RSES Refrigerant Management 5 — Questions and Answers
Question 1: A refrigerant is considered 'reclaimed' when it has been reprocessed to meet what standard?
- ASHRAE Standard 34 purity levels
- ARI/AHRI Standard 700 purity specifications (Correct answer)
- EPA Section 608 recovery efficiency standards
- DOT transportation specifications
Correct answer: ARI/AHRI Standard 700 purity specifications
Reclaimed refrigerant must meet AHRI Standard 700 purity specifications, which are equivalent to virgin refrigerant quality, before it can be resold.
Question 2: Which refrigerant application requires EPA Section 608 Type III certification?
- Small appliances (sealed hermetic systems)
- High-pressure refrigerants (R-22, R-410A)
- Low-pressure refrigerants (R-11, R-113, R-123) (Correct answer)
- Motor vehicle air conditioning
Correct answer: Low-pressure refrigerants (R-11, R-113, R-123)
Type III certification covers low-pressure appliances using refrigerants such as R-11, R-113, and R-123, which operate below atmospheric pressure.
Question 3: What does 'fractionation' mean in the context of refrigerant blends, and when is it most likely to occur?
- Separation of oil from refrigerant during normal operation
- Preferential evaporation of blend components causing composition changes, most likely during vapor-only leaks (Correct answer)
- Crystallization of refrigerant at low temperatures
- Chemical decomposition of refrigerant at high temperatures
Correct answer: Preferential evaporation of blend components causing composition changes, most likely during vapor-only leaks
Fractionation occurs in zeotropic blends when components evaporate at different rates during a vapor leak, changing the remaining blend's composition and properties.
Question 4: Under current EPA regulations, what must happen to refrigerant recovered from a system before it can be returned to a different system owned by a different customer?
- It must be tested for moisture content only
- It must be sent to a certified reclaimer and meet AHRI 700 standards (Correct answer)
- It must be filtered through a new filter-drier
- It can be transferred directly without any processing
Correct answer: It must be sent to a certified reclaimer and meet AHRI 700 standards
Refrigerant recovered from one customer's equipment must be reclaimed to AHRI 700 standards before being used in another customer's equipment.
Question 5: What is the primary reason ammonia (R-717) is NOT widely used in comfort air conditioning despite its excellent thermodynamic properties?
- It has a very high GWP
- It is toxic and has a strong pungent odor detectable at very low concentrations (Correct answer)
- It requires extremely high operating pressures
- It is not compatible with copper tubing
Correct answer: It is toxic and has a strong pungent odor detectable at very low concentrations
Ammonia is toxic (ASHRAE B2L classification) and has a pungent odor detectable at 5 ppm, making it unsuitable for occupied building comfort cooling applications.
Question 6: When charging a system with an HFC refrigerant blend like R-404A, the refrigerant must be charged in which state to prevent fractionation?
- Vapor only from the high side
- Liquid only (Correct answer)
- Liquid on high side, vapor on low side
- Either vapor or liquid — it doesn't matter for HFC blends
Correct answer: Liquid only
Zeotropic HFC blends like R-404A must always be charged as a liquid to ensure the correct mixture ratio enters the system and prevent fractionation.
Question 7: An EPA Section 608 certification is valid for how long before it needs to be renewed?
- 2 years
- 5 years
- 10 years
- It does not expire — it is valid for life (Correct answer)
Correct answer: It does not expire — it is valid for life
EPA Section 608 technician certification does not expire and is valid for the lifetime of the technician who passed the approved certification exam.
RSES Refrigerant Management 5
A refrigerant is considered 'reclaimed' when it has been reprocessed to meet what standard?