatics. Their real problem had been hiring the cheapest SOB's they could find to install em. Then doing the same when it came time to hire someone to try to fix the mistakes of the first contractors.

    I'll not argue about the rest of your point. Except to say that I think the 99.5% is a bit high.

    However, certainly there are quite a few, too many, in the DDC installation biz who lack a lot of knowledge about HVAC systems. Other than what they might have learned in an introductory course, or from reading Honeywell's Gray manual. Which is a good reference, but hardly comprehensive as concerns all one needs to know.

    And there are more than just a couple folks who call themselves HVAC techs, who could use a bit more education in that field, themselves.


  2. #15
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    "Now, I'm supposing somebody could do all that with pneumatics. But I'm also betting it'd be one heck of a complicated system. And would take bloody well forever to keep calibrated and adjusted, or to troubleshoot."

    Osiyo
    That sure sounds like you are saying that pnuematic controls will "And would take bloody well forever to keep calibrated and adjusted, or to troubleshoot" to me.

    Not so. Never has been. Bunch of guys on here have already said they have systems 30 plus years running like almost new without much calibration, adjustments or trouble shooting. I am one of them.

    And yes, there are many pneumatic building that have unskilled personal that take care of them including using coat hangers on the dampers. I know, I have re-done, rebuilt many myself.

    But those same personnel are going to do the same with any type of control system including DDC. I also run into that and so do a lot of people on this board.

    One of the "benefits" that I see most DDC people say is that the DDC system will take care of itself. And that they just set there for years and work trouble free. Baloney.

    I have a college campus were the people in charge of the central system have replaced the sensors with fixed resistors so everything always looks normal. But the managers who watch over this system don't know this. They think the central campus system is great. And they print out all reports each month on how much energy they save. It's a long story but the campus electronics guys who are in charge of running this sytem found it easier to installed fixed resistor in place of finding ther problems because of the constant problems.

    Another large campus electronic firm had all the old pneumatics removed and had DDC controls installed because they are the "save all" of controls. Well, long story again, anyway they had tremendous problems controlling temperatures where the employess called the local Labor & Industries board. Short end to this was the maintenance crew never changed the filters or belts so the main AH system had no air flow and the chiller was shuttiing down on barrel freeze protection. Why? -- because they have a DDC control system which was suppose to take care of all the problems as it was sold to them. This is what the maintenance supervisor told me as I was standing in front of his central system. They quit doing all maintenance because, as he said, they now have a modern control system which will take care of everything. No kiddin.

    These two examples are not isolated incidents but an almost weekly event in my business.

    And in my experience the 99.5% figure is accurate. If trained HVAC people could take control of anytype of control systems all of us would be better.

    I don't mind if one states you can do more with DDC controls systems - because you can. But when this ugly sales and know it all attitude shows up about DDC systems are the only way to go and bla, bla, bla then it's an untruth to our whole industry. Keep the electronic guys behind the bench and only let skilled HVAC people design, install and sell these systems, pneumatic or otherwise. But it will never happend. That's why I am so busy.
    "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. #16
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    This is a great thread guys! Very informative for me. Thanks.

    Norm

  4. #17
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    Originally posted by DeltaT
    "Now, I'm supposing somebody could do all that with pneumatics. But I'm also betting it'd be one heck of a complicated system. And would take bloody well forever to keep calibrated and adjusted, or to troubleshoot."

    Osiyo
    That sure sounds like you are saying that pnuematic controls will "And would take bloody well forever to keep calibrated and adjusted, or to troubleshoot" to me.
    And they do, in very large installations, DeltaT. Which are the bulk of the systems I deal with.

    I am an electronics guy, AND a mechanical guy, DeltaT. Have been on both sides of the house.

    The very reason I made my comment that I have seen very old pneumatic controls installations, which still worked fine. But stipulated that I wouldn't say they worked just like when new. Because they didn't. Possibly one would find such well tuned up and adjusted systems in any commercial electrical power generating plants that might still use pneumatics (I don't know of any such), and quite possible, even likely, one would find well tuned and maintained pneumatic systems in manufacturing plants. In both cases, the type of installation where the owner/operators would pay what it takes to keep everything working well and properly adjusted. I have seen a couple such examples. ie On the ships upon which I served until I retired from the Navy in 1991. The ones still using extensive pneumatics. And, as a civilian, one of our large commercial customers is a medical devices manufacturer, with multiple facilities. Some of which are still using pneumatics. As I stated before, in each eample I'm giving, the owners spent what it took to have folks onhand to routinely, actually, really ... no **** ... go and measure, test, and adjust or repair as necessary to keep things operating right. And doing so kept a man or more pretty busy. Near full time.

    I will stress, I'm referring to BIG friggin installation.

