PE Mechanical: HVAC & Refrigeration covers just 4 topics, and the three major ones — Equipment and Components, Distribution and Systems, and Loads and Psychrometrics — are closely weighted, each worth 18–36 questions. Distribution and Systems and Loads and Psychrometrics share the highest difficulty rating, so the exam's difficulty is spread almost as evenly as its question count.
70–105, across 4 topics
Effective October 2025
8 or 8.5 hours testing; 9 or 9.5 hours for the appointment
Ranked by question count weighted against the spec's own difficulty rating — not question count alone, since a smaller topic rated harder can be worth more study time than a bigger, easier one.
Cooling towers and fluid coolers · Boilers and furnaces · Heat exchangers · Condensers/evaporators
Air distribution systems and ductwork · Air quality and ventilation · Fluid distribution systems and piping · Control concepts
Heating/cooling loads · Heating/cooling processes · Humidification/dehumidification processes
Every topic in the official NCEES spec, with its question range and share of the exam. Study Scheduler allocates your study hours in this same proportion automatically.
HVAC Loads and Psychrometrics, HVAC and Refrigeration Distribution and Systems, HVAC Equipment and Components, and a smaller Supportive Knowledge topic — four subjects that together define the discipline.
Distribution and Systems and Loads and Psychrometrics share the highest difficulty rating, though Equipment and Components actually carries slightly more questions.
For how many hours to budget, week-by-week study plans, and how Study Scheduler weights your plan — see the full PE study guide.
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