Fundamentals of Air Conditioning Systems Flashcards

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

Answer: Remove moisture and contaminants from the refrigerant

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

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

Answer: Pressure between the compressor discharge and the metering device inlet

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

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

Answer: The boiling point increases

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

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

Answer: 10°F

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

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

Answer: R-410A

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

What is the purpose of the reversing valve in a heat pump system?

Answer: To reverse refrigerant flow direction, switching between heating and cooling modes

The reversing valve redirects refrigerant flow so the outdoor coil becomes the evaporator in cooling mode and the condenser in heating mode, or vice versa.

What does SEER stand for and what does it measure?

Answer: Seasonal Energy Efficiency Ratio — cooling output per unit of electrical energy input over a season

SEER measures the total cooling output in BTUs divided by the total electrical energy consumed in watt-hours over a typical cooling season.