Reta book 2 questions and answers
graded A+ latest update
Density - correct answer ✔✔ Which of the following factors listed does NOT affect heat
transfer?
Wood - correct answer ✔✔ Which of the following is an example of a poor conductor of heat?
The number of BTUs that will pass in one hour through a material 1" thick with the area of 1ft
sq if the temperature difference from one side to the other is 1f - correct answer ✔✔ What is
thermal conductivity (k)?
Warm dry air - correct answer ✔✔ Which is NOT a common source of fouling of a heat
exchange surface?
The higher the k-factor, the greater the thermal conductivity - correct answer ✔✔ Which
statement is true
There is no impeding substance such as ice, dirt, or oil on the surfaces of the heat exchanger
tubes. - correct answer ✔✔ Optimum U-factor for the given material that the heat exchanger is
made of results when?
It is reduced - correct answer ✔✔ What happens to the cooling capacity when airflow is
decreased across heat exchange surfaces?
Centrifugal fans are quieter - correct answer ✔✔ What is the advantage centrifugal fans have
over propeller fans?
,Cannot change the k-factor of the metal but has some control of the overall U-factor for the
evaporator as a unit. - correct answer ✔✔ The operating engineer
Evaporator size - correct answer ✔✔ What is a limiting factor of evaporator capacity that the
operator cannot control?
Periodically remove oil from the oil collection points - correct answer ✔✔ What is the best way
to keep an evaporator from being affected by oil build-up?
Cleanliness of the evaporator - correct answer ✔✔ The effectiveness of a heat transfer surface
depends on several factors. One factor the operator has control over is?
They require less motor horsepower per CFM - correct answer ✔✔ One advantage of using axial
type fans is?
Increased U-factor - correct answer ✔✔ Which of the following is NOT a result of scale build-up
on a condenser coil?
The rate of heat that is transferred will be cut in half - correct answer ✔✔ If R-value is doubled,
what will happen to the heat transfer rate, assuming the temperature difference and the area
do not change?
The capacity of the evaporator is increased by 50% - correct answer ✔✔ What happens to the
theoretical capacity of an evaporator in a 0*f freezer if the ammonia evaporating temperature is
dropped from -10*f to -15*f
Cause efficiency loss and potential damage to the suction line - correct answer ✔✔ Damaged
insulation on the suction line in an ammonia refrigeration system will?
, The temperature at which moisture will condense out of the air - correct answer ✔✔ The dew
point is?
An indication of the sensible heat content of the air - correct answer ✔✔ The dry bulb
temperature is?
An increase in the infiltration load on a refrigeration system - correct answer ✔✔ A high relative
humidity will cause?
Requires more evaporative condenser capacity if it is relatively high - correct answer ✔✔ Wet
bulb temperature?
Is heavier than warm air - correct answer ✔✔ Cold air?
Air that has zero moisture content - correct answer ✔✔ Dry air?
The air has less ability to absorb moisture - correct answer ✔✔ Higher wet bulb temperatures
reduce evaporative condenser capacity because?
The total heat content of the dry air and the moisture in the air - correct answer ✔✔ On a
psychrometric chart, enthalpy is used to describe?
Absolute water content stays fixed even if the temperature of the air changes - correct answer
✔✔ The difference between absolute water content in air and relative humidity is?
The dry bulb, wet bulb, and dew point temperatures are the same - correct answer ✔✔ At
100% relative humidity?
graded A+ latest update
Density - correct answer ✔✔ Which of the following factors listed does NOT affect heat
transfer?
Wood - correct answer ✔✔ Which of the following is an example of a poor conductor of heat?
The number of BTUs that will pass in one hour through a material 1" thick with the area of 1ft
sq if the temperature difference from one side to the other is 1f - correct answer ✔✔ What is
thermal conductivity (k)?
Warm dry air - correct answer ✔✔ Which is NOT a common source of fouling of a heat
exchange surface?
The higher the k-factor, the greater the thermal conductivity - correct answer ✔✔ Which
statement is true
There is no impeding substance such as ice, dirt, or oil on the surfaces of the heat exchanger
tubes. - correct answer ✔✔ Optimum U-factor for the given material that the heat exchanger is
made of results when?
It is reduced - correct answer ✔✔ What happens to the cooling capacity when airflow is
decreased across heat exchange surfaces?
Centrifugal fans are quieter - correct answer ✔✔ What is the advantage centrifugal fans have
over propeller fans?
,Cannot change the k-factor of the metal but has some control of the overall U-factor for the
evaporator as a unit. - correct answer ✔✔ The operating engineer
Evaporator size - correct answer ✔✔ What is a limiting factor of evaporator capacity that the
operator cannot control?
Periodically remove oil from the oil collection points - correct answer ✔✔ What is the best way
to keep an evaporator from being affected by oil build-up?
Cleanliness of the evaporator - correct answer ✔✔ The effectiveness of a heat transfer surface
depends on several factors. One factor the operator has control over is?
They require less motor horsepower per CFM - correct answer ✔✔ One advantage of using axial
type fans is?
Increased U-factor - correct answer ✔✔ Which of the following is NOT a result of scale build-up
on a condenser coil?
The rate of heat that is transferred will be cut in half - correct answer ✔✔ If R-value is doubled,
what will happen to the heat transfer rate, assuming the temperature difference and the area
do not change?
The capacity of the evaporator is increased by 50% - correct answer ✔✔ What happens to the
theoretical capacity of an evaporator in a 0*f freezer if the ammonia evaporating temperature is
dropped from -10*f to -15*f
Cause efficiency loss and potential damage to the suction line - correct answer ✔✔ Damaged
insulation on the suction line in an ammonia refrigeration system will?
, The temperature at which moisture will condense out of the air - correct answer ✔✔ The dew
point is?
An indication of the sensible heat content of the air - correct answer ✔✔ The dry bulb
temperature is?
An increase in the infiltration load on a refrigeration system - correct answer ✔✔ A high relative
humidity will cause?
Requires more evaporative condenser capacity if it is relatively high - correct answer ✔✔ Wet
bulb temperature?
Is heavier than warm air - correct answer ✔✔ Cold air?
Air that has zero moisture content - correct answer ✔✔ Dry air?
The air has less ability to absorb moisture - correct answer ✔✔ Higher wet bulb temperatures
reduce evaporative condenser capacity because?
The total heat content of the dry air and the moisture in the air - correct answer ✔✔ On a
psychrometric chart, enthalpy is used to describe?
Absolute water content stays fixed even if the temperature of the air changes - correct answer
✔✔ The difference between absolute water content in air and relative humidity is?
The dry bulb, wet bulb, and dew point temperatures are the same - correct answer ✔✔ At
100% relative humidity?
