Recent content by NHEngineer037

What he said she said he said is right. Thanks!

New Hampshire is in

Passed the PE!  Can I change my credentials from EIT to PE or do I need to wait for something?  I want to change those dang letters!

There are super heated tables?  What page are those on in Fundamentals? 

ASHRAE Fundamentals Chapter 30 has all the charts you need for refrigerants... all of them. When I start a refrigeration problem, the first thing I do is sketch the shape of the process that you would on the P-H curve, on my sheet of scrap paper.  You know...a rectangle with the right side of...

Ahhhhhhhhhhhhhhhh!!! Now I see. The ventilation rate is given in ft^3/hr, not CFM. You got me, PPI... you got me.

Anyone out there work the PPI Mechanical Practice Examination (3rd edition) HVAC+R practice problems?  I have an issue with problem #50 on page 14. I am calculating a crawl space temp of 30 F.  The solution says it is 11.9 F.  I calculated my solution two different ways and suspect the...

This question also applies to mixing problems. I was taught in school that you use mass flow rates of the air, not CFM, to determine how to weigh the T, W, or H or mixing airstreams.  A bunch of solutions seems to favor just using CFMs, which is OK if the solutions have a large spread, but...

I am not sure how to best attack psychrometric equations on exam day.  Q=1.08 * CFM * deltaT  -or-  Q= 1/spVol * 60 * 0.24 * CFM* delta T Q=4.5 * CFM * deltaH  -or-  Q = 1/spVol * 60 * CFM* deltaH My go to method is the more detailed approach and taking the extra 3 seconds to get the specific...

I bought the HVAC-R exam and found it very helpful.

Does anyone know if refrigerant tables and pressure-enthalpy diagrams are provided during the exam that we can write on? If I flip to my own refrigeration tables in ASHRAE or in a binder and put my pencil to paper to trace something out, that is a test taking no-no, right? Thank you, Ryan

Justin! That is what I was missing! Well done. Thank you, Ryan

Problem 130: The pump has the following to overcome: 160' wc + 20' wc (friction) + 1 atmosphere. (160+20)*.0438 = 77.9 psi 1 atm = 14.6 psi 77.9 + 14.6 = 92.5 psia Regardless of the upstream pressure at the pump, the outlet still needs to be 92.5 psia.  That is the highest pressure in the...

Could I trouble somebody that has the appendix scanned to forward me a copy at [email protected] ?  Many thanks! Ill reply to this once received. 

thanks for doing that!