    However, to get back to reality, and the norm representing most installations. Most property owners don't take care of their property and equipment so well. It's more normal for me to find exactly the sorts of things I've mentioned in the posts I've made. ie A recent customer. Building was in fair to middling shape. A sizeable building. 34 air handlers. Of assorted types. Some dedicated to single large spaces. Some zoned with hot decks and cold decks. Some feeding constant volume boxes with reheats, and they even had a few VAVs with reheats tossed in. No big problems or issues ... that they were aware of. Hired us to retrofit DDC controls as a matter of trying to modernize and maybe save some energy.

    Their in-house maintenance guys had done best job they could. But the reality was, and is, just like what most face ... they didn't have adequate personnel to actually troubleshoot, test, and fix like they would have liked to have done. So a lot of things went unnoticed. And they concentrated on fixing those things occupants actually complained actively about.

    Hell, DeltaT, even the building maintenance supervisor told me that he knew that sometimes they kinda took shortcuts. And that in some cases, well, if it worked well enough, that was good enough. Even if it wasn't right and as it should be. Like anyone else, he and his department only had so many people, so much budget money. And very unlikely owner was gonna give him more help on his crew.

    Chuckle, but he sure was surprised at just how many existing discrepencies and problems we uncovered. Some, no one knew about. ie inoperable OA dampers. An AHU putting out less than 1/4th rated capacity. Etc. Some, occuplants had noted, but as issue wasn't severe or unbearable, they just sort of gotten used to living with. More than once, an occupant told me he or she thought local system was "supposed" to work like the way it did.

    Now, I am, as I've said before, an old pneumatics guy. Could have myself, personally, fixed up the pneumatics in that building so that they worked correctly. If I'd had the time, and the money. But if I were in that maintenance supervisor's place, I'd have had to operate under the same constraints he had to deal with. Only so many workers, just so much time, and only so much budget money. And he had a LOT of others things he had to do in a day. HVAC systems were just part of his responsibilities. He also had to address calls for not working electrical systems, plumbing leaks, somebody's key broke in a door lock, somebody sucked down one too many adult beverages the night before and left the inevitable results splattered all over a bathroom, so forth and endlessly on.

    Guy knew what he SHOULD be doing as concerns HVAC controls, to have em fine tuned and working right. But didn't have the time. Especially given the amount of time it takes to REALLY examine a system and control, and tweak it the way it should be. As versus just "making it work".

    As stated, I've DONE both. I know exactly what the heck it takes to do DDC controls, or to do pneumatics. And I durned well know about testing and troubleshooting, calibration and adjustments, and know how long that stuff takes.

    So I wasn't the least bit surprised when in the end, after said building maintenance supervisor got to see, and get used to his new system and it's front end. That he got real enthusiastic and excited when it dawned on him that SEE the various components working. See command, and results of command. See valve open and pipe or duct heat up or cool down. Eyes lit up.

    I KNOW what he was thinking even before he said it. He was thinking about all the friggin walking time, draggin around of ladders, lifitng ceiling tiles, sticking thermometers in test hole after yah drilled one, breaking line and adding hand gage, etc and all the time all that stuff took. Just so yah could ID where the problem was.

    Hell, I didn't even have to prompt him. I know some guys in these forums don't think much of building maintenance people. But this guy is no idiot. He was looking at some rooms and saw low space temps. Looked at reheats and saw they were trying to heat, valves open, duct temps had increased, but not as much as they should. Without word one from me he knew, switched to screen where he could see discharge temp from associated air handler. AH HAAAA ... he grunts. "That's too low, why?" he calls up set points, looks at valve and damper positions.

    Now, electronic PID loops are new to him, as are some of the types of resets we use. So he did quiz me on those. Asking for an explaination. So I explained. Plus showed him an add on screen we installed which he could call up. We've BTDT before with customers. So we add a button that can be clicked and they can call up a graphic screen which does an on-screen graphic plot. Standard x-y coordinate thing. This variable is X, that one is Y, throw in values and it'll draw the graph and you can SEE what the calculated results will be for any given X-Y values. They like that. Little light bulb goes off in heads. "Ohhh, okay, I can see it now."

    We went thru that. And I showed him all was good. But discharge still too low. Reason? Part of contract was that some new things had been added. One such was some Heat Recovery Units. He'd not clicked on screen to show the one now attached to his air handler. I showed him. And showed him where he could see that ERU wasn't working right. Wasn't picking up heat from exhausted air and returning it to OA intake. Could be seen clear as day when I showed him the screen. He'd seen little buttom marked "ERU" but hadn't thought to click on it.

    Chuckle, designer of his new system only called for part of total air stream to be run thru ERU. Enough to ensure minimium OA requirements despite very low OA temps. AHU screen proper only showed MAT at point that would NOT give picture of air temp at injection point of that ERU connection. That was my guys' fault. Since corrected. One had to look at ERU screen, before I changed the screen layouts, to see that ERU was injecting some really friggin COLD air into AHU. Colder than heat coil of AHU was meant to deal with. Thus the very low discharge. Which was lower than reheats in rooms could deal with.

