HVAC Study Guide 2026
Everything you need to pass the HVAC exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 HVAC Exam Format at a Glance
📚 HVAC Topics to Study (27)
✍️ Sample HVAC Questions & Answers
1. A recovery cylinder is color-coded gray with a yellow top. What does this indicate?
Gray body with yellow top is the standard color code for cylinders containing mixed or unknown refrigerant, as established by ARI (now AHRI) guidelines for recovery cylinders.
2. What IAQ hazard does a malfunctioning heat exchanger in a forced-air furnace pose?
A cracked or corroded heat exchanger allows combustion gases—including deadly carbon monoxide—to mix with the circulated air supply, posing serious carbon monoxide poisoning risk.
3. What role does collaboration play in energy efficiency for HVAC professionals?
Collaboration leverages diverse perspectives and combined expertise to achieve better outcomes than any individual could alone.
4. What is a 'Variable Air Volume' (VAV) system and how does it differ from a 'Constant Volume' (CAV) system?
A VAV system delivers conditioned air at constant supply temperature but modulates the volume delivered to each zone using VAV terminal boxes, matching supply to actual demand.
5. What problems arise from excessively high water velocity in hydronic piping?
Excessively high water velocity causes erosion-corrosion at fittings and elbows, generates flow noise, and can cause air bubbles to be entrained.
6. What is the purpose of a heat exchanger when connecting a hydronic loop to a pool or snowmelt slab?
A plate heat exchanger separates the primary heating loop from secondary loops that may contain different chemicals or operate at different pressures, while efficiently transferring heat.
🎯 Free HVAC Practice Tests
📖 HVAC Guides & Articles
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