EPA 609 Retrofitting R-12 Systems to Alternative Refrigerants

Question 1

When an R-12 MVAC system is retrofitted to R-134a, what must be done with the original R-12 service fittings?

Accepted Answer

They must be converted to R-134a-specific fittings or permanently disabled

Answer

EPA SNAP rules require each substitute refrigerant to have its own unique service fittings. Old R-12 fittings must be replaced with R-134a fittings or permanently disabled so nobody can charge the wrong refrigerant into the system.

Question 2

Which of the following must appear on the label applied to a retrofitted MVAC system?

Accepted Answer

The new refrigerant, retrofit date, technician or shop name, and lubricant type

Answer

The retrofit label tells future technicians what is in the system: the refrigerant used, the amount charged, the lubricant type and amount, the date of the retrofit, and who did the work.

Question 3

Before retrofitting an R-12 system to R-134a, what must the technician do with the remaining R-12?

Accepted Answer

Recover it with approved equipment

Answer

Venting refrigerant is illegal under the Clean Air Act. Any R-12 left in the system must be recovered with EPA-approved equipment before the conversion starts.

Question 4

Why is the lubricant usually changed or flushed during an R-12 to R-134a retrofit?

Accepted Answer

Mineral oil used with R-12 does not mix well with R-134a, so PAG or POE oil is used

Answer

R-12 systems use mineral oil, which does not mix well with R-134a and returns poorly to the compressor. Retrofits normally switch to a compatible synthetic lubricant such as PAG or POE.

Question 5

Under EPA SNAP rules, is it acceptable to 'top off' a partly charged R-12 system with R-134a?

Accepted Answer

No, refrigerants must not be mixed, and a full retrofit is required to switch

Answer

Mixing refrigerants contaminates the system and the recovery equipment. Moving to a substitute refrigerant requires a full retrofit that meets SNAP conditions: unique fittings, a label, and recovery of the original refrigerant.

EPA 609 - EPA Section 609 Refrigerant Certification Practice Test

EPA 609 - EPA Section 609 Refrigerant Certification Practice Test

EPA 609 Retrofitting R-12 Systems to Alternative Refrigerants