Automotive Air Conditioning Service Flashcards

Which EPA section requires technicians who service motor vehicle air conditioners to be certified?

Answer: Section 609

EPA Section 609 specifically regulates the servicing of motor vehicle air conditioners and requires technician certification.

When recovering refrigerant from a vehicle with a small refrigerant charge (less than 200 grams), what is the minimum required recovery efficiency?

Answer: 90%

For systems with less than 200 grams of refrigerant, recovery equipment must achieve at least 90% efficiency.

A vehicle A/C system low-side gauge reads 10 psi and the high-side reads 100 psi with R-134a. What does this most likely indicate?

Answer: Low refrigerant charge or compressor failure

Both abnormally low pressures on high and low sides indicate either a low refrigerant charge or a non-functioning compressor.

What type of oil is used in automotive A/C systems that contain R-1234yf refrigerant?

Answer: PAG oil

PAG (polyalkylene glycol) oil is the correct lubricant for R-1234yf automotive A/C systems.

Before opening an automotive A/C system for repairs, the technician must:

Answer: Recover all refrigerant using certified equipment

Federal law requires complete refrigerant recovery using EPA-approved equipment before opening any A/C system.

The Global Warming Potential (GWP) of R-1234yf compared to R-134a is approximately:

Answer: Much lower — about 4

R-1234yf has a GWP of approximately 4, far lower than R-134a's GWP of 1,430, making it more environmentally friendly.

Which component in an automotive A/C system removes moisture from the refrigerant circuit?

Answer: Accumulator or receiver-drier

The accumulator (used with orifice tube systems) or receiver-drier (used with expansion valve systems) contains desiccant to absorb moisture.