    Anyway, point was guy was just impressed as hell that he could troubleshoot in mere moments. At least pinpoint problem enough so he knew where to go and look. As versus spending a couple hours running here and there, attaching hand held instruments, determining, "No, this part is working fine. Problem must be elsewhere." And all the while draggin around ladder, tool bag, and having to deal with occupants stopping him and asking "What the hell is wrong?" and him having to tell em that he didn't have a clue yet. But was working on it.

    DeltaT, I know you know as well as I do that in HVAC work, and many other types of work, one often spends a hour, 2 hours, sometimes several hours just finding a problem which only takes 15 minutes to fix. That's what this fellow was excited about.

    That it was a fancy "electronic" system, he didn't give a rip about. Oh, there are some other things in his new system he likes. But what he likes best is that for the first time he really can see the "Big Picture" of what's going on in his building. And can see that he and his guys can save a lot of "chasing around finding the problem" time.

    FWIW, he's already told me has has little to no interest in learning the insides of DDC systems. Has enough on his plate already. But I did spend time with him showing him how to do some basic troubleshooting so he can determine if the controller is working or not. Or if it's something else. Plus I showed him a few tricks of the trade. ie How to operate HOA switches on controllers. ie He just needs to look at neatly printed, laminated points sheet we attach to inside of door of every box containing one of our controllers. Which lists what's connected to what. In PLAIN ENGLISH. ie BO1 has descriptive line saying "AHU 21 Supply Fan Start/Stop". He has a master copy of every controller points list in his office, plus the laminated copy placed in every cabinet we install.

    I also showed him how to disengage clutch of small Belimo valve motors or damper actuators,to manually position. For larger ones showed him how to use little manual cranking wrench. Also showed him how, if it's necessary, to tap this wire to ground to move a tri-state motor this way, this other one to move it that way. And so forth and so on. So he's not totally helpless. Knows how to make do until something can be fixed.

    "Not so. Never has been. Bunch of guys on here have already said they have systems 30 plus years running like almost new without much calibration, adjustments or trouble shooting. I am one of them."
    I'll take your word for it. Haven't been in your shoes so could hardly say you're wrong. But I have not. I have seen systems that old that are still working ...okay, tho. Could be I'm just more nitpicky that other folks.

    And yes, there are many pneumatic building that have unskilled personal that take care of them including using coat hangers on the dampers. I know, I have re-done, rebuilt many myself.
    Uh huh. And there service personnnel called in as contractors who aren't just a lot better.

    And there are very good people in-house, and as contractors, too.

    The point I was trying to make.

    A hack is a hack, whether he's installing pneumatic controls or DDC.

    Also, all of us, pneumatic AND DDC, can use a bit more learning and education in our fields than we probably have. Even those with lots of experience can also use a little brushup and refresher from time to time. Geez, if I could remember all the stuff I've forgotten over the years, I'd be positively brilliant.

    But ... I'm not ... so I must've forgotten a lot. <G>


  5. #18
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    Originally posted by NormChris


    This is a great thread guys! Very informative for me. Thanks.

    Norm
    Heck, most all of the threads are informative to me, Norm. I have come to a conclusion. That the more I know, the more I realize just how much I don't know. A couple years ago I had an opportunity to sit in a class, at company expense. They'd hired a fellow who teaches at one of the local private tech schools. A well respected one, locally, at least. And were having him come to our building to give his classes. A series of em. 4 hrs per night, one night per week, for 6 weeks.

    Pretty basic class, an introduction to controls theory as applied to HVAC equipment. Neither a pneumatics nor DDC specific course. General theory, that applied to whatever sort of controls. P, PI, and PID. Etc.

    Students were to be company employees, and they ran the gamit. Everything from young apprentice pipefitter, to managers and salesmen, and even a few engineers. As you probably know, just because someone can wave a sheepskin in front of your face, it doesn't mean he or she has a good grasp of everything he or she might need to know. And we'd found some of our sales people, project managers, and some of the engineers could use a little brush up on their knowledge of control theory.

    Anyway, I heard about it. Wasn't one of the ones originally scheduled to attend. When I inquired of the back office as to why not, my boss just looked at me and said "Oh hell, what's this guy gonna teach you? You do this stuff for a living."

    Uh huh, sure. The instructor was an old Honeywell engineer, retired from Honeywell. Had worked his way up from a field tech to an engineering position. Now doing this teaching gig.

    I told my boss that I'd not yet EVER found anyone willing to try to teach me something, from whom I'd not been able to learn something new. Or from whom I'd been able to relearn something long forgotten. I wanted a seat in the class.

