Complete exam guide
PE Mechanical HVAC & Refrigeration
The most-taken of the three Mechanical depths — an equipment- and systems-heavy exam. 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.
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What this depth is — and who should take it
HVAC & Refrigeration is the largest of the three PE Mechanical depths 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 depth 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 depths? See which depth to take and the pass rates by depth.
Exam at a glance
- Questions
- 80, one depth
- 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
- ~69–73%
- Repeat-taker pass
- ~47–51% — 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 the most recent NCEES figures; NCEES refreshes them mid-2026.
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, Handbook-cited; 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 — about a quarter of the exam and the one to make automatic first, because the chart has to be reflexive under time pressure.
Your reps — The bank over-indexes the chart, and the tutor walks each process (sensible/latent, mixing, humidification) 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).
How to prepare for this depth
Don't study the areas evenly — weight your time to where the points and the difficulty are.
- 1
Make psychrometrics automatic first — it's ~a quarter of the exam and the highest-leverage area to lock in. The chart and the standard processes should be reflexes, not derivations.
- 2
Drill broadly across equipment — it's the biggest block, so cover the full spread before exam day.
- 3
Over-practice heat transfer — exam problems push past the routine versions.
- 4
Cover distribution and controls for judgment, not just math.
- 5
Don't skip supportive knowledge — codes, acoustics, economics, and electrical are cheap points if you've touched them.
- 6
Rehearse the closed-book Handbook every time — the HVAC/refrigeration, heat-transfer, and thermodynamics sections, plus the psychrometric chart and refrigerant property tables.
- 7
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 depth; for the calendar, see how long to study.
How CastorPrep helps
Practice
Exam-real problems
Tagged to all 4 areas and their 19 subtopics, so practice matches the real exam weighting.
Tutor
Grounded AI tutor
Names the step you missed and explains why — citing the Handbook section you'd use on exam day.
Mocks
Full-length mocks
Blueprint-weighted to this depth, so you rehearse your eight-hour pace on a realistic mix.
Diagnose
The diagnostic
Maps your weak areas to the blueprint and ranks what to drill first.
One plan, everything included. 7-day free trial, no card — see pricing.
Going deeper
About the exam
How to prepare
Or browse all resources.
Frequently asked
How is the HVAC & Refrigeration depth 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 depth 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 depth for me?
It's the right one if your work is building mechanical systems, HVAC design, or refrigeration. You sit one depth — pick the one that matches your day-to-day. (See which depth to take for the full breakdown.)
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.
See whether it clicks before you pay a cent.
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