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rudy_2 Member Posts: 135
If anyone is thinking of taking the NATE exam, a friend of ours, Norm Christopherson, put together 100 sample questions for the Bacharach Training website.

Even if you are not taking the test, it might be a good review.

He has also contributed some other articles you all might find interesting.



  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Interesting thing from the section on water properties...

    "If you ask most people, which is heavier, dry air or water vapor, they will answer, water vapor. This is obviously incorrect when you consider the fact that clouds (A collection of water vapor) are high in the sky. If water vapor were denser than dry air we would all be constantly in the fog, which would account for some of our foggy thinking. Actually, a solid understanding of water vapor is important to an understanding of the study of psychrometrics." (From Norm Christopherson)
  • Tom Meyer
    Tom Meyer Member Posts: 300
    If anyone wants to take the Nate Certification Exams

    We give them, along with RPA certification, EPA 608/609, and the ESCO HVAC Excellence series.

    Senior Designer/Trainer
    Precision Hydronics Corporation
  • jerry_2
    jerry_2 Member Posts: 12
    why clouds are up there

    Yes, water vapor (H20,molecular weight 18) weighs less that air (N2 molecular weight 28, O2 molecular weight 32...). This has little to do with why clouds form. I think I can still spell adiabatic cooling. :)
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