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Thread: Balancing, Tuning or Trouble shooting

  1. #1
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    Balancing, Tuning or Trouble shooting

    I have been taught that balancing is a tuning process. My Boss has got the crazy notion that by calling in a balancing contractor it will fix the cooling and heating issues in our building. I am trying to tell him we need to evaluate what is broken, ie; thermostat, VAV, and water flow threw the re-heats, before we call in a balancing contractor, what do you think?

  2. #2
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    They sort of go hand-in-hand.
    I do a triple evac with nitro to remove non condensables.

    I'm feelin' a little peculiar.

  3. #3
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    A good balancer will find the problems for you. Given that you should find and fix the problems you can find.
    No man can be both ignorant and free.
    Thomas Jefferson

  4. #4
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    Prison Dog,
    I agree with both Wayne and Bbeerme.
    I will add, having been a "Controls Guy" for over 20 years, that many of your "... cooling and heating issues..." have already been identified (by you). As Wayne said "...find and fix the problems you can...".

    By far the biggest issues I have had to find and fix were the result of well meaning operators that didn't fully understand the long term effects of their actions.

    3 examples:
    1. Occupant is warm/hot. Quick fix is to increase the Max flow of a VAV box. Do that 10-20-50-60 times throughout a building/system and bad things result. This may happen over several years.
    2. Occupant is cold. Someone (wrongly) thinks increasing the Heating CFM fixes the problem. It might, by chance, help but not usually.
    3. Someone decides that a Sensor (Thermostat) is in the wrong location and moves it to "even out" conditions in a space. They didn't consider that the new location; is under a diffuser, above/behind a Computer Monitor or get's hit with direct winter sun.
    If sense were so common everyone would have it !
    You cannot protect the Stupid from themselves !
    "Experience is the ability to recognize a mistake Before you make it again!" (Stolen Quote)

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  6. #5
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    A good T&B can get rid of problems often blamed on T'stats or the occupants or what might enter a tech's head. A building has to start right. People in T&B have heard all the stories about how a building's problems are poor design, bad engineering, b!tchy occupants, won't leave the t'stat alone, and chasing ideas around the clock when the building needs to start off correct then if problems persist, one possibility has been eliminated as a cause.
    Then there are the buildings that were said no one can fix only to find they can be.

    A clue that the problem might be T&B is when cardboard is seen blocking the outlets or people have brought little heaters for their feet..
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  7. #6
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    Crazy notion?

    My advice......

    Call in a good balancing contractor, and have them do a survey of your building. Unless you have the proper tools and knowledge, your efforts to evaluate what is broken is wasting time and money. Thermostats are easy, but, for example.........

    There are a wide variety of types and styles of VAV terminal units.

    A VAV might be pressure independent, pressure dependent, series fan powered, parallel fan powered, some with reheat, others without, and this is only a little bit of what you need to know to diagnose the proper operation of a typical VAV. How do you propose to evaluate these VAV's?

    How do you know what the proper water flow through your coils is? Do you have the engineering numbers available? Do you have a water machine to set the proper pressure drops, and the knowledge of how to balance water systems?

    You might have airflow issues. How do you propose to diagnose and resolve airflow issues?

    I'll stop here........... Your boss is not crazy. Your boss is on the correct path.

  8. #7
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    What a balancer hates is to fire up a VAV only to find out it doesn't respond. Balancers don't fix those problems. Unless you are going to pay the balancer to trouble shoot the facility separately from the balance you will be in a fight. It doesn't take instruments to tell if the equipment is running. It doesn't take a balancer to see if the ducts are hooked up. It doesn't take a balancer to find out if the control program responds.
    Check what you can and fix what you know is wrong then call the balancer. I have been called to balance jobs where the controls had not been commissioned. You can guess how much balance got done.
    No man can be both ignorant and free.
    Thomas Jefferson

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  10. #8
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    Is the original balance report available? Are design drawings available? I’ve solved many problems be putting buildings back to design settings.

    TAB contractors I’ve worked with expect the equipment to function. Or you get an incomplete report, the preliminary readings only. It’s not their job to troubleshoot your equipment. How would they bid the work. If they are associated with a repair contractor it presents a conflict of interest.

