Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the
question.
1)
1)
Infrared cameras are used to check:
A)
Thermal leakage.
B)
Percentage of CO2.
C)
CO parts per million.
D)
Air particle count.
Answer:
A
A)
B)
C)
D)
2)
2)
The two most common pollutant pathways are:
A)
From equipment surfaces and through infiltration.
B)
Through leaky return air ducts and building infiltration.
C)
Through ventilation ducts and building infiltration.
D)
Outside to inside and from one area inside to another area inside.
Answer:
D
A)
B)
C)
D)
3)
3)
The most effective method for maintaining acceptable indoor air quality is:
A)
Reduction and/or elimination of the pollutant sources.
B)
Increased ventilation.
C)
Banks of ultraviolet lights installed in the ductwork and over the coil.
D)
Better quality filtration.
Answer:
A
A)
B)
C)
D)
1
4)
4)
VOCs are:
A)
Vociferous organic cyclamates.
B)
Very odorant compounds.
C)
Volatile odorant compounds.
D)
Volatile organic compounds.
Answer:
D
A)
B)
C)
D)
5)
5)
Why is environmental tobacco smoke difficult to remove from the air?
A)
Tobacco smoke has an estimated 4,000 compounds in it.
B)
Most people cannot detect the presence of tobacco smoke in the air.
C)
The majority of office workers smoke, producing large quantities of pollutants to remove.
D)
It is hard to see.
Answer:
A
A)
B)
C)
D)
6)
6)
Carbon monoxide usually enters the living space:
A)
Through infiltration from the outside.
B)
Through excessive ventilation from the outside.
C)
From one area of the building to another.
D)
Through the respiration of the building occupants.
Answer:
C
A)
B)
C)
D)
7)
7)
What is one way a technician can make IAQ happen safely and effectively?
A)
Provide solutions to address a customer’s concerns.
B)
Get a job done as quickly as possible.
C)
Let customers know about your company’s procedures.
D)
Be proactive by performing troubleshooting on your own without guidance.
Answer:
A
A)
B)
C)
D)
2
8)
8)
What instrument is used primarily for measuring leakage in ductwork?
A)
A duct blaster
B)
A magnehelic gauge
C)
An inclined manometer
D)
Duct leakage cannot be directly measured.
Answer:
A
A)
B)
C)
D)
9)
9)
The two major categories of pollutants that must be controlled when addressing indoor air quality
are:
A)
Natural and man–made.
B)
Volatile and nonvolatile.
C)
Carcinogenic and pathogenic.
D)
Chemical and biological.
Answer:
D
A)
B)
C)
D)
10)
10)
To ensure critical steps are not missed in an IAQ test procedure, the technician should:
A)
Record all readings both electronically and on paper.
B)
Use an electronic IAQ meter with integral prompts.
C)
Take all readings twice.
D)
Use an IAQ checklist.
Answer:
D
A)
B)
C)
D)
11)
11)
What does amplification mean in indoor air quality terms?
A)
The combined effect of multiple forms of pollutants
B)
Noise pollution that is increased in volume because of metal ducts
C)
A contaminant’s ability to grow and spread
D)
The transmitting of mechanical unit sounds through short metal returns
Answer:
C
A)
B)
C)
D)
3
12)
12)
How is Indoor Air Quality (IAQ) defined?
A)
Air that is within the human comfort range and free of noxious substances
B)
Air that is free from toxins, irritants, and noxious chemicals
C)
The state of the air contained within an enclosed building
D)
Cleaning the air inside a building to acceptable levels
Answer:
C
A)
B)
C)
D)
13)
13)
How does increased ventilation sometimes help to improve indoor air quality?
A)
The contaminated indoor air is replaced with pollutant–free outside air.
B)
It reduces the contaminant level through dilution.
C)
The pollutants are purged using a pollutant purge timer, PPT.
D)
It improves the efficiency of the HEPA filters by increasing the velocity of air across the
filters.
Answer:
B
A)
B)
C)
D)
14)
14)
What is the odorant commonly used in natural gas?
