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 (99)
✍️ 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. Which component in a refrigeration system separates refrigerant vapor from liquid to ensure only vapor enters the compressor in a flooded evaporator system?
A suction accumulator is installed in the suction line to separate and hold any liquid refrigerant, allowing only vapor to pass to the compressor.
3. 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.
4. 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.
5. In a demand-controlled ventilation (DCV) system, CO2 sensors are used to:
DCV uses CO2 as a proxy for occupancy; as CO2 rises above setpoint (typically 1100 ppm), the controller opens outdoor air dampers to dilute contaminants and provide fresh air.
6. What type of mastic sealant is recommended for sealing HVAC duct joints in unconditioned spaces?
UL 181-listed duct mastic reinforced with fiberglass mesh tape provides a durable, airtight seal that remains flexible across temperature cycles in unconditioned spaces.
🎯 Free HVAC Practice Tests
📖 HVAC Guides & Articles
- When Was HVAC Invented? A Complete History of Heating, Cooling, and Ventilation
- HVAC Maintenance Anderson: Costs, Checklists, Seasonal Schedules, and How to Choose a Local Pro
- HVAC Bachelor Degree: Career Paths, Duties, Salary, and Whether It Is Worth It
- HVAC Academy: Complete Guide to Training Programs, Requirements, Costs, and Certification
- HVAC Contractors Colorado: How to Find, Hire, and Work With the Best in the State
- HVAC BMS: How Building Management Systems Control Your HVAC and Why It Matters
- HVAC Tech Day: What It Is, Why It Matters, and How to Celebrate and Advance Your HVAC Career
- HVAC MERV Rating: Complete Guide to Air Filter Efficiency, How to Choose the Right Rating, and What It Means for Your Home
What Practice Test Geeks adds beyond an AI chat for HVAC
An AI chatbot can quiz you, but it can't reproduce the exam conditions or keep your record. Here you get:
- A timed, full-length HVAC mock exam — 100 questions in 180 minutes with a 70% pass mark, modeled on the official exam's question count and time limit, followed by a score report broken down by exam domain.
- A fixed HVAC question bank: the same test every attempt, so your score is comparable from one try to the next instead of changing with every regenerated quiz.
- Progress saved on your device: completed tests, scores and missed questions stay in My Progress, so you can retake only what you got wrong.
- A printable HVAC cheat sheet you can print or save as a PDF.
- HVAC flashcards built from the same question bank.
- Free HVAC practice tests with the correct answer shown after each question.