    I was right. I learned a few new things.

    Of course, for me, that's easier than with some. There is SOOOO much I still don't know.

  6. #19
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    Two things irritate me about what you are saying/inferring:
    1) Pneumatic controls take a lot of maintenance.
    2) DDC controls will not take a lot, if any, maintenance.
    3) Once DDC controls are installed there is very little need for skilled, trained HVAC/controls personel to be on board.
    4) Large building with pneumatic controls have more problems/requirements for maintenance/repair/complications.

    OK, I can't count.

    The reason most HVAC systems, including any type of control systems, is defunk when you get there is the lack of the williness of owners/managers to provide & investment in skilled personel [which you already mention to your credit] AND/OR the plain lack of skilled personnel - period.

    This is a nationwide industry crisis and will remain that way, in part but not the total fault of DDC controls and the like, because these very systems are marketed as a plug & play installation where skilled craftsman are not needed once installed. Hecht, it doesn't even take skilled craftsman to install the stuff already. That's exactly what you have been selling as a selling point to your customers.

    The lack of skilled personnel and the demise of those controls is also true of DDC systems now in place in those very buildings where the [whatever] controls were removed and replaced with DDC. I can tell you story upon story of my trobleshooting of all types of DDC systems over the past years all due to installation/design/product and/or maintenance failures. AND in many of the DDC controls an added, never seen before nusiance shows up in erratic operations with, ironically, any self testing procedures, most of the time if not always, proving that there is nothing wrong when, in fact, the customer is steaming mad cause he knows his systems are not working correctly otherwise he would not have called (you) them.

    As for the size of building and control systems and complications I disagree again. Granted there are more controls and, maybe, more sequencies of operation. But once basic control theory is understood along with basis HVAC training any pneumatic/electric/electronic control system is very easy to understand and work on.

    We can compare sizes of building that you have worked on and that I have and I bet I will come out ahead.

    One of my points is, DDC control systems have been and will undergo the same problems that [blank] control systems have experienced, which is lack of knowledge/design/installation, etc. etc..

    Most DDC control systems are being sold not to solve a problem or to improve control, but to benefit the builder of those DDC control systems.

    Want some proof of that? Go ask just about any DDC control system maker for info/copies/parts/components on their software, hardware or over the counter parts availability.
    "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

  7. #20
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    Originally posted by DeltaT
    Two things irritate me about what you are saying/inferring:
    1) Pneumatic controls take a lot of maintenance.
    2) DDC controls will not take a lot, if any, maintenance.
    3) Once DDC controls are installed there is very little need for skilled, trained HVAC/controls personel to be on board.
    4) Large building with pneumatic controls have more problems/requirements for maintenance/repair/complications.

    OK, I can't count.
    LOL. No problem. I have difficulty doing higher math if I have my shoes on.

    1) Pneumatic controls take -ADEQUATE- maintenance, repair and adjustment if you want to ensure they work RIGHT. As versus just work. Unless you've actually gone to the controls, thrown on calibrated and known good instruments, you don't know that they're working as correctly as they should, and could. But, as I alluded to before, it could be that I'm just more nitpicky than some. Probably comes from years of being a Navy snipe. Where, if spec said danged thing was supposed to be operating at such and such a spec, =/- 2%. I wanted to make sure danged thing worked at said spec within +/- 2%. And I'd be checking with certified calibrated instruments. And not just because regs said so. Because the durned equipment worked better, lasted longer if it was tuned right. I was a lazy Snipe. Liked to drink my coffee with feet kicked up on my desk and tell tall sea stories. As versus fixing damned machine again and again. It was my pride and joy the first time we completed a 9 month cruise and none of my equipment, and I had more per man than any other shop on the ship, had a single hour's worth of unplanned down time. To me, being bored to death meant yah were doing your job right. <G>

    2) Precisely where have I ever said DDC equipment requires little or no maintenance? If you took anything I said to mean that, I'm afraid you're mistaken. Now in past posts I have said that we have DDC systems installed for 10 or more years which are still working, and working well. But that's not the same as saying they require little or no maintenance. However, a decent system, well designed and installed, using equipment from a decent manufacturer requires no more maintenance than most anything else. <Shrug> Things fail. Even new ones. FWIW, the guys in our service department tell me that most of their automation/DDC work involves correcting operator errors, and/or fixing the usual stuff. Valve or damper motor went bad (not frequent as we use exclusively Belimo stuff or off the shelf pneumatic actuators), a linkage broke, somebody cut a wire while doing some other work, etc. There is an occassional controller replacement. But after the warranty period this is actually rare, for us. Typically durned thing will roll over and play dead cockroach in the first days or weeks if it's got a factory fault. Heck, I got a small collection of old controllers, various makes and models, that worked well for over a decade. And were removed only because building owner decided to automate whole building. ie An old controller that only controlled one or two AHUs, and was obsolete. So not suitable for use in whole building conversion. Chuckle, just got a whole Network 8000 system that way. Gave it to one of the pipefitters who is one of my techs. He was thinking about putting it in his house and putting it back to work. Reasonable enough as my own home has an "old" system at work in it. Long obsolete, but it's still working like a charm.

