Free Event: Join us on 8/27 as our instructors break down the NCEES PE Civil code changes and answer your questions. Register Now.

HVAC and Refrigeration Six-Minute Problems

Available in Print or eTextbook

Content maps for the October 2025 exam (and after) now included as a PDF download.

HVAC and Refrigeration Six-Minute Problems, Second Edition offers comprehensive practice for the NCEES PE Mechanical HVAC and Refrigeration exam. The content is always up-to-date to the latest exam specifications and codes. Time-tested, detailed instructional design provides you with the most efficient and effective practice.  

Features include:
  • 85 challenging multiple-choice problems, similar in format and difficulty to the actual exam
  • A hint for each problem, to help you get started on the right path
  • Step-by-step solutions outlining how to answer problems quickly and correctly
  • Explanations of the three “distractor” answer choices, so you can see where common errors occur and learn how to avoid them
eTexbook access benefits include:
  • 1-year of access
  • ability to download the entire eTextbook to multiple devices, so you can study even without internet access
  • an auto sync feature across all your devices for a seamless experience on or offline
  • unique study tools such as highlighting in six different colors to tailor your study experience
  • features like read aloud for complete hands-free review
HVAC and Refrigeration Six-Minute Problems Book Cover
$95.00
PUB YEAR
2017
FORMAT
Paperback or eTextbook
PRINT ISBN
9781591265528
PID# 579419

FAQs

The best PE prep course depends on your exam discipline, schedule, and how deep a review you need, but strong courses share three traits: structured review aligned to NCEES specifications, an extensive exam-like practice-problem bank, and full-length practice exams with diagnostics. PPI offers live-online and self-paced options across PE disciplines so you can match the format to how you learn.
Plan for 200–300 hours of study. With a full-time job, that's about five to seven months at 10–15 hours per week; six months is a good default. Focus your hours on practice problems and the discipline-specific reference material, and take full-length practice exams to build endurance for the 8-hour format.
The PE exam is rigorous and discipline-specific, so difficulty varies by field. Per NCEES (January 2026), first-time pass rates ranged widely: for example, Mechanical: Thermal & Fluid Systems 77%, Environmental 67%, Civil: Water Resources & Environmental 71%, Civil: Structural 61%, and Chemical 63%. The exam becomes more manageable when its content matches your day-to-day work, so most candidates plan several months of focused study.
The most effective PE prep combines structured review of your discipline's topics, a large bank of exam-like practice problems, and full-length timed practice exams to build pace for the 8-hour day. Master your reference materials so lookups are fast, target weak areas first, and simulate exam conditions. PPI's discipline-specific review courses and practice exams structure all three.

Some states require a BS degree from an ABET-accredited engineering program to sit for the PE exam. Other states allow you to take the PE exam with a degree in engineering technology, physics, math, or chemistry—or without any degree—as long as you’ve met the required work experience. Check your state requirements to see if you can take the PE exam without an engineering degree.

You should prioritize your engineering interests and professional background when determining which PE exam to take. The difficulty level of each discipline is also important to consider. Reach out to licensed engineers in your network for additional perspectives, too.
You can take most PE exams once per three-month testing window and no more than three times per year. Certain PE exams are only offered once per year in October. Some licensing boards are more restrictive, so check your state licensing board to confirm how often you can retake the exam.

Most states allow you to take the PE exam after passing your FE exam and gaining at least four years of post-college work experience. However, some states now allow examinees to sit for the PE exam before completing their work experience. Check your state requirements to see when you’re qualified to sit for the exam.

By NCEES pass rates (January 2026), the highest first-time pass rates were PE Agricultural & Biological (81%), Mining & Mineral Processing (80%), Fire Protection (78%), and Mechanical: Thermal & Fluid Systems (77%). But the truly 'easiest' PE exam is the one whose content matches your daily work: alignment with your experience beats raw pass-rate statistics. Choose the discipline that supports your career goals.

