Donald's Commercial
Refrigeration-chapter 2 Questions
and Answers 100% Correct
What is considered the "evaporator temperature?" - ANSWER - The temperature of
the refrigerant inside the evaporator tubing.
How do you calculate evaporator temperature from the suction pressure? - ANSWER
- Use a P/T chart.
How is evaporator TD calculated for a walk-in cooler? - ANSWER - Subtract the SST
from the box temperature.
What is "hot pull-down"? - ANSWER - When the evaporator is subject to higher
temperatures and loads than under normal operating conditions.
During hot pull-down what is the evaporator experiencing? - ANSWER - Starving
because the refrigerant is boiling off quickly.
What is the approximate humidity in a walk-in refrigerator with a 10 degree F TD
evaporator? - ANSWER - 85 percent.
As TD increases, how does it affect box humidity? - ANSWER - Decreases humidity.
If airflow across an evaporator is decreased, what effect does it have on evaporator
temperatures and suction pressure? - ANSWER - Evaporator temperature and
suction pressure both decrease.
Why are multiple circuits used on larger evaporator coils? - ANSWER - They provide
less pressure drop than a long single circuit evaporator.
Refrigeration-chapter 2 Questions
and Answers 100% Correct
What is considered the "evaporator temperature?" - ANSWER - The temperature of
the refrigerant inside the evaporator tubing.
How do you calculate evaporator temperature from the suction pressure? - ANSWER
- Use a P/T chart.
How is evaporator TD calculated for a walk-in cooler? - ANSWER - Subtract the SST
from the box temperature.
What is "hot pull-down"? - ANSWER - When the evaporator is subject to higher
temperatures and loads than under normal operating conditions.
During hot pull-down what is the evaporator experiencing? - ANSWER - Starving
because the refrigerant is boiling off quickly.
What is the approximate humidity in a walk-in refrigerator with a 10 degree F TD
evaporator? - ANSWER - 85 percent.
As TD increases, how does it affect box humidity? - ANSWER - Decreases humidity.
If airflow across an evaporator is decreased, what effect does it have on evaporator
temperatures and suction pressure? - ANSWER - Evaporator temperature and
suction pressure both decrease.
Why are multiple circuits used on larger evaporator coils? - ANSWER - They provide
less pressure drop than a long single circuit evaporator.
