EPA Section 608 Universal Certification ExamCoreMedium
A technician is servicing an existing refrigeration system that uses R-22. Due to the phase-out of R-22, the customer is considering a 'drop-in' substitute. Which of the following statements about 'drop-in' refrigerants is true?
- ADrop-in refrigerants typically have a lower Global Warming Potential (GWP) than the original refrigerant.
- BA true drop-in refrigerant requires no system modification or oil change.
- CMost 'drop-in' refrigerants require an oil change and may necessitate component adjustments.
- DDrop-in refrigerants are always completely compatible with the existing oil and system components.
Show answer & explanationAnswer & explanation
Correct answer: C. Most 'drop-in' refrigerants require an oil change and may necessitate component adjustments.
While marketed as 'drop-in,' most substitute refrigerants are not truly drop-in. They often require an oil change (e.g., from mineral oil to POE) and potentially adjustments to expansion valves or other components to achieve optimal performance.
Why the other options are wrong
- A. Some may have lower GWP, but it's not a universal truth for all 'drop-ins' and not the primary defining characteristic of their application.
- B. This is the ideal but rarely achieved scenario for 'drop-in' refrigerants in practice.
- D. This is false; compatibility is rarely 100% and often requires oil changes.
'Drop-in' Refrigerants
Refrigerants marketed as replacements for phased-out substances, implying minimal system changes, but often requiring oil changes or component adjustments in practice.
- Rarely a 'true' drop-in; usually requires some modification.
- Oil compatibility is a major concern (e.g., mineral oil vs. POE).
- Performance may differ from the original refrigerant.
- Examples include R-407C as a potential R-22 replacement.
Memory trick: Don't just drop it in, check the oil and adjust!