It is an 8-hour exam. It contains 80 total questions: 40 multiple-choice questions in the 4-hour AM session, and 40 multiple-choice questions in the 4-hour PM session.
PE exams are closed-book, computer-based test (CBT)s; your only reference is an electronic resource(s) supplied by NCEES on-screen. For the PE exam, NCEES will typically provide a discipline-specific reference handbook and one or more design standards. NCEES states which design standards will be available on the exam website in the specifications documentation.
The PE exam tests for a minimum level of competency in engineering. You need a minimum of four years of post-college work experience to be able to sit for the exam.

What Our Customers Say

Matthew
“Just wanted to let you know, I received results for PE Exam today…PASS!! Thank you to PPI…Specifically Josh Ogle and Richard Austin, my instructors for the April 2021 review courses."
Calvin
"The PPI surveying course was a good overview and provided many useful study materials. This course is particularly useful when paired with the PPI Civil PE Review Course since it amplifies some lessons you will have in the overall review session."
Keivan
"The study materials are very useful. The key to passing the exam is to practice as much as you can."
Nicholas
"All you need to do to pass this exam is work all of the homework problems assigned, work both of the practice exams, and go to class. Also, ask questions! The instructors are more than happy to answer them for you. That's about it!"
Jesse
"The course was great. Really helped with knowing just what kind of questions would be expected on the exam, and the review material was a great reference to bring to the exam!"
Tamara
"There is no better way to get to know the contents of MERM than the PPI Review Course. Highly recommended as a foundation for PE preparation."
PE Mechanical Customer
"This course is a must for everyone. It is much more difficult than the actual test, but it will leave no stone unturned. You WILL be prepared for the exam if you attend the lectures and do the homework."
Kevin
"The structure provided by the course is what I needed to force myself to sit down and study. The knowledge and test-taking tips from the instructor were very helpful. Course notes were a great reference on the exam. Quite often, class examples were very representative of actual exam problems."
Brad
"This was a good class overall. The best part was receiving a good study structure, being held accountable for doing it, and having a place to ask questions and review the concepts. I know this review course was the reason I passed. You also have to put in the effort, but it is worth it in the end."
Thomas
"This test is definitely not one to attempt without some help or guidance. PPI does a solid job of keeping attendees on a schedule and giving them an overall review of the required materials."
Ion
"This course is a good review prior to taking the PE exam. The instructor offered valuable advice that only experience could bring. Thank you for your guidance and thank you PPI. I highly recommend this course to everybody who wants to pursue a technical career."
PE Mechanical Customer
“The instructor was very knowledgeable in the exam topic areas and answered all questions. The course materials were very helpful in learning what will be on the exam. It was often more difficult than the actual exam questions, but they will prepare you for the test."
Justin
"This review course is very rigorous, but the amount of problems and difficulty of subjects cover what you need to be prepared for the exam. The course also allows you to interact with other PE exam takers to be able to ask them questions and learn from other students.”
PE Mechanical Customer
“The instructor provided basic theory and techniques that were very helpful in the homework, practice exams, and, of course, the actual exam. There was also good feedback and help from the other students. It's definitely hard work, but definitely worth it!"
Maureen
"I was very rusty in all of the areas I hadn't used in my day-to-day work. I have been out of school for 30 years, and the structured lectures and homework helped me get back in practice. I went into the exam nervous and left confident. I wouldn't have been able to do this without PPI."
David
"The course i s tailored to provide a structured roadmap to help you review all the required materials to master the PE exam. The instructor in particular was very helpful, and his tips were solid gold. I would definitely recommend the PPI course for future PE exam applicants."
Kelly
"This course is a great resource for studying for the PE exam. The course follows a rigorous but helpful schedule. The office hours are a great resource for anyone who needs questions answered outside of class. I felt very prepared going into the exam."
PE Mechanical Customer
“The interaction with the instructor and other students was very helpful and gave some great insights for preparation as well as content and problem solving methods. You will not regret taking this prep course because it will make you feel absolutely ready when you enter those doors on exam day."
Michael
"This course is a very valuable tool to prepare for the exam. Not only does it give a structured study plan to follow, but the instructor follows the topic breakdown, which ensures you keep up on your end as well. The class material, homework, and discussions were all great for preparation.”
Jesse
"This review course is well worth the time. The review materials are a good representation of what you could see on the PE exam. The live instructor feedback is valuable."