313D Fundamentals of Air Conditioning Systems 3

Question 1

What is the function of a filter-drier in a refrigerant circuit?

Accepted Answer

Remove moisture and contaminants from the refrigerant

Answer

The filter-drier contains desiccant material that absorbs moisture and captures particulates to protect system components.

Question 2

Which pressure in an air conditioning system is referred to as the 'high side'?

Accepted Answer

Pressure between the compressor discharge and the metering device inlet

Answer

The high side spans from compressor discharge through the condenser and liquid line to the inlet of the metering device.

Question 3

What happens to the boiling point of a refrigerant when pressure increases?

Accepted Answer

The boiling point increases

Answer

Higher pressure raises the saturation (boiling) temperature of a refrigerant, which is why condenser pressures are higher than evaporator pressures.

Question 4

A technician measures a suction pressure equivalent to 40°F saturation temperature. The suction line temperature is 50°F. What is the superheat?

Accepted Answer

10°F

Answer

Superheat equals the actual suction line temperature (50°F) minus the saturation temperature at suction pressure (40°F), which is 10°F.

Question 5

Which refrigerant is classified as an HFC and is commonly used in residential air conditioning systems manufactured after 2010?

Accepted Answer

R-410A

Answer

R-410A is an HFC refrigerant that replaced R-22 in residential AC systems due to its zero ozone depletion potential.

(313D) Residential Air Conditioning Systems Mechanic Certification Practice Test