QUESTIONS & ANSWERS || 2025 UPDATE.
1. Conduction is defined as heat energy that is: moving through a solid sub-
stance
2. What is the primary purpose of a refrigeration system ?: achieve and maintain
a temperature
3. What is a hazard of trapping liquid ?: A possible release
4. How much can the pressure of trapped liquid increase per degree Fahren-
heit of temperature increase: 100 to 150 psi
5. Mechanical refrigeration is a series of steps that: moves heat energy from a
space or object to an area where it can do no harm
6. How does the refrigeration compressor maintain the temperature in the
system evaporators ?: Drawing out vaporized refrigerant at a rate to maintain the
desired evaporating pressure
7. Which natural refrigerant is considered to be non- flammable: Carbon Diox-
ide
8. Heat energy always flows: from an object at a higher temperature to an object
at a lower temperature
9. 32 psia equals: 17.3 psig
10. 0 ° F is equal to: -18 ° C
11. Why does the refrigerant in the condenser change state from vapor to
liquid: The refrigerant loses heat energy to the surrounding environment
12. If a liquid is below its saturation temperature what is its condition ?: Sub-
cooled
13. What are the four necessary components of a mechanical refrigeration
system ?: expansion device , evaporator , compressor , condenser
14. Superheat is found at which points of a typical system ?: The compressor
suction and compressor discharge line
15. What are the replacement blended refrigerants called ?: An azeotrope or
zeotrope
16. What is one positive characteristic of halocarbon refrigerants ?: They are
usually not flammable
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, 17. What is the primary reason for concern about HCFC- 22 concentration in
an engine room ?: Oxygen deprivation
18. O psig is equal to: 14.7 psia
19. Discharge vapor from all compressors: will contain some level of superheat
20. Which category of compressor " traps " a volume of refrigerant vapor prior
to compression ?: Positive displacement
21. When suction pressure rises , the operator should: start another compressor
22. The crankcase oil heater should be ON: when the compressor is off .
23. Slugging is caused by: oil or liquid refrigerant
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