A)
Mercaptan
B)
Propane
C)
Natural gas has its own odor and does not need an odorant added.
D)
Sulfur dioxide
Answer:
A
A)
B)
C)
D)
15)
15)
To correctly identify pollutant pathways, technicians must understand:
A)
The interaction of the building and its associated systems.
B)
How to use a particle counter.
C)
The biology of potential microbial pollutants.
D)
How to use a blower door.
Answer:
A
A)
B)
C)
D)
4
16)
16)
State the primary difference between a detector and a meter.
A)
They are two words for the same instruments.
B)
A detector simply detects the presence of a contaminant. A meter measures the amount of
the contaminant.
C)
Detectors are calibrated in standard units and meters are calibrated in metric units.
D)
A meter simply detects the presence of a contaminant. A detector measures the amount of
the contaminant.
Answer:
B
A)
B)
C)
D)
17)
17)
What instrument is used for measuring leakage rates in a building?
A)
A blower door
B)
A duct blaster
C)
Either a blower door or a duct blaster
D)
Leakage rates cannot be directly measured.
Answer:
A
A)
B)
C)
D)
18)
18)
What factors must be controlled to achieve acceptable indoor air quality?
A)
Air ventilation, filtration, and distribution
B)
Chemical pollutants, biological pollutants, and ventilation
C)
Building pressure, infiltration, and ventilation
D)
Temperature, humidity, velocity, and pollutant level
Answer:
D
A)
B)
C)
D)
5
19)
19)
The HVACR technician’s role in indoor air quality is to:
A)
Perform laboratory tests on collected material.
B)
Communicate with the building owner and the occupants on how the interacting systems of
a building affect indoor air quality.
C)
Perform microscopic analysis to determine the origin of pollutants.
D)
Install HEPA filters to alleviate all indoor air–quality concerns.
Answer:
B
A)
B)
C)
D)
20)
20)
Digital manometers can be used to check:
A)
Percentage of CO2.
B)
CO ppm.
C)
Air particle count.
D)
Vents for proper operation.
Answer:
D
A)
B)
C)
D)
21)
21)
What are the three most common ways to reduce pollutants in indoor air?
A)
HEPA filters, electronic air cleaners, and UV lights
B)
HEPA filters, UV lights, and ozone generators
C)
Source removal, ventilation, and filtration
D)
Creating a negative building pressure, filtration, and ventilation
Answer:
C
A)
B)
C)
D)
22)
22)
The route that a pollutant takes to enter a building or area is called:
A)
The point of origination.
B)
An entry route.
C)
A pathway.
D)
Point of genesis.
Answer:
C
A)
B)
C)
D)
6
23)
23)
Pollutants that require lab testing for positive identification include:
A)
Asbestos, radon, and mold.
B)
All types of pollutants require lab testing.
C)
Pollen, tobacco smoke, and fiberglass.
D)
Atmospheric dust, pollen, and asbestos.
Answer:
A
A)
B)
C)
D)
24)
24)
What is the difference between infiltration and ventilation?
A)
Ventilation is air that leaks in, while infiltration is drawn in on purpose.
B)
They are essentially two words for the same thing.
C)
Infiltration occurs in winter and ventilation in the summer.
D)
Infiltration is air that leaks, while ventilation is drawn in on purpose.
Answer:
D
A)
B)
C)
D)
25)
25)
Solar heat gain is considered when calculating:
A)
The heat gain on all the house surfaces.
B)
The heat gain of the windows.
C)
Both the heat gain and loss of the windows.
D)
The heat loss of the windows.
Answer:
B
A)
B)
C)
D)
26)
26)
Oversized equipment operates:
A)
At the same efficiency as correctly sized equipment.
B)
More efficiently than correctly sized equipment.
C)
About the same efficiency, but also has reserve capacity.
D)
Less efficiently than correctly sized equipment.
Answer:
D
A)
B)
C)
D)
7
27)
27)
What is sensible heat gain?
