Complete exam guide
PE Mechanical HVAC & Refrigeration
The most-taken of the three PE Mechanical exams — equipment- and systems-heavy. It's the right one if your work is building mechanical systems, HVAC design, or refrigeration. Here's exactly what it covers, where the points are, and exam-real practice with a grounded AI tutor.
01
What this exam is — and who should take it
HVAC & Refrigeration is the largest of the three PE Mechanical exams by candidate volume. It's built for engineers whose day-to-day is heating, ventilation, air conditioning, and refrigeration — building-mechanical design, systems, energy, and equipment work. You only pass one exam to get licensed, so the rule is simple: sit the one that matches your work, where your existing knowledge does the most for you.
Comparing the three exams? See which exam to take and the pass rates by exam.
Exam at a glance
- Questions
- 80, on the one exam you sit
- Testing time
- 8 hours (~9-hour appointment)
- Format
- Computer-based, year-round (Pearson VUE)
- Reference
- Closed-book — NCEES Handbook on-screen
- Units
- U.S. customary (USCS)
- Calculator
- NCEES-approved model
- First-time pass
- ~69–71%
- Repeat-taker pass
- ~40–47% — the gap is preparation, not ability
NCEES scores against a scaled cut score — there's no published passing percentage. Expect standard multiple choice plus alternative item types (drag-and-drop, point-and-click, multiple-correct, fill-in). Areas and weights follow the NCEES specification effective October 2025. Pass rates shown are from the July-2026 NCEES refresh (January–June 2026 population); NCEES refreshes them each July and January.
02
What's on the exam — and where we put your reps
4 areas. NCEES gives each a question range, not a fixed count, and every form totals 80 (official area titles + ranges per the NCEES specification).
HVAC Equipment and Components
24–36 of 80Where points go
The single biggest block — cooling towers, boilers and furnaces, heat exchangers, chillers/condensers/evaporators/heat pumps, pumps/compressors/fans (curves, NPSH), coils, and energy recovery. The real problems run tough and the breadth is wide — that's the risk.
Your reps
The tutor walks each sizing and selection step from the problem's worked solution; the bank spreads reps across every equipment subtopic so thin spots get found in practice, not on exam day.
HVAC and Refrigeration Distribution and Systems
20–30 of 80Where points go
Ductwork and air distribution, air quality and ventilation, piping, control concepts, and refrigeration systems — often multi-step with extraneous data, and rewarding judgment (what a valve or economizer actually does) over plug-and-chug.
Your reps
Full-system problems tagged per subtopic, with the tutor naming the controlling relationship instead of just the formula.
HVAC Loads and Psychrometrics
18–27 of 80Where points go
Heating and cooling loads, the psychrometric chart processes, and humidification/dehumidification — 18–27 questions, and the chart has to be reflexive under time pressure, so make it automatic early.
Your reps
Every chart process — sensible and latent, mixing, humidification — practiced subtopic by subtopic, with the tutor walking each one step by step.
Supportive Knowledge (HVAC and Refrigeration)
8–12 of 80Where points go
Codes and standards, acoustics and vibration, economics, and electrical concepts — cheap points that go under-prepared precisely because the block is small.
Your reps
Covered, so you don't leave easy questions on the table.
Area titles and question ranges per the NCEES specification (eff. October 2025).
03
How to prepare for this exam
Don't study the areas evenly — weight your time to where the points and the difficulty are.
- 01
Drill broadly across equipment and components first — it's the biggest block (24–36 questions), so cover the full spread before exam day.
- 02
Make the psychrometric chart automatic — loads and psychrometrics carry 18–27 questions, and the chart has to be a reflex, not a derivation.
- 03
Over-practice heat transfer — exam problems push past the routine versions.
- 04
Cover distribution and controls for judgment, not just math.
- 05
Don't skip supportive knowledge — codes, acoustics, economics, and electrical are cheap points if you've touched them.
- 06
Rehearse the closed-book Handbook every time — the HVAC/refrigeration, heat-transfer, and thermodynamics sections, plus the psychrometric chart and refrigerant property tables.
- 07
Practice timed, then finish with full-length mocks — pace decides a lot of points, so train it.
Drill the high-yield topics:
That's the problem-first method applied to this exam; for the calendar, see how long to study.
04
How CastorPrep covers the HVAC & Refrigeration exam
Exam-real problems, solved step by step.
Written to your exam's NCEES specification, area by area, and each one comes with a worked solution that shows the method, not just the number. Tagged to all 4 areas and 19 subtopics of the HVAC & Refrigeration exam, so practice follows the real weighting.
- A worked solution on every problem
- The Handbook section where the method has one
- All five of the exam's item formats, from fill-in to drag-and-drop
4,000 cfm of outdoor air at 95°F mixes with 12,000 cfm of return air at 75°F. Find the mixed-air dry-bulb temperature.
✓ Correct. The correct answer is B.
Worked solution
Weight by mass flow, not 50/50 — the outdoor air is a quarter of the stream:
06
Frequently asked
How is the HVAC & Refrigeration exam structured?
80 questions over a nine-hour appointment (~8 hours of testing), closed-book with the on-screen NCEES Reference Handbook, computer-based and offered year-round at Pearson VUE. Standard multiple choice plus alternative item types (drag-and-drop, point-and-click, multiple-correct, fill-in).
What units does this exam use?
U.S. customary (USCS).
What score do I need to pass?
NCEES uses a scaled cut score and doesn't publish a fixed passing percentage — the goal is mastery of the tested areas, not a magic number.
Is HVAC & Refrigeration the right exam for me?
It's the right one if your work is building mechanical systems, HVAC design, or refrigeration. You sit one exam — pick the one that matches your day-to-day.
How long should I study?
Most candidates need ~200–300 hours over about four months, weighted to weak and heavy areas.
What if it takes more than one attempt?
It's offered year-round, within NCEES/state-board attempt limits. A retake plan that changes the method — not just the hours — is what moves the score.