#1
Which of the following is a common refrigerant used in HVAC systems?
R-134a
ExplanationR-134a is commonly used due to its low toxicity and non-flammability.
#2
What does HVAC stand for?
Heat, Ventilation, and Air Conditioning
ExplanationHVAC stands for systems that control air quality and temperature in buildings.
#3
What is the purpose of a condenser in a refrigeration system?
To cool the refrigerant and condense it from a vapor to a liquid
ExplanationThe condenser converts refrigerant vapor into liquid by removing heat.
#4
Which of the following is NOT a safety precaution when working with refrigeration systems?
Using a cell phone while handling refrigerants
ExplanationUsing a cell phone poses risk of ignition in presence of flammable refrigerants.
#5
What is the purpose of an evaporator in a refrigeration system?
To absorb heat from the surrounding environment
ExplanationEvaporator absorbs heat, turning liquid refrigerant into vapor.
#6
Which of the following statements about HVAC system filters is true?
Dirty filters can decrease airflow and reduce efficiency
ExplanationDirty filters obstruct airflow, reducing system efficiency.
#7
What is the purpose of the expansion valve in a refrigeration system?
To regulate the flow of refrigerant into the evaporator
ExplanationExpansion valve controls refrigerant flow, ensuring optimal cooling.
#8
What is superheat in a refrigeration system?
The temperature increase of the refrigerant vapor above its boiling point at a particular pressure
ExplanationSuperheat ensures all refrigerant is vapor before entering the compressor.
#9
What is the purpose of refrigerant recovery during HVAC maintenance?
To collect and reuse refrigerant
ExplanationRecovering refrigerant prevents environmental harm and saves costs.
#10
What does the term 'ton' refer to in HVAC systems?
A unit of cooling capacity equal to 12,000 BTUs per hour
ExplanationA 'ton' is a measure of cooling capacity, equivalent to 12,000 BTUs per hour.
#11
Which of the following refrigerants has the lowest global warming potential (GWP)?
R-32
ExplanationR-32 has a lower GWP compared to other commonly used refrigerants.
#12
Why is it important to maintain proper refrigerant levels in an HVAC system?
To ensure optimal system efficiency and performance
ExplanationCorrect refrigerant levels optimize HVAC system performance.