I just PASSED the HVAC/Refrigeration exam after taking Dr. Tom's Classroom review course - this was my experience.
- I graduated in CIVIL ENGINEERING (Environmental/Water Resources) and I am an "Energy" Engineer, so I deal with ALL TYPES of mechanical systems: chillers, boilers, air compressors, conveyors, lighting, HVAC... whatever. So since I didn't specialize in ANYTHING, but knew a bit of EVERYTHING, I decided to take the Thermo/Fluids exam.
- THEN THEY CHANGED THE EXAM WITH NO NOTICE. After reviewing the new specs, they'd dropped the "General" AM section and the PM was almost ALL Thermo II and Heat Transfer, the only two subjects I didn't take in college, so I changed to HVAC/Refrigeration.
- I continued on Dr. Tom's method, but SKIPPED Thermo II sections, since they're not on the HVAC/Ref Exam.
- I purchased ($35) Engineer Pro Guides Review Book and Practice Test ($35 - but didn't really need it, so I don't recommend) to cover the rest of the material.
- Purchased both NCEES Practice Exam & Six Minute Solutions
- Because of the teaching method, thoroughness of the review and organization of materials I HIGHLY ADVISE taking DTC, even if you're doing HVAC/Refrigeration, just get the supplemental materials and go through them to make sure you've covered EVERYTHING.
NOTICE: Engineer Pro Guides had quite a few typos and Errors, but so did the NCEES. Going though the sections, and working the problems, I simply emailed the author and he sent me corrections within 24 hours. On the other Hand, NCEES sent out their errata 2 weeks before the exam.
Good luck to all in Oct 2017!