310S Heating, Ventilation and Air Conditioning (HVAC)

Question 1

What refrigerant replaced R-12 (Freon) in automotive A/C systems to reduce ozone depletion?

Accepted Answer

R-134a

Answer

R-134a replaced R-12 due to its significantly lower ozone depletion potential, becoming mandatory in North American vehicles after 1995.

Question 2

What is the primary function of the receiver-drier in an automotive A/C system?

Accepted Answer

To remove moisture and filter contaminants from the refrigerant

Answer

The receiver-drier stores liquid refrigerant, removes moisture using a desiccant, and filters contaminants from the high-pressure liquid line.

Question 3

In an A/C system using a fixed orifice tube, which component stores refrigerant and separates liquid from vapour on the low side?

Accepted Answer

Accumulator

Answer

The accumulator is located on the low-pressure side between the evaporator and compressor, storing excess refrigerant and preventing liquid slugging at the compressor.

Question 4

In what physical state does refrigerant enter the evaporator during normal A/C system operation?

Accepted Answer

Low-pressure liquid/vapour mixture

Answer

After passing through the expansion device, refrigerant enters the evaporator as a low-pressure liquid/vapour mixture, absorbing heat from cabin air as it evaporates.

Question 5

What is the primary function of the condenser in an automotive A/C system?

Accepted Answer

To release heat from the refrigerant to the outside air

Answer

The condenser removes heat from high-pressure refrigerant vapour, causing it to condense into a liquid as outside air flows through its fins.

Red Seal Auto Tech 310S Practice Test

Red Seal Auto Tech 310S Practice Test

310S Heating, Ventilation and Air Conditioning (HVAC)