EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Hard

A client notices a strong, pungent odor similar to ammonia near their high-pressure air conditioning system. The system uses an unknown refrigerant. What is the MOST likely refrigerant being used in this system?

  1. AR-717
  2. BR-134a
  3. CR-410A
  4. DR-22
Show answer & explanation

Correct answer: A. R-717

R-717 is the chemical designation for ammonia. Ammonia is known for its strong, pungent, and distinct odor, which is often described as similar to household ammonia. While it is a natural refrigerant, it is toxic and flammable, requiring specific safety precautions.

Why the other options are wrong

  • B. R-134a is an HFC refrigerant and typically has a faint, ethereal odor, not pungent or ammonia-like.
  • C. R-410A is an HFC blend; it has a very faint, almost odorless characteristic, not a strong pungent smell.
  • D. R-22 is an HCFC refrigerant and also has a faint, ethereal odor, not a strong pungent smell.

R-717 (Ammonia) Odor

R-717, or ammonia, is a natural refrigerant characterized by its strong, pungent, and irritating odor, which makes leaks easily detectable.

  • Chemical formula is NH₃.
  • Distinctive pungent, ammonia-like smell.
  • Classified as a high-pressure refrigerant.
  • Toxic and flammable, requiring careful handling.

Memory trick: Pungent ammonia, R-717's true aroma!

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