    3) If anyone claimed a sizeable building with DDC did not require someone on hand who was skilled and trainned in HVAC, said person is a fool. The equipment itself is still the same damned equipment. Fans, valves, dampers, heat exchangers, contactors and relays, pumps, and so forth. That the controls are DDC does not change ANYTHING as concerns the needed and necessary care and feeding of the equipment being controlled. It can make troubleshooting somewhat easier. But the operator needs to know enough to interpret the data he's seeing. And he needs to actually know how to fix the mechanical and electrical equipment being controlled. DDC systems can NOT think. Not really. If anyone thinks so, they evidently are greatly misinformed themselves. DDC controllers and computers are dumber than rocks. Compared to a human.

    4) Large buildings with lots of equipement, and ANY sort of controls require a lot of care and feeding. DDC systems, properly installed and running, can simply make that care and feeding a little faster and more efficient, as it can present the many bits of info in one place. As versus, for example, some guy having to try to hot foot it thru an 18 story office building first thing in the morning to physically go see if everything is okay. Or wait for a catastrophic failure with resultant occupant complaint. Now in some large manufacturing complexes, that use pneumatics, they do bring back lines to a central control station so operator can overall status of plant remotely. But this is rarely if ever done at ordinary stores, office buildings, etc. It means pulling a hell of a lot of bundles of tubing back to the central control room. And takes up a bunch of wall space for the display gages.

    Those are the things I've said, DeltaT.

    Kindly don't put things in my mouth I've never said.

    The reason most HVAC systems, including any type of control systems, is defunk when you get there is the lack of the williness of owners/managers to provide & investment in skilled personel.
    BINGO !!!! Absolutely correct. It's isn't the kind of control system, it's the personnel involved.

    This is a nationwide industry crisis and will remain that way, in part but not the total fault of DDC controls and the like, because these very systems are marketed as a plug & play installation where skilled craftsman are not needed once installed. Hecht, it doesn't even take skilled craftsman to install the stuff already.
    Hmmm. Of course, I have no idea about what it's like in your area DeltaT. But that's not a marketing ploy I've ever heard in this area.

    BTW, nope, doesn't take a lot of special skills to install DDC systems. Just quite normal ones. It's the proper programming, setup, commissioning, and testing; follwing a proper system design in the first place; which takes skill. For most of our installations, we just hire regular electricians to pull the wire, pipe the conduit, mount controller panels on walls, terminate, etc. This isn't rocket science. We provide em with wiring diagrams. Plus I or a tech will go to the job site before they get very far along with big magic marker and mark big "X" with note, "DAT sensor goes here.", etc. We've about given up trying to teach em how to properly mount and install a damper motor. So for that, and for things like installing pressure sensors in piping, etc we send one of our in-house pipe fitters who is also an automation tech. Our automation techs are about evenly divided, half being pipe fitters, half being electrical/electronics types. We find the mix of skills works well. The techs help each other out. Each having own strenghts and weaknesses, and each knowing what those are. But for installation, unless it's just a small job, we farm out the majority of the labor to electricians. It's simple work. Setup, programming, etc is what takes the skill. And that's done by our automation techs. All ours, except for a couple newbies, carry more than one licensing/certification. An electronics or electrical type with no or little HVAC experience, will only be a helper (in our automation department), regardless of how long he's been an electrician or whatever, his journeyman status, or anything else. Until he's proven his HVAC knowledge on the job and passed certain testing. We're certainly not gonna put him in charge of anything until then. And I can say that as an electrician, DeltaT. While I am now an engineer, I have the licenses and the experience as an electrician. And as a HVAC mechanic. And as a Chief A (unlimited horsepower) Boiler type. Chuckle, in fact my lead automation tech is a pipefitter, who also happens to have a couple electrician's licenses. We find it works best if our automation techs, and the project managers, are multiple skilled people.

    That's exactly what you have been selling as a selling point to your customers.
    No, I haven't, DeltaT. I've never told a customer anything like that. Not even close.

    I can tell you story upon story of my trobleshooting of all types of DDC systems over the past years all due to installation/design/product and/or maintenance failures.
    I've got no reason to doubt you. I find this perfectly believeable.

    AND in many of the DDC controls an added, never seen before nusiance shows up in erratic operations with, ironically, any self testing procedures, most of the time if not always, proving that there is nothing wrong when, in fact, the customer is steaming mad cause he knows his systems are not working correctly otherwise he would not have called (you) them.
    No reason for me to doubt you here, hell, I've seen the same many times.

