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For the exam..   I would only recommend you to use the Mollier diagram.  It's faster and everything is right there on one page.

Your Mollier Diagram..  A71 in the Appendix.

The isentropic is a chart look up.

Damn...  I screwed up again.  

Speed of sound is a function of absolute temperature.  So I came up with 512 ft/sec. Answer should be (A)

In hind sight,  I should have delveloped the equation as a function of gpm instead of velocity.

What I did was develope a TDH equation as a function of pipe velocity and plotted it on the pump curve. This is a system curve.   I also guesstimated what a second pump would add flow wise.  Where the two curves crossed was my answer.  I hope the answer is (D)....

I come up with (C)  ...   I am not used to doing these types of problems though...

Confusing question.. Reduces the pressure losses.

I think it's (C)...   Convert 5gpm to lbm/hr..  Then find grains of moisture at the outlet of the coil from MR=cfm/1000 X .642 X delta grains.  Draw coil line from inlet air to ADP.  Read DB temp at the intersection of coil line and outlet grains.    Plug into the bypass  equation.

I got (B).    h1=1403.4 and h2r=1039.8  h2i=925 Mine is wrong.  your chart reads h2i=1050 Yep.  Should be (A)...   I read the .2 psia curve initially, I think.

Conservation of mass flow and velocity constraint.   m1=m2,   rho1 A1 V1= rho2 A2 V2   and    V2 = 4*V1...  Combine and simplify.   V= velocity   v=specific volume= 1/rho

I got (C)

Excellent!  Good luck!  You will do well! PS...  You will probably feel the same way about the PE exam.  That is to be expected.

McKenz007, CONGRATS!!!! The FE was the hardest exam I have taken.  The hard part is done..  On to the PE!

I come up with (B) I solved for the downstream quality and the computed the specific volume, using the quality.  Then used v2/a2 = 4 * v1/a1 and solved for a2.  Then computed diameter from a2.   I came up with diameter d2 = 3.85 in. On a side note:  NEVER use a solenoid as an expansion...

I do agree with the (5/12)....  thats diameter of the orifice, 5 in divided by 12 in/ft....  the are using the form pi*d^2/4 for the area. Why do you think .4175?  The diameter ratio is .5...  

I agree with you..  They should have checked the Re for the orifice rather than the pipe. I tried searching the internet for an errata for this book but have not found it. Nice find!

You should expect to use the ASHRAE books for the exam.  Just a wealth of information in those books.  Hard to tell what they could pull out... I would use the most recent version possible.  I took 2009-2012 versions and was ok for the 2016 exam.    If you are taking the HVAC & R exam, you...

A curb is just a support for the unit to sit on.  The rubber roofing material is usually adhered to the curb to maintain waterproofing.  The actual units sits on top of the curb with duct penetrations thru the curb supports, if your unit has those types of connections.  The coil is inside the...