A)
Heat gain that causes the air temperature in the house to increase
B)
Heat gain that falls within the parameters of the Department of Energy’s “Good Sense”
program
C)
Heat gain that can be logically deduced by studying the manufacturer’s installation
instructions
D)
Heat gain that results from increased moisture in the air in the house
Answer:
A
A)
B)
C)
D)
28)
28)
The grains of moisture difference in the weather data tables are used for calculating:
A)
The latent heat gain.
B)
The latent heat loss.
C)
The cooling temperature difference.
D)
The sensible heat gain.
Answer:
A
A)
B)
C)
D)
29)
29)
What type of load study is recommended for duct design?
A)
A shell load study
B)
A room–by–room load study
C)
A monolithic load study
D)
A unified load study
Answer:
B
A)
B)
C)
D)
30)
30)
What is meant by the temperature daily range?
A)
The daily range is the difference between the average high and the average low
temperatures during the day.
B)
The daily range is the difference between the high temperatures for a particular location
over a cooling season.
C)
The daily range is the difference between the indoor and outdoor temperatures for a cooling
season.
D)
The daily range is the difference between the indoor and outdoor temperatures during the
day.
Answer:
A
A)
B)
C)
D)
8
31)
31)
A load study that calculates the load for each individual room as well as the entire house is called:
A)
A shell load calculation.
B)
A composite load calculation.
C)
A room–by–room load calculation.
D)
A unified load calculation.
Answer:
C
A)
B)
C)
D)
32)
32)
The grains of moisture difference in the weather data tables are used for calculating:
A)
The cooling temperature difference.
B)
The latent heat loss.
C)
The sensible heat gain.
D)
The latent heat gain.
Answer:
D
A)
B)
C)
D)
33)
33)
In selecting the outside cooling design conditions for Manual J8, a temperature is chosen for each
area that:
A)
Represents an average of the outdoor temperature during the cooling season.
B)
Is exceeded 1 percent of the year.
C)
Is based on the geographical latitude of the area.
D)
Is the highest recorded temperature for that area.
Answer:
B
A)
B)
C)
D)
34)
34)
How is the R value determined for a composite structure, such as a wall?
A)
The R values of all the individual components are added together and averaged.
B)
The R value of the component with the highest R value is used.
C)
The R values of all the individual components are added together.
D)
The R value of the component with the lowest R value is used.
Answer:
C
A)
B)
C)
D)
9
35)
35)
What is the HTM for a surface with a U valve of 1.5 and a temperature difference of 30?
A)
B)
C)
D)
Answer:
B
A)
B)
C)
D)
36)
36)
Compared to a system in an area with a low daily temperature range,a system in an area with a
high daily temperature range would require:
A)
A little less heating capacity.
B)
A little more cooling capacity.
C)
A little less cooling capacity.
D)
A little more heating capacity.
Answer:
C
A)
B)
C)
D)
37)
37)
In Manual J, fenestration means:
A)
Openings made in the building envelope for the purpose of providing ventilation.
B)
Anything that light can pass through.
C)
The material used to seal around openings.
D)
A barrier against infiltration.
Answer:
B
A)
B)
C)
D)
38)
38)
The two types of load calculations outlined in Manual J8 are:
A)
Residential load procedure and commercial load procedure.
B)
Peak load procedure and average load procedure.
C)
Square footage factor procedure and air change factor procedure.
D)
Daily load procedure and seasonal load procedure.
Answer:
B
A)
B)
C)
D)
10
39)
39)
A load study that treats the whole house as one big room is called:
A)
A multiroom load calculation.
B)
A shell load calculation.
C)
A unified load calculation.
D)
A monolithic load calculation.
Answer:
B
A)
B)
C)
D)
40)
40)
Infiltration calculations in Manual J8 are based on:
A)
Blower door measurements.
B)
Estimates of air changes in the house.
C)
Taking accurate measurements of airflow around windows and doors.
D)
Thermal imaging measurements.