    As for the size of building and control systems and complications I disagree again. Granted there are more controls and, maybe, more sequencies of operation. But once basic control theory is understood along with basis HVAC training any pneumatic/electric/electronic control system is very easy to understand and work on.
    Hell, I still can't find anything you're saying I can take much issue with.

    [QUOTE]One of my points is, DDC control systems have been and will undergo the same problems that [blank] control systems have experienced, which is lack of knowledge/design/installation, etc. etc..[QUOTE]

    Agreed.


    Most DDC control systems are being sold not to solve a problem or to improve control, but to benefit the builder of those DDC control systems.

    Want some proof of that? Go ask just about any DDC control system maker for info/copies/parts/components on their software, hardware or over the counter parts availability.
    Not sure if I agree with the first part. I think most folks in the DDC business have the best intentions. I'm just not so sure their knowledge is adequate.

    As concerns the makers of the equipment. What do yah expect? They're manufacturers of equipment. Not the users. We routinely feed back info to manufacturers telling em they've just had the dumber idea. The good ones listen, and fix it.


  8. #21
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    osiyo
    I've pushed my points enough and appreciate your feed back and knowledge. We probably are more headed in the same direction then shows up here. Most DDC control people I work with I would like to push off a roof -- not because that they are DDC control people but because they pretty much insult this industy in their methods, installations and promises. You, I have a feeling -- I would not try to push off a roof.

    As a troubleshooter I try to read and see what it there and in your above posts you mentioned a couple of times about large frigin systems and that is where I took my reply from concerning complicated control systems statements. It's always possible you meant something else.

    To clarify I am not against DDC control systems at all. I think they are cool and was on the ground floor as they were being developed by real HVAC control companies using HVAC control basics.

    What I continue to be against is the electronic type, eggheads as mentioned before, that got into our business through the introduction of the affordable personal computer and their infiltration into this business with emphasis on bells and whistles in place of good design, installation and FULL service.

    Ironically, some of the worst abusers now are some of the large control companies I use to work for and respect.

    But they sure keep me amazingly busy.

    Thanks again
    "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

  9. #22
    Just my take on it but I think PNEU is dying. Why would anyone want to stay with it? How much does it cost to keep the compressor and drier running not to mention the service calls to figure out whats wrong if there is a problem. I have seen my share of poor DDC installations.

    Most DDC problems I have seen is poor planning / programming and a salesman that promises the customer that the controls will fix everything. Kind of hard to fix a refrigerant leak or a faulty OA damper actuator with a PID loop. (you still have to get out the hand instruments.)

    The other problem I have seen is people who don't have a clue trying to troubleshoot complex PNEU control loops. A point list and sequence of operation are absolutely essential no matter what type of controls you are using.

    Oh yeah, I still quiver when I see a fist sized bundle of copper lines going to a panel and the customer wants to know what is wrong but it goes with the job..........


  10. #23
    Join Date
    Oct 2003
    Location
    Minnesota
    Posts
    1,376
    Originally posted by DeltaT
    osiyo
    I've pushed my points enough and appreciate your feed back and knowledge. We probably are more headed in the same direction then shows up here.
    I think so, and have thought so all along.

    As a troubleshooter I try to read and see what it there and in your above posts you mentioned a couple of times about large frigin systems and that is where I took my reply from concerning complicated control systems statements. It's always possible you meant something else.
    I was only talking about the shear amount of time to make it from here to there, then to over there, back over yonder, etc. In large installations, one can end up spending the majority of one's time just getting from here to there. Then yah finally isolate the problem, or think you have, just to find out yah need exactly the one size allen wrench yah haven't got with yah, and it's tromp clear across the building and down 5 floors to go get it.

    Yep, some systems in large installations can get durned complex, also. But owning mechanic can figure that part out if he's inclined to want to be good at what he does.

    What I continue to be against is the electronic type, eggheads as mentioned before, that got into our business through the introduction of the affordable personal computer and their infiltration into this business with emphasis on bells and whistles in place of good design, installation and FULL service.
    Understood. And I can't see anything in the above statement that I can disagree with. There are those types who get into the business.

    <Shrug> In the case of the manufacturers, if their stuff is garbage and not suitable, we send em messages to fix it and make it right. If they don't, we drop their line of crap. It's pretty simple. There are others who'll be more cooperative. And our attitude is that we're interested in pleasing our customers. Not the folks we buy parts from. It's the customers we have to look in the eye daily. It's the customers who sign the checks that pay us.

    In the case of the above types who get into the actual installation and service part of the biz. Well, what can one say? There are shysters and hacks who get into almost any sort of business if they smell a buck to be made.

