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Thread: MeasureQuick Airflow Estimate

  1. #1
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    MeasureQuick Airflow Estimate

    Could someone explain how MeasureQuick comes to a CFM estimate?

    I finally had a chance to try the Fieldpiece probes and loved the combination. The airflow estimate feature seems like it would be great on service calls where you wouldn't have time to drill holes for a timed anemometer traverse or have access to blower charts.

    I remember reading a post from Jim a while back about the estimate being fairly accurate if the charge was close but I can't find it now. If a system is dirty or the charge is off does the estimate become useless?

    Thanks

  2. #2
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    I downloaded the Measure Quick app, but have not used it.I have a new fieldpiece 480.I'm just learning to use it with the fieldpiece app.My understanding is that the measure Quick also works withe Fieldpiece.Is this true.If so, which app is better?Which app would you use ,and what is the reason for using one or the other?How does it calculate airflow? I do also own fieldpiece probes.

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    Quote Originally Posted by Gleng View Post
    I downloaded the Measure Quick app, but have not used it.I have a new fieldpiece 480.I'm just learning to use it with the fieldpiece app.My understanding is that the measure Quick also works withe Fieldpiece.Is this true.If so, which app is better?Which app would you use ,and what is the reason for using one or the other?How does it calculate airflow? I do also own fieldpiece probes.
    MQ is the better app by far. I don't use the FP app at all. Also, the MQ app will work with different brands simultaneously. Seriously, no comparison. MQ.

    Tools that work with MQ

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  5. #4
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    Agree with Vin.

    I use the MQ app with Testo probes. Works great. Only use the Testo app for basic stuff like pressure testing.

    Don't know how the airflow estimate feature works. Hopefully someone else can come along and explain it.

  6. #5
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    I haven't really used the app, but it's probably asking you for nominal tonnage and SEER rating - using that information with your refrigerant pressures and temperatures to determine whether the system is properly charged, then taking your return and supply wet and dry bulb temperatures to calculate the difference in enthalpy.

    Sent from my Moto Z (2) using Tapatalk

  7. #6
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    I believe mQ treats that calculation as proprietary. Jim has explained it to me and the Enginering team at some major utility consultants all to our satisfaction.

    I’m sure if he gets a chance, he can elaborate.


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  8. #7
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    Tools that work with MQ[/QUOTE]

    Downloadable version of that chart (I created the original)

    https://www.trutechtools.com/assets/...%20REV%202.pdf

    Complete selection of compatible products:

    https://www.trutechtools.com/MeasureQuick


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    Bill Spohn
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  9. #8
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    IM assuming it takes the tonnage and blower type you enter as well as other reading but primarily the WB/DB sticks in supply and return give it a way to determine AF by the other settings you entered..

  10. #9
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    do you trust the airflow readings to be correct, without using other instruments such as hot wire anemometer,staic pressure, heat rise method, etc. Do you have any other info you could post as to how MQ calculates the airflow?

  11. #10
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    when will the Fieldpiece 480 be compatible with MQ,Thanks

  12. #11
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    I'd be curious to see how few inputs the app needs before it spits out an airflow number.

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  13. #12
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    Quote Originally Posted by acguytx View Post
    IM assuming it takes the tonnage and blower type you enter as well as other reading but primarily the WB/DB sticks in supply and return give it a way to determine AF by the other settings you entered..
    I'd add: SH, SST & TEET

  14. #13
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    The estimated airflow is basically a mass flow calculation and is a more accurate way to get airflow in a residential system than an anemometer or even a capture hood in many cases simply because of the duct design. For the most precise readings, you need to have superheat within 25 degrees of the target, you need ODA temperature and liquid line temperature as well as the SEER set in the profile. We do not go into details of the actual calculation as we treat it as a trade secret. It has been highly refined over the past few years. We tested it against several other methods at NIST labs and were consistently within a few percents of their equipment. I can assure you that it is very accurate and reliable.
    JLB,

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  16. #14
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    Has it been tested and rated by AMCA? If so what did they have to say? Does calibration have to be NIST tracible or does it only do calculations? That all counts if used by a certified balancer. If used by a certified balancer all the test equipment has to have calibration that is NIST tracible. The way it works may be a secret but balancers have to know enough about it to have confidence they can use it without being overridden by their certifying agency. Does it work with a system that is not working properly and if not does it alert you there is a problem?
    Not trying to throw cold water on this but I think certified balance of residential systems will eventually be mandated and wondering how this would fit in or if it will.
    No man can be both ignorant and free.
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  17. #15
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    Quote Originally Posted by WAYNE3298 View Post
    Has it been tested and rated by AMCA? If so what did they have to say? Does calibration have to be NIST tracible or does it only do calculations? That all counts if used by a certified balancer. If used by a certified balancer all the test equipment has to have calibration that is NIST tracible. The way it works may be a secret but balancers have to know enough about it to have confidence they can use it without being overridden by their certifying agency. Does it work with a system that is not working properly and if not does it alert you there is a problem?
    Not trying to throw cold water on this but I think certified balance of residential systems will eventually be mandated and wondering how this would fit in or if it will.
    That was never the intent nor do we advertise it that way. It is an indirect measure of airflow and not a volumetric measure. It is far better then what most techs have to measure airflow which is typically nothing. It is far more accurate than most instruments for use on residential airflow as the airflow is far from laminar. We have lab tested in multiple labs and it is a very good method to determine airflow. We can only determine the airflow/ton then we multiply it by the nominal tonnage to get system airflow. The ratio is all the same so it really does not matter if you put the wrong tonnage in as far as CFM/ton.

    It is a total airflow calculation and cannot be used for measurement at a register. Remember, air balancing with a hood or anemometer only works well if the ducts are tight. If you have leakage downstream of the point of measure the hood will not account for it. The way that it is done in MQ, if the measured and the estimated do not agree we can flag it as an issue. I outlined above the conditions for it to make an accurate measurement. As long as the evaporator is not completely starved (within about 25 degrees of target SH) it works very well and we do not let the software use the calculation until we confirm the system is stable and the parameters are within the range that it can provide good data.
    JLB,

  18. #16
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    Thanks for answering my questions Jim.
    No man can be both ignorant and free.
    Thomas Jefferson

  19. #17
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    Quote Originally Posted by jim bergmann View Post
    As long as the evaporator is not completely starved (within about 25 degrees of target SH) it works very well and we do not let the software use the calculation until we confirm the system is stable and the parameters are within the range that it can provide good data.
    That is awesome. Thank you.

  20. #18
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    When will the MQ app work with the Fieldpiece 480.I have fieldpiece job link probes and Psychometric probes, but I find myself using the 480 more often.I guess i'm just so used to breaking out a manifold(old School,habit).Thanks for all your good work towards helping servicemen in the HVAC field.

  21. #19
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    Quote Originally Posted by Gleng View Post
    When will the MQ app work with the Fieldpiece 480.I have fieldpiece job link probes and Psychometric probes, but I find myself using the 480 more often.I guess i'm just so used to breaking out a manifold(old School,habit).Thanks for all your good work towards helping servicemen in the HVAC field.
    The SM480v and 380v both are joe supported. Go to the toolbox, scan for new tools and I’ll come up under the Fieldpiece probes
    JLB,

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