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  1. Slay the P.E.

    April 2018 15K SPAM thread

  2. Slay the P.E.

    I hereby refuse or will do tomorrow to view the results

  3. Slay the P.E.

    Guess the date!

  4. Slay the P.E.

    HVAC&R Practice Problem of the week

    Hi ManojD. We have an e-book titled "Psychrometrics and Basic HVAC System Calculations Practice Problems for the HVAC&R Exam"  You can download free sample pages here: https://www.slaythepe.com/hvacr-psychrometrics.html and then if you like it, you can buy it from our store page. 
  5. Slay the P.E.

    April 2018 15K SPAM thread

    roughly 12.5% of the way to 15K spam
  6. Slay the P.E.

    April 2018 15K SPAM thread

    upgraded from "supporting member" to "vendor" spam
  7. Slay the P.E.

    April 2018 15K SPAM thread

  8. Slay the P.E.

    Lyric battle!

    Get what's mine, take what's mine I'm a star, I'm a star 'Cause I slay, slay I slay, hey, I slay, okay I slay, okay, all day, okay I slay, okay, I slay okay We gon' slay, slay Gon' slay, okay We slay, okay I slay, okay I slay, okay Okay, okay, I slay, okay
  9. Slay the P.E.

    April 2018 15K SPAM thread

  10. Slay the P.E.

    HVAC&R Practice Problem of the week

    Yes! This is correct. It requires trial-and-error. Nice work. This time you used the appropriate definition of COP. The one with absolute temperatures is only for Carnot cycles.
  11. Slay the P.E.

    HVAC&R Practice Problem of the week

    Are you sure you can use that definition of COP here?
  12. Slay the P.E.

    HVAC&R Practice Problem of the week

    100 psi is also incorrect. What's the 140? Where are you getting that?
  13. Slay the P.E.

    HVAC&R Practice Problem of the week

    @Vel2018 200 is not correct. How did you find T_high using COP?
  14. Slay the P.E.

    HVAC&R Practice Problem of the week

    If you didn't have answer choices you could plug-in and try, you would have to take that approach. Also, I think I should've put in the problem statement that the compressor may be assumed to operate isentropically.  
  15. Slay the P.E.

    HVAC&R Practice Problem of the week

    Hi Jimbo. You're not overthinking it. I think it might be just a tad too gnarly for the PE exam because it involves a trial-and-error approach -- something I don't think I've ever seen in any official NCEES test prep material. Remember you are given COP (which relates several enthalpies) and...
  16. Slay the P.E.

    TFS practice problem of the week...

    Correct. @nathanielnzrn see this post: http://engineerboards.com/topic/30175-tfs-practice-problem-of-the-week/?do=findComment&comment=7481226
  17. Slay the P.E.

    HVAC&R Practice Problem of the week

    You’re right about the SCFM. No need to change to mass. Moisture content can be a game changer with respect to cp of air. Don’t always assume that in Psychrometrics problems. The proper thing to do is an energy balance to get h6 and a water mass balance to get w6
  18. Slay the P.E.

    HVAC&R Practice Problem of the week

    Ok. I see now. The enthalpy part is correct. That's how you obtain h6.  The way you are finding T6 is not correct, though. Where does that equation come from?
  19. Slay the P.E.

    HVAC&R Practice Problem of the week

    I'm sorry. Its hard to follow what you did. What's this 1.8? No units.. confusing. Are you saying h2-h1=1.8 Btu/lbm? That doesn't seem right. Then you say you got "enthalpy change 1.8 on 5-6" so it seems to me you are saying h2-h1 = h6-h5 which is not correct. Again, I'm sorry you may be doing...
  20. Slay the P.E.

    HVAC&R Practice Problem of the week

    hmmm... Not quite accurate, though. The change in temperature and enthalpy would be the same only if the flow rates at 5 and 2 were the same -- but they're not.
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