HVAC Refrigeration Fundamentals 2 — Questions and Answers
Question 1: What is the function of the condenser in a refrigeration system?
- Absorb heat from the refrigerant and reject it to the outside air (Correct answer)
- Absorb heat from the indoor air into the refrigerant
- Compress the refrigerant vapor
- Expand the refrigerant to lower its pressure
Correct answer: Absorb heat from the refrigerant and reject it to the outside air
The condenser removes heat from the high-pressure refrigerant vapor and rejects it to the outdoor environment, causing the refrigerant to condense into liquid.
Question 2: What does a filter-drier do in a refrigeration system?
- Filters air entering the return duct
- Removes moisture and contaminants from the refrigerant (Correct answer)
- Dries the condenser coil after rain
- Filters compressor oil
Correct answer: Removes moisture and contaminants from the refrigerant
A filter-drier removes moisture, acids, and debris from the refrigerant to protect system components from corrosion and blockage.
Question 3: Which refrigerant is classified as an A2L (mildly flammable) refrigerant?
- R-22
- R-410A
- R-32 (Correct answer)
- R-134a
Correct answer: R-32
R-32 is classified as an A2L refrigerant, meaning it has low toxicity but is mildly flammable, requiring special handling precautions.
Question 4: What tool is used to measure both high-side and low-side pressures in a refrigeration system?
- Manometer
- Anemometer
- Manifold gauge set (Correct answer)
- Psychrometer
Correct answer: Manifold gauge set
A manifold gauge set connects to the high-side and low-side service ports to simultaneously read system pressures.
Question 5: What is the purpose of a sight glass in a refrigeration system?
- To see inside the air handler
- To observe refrigerant flow and detect moisture or bubbles in the liquid line (Correct answer)
- To measure airflow through the evaporator
- To check oil level in the compressor
Correct answer: To observe refrigerant flow and detect moisture or bubbles in the liquid line
A sight glass allows technicians to observe the refrigerant stream in the liquid line and detect bubbles (indicating low charge) or moisture (via color indicator).
Question 6: In a standard vapor-compression cycle, what state is the refrigerant as it enters the evaporator?
- High-pressure superheated vapor
- High-pressure subcooled liquid
- Low-pressure liquid/vapor mixture (Correct answer)
- Low-pressure superheated vapor
Correct answer: Low-pressure liquid/vapor mixture
After passing through the metering device, the refrigerant enters the evaporator as a low-pressure mixture of liquid and vapor.
HVAC Refrigeration Fundamentals 2
What is the function of the condenser in a refrigeration system?