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  12. #9
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    Quote Originally Posted by WAYNE3298 View Post
    What a balancer hates is to fire up a VAV only to find out it doesn't respond. Balancers don't fix those problems. Unless you are going to pay the balancer to trouble shoot the facility separately from the balance you will be in a fight. It doesn't take instruments to tell if the equipment is running. It doesn't take a balancer to see if the ducts are hooked up. It doesn't take a balancer to find out if the control program responds.
    Check what you can and fix what you know is wrong then call the balancer. I have been called to balance jobs where the controls had not been commissioned. You can guess how much balance got done.
    I guess I didn't make myself clear. I'll repeat..... Leave it the hell alone.

    Have the survey completed first. Sure, maybe repair the stuff that you're positive you can repair, then leave the rest of it alone.

    I've seen numerous situations, (for example...a comfort balance) where "Crankshaft" dove in and fixed everything before we hit the job. It was a royal cluster.

    If it's left alone, we can balance what works properly, and leave the owner with a deficiency report for what doesn't. The owner can then make the decisions about what and how to approach the needed repairs.

    This approach helps to lessen the "fire up the vav only to find it doesn't respond" scenario. And those situations have potential to get very expensive.

    Some day I should tell the long ago story of the 2x4's that some maintenance "Crankshaft" was using to hold fire dampers open. (In a hospital) That there was a come to Jesus moment.

  13. #10
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    There is no excuse for shoddy work and that includes maintenance. In the 25 years I did TAB all too often I was called in to balance a facility that was "ready to balance" only to find VAV's that had never been energized, Fire dampers closed, AHU'S not tracking each other or maintaining static set point, Low voltage to the facility and numerous other problems.
    If you want the balancer to troubleshoot they will not have a problem with that if you tell them up front because they can price the job accordingly. I only worked for one engineer that would tell me up front there were problems. I would balanced a building with closed fire dampers by opening them and closing them after balance was done. You wouldn't believe how many calls I got from owners and engineers asking how the balance could have been done with closed fire dampers. This in spite of the way it was done was clearly stated in capitol letters in the balance summary and a notice sent in writing to the contractor that the dampers had a problem. In every case I got the call the caller had not even checked to see if the damper had been fixed.
    The first post here was inquiring about how to approach the problem of getting the building fixed and I'm saying the best approach is to fix what you can and then call the balancer but in any case be straight up with the balance contractor. The only thing they have to sell is time and they can't give it away. Time pays for the high dollar instruments they have to buy and keep calibrated.
    I don't totally disagree with Artrose but urge you to be up front no matter which course you take.
    No man can be both ignorant and free.
    Thomas Jefferson

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  15. #11
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    The ol' chicken/egg problem.
    The equipment needs to be commissioned before T&B can be completed because the equipment has to work before the T&B can be done.
    But T&B needs to be done before commissioning can be completed because the commissioner has the last word about saying the building is functional.
    A catch 22.
    Seems most T&B's face increased costs to complete their job by having to go back, sometimes more than once. before the equipment is actual ready for them.
    Then there's the issue of the wait for whatever contractor is responsible.
    Ahh, the good ol' days before commissioning.... No one knew if the building worked or not but everyone got paid and crossed fingers until the warranty expired.
    The bigger the building and the more complex the worse the problems were. We have a large court house that has never worked. But all were paid.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  16. #12
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    Reminds me of a city library a long time ago. Maybe 25 yrs ago, so some details are fuzzy, other points were so wild, memory is perfect.

    We had a few calls for other 'local' city buildings. When I say local, the business was centered in the same city. So any monies the city spent, they'd get a 'rebate' in taxes that they spent, rebate meaning local sales tax for items bought (like lunches, etc), and property taxes being paid, things like that. Point being that somehow someway word started to get around that we could come in and resolve long standing issues; so it was a win win for them to use the/that company I was working for.

    Back story:
    They did a major remodel to modernize (make things more 'pretty') and nothing (HVAC wise) worked well after that. That's it, that's the back story.

    So I was sent in on a service call. Maintenance or engineer guy met me onsite. Walked me around, explained problems, told of several contractors coming in and all said A/C compressor was undersized. Engineer re-ran calcs and was absolutely standing by his results. Kept telling the city they did something wrong. Guy was essentially just venting and wasting my time, although he meant well. At the heart of it, he was probably just frustrated.

    So (when it was my turn to speak [LOL]), I told him to let me get my tools and show me the compressor.

    Compressor was an open drive Carrier 5H series.

    I don't think I even initially put my gauges on before I saw the (potential) problem.