    In field work, I've noted that some of the worst are ex-computer and IT sorts who've decided to get into the BAS biz. It seems as if the computer and IT world has bred more than it's fair share of fat headed "I know more than you ever will ..." types. LOL ...

    Seemly convinced that their ideas, and ways of doing things are the only right way, that YOU, you dumb hick, should never question them, and that you should feel blessed and happy to accept what they give yah and learn to live with it and deal with it.

    We've had a few come to work for us. Most of whom are now working elsewhere. A couple got with the program, once we stomped on their toes and proved to em that they weren't nearly as smart as they thought they were. Went into humble and learning mode, and went on to do okay. Another, well he's damned brilliant when it comes to OS's, networks, and a number of others things we find handy. So he still works for us. But he's had us kick him where it hurts on a number of occassions, and nowadays he has a very limited scope of things we allow him to do. Other things he's not allowed to touch. And he has final say on nothing, nothing at all.

    As stated, the rest work elsewhere, now. Problems with em being primarily two.

    1)Nasty tendency to TELL customer what he or she needs or wants, as versus asking then delivering what customer wants. This isn't good for business. You can create a technically perfect system, that works exactly the way yah intended it to. But if it doesn't fit the requirements of the HVAC system's designer and sequence of operation required for said system to perform as it should, and if it doesn't fit customer's ideas of how they want things to work ... it still sucks.

    2)Said types have a nasty tendency to do all their thinking and troubleshooting from in front of a computer. Too many look at program and data and if bit or byte changes as program calls for it to do, they proclaim everything is working, and any problems are not their problem. Not good. Just a friggin computer program. Means nothing unless you go verify item at the end of the wires. Is the temp sensor working right, within specs as concerns accuracy, located in the right spot, of the right kind, etc. Okay, fine, puter says motor moving ... but IS it moving? In the right direction? The right amount? Etc. And DO NOT, don't yah DARE, tell me you verified damper is closed just because durned front end screen says so. Get off your lazy ass and go pop a cover, or make a hole, and LOOK.

    Those are the sort of problems I've had with a number of the computer Guru types that've tried getting into the biz and came to work for us. Lazy, physically. Seemingly hate getting dirty, or getting all sweaty by climbing up a ladder in an operating boiler room to physically verify an actuator motor up against the ceiling is really connected and moving as it should. They just look at screen, if it says actuator moving, they figure their job is done.

    You see? I have my own pet peeves with some people who get into our biz. One fellow of the type I mention above, now works elsewhere. Chuckle, and recently I ran into his new boss. Who asked me, "Is he always like this? Sometimes he pisses me off so much I want to just hit him with the biggest pipe wrench I can find."

    To which I replied, "That's why he doesn't work for me any more. He's all yours. Have fun."

    What can I say, DeltaT? There are gonna be jokers in every deck, and in every biz. Time will weed out the real players from the wannabes. People such as we're discussing will either learn, or they'll be history.

    IMHO, in the field, we need more HVAC types to get interested and to get educated on DDC controls, electrical and electronic systems. And for the electrician and electronic types getting into BAS, we need for more of them to get themselves educated about HVAC systems.

    IMHO, the system we us at the company where I work, where we form teams that have both electrical and pipefitter automation techs on same team, works well. As the two seem to compliment each other well. What one does not know, the other usually does. Not that we send two men to a one man job. But since guys are on same team, work together sometimes, know and trust each other, they're all the time calling each other on Nextel and knocking heads together to compare ideas and learn from each other. When needed, we have no problem when one calls the other and yelps "Help !". And the guy called makes time to run to the other's location for a look-see and show and tell session. In the end, this makes BOTH guys better technicians.

    Hell, one of the tech's on my team is a 19 year experienced pipe fitter who's been doing commercial HVAC all that time. And while I am myself an old boiler and HVAC guy, if yah don't think that fellow teaches me something new from time to time, you'd be mistaken. I know a lot. But there are still even more things I don't know. He's seen and done things, and learned things I have not. And vice versa.

    But they sure keep me amazingly busy.
    Heck, then it's not all a bad thing. You can make a nice living fixing other people's dumbassed mistakes.

    Tho, I do understand that sometimes one gets really pissed when you're looking at a job that's a mess made by someone else. And your customer is looking at you with doubts and suspicions. Are you gonna screw him or her, too? Are you as incompetent and full of BS as that last guy?

    That sort of thing can get on one's nerves, especially if you're the sort who takes pride in your work and your skills.

    I know, sometimes I feel exactly the same way. And am cussing under my breath (I don't let customer hear me), "You idiot ! What the hell were you doing and what were you thinking?". As I'm looking over somebody else's mess. The other thought is, "You a-hole, you're giving us all a bad rep !!!" That last thought, I don't like, not even a little. To me, this isn't just a living. It is that. But it's also my advocation, my identity, and something I take pride in. I like to look customer straight in the eyes and have no shame, and to have pride in self and my work. Which is kinda hard to do when customer has just been shafted by last 2 or 3 guys he's done business with.