Answer:
B
A)
B)
C)
D)
41)
41)
How is a U factor calculated for a building panel built of several different materials?
A)
Take the reciprocal of the lowest R value.
B)
Average the R values of the different materials and then find the reciprocal.
C)
Add the R values of the different materials and then find the reciprocal.
D)
Take the reciprocal of the highest R value.
Answer:
C
A)
B)
C)
D)
42)
42)
For purposes of Manual J8 tables, daily temperature ranges are normally listed as:
A)
An average temperature difference.
B)
Level A, B, or C.
C)
Category 1,2, or 3.
D)
Low, medium, and high.
Answer:
D
A)
B)
C)
D)
11
43)
43)
Why is the cooling temperature difference often different from the difference between the indoor
and outdoor temperatures?
A)
The cooling temperature difference takes latent heat gain into account.
B)
The cooling temperature difference takes heat storage and daily temperature range into
account.
C)
Air–conditioning equipment manufacturers use their own temperature scale established by
AHRI, which is different from either Fahrenheit or Celsius.
D)
ACCA weather data is more accurate than the National Weather Bureau.
Answer:
B
A)
B)
C)
D)
44)
44)
To improve humidity control for air–conditioning systems installed in humid climates, the
air–conditioning system selected should:
A)
Be sized somewhat larger than the load study indicates to allow for extra latent cooling.
B)
Have a high sensible cooling capacity and higher–than–normal airflow.
C)
Have a high latent cooling capacity and not be oversized.
D)
Be sized larger than normal, have a high sensible capacity, and higher–than–normal
airflow.
Answer:
C
A)
B)
C)
D)
45)
45)
What is latent heat gain?
A)
Heat gain that results from increased moisture in the air in the house
B)
Heat gain that is not anticipated by the building designer
C)
Heat gain that building designers hide through increased use of insulating materials
D)
Heat gain that causes the air temperature in the house to increase
Answer:
A
A)
B)
C)
D)
12
46)
46)
The largest loads in commercial heat gain calculations include heat gain from:
A)
Walls, ceilings, and floors.
B)
Windows, doors, and floors.
C)
Lights, people, machinery, and ventilation.
D)
Floors, walls, and partitions.
Answer:
C
A)
B)
C)
D)
47)
47)
The distance from the register that the air will travel before it slows down to the terminal velocity
listed in the engineering data is known as a register’s:
A)
Reach.
B)
Throw.
C)
Effective length.
D)
Z dimension.
Answer:
B
A)
B)
C)
D)
48)
48)
What adjusted friction rate should be used to size a duct for a design friction rate of 0.1 in WC if
the duct has a total equivalent length of 75 feet?
A)
0.1 in WC because the duct length is irrelevant
B)
0.10 × (75/100) = 0.10 × 0.75 = 0.075 in WC
C)
0.10 × (100/75)= 0.10 × 1.33 = 0.133 in WC
D)
The friction rate cannot be determined with the information given.
Answer:
C
A)
B)
C)
D)
49)
49)
Factors used in selecting supply air registers are:
A)
Boot size and register inventory.
B)
Required CFM, throw, face velocity, and static pressure drop.
C)
Round duct diameter and boot size.
D)
Round duct diameter, boot size, and room dimensions.
Answer:
B
A)
B)
C)
D)
13
50)
50)
What does the equivalent length of a duct fitting mean?
A)
It is a factor that allows comparison of two different–diameter ducts.
B)
It is the maximum length that any duct run may be.
C)
It is the length that air will travel after it leaves a supply register.
D)
It is the length of straight duct that would have a pressure drop equal to the pressure drop
through the fitting.
Answer:
D
A)
B)
C)
D)
51)
51)
How is the equivalent length of a duct determined?
A)
Add the trunk duct length to takeoff with the branch duct length and subtract the
equivalent lengths of all fittings used from blower to register.
B)
Add the trunk duct length to takeoff, the branch duct length, and equivalent lengths of all
fittings used from blower to register.
C)
Add the trunk duct length to takeoff and the branch duct length.
