CFESA Refrigeration Chapter 9
What problems can be caused by moisture in a refrigeration system? - answer
Blockages at the RCD from the moisture freezing. Corrosion of the metal
parts of the system, and the formation of acids, compressor burnouts.
How can moisture get into a refrigeration system? - answer From air in the system, poor
service practices, leaks in the system,
contaminated refrigerant or oils.
When water mixes with refrigerant what does the chemical reaction create? - answer
Acids
How do you keep water out of a refrigeration system? - answer Good service practices,
deep evacuation, and the use of filter driers
How susceptible is mineral oil to moisture? - answer Not very bad
How susceptible is POE oil to moisture? - answer Very susceptible
What precautions can you take when handling refrigeration oils to prevent
moisture problems? - answerPour out the amount of oil that you need in a separate
container and seal off
the original container very quickly.
What should you do if you intend to reuse the refrigerant that you removed
from the system? - answerRecover it into a clean evacuated recovery cylinder through a
drier, and
return it to the system through a filter drier
What is the function of a refrigeration drier? - answerTo remove moisture, and/or acids
from the system depending on the type of
drier
What materials are used to make driers? - answerActivated alumina, molecular sieve,
and silica gel.
What kind of driers must be used with HFC refrigerants? Why? - answerMolecular
sieve, silica gel, or one of these with no more than 25% activated
alumina.
What role does activated alumina play in driers? - answerActivated alumina removes
the lubrication properties of the oil.
What problems can be caused by moisture in a refrigeration system? - answer
Blockages at the RCD from the moisture freezing. Corrosion of the metal
parts of the system, and the formation of acids, compressor burnouts.
How can moisture get into a refrigeration system? - answer From air in the system, poor
service practices, leaks in the system,
contaminated refrigerant or oils.
When water mixes with refrigerant what does the chemical reaction create? - answer
Acids
How do you keep water out of a refrigeration system? - answer Good service practices,
deep evacuation, and the use of filter driers
How susceptible is mineral oil to moisture? - answer Not very bad
How susceptible is POE oil to moisture? - answer Very susceptible
What precautions can you take when handling refrigeration oils to prevent
moisture problems? - answerPour out the amount of oil that you need in a separate
container and seal off
the original container very quickly.
What should you do if you intend to reuse the refrigerant that you removed
from the system? - answerRecover it into a clean evacuated recovery cylinder through a
drier, and
return it to the system through a filter drier
What is the function of a refrigeration drier? - answerTo remove moisture, and/or acids
from the system depending on the type of
drier
What materials are used to make driers? - answerActivated alumina, molecular sieve,
and silica gel.
What kind of driers must be used with HFC refrigerants? Why? - answerMolecular
sieve, silica gel, or one of these with no more than 25% activated
alumina.
What role does activated alumina play in driers? - answerActivated alumina removes
the lubrication properties of the oil.
