MECH FINAL EXAM QUESTIONS & ANSWERS
A substance contains the most heat when it is in the - Answers :gaseous state
Sensible heat is: - Answers :Heat added that results in a temperature rise that can be
sensed with a thermometer
Latent heat is: - Answers :Heat input that can be both: result in a change of state and
cannot be sensed
Air temperature, humidity, and air movement directly affect: - Answers :body comfort
Human perspiration takes advantage of the ___________ of water for a cooling effect. -
Answers :latent heat of vaporization
Intensity can be measured with a temperature scale such as Fahrenheit. Which of the
following has the highest level of intensity? - Answers :match burning - flame
temperature is 2000 degrees Farenheit
What is a ton of refrigeration? - Answers :the refrigeration effect equal to the melting of
one ton of ice in 24 hours
The direction of heat flow is: - Answers :from a warm to a cold surface
How much sensible heat needs to be removed with an air conditioning system to drop
the temperature of 60,000 cubic feet per hour of air from 70 degrees Fahrenheit to 50
degrees Fahrenheit. - Answers :21,600 Btu/hr
A convenience store has a tub with 41.66 pounds of ice in it. If all of this ice melts in one
hour, how many tons of refrigeration have been done? - Answers :0.5 tons
The schedule in the attached figure shows 14 fins per foot for the water chilled water
coil. Which of the following statements is correct? - Answers :It should be 14 fins per
inch
Condensation occurs when the temperature of a surface is below the ________ of the
surrounding air. - Answers :Dew point
How much pressure in psi does a storage tank at a height of 200 feet create at ground
level? - Answers :86.6
What kind of phase change occurs to the refrigerant in an evaporator? - Answers :latent
heat of vaporization
As air passes through a sensible heating coil, what happens to the DB temperature? -
Answers :Goes Up
, As air passes through a sensible heating coil, what happens to the relative humidity -
Answers :Goes down
As air passes through a sensible heating coil, what happens to the humidity ratio? -
Answers :Stays the same
As air passes through a sensible heating coil, what happens to the enthalpy? - Answers
:Goes up
As air passes through a sensible heating coil, what happens to the specific volume? -
Answers :Goes up
As air passes through a sensible heating coil, what happens to the Wet Bulb
temperature? - Answers :Goes up
Which one of the following conditions has the lowest moisture content? - Answers :30 F
DB, 80% RH
1.1 How does "sustainable" design differ from energy effective design? - Answers
:Energy is only one aspect of sustainable design. In addition, sustainability involves
comfort, environmental impact, maintainability, appropriateness for intended use and
many other factors.
1.2 What is the relationship between building codes and sustainable design? - Answers
:Sustainable design inherently produces buildings which exceed minimum requirements
of codes and standards.
1.3 How does saving energy help to protect the environment? - Answers :Using less
energy reduces air pollution from burning fossil fuels.
1.4 What is ASHRAE Standard 55 called? - Answers :Thermal Environmental Comfort
Conditions for Human Occupancy, comfort involves factors including temperature, air
velocity and humidity.
2.1 State the factors that affect environmental comfort and their general ranges of
values, where applicable. - Answers :Temperature and humidity - low limit values for
comfort are 68F, 3O% RH; high limit values for comfort are 79F, 55% RH. Air motion
should be between lO feet per minute and 5O feet per minute. Radiant effects from cold
and warm surfaces can also affect comfort.
2.2 Briefly describe the difference between sensible and latent heat. - Answers
:Sensible heat produces temperature change. Latent heat affects the amount of water
vapor in the air.
A substance contains the most heat when it is in the - Answers :gaseous state
Sensible heat is: - Answers :Heat added that results in a temperature rise that can be
sensed with a thermometer
Latent heat is: - Answers :Heat input that can be both: result in a change of state and
cannot be sensed
Air temperature, humidity, and air movement directly affect: - Answers :body comfort
Human perspiration takes advantage of the ___________ of water for a cooling effect. -
Answers :latent heat of vaporization
Intensity can be measured with a temperature scale such as Fahrenheit. Which of the
following has the highest level of intensity? - Answers :match burning - flame
temperature is 2000 degrees Farenheit
What is a ton of refrigeration? - Answers :the refrigeration effect equal to the melting of
one ton of ice in 24 hours
The direction of heat flow is: - Answers :from a warm to a cold surface
How much sensible heat needs to be removed with an air conditioning system to drop
the temperature of 60,000 cubic feet per hour of air from 70 degrees Fahrenheit to 50
degrees Fahrenheit. - Answers :21,600 Btu/hr
A convenience store has a tub with 41.66 pounds of ice in it. If all of this ice melts in one
hour, how many tons of refrigeration have been done? - Answers :0.5 tons
The schedule in the attached figure shows 14 fins per foot for the water chilled water
coil. Which of the following statements is correct? - Answers :It should be 14 fins per
inch
Condensation occurs when the temperature of a surface is below the ________ of the
surrounding air. - Answers :Dew point
How much pressure in psi does a storage tank at a height of 200 feet create at ground
level? - Answers :86.6
What kind of phase change occurs to the refrigerant in an evaporator? - Answers :latent
heat of vaporization
As air passes through a sensible heating coil, what happens to the DB temperature? -
Answers :Goes Up
, As air passes through a sensible heating coil, what happens to the relative humidity -
Answers :Goes down
As air passes through a sensible heating coil, what happens to the humidity ratio? -
Answers :Stays the same
As air passes through a sensible heating coil, what happens to the enthalpy? - Answers
:Goes up
As air passes through a sensible heating coil, what happens to the specific volume? -
Answers :Goes up
As air passes through a sensible heating coil, what happens to the Wet Bulb
temperature? - Answers :Goes up
Which one of the following conditions has the lowest moisture content? - Answers :30 F
DB, 80% RH
1.1 How does "sustainable" design differ from energy effective design? - Answers
:Energy is only one aspect of sustainable design. In addition, sustainability involves
comfort, environmental impact, maintainability, appropriateness for intended use and
many other factors.
1.2 What is the relationship between building codes and sustainable design? - Answers
:Sustainable design inherently produces buildings which exceed minimum requirements
of codes and standards.
1.3 How does saving energy help to protect the environment? - Answers :Using less
energy reduces air pollution from burning fossil fuels.
1.4 What is ASHRAE Standard 55 called? - Answers :Thermal Environmental Comfort
Conditions for Human Occupancy, comfort involves factors including temperature, air
velocity and humidity.
2.1 State the factors that affect environmental comfort and their general ranges of
values, where applicable. - Answers :Temperature and humidity - low limit values for
comfort are 68F, 3O% RH; high limit values for comfort are 79F, 55% RH. Air motion
should be between lO feet per minute and 5O feet per minute. Radiant effects from cold
and warm surfaces can also affect comfort.
2.2 Briefly describe the difference between sensible and latent heat. - Answers
:Sensible heat produces temperature change. Latent heat affects the amount of water
vapor in the air.