D)
Add the equivalent lengths of all fittings from blower to register.
Answer:
B
A)
B)
C)
D)
52)
52)
The air in a duct system should be distributed based upon:
A)
The number of air changes desired and the volume of each room.
B)
Delivering an equal volume of air to each room.
C)
The square footage of the rooms.
D)
The heat load of the rooms.
Answer:
D
A)
B)
C)
D)
53)
53)
What is the recommended face velocity for a return air filter grille?
A)
300400 ft per minute
B)
6001,000 ft per minute
C)
1,0001,500 ft per minute
D)
500600 ft per minute
Answer:
A
A)
B)
C)
D)
14
54)
54)
Why is minimizing duct restriction so important?
A)
Excessive restriction causes excessive noise.
B)
The system cannot operate properly against excessive air restriction.
C)
Incorrect terminal velocities can cause discomfort.
D)
Excessive restriction can increase operating cost.
Answer:
B
A)
B)
C)
D)
55)
55)
What is the total available static pressure for the ductwork in a system with the following specification
Blower: 0.6″ WC total external static at design airflow
Evaporator Coil: 0.25 in WC static pressure drop at design airflow
Filter: 0.15 in WC static pressure drop at design airflow
Registers and Grills: 0.05” WC static pressure drop at design airflow
A)
10 in WC available static pressure
B)
0.25 in WC available static pressure
C)
0.15 in WC available static pressure
D)
0.6 in WC available static pressure
Answer:
C
A)
B)
C)
D)
56)
56)
The noise criteria (NC) rating system used to rate the sound levels of registers and grilles is:
A)
The average decibel reading of five specific frequencies of sound.
B)
The decibel reading at a frequency of 1,500 Hz.
C)
Based on graphical analysis of standing pressure waves.
D)
A subjective scale ranking registers from 110.
Answer:
B
A)
B)
C)
D)
15
57)
57)
The three primary goals of duct design are:
A)
Provide air for heating, provide air for cooling, and filter the air.
B)
Provide a register for each room, ensure that occupants feel the air, and make the operation
of the unit obvious.
C)
Static pressure, velocity pressure, and total pressure.
D)
Allow the system to circulate enough air to operate properly, distribute air proportionately
with the heat load, and keep airflow noise to a minimum.
Answer:
D
A)
B)
C)
D)
58)
58)
What friction rate should be used to size a duct for a design friction rate of 0.12 in WC if the duct
has a total equivalent length of 150 ft?
A)
0.12 × (100/150) = 0.67 × 0.12 = 0.08 in WC
B)
0.1 in wc because that is the standard factor
C)
0.12 in WC because the duct length is irrelevant
D)
0.12 × (150/100) = 0.12 × 1.5 = 0.18 in WC
Answer:
A
A)
B)
C)
D)
59)
59)
Duct systems are designed to provide conditioned air that matches:
A)
A duct’s total equivalent length.
B)
The needs of the structure.
C)
The surrounding buildings.
D)
The previous duct design installed by the technician.
Answer:
B
A)
B)
C)
D)
60)
60)
The equivalent length of the runs in a residential house will often be how long?
A)
B)
C)
D)
Answer:
D
A)
B)
C)
D)
16
61)
61)
Why should air velocity in branch ducts be limited to 600 feet per minute?
A)
To encourage proper mixing of the air inside the duct
B)
To keep the blower speed down to a reasonable RP
C)
To allow the air to establish an insulating air boundary layer inside the duct
D)
To minimize air noise
Answer:
D
A)
B)
C)
D)
62)
62)
The formula for determining the static available for the duct system is:
A)
Available duct static = 0.15 to 0.2 in WC.
B)
Available duct static = total available static – total fixed static losses.
C)
Total available duct static = 0.1 in WC.
D)
Available duct static = total fixed static losses.
Answer:
B
A)
B)
C)
D)
63)
63)
To minimize air noise, the face velocity of the air leaving a supply register should be kept:
A)
Under 600 ft per minute.
B)
Over 600 ft per minute.
