PE HVAC&R · study guide · October 2025 outline
HVAC PE exam prep, weighted to the 2025 outline
Good HVAC PE exam prep follows the four areas of the October 2025 outline and the one reference you get on exam day. By the midpoints of the published ranges equipment is about a third of the exam and supportive knowledge about a ninth, so spend your hours in that order, then drill the on-screen handbook until look-ups take seconds.
PE Mechanical HVAC & Refrigeration practice test Exam facts
Updated Oct 29, 2026 · Not affiliated with NCEES.
- ExamPE Mechanical HVAC & Refrigeration
- questions80
- equipment, by range midpoints34%
- specifications in forceOctober 2025
- Checked
Where the questions are
Shares from the middle of each range (our arithmetic on the October 2025 specifications):
- Equipment and components, 24–36 items: about 34%.
- Distribution and systems, 20–30 items: about 29%.
- Loads and psychrometrics, 18–27 items: about 26%.
- Supportive knowledge, 8–12 items: about 11%.
The ranges overlap on purpose: the bottoms add up to 70 and the tops to 105, so one form can lean on loads and the next on equipment. Treat the shares as a budget, not a forecast. Psychrometrics also runs through coil, mixing and ventilation problems in the other areas, so it can repay more time than its own range suggests.
Three passes through the material
- Learn, area by area, biggest first. Work each area page and a review text side by side. Finish every topic in the outline, including the small ones: one missed acoustics idea costs as much as one missed load calculation.
- Rehearse the look-ups. Download the PE Mechanical reference handbook from MyNCEES and solve problems with it on screen, using its search box. Note where each chart, table and equation sits until you stop scrolling.
- Timed mixed sets. Run the practice exam at six minutes a problem, then a full timed sitting close to the date. Review every miss by asking which step failed: the concept, the look-up or the unit.
New in October 2025, missing from older books
- Psychrometric processes at low temperature, beside sea level and 5,000 ft.
- Thermal storage with chillers and heat pumps.
- Cavitation, pump curves and NPSH with pumps, compressors and fans.
- Economic analysis and electrical concepts inside supportive knowledge.
The full comparison: what changed.
MERM or the handbook?
Both, for different jobs. The Mechanical Engineering Reference Manual (MERM, by Michael R. Lindeburg, published by PPI) is a review textbook for the PE Mechanical exams: use it to learn and to see worked methods. It stays at home. In the exam room the PE Mechanical reference handbook on screen is the one reference you get, and the exam gives you no codes or standards.
So practice with the book you will actually have. A method you know from MERM is worth little if you cannot find its chart or table in the handbook in under a minute. Before you buy any review book or course, check that it maps to the four current areas rather than the 2020 split.
Traps that cost points in every area
- SI drills. USCS only; skip metric problems from general HVAC sources.
- Sea-level constants at altitude. The 1.08 and 4,840 airflow factors assume standard air; rebuild them from the site density (loads and psychrometrics).
- Gauge vs absolute pressure. Steam and refrigerant tables are in absolute pressure; the principle is explained on FE Environmental fluid mechanics.
- Tons, Btu/h and kW. One ton is 12,000 Btu/h; efficiency ratings convert through 3.412 (equipment and components).
- Decibels do not add. Sound levels combine on a log scale (supportive knowledge).
Practice by area
- HVAC Loads and Psychrometrics18–27 items on the exam
- HVAC and Refrigeration Distribution and Systems20–30 items on the exam
- HVAC Equipment and Components24–36 items on the exam
- Supportive Knowledge (HVAC and Refrigeration)8–12 items on the exam
HVAC PE exam prep, quick answers
Is MERM enough to pass?
It is a review text, not the exam reference. Pair it with the PE Mechanical reference handbook, which is the only book on screen, and with timed problems in USCS units.
Should I still study the 2020 Principles topics?
As tools, yes: thermodynamics, heat transfer and fluids appear inside applied problems. As separate areas, no; the October 2025 outline has four applied areas only.
What should I study first?
Equipment and components, the largest area at 24–36 items, then distribution and systems.
Practice between study sessions
PE Mechanical HVAC & Refrigeration questions, answers and worked solutions in a study app.
Not affiliated with NCEES.