EPA 609 Study Guide 2026
Everything you need to pass the EPA 609 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.
📋 EPA 609 Exam Format at a Glance
📚 EPA 609 Topics to Study (21)
✍️ Sample EPA 609 Questions & Answers
1. Which refrigerant was primarily targeted for phase-out under the Montreal Protocol as implemented in US law?
R-12 (CFC-12) was the primary MVAC refrigerant phased out due to its high ozone depletion potential under the Montreal Protocol.
2. The high-pressure side of an MVAC system runs between which components?
The high-pressure side runs from the compressor outlet through the condenser and to the metering device inlet.
3. What device in an MVAC system controls the flow of refrigerant into the evaporator?
A TXV or orifice tube meters liquid refrigerant into the evaporator, maintaining the correct pressure drop for proper evaporation.
4. A refrigerant identifier should be used before recovering refrigerant from an MVAC system primarily to:
Contaminated or mixed refrigerants can damage recovery machines and cross-contaminate the recovery cylinder; identifying the refrigerant type first protects equipment and ensures proper handling.
5. What is the ozone depletion potential (ODP) of R-134a?
R-134a has an ODP of zero, which is why it was approved as a replacement for the ozone-depleting R-12.
6. Frost or ice forming on the orifice tube or expansion valve in an MVAC system usually signals:
A restriction or moisture freeze at the metering device causes a dramatic pressure and temperature drop immediately downstream, leading to ice formation.