C)
Over 1,000 ft per minute.
D)
Under 1,000 ft per minute.
Answer:
A
A)
B)
C)
D)
64)
64)
What does the duct calculator tell a technician about static pressure and airflow?
A)
It shows the amount of CFM that each different size duct can carry.
B)
It shows the amount of static pressure loss per 100 feet of duct for a given duct size and
airflow.
C)
It shows how much air can travel through a particular duct size at a given static pressure.
D)
It shows the size duct needed for a particular BTU capacity.
Answer:
B
A)
B)
C)
D)
17
65)
65)
What is the purpose of the bypass damper used in many zone systems?
A)
To bypass low– and high–temperature limits on the equipment when only one zone is
calling
B)
To allow outdoor air to bypass the equipment during free cooling
C)
To recirculate air that is not being used by the active zones
D)
To allow outdoor air to bypass the equipment during zone ventilation mode
Answer:
C
A)
B)
C)
D)
66)
66)
A variable–air–volume system changes the amount of air the fan delivers in order to:
A)
Deliver the maximum air allowed by the fan.
B)
Keep the equipment operating at capacity.
C)
Bypass the supply air.
D)
Match the zone requirements.
Answer:
D
A)
B)
C)
D)
67)
67)
Why don’t variable–air–volume zone systems need any method of controlling excess air?
A)
All the dampers pass a little air, even when they are closed.
B)
The fans used are not capable of producing excess air.
C)
Any excess air is automatically diverted outside.
D)
They reduce the system airflow to match the number of zones calling.
Answer:
D
A)
B)
C)
D)
18
68)
68)
What is the purpose of a plenum thermostat?
A)
To control the plenum heat strips that prevent the supply air temperature from dropping
too low
B)
To cycle off the heating or cooling equipment if the air gets too hot or cold in the plenum
when only one or two zones are calling
C)
To control the zone dampers based on the plenum temperature
D)
To control the heating and cooling equipment to maintain the desired temperature in the
supply plenum at all times
Answer:
B
A)
B)
C)
D)
69)
69)
What is a dump zone in a zoned air system?
A)
The location where exhaust air exits the building
B)
An area used for dumping excess air and capacity when only one zone is calling
C)
The area where refrigerant is vented while reducing system capacity during low–load
operation
D)
The area immediately under a supply register
Answer:
B
A)
B)
C)
D)
70)
70)
How are motorized dampers controlled when they are used as bypass dampers?
A)
They are wired using the G terminal on the master thermostat.
B)
A pressurestat measures the static pressure across the blower.
C)
They are wired in parallel with the zone dampers.
D)
They are wired in series with the zone dampers.
Answer:
B
A)
B)
C)
D)
19
71)
71)
Why do communicating zone systems NOT use bypass dampers?
A)
They do not use any high– or low–temperature limits.
B)
They control airflow and system capacity based on the number of calling zones.
C)
They can operate in free cooling mode without a bypass damper.
D)
They do not have a zone ventilation mode.
Answer:
B
A)
B)
C)
D)
72)
72)
What is the purpose of the zone 1 (master) thermostat in the basic zone control system?
A)
The zone 1 thermostat determines the on and off cycling of the unit.
B)
The zone 1 thermostat controls the operation of all zone dampers.
C)
The zone 1 thermostat controls the master bedroom.
D)
The zone 1 thermostat determines the operational mode of the equipment.
Answer:
D
A)
B)
C)
D)
73)
73)
A duct system that allows control over different portions of the house using one unit and a single
duct system is called a:
A)
Zone system.
B)
Multistage system.
C)
Radial system.
D)
Cascade system.
Answer:
A
A)
B)
C)
D)
74)
74)
What is the disadvantage of air bypass?
A)
Excessive air noise in the zones that are calling
B)
Excessive air noise in the zones that are not calling
C)
Evaporators can freeze and furnaces can trip on high limit.
D)
It creates a negative pressure in the zone that is calling.
Answer:
C
A)
B)
C)
D)
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