    Thanks again
    Thank you. I've actually enjoyed your thoughts and observations. Most of which agree with my own. More so than otherwise. Sometimes I have wondered if I'm the only one who sees some of the stuff I do.

  11. #24
    Join Date
    Oct 2003
    Location
    Minnesota
    Posts
    1,376
    Originally posted by floating point
    Most DDC problems I have seen is poor planning / programming and a salesman that promises the customer that the controls will fix everything. Kind of hard to fix a refrigerant leak or a faulty OA damper actuator with a PID loop. (you still have to get out the hand instruments.)
    Exactly. A GOOD controls contractor must be able to, and be willing to, thoroughly troubleshoot problems. And since there is very real, actual, physical equipment attached at the end of all those wires, and represented by the pretty pictures on a front end screen, he can never know his system is actually working right unless he goes there, to the end of the line and looks and tests equipment being controlled.

    The answer of "Well, Mr Customer, my end of things is working fine. It's not my problem." Doesn't fly. Not really. You got to verify that your stuff really does work, and yah can't do that from the front end screen. That's just computer bits and bytes. Not real world.

    It's like a recent small job I went on. Another contractor installed some controls on a site. Customer has had nothing but fits since then. Original contractor claimed his stuff working right, problems weren't his.

    Uh huh, sure. Customer got pissed enough to dump other company, asked us to take a look.

    I found things like poorly located sensor probes for air flow measuring stations. That was unsatisfactory especially as sequence of operation called for using that info as control data. There is an old phrase that holds true in the computer world. GIGO, garbage in- garbage out. They were getting bum data. I and a tech relocated probes to better location. And I had a balancer show up and take his readings to give me real data. I adjusted scaling on controller to cause it's readings to match balancer's numbers.

    MAT sensor was single thermistor stick type. WRONG. Gave bogus info. I had it replaced with 25 foot, 9 thermistor, averaging sensor. At partial damper positions, velocity would be high, and stratification extreme, old sensor gave inaccurate data. New one fixed that.

    Some dummy installed freezestats in MA box, ahead of heating coils. Units kept tripping out on freeze when trying to bring in required OA when it was cold outside. Unit would work for a while. Trip out and sit there til freeze sensor warmed up again. Then restart for a little while til it tripped again. (Autoreset freezestats) No wonder it was taking forever to warm up spaces served. Coupled with bad selection of MAT sensors, I was surprised system worked at all on cold days.

    PID loop setting for dampers and valves ... sucked. Badly. Valves and dampers constantly hunting and making wild swings that were just plain unsatisfactory.

    Etc.

    Just because somebody knows how to program a DDC controller, build a points database, adequately put system onto a network, etc ... does not mean they're a good HVAC contractor. Yah gotta know and understand what you're controlling. Why, how, and the basic principles of good HVAC system operation.

    It was obvious to me original contractor was lacking on understanding, or just too friggin lazy to get off ass and go look, feel, touch, and measure the stuff at the end of those wires.


  12. #25
    Join Date
    Jul 2001
    Location
    Canada
    Posts
    1,808
    In the past 30 years I have seen both PNEUMATIC and DDC systems designed , installed , operated , serviced , destroyed by MORONS who think that they know everything.

    Both systems require MAINTENANCE , CALIBRATION, sad part is that the person ( $ trained not TECH trained ) making the decision thinks " well my computer at home has ran for 3 years without anything being done to it , so the COMPUTERIZED controls must be the same "

    I have 2 large complexs that are Fully DDC controlled with a Complete PNEUMATIC backupsystem in place as they cannot afford a shutdown do to a computer glitch , software burp , device melt down.

    The yearly service requirements for both systems is very well stipulated and followed.

  13. #26
    Join Date
    Nov 2001
    Location
    Seattle, WA
    Posts
    7,749
    Originally posted by Control Man
    I have 2 large complexs that are Fully DDC controlled with a Complete PNEUMATIC backupsystem in place as they cannot afford a shutdown do to a computer glitch , software burp , device melt down.
    Now that's one I haven't run across. Funny.

    Years ago when I was working for Honeywell we had a hospital admin/tech person call us for a meeting about his new hospital and new control system. He opened the pneumatic control main panel, grabbed a tube and pulled it off, waved it in my branch managers face and yelled (really) "do you think we are fools? You didn't put in any wire inside these lines"

    Control man is certainly right. Lack of knowledge works both sides of the street. But it seems more specialized in the newer electronic systems for whatever you want to call them.

    I miss the good old days where you had to spend a great amount of time training and developing skills. And were appreciated and got paid well for being a better skilled person.
    "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

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