    Near the center of the end bell opposite of the open drive end, there is a 1/8" female pipe thread fitting. If I remember correctly, the purpose of that is for a pneumatic signal for a reset. Never saw it used, so it was always left open.

    This particular compressor had a grease fitting screwed into that open female pipe thread fitting. So it was regularly being pumped full of grease. More pneumatic air pressure would make the compressor unload. Great for comfort control on hot/cold days. This was before the energy savings of the electronic stuff we see nowadays.

    Called in the maintenance guy and asked him if this was regularly greased, he replied, of course. I told him that's not a grease port.

    As I unscrewed the grease fitting, the compressor all of the sudden began to load up. It's really a beautiful sound listening to those babies loading and unloading through their five stages.

    Maintenance guy was astonished. He's like: that's it? That's all that is/was wrong? That one little teeny tiny fitting?

    Yup. Probably.

    LOL on my part.




    Quote Originally Posted by hvacker View Post
    The ol' chicken/egg problem.
    The equipment needs to be commissioned before T&B can be completed because the equipment has to work before the T&B can be done.
    But T&B needs to be done before commissioning can be completed because the commissioner has the last word about saying the building is functional.
    A catch 22.
    Seems most T&B's face increased costs to complete their job by having to go back, sometimes more than once. before the equipment is actual ready for them.
    Then there's the issue of the wait for whatever contractor is responsible.
    Ahh, the good ol' days before commissioning.... No one knew if the building worked or not but everyone got paid and crossed fingers until the warranty expired.
    The bigger the building and the more complex the worse the problems were. We have a large court house that has never worked. But all were paid.
    I do a triple evac with nitro to remove non condensables.

    I'm feelin' a little peculiar.

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  18. #13
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    Quote Originally Posted by WAYNE3298 View Post
    There is no excuse for shoddy work and that includes maintenance. In the 25 years I did TAB all too often I was called in to balance a facility that was "ready to balance" only to find VAV's that had never been energized, Fire dampers closed, AHU'S not tracking each other or maintaining static set point, Low voltage to the facility and numerous other problems.
    If you want the balancer to troubleshoot they will not have a problem with that if you tell them up front because they can price the job accordingly. I only worked for one engineer that would tell me up front there were problems. I would balanced a building with closed fire dampers by opening them and closing them after balance was done. You wouldn't believe how many calls I got from owners and engineers asking how the balance could have been done with closed fire dampers. This in spite of the way it was done was clearly stated in capitol letters in the balance summary and a notice sent in writing to the contractor that the dampers had a problem. In every case I got the call the caller had not even checked to see if the damper had been fixed.
    The first post here was inquiring about how to approach the problem of getting the building fixed and I'm saying the best approach is to fix what you can and then call the balancer but in any case be straight up with the balance contractor. The only thing they have to sell is time and they can't give it away. Time pays for the high dollar instruments they have to buy and keep calibrated.
    I don't totally disagree with Artrose but urge you to be up front no matter which course you take.
    Went away and thought about it. I have high respect for Wayne's intellect, experience, and they way he shares, and because of this, I hate it when we experience our occasional disagreements, but in this case I think I've found the disconnect.

    I was suggesting a building survey, not a balance job. And, a survey can have lots of negotiables contained within the work agreement. You might agree to nothing more than discovery, or agree to balance what can be reliably balanced, or agree to a certain degree of repair, or any number of other arrangements, or services.

  19. #14
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    When doing the original balance BBeerme the system probably worked because the fitting most likely didn't have enough grease in it to screw up the works. I'll bet that one drove everyone crazy. They probably wasted a lot of money taking low bids before they realized that wasn't ever going to fix the problem.
    No man can be both ignorant and free.
    Thomas Jefferson

  20. #15
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    No hard feelings here Artrose because I believe in speaking out when people don't agree. I respect you and your opinions and that isn't going to change. We are not that far apart anyway. What almost always happened to me was I was ask for a bid to do the TAB and was never alerted to the fact there were problems. It cost me a lot of time and the owner wouldn't pay because rightly so it wasn't the owners fault.
    A building survey is a good idea. I don't think you would blind side a TAB guy.
    No man can be both ignorant and free.
    Thomas Jefferson

  21. #16
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    I was going to post to Artrose that when questions are asked about TAB, and Wayne answers, Listen.

    If you do not listen, it's not on Wayne !!

    LOL. But it seems things are moving forward . . .
    I do a triple evac with nitro to remove non condensables.

    I'm feelin' a little peculiar.

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