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78)
78)
What is the purpose of the hot reactivation air stream in a desiccant wheel dehumidifier?
A)
To evaporate the water running over the wheel
B)
To dry out the saturated desiccant
C)
To heat the evaporator
D)
To cool the condenser
Answer:
B
Explanation:
A)
B)
C)
D)
79)
79)
What is the purpose of a reheat coil when dehumidifying?
A)
To prevent the air from freezing.
B)
To decrease the relative humidity by increasing the air temperature.
C)
To dry the moisture out of the air.
D)
To regenerate the evaporator coil.
Answer:
B
Explanation:
A)
B)
C)
D)
80)
80)
The air leaving an air conditioner typically has:
A)
A low relative humidity with more water in the air.
B)
A low relative humidity with less water in the air.
C)
A high relative humidity with more water in the air.
D)
A high relative humidity with less water in the air.
Answer:
D
Explanation:
A)
B)
C)
D)
81)
81)
Why is it advantageous to maintain a positive pressure in a building?
A)
To reduce exfiltration
B)
To simplify system fan and duct design
C)
To reduce drafts
D)
To minimize system ventilation heat load
Answer:
C
Explanation:
A)
B)
C)
D)
21
82)
82)
Areas of the country where dehumidification is vitally important to summer comfort include:
A)
Southwestern desert areas.
B)
Southeastern United States.
C)
Any location that is unusually dry in the summer.
D)
Areas where evaporative air conditioning is popular.
Answer:
B
Explanation:
A)
B)
C)
D)
83)
83)
Select the characteristics of a small console dehumidifier. You may choose more than one.
A)
Connects to duct system
B)
Does not require a drain
C)
Must sit in the room being conditioned
D)
Can provide high-efficiency air filtration
E)
Can provide outside ventilation
Answer:
B, C
Explanation:
A)
B)
C)
D)
E)
84)
84)
A refrigeration cycle dehumidifier is similar to:
A)
A commercial freezer with an automatic defrost cycle.
B)
An evaporative air conditioner.
C)
A gas-fired furnace with an integrated compressor.
D)
A window unit with a single airflow over both the evaporator and condenser.
Answer:
D
Explanation:
A)
B)
C)
D)
22
85)
85)
To improve an air conditioner's dehumidification capacity:
A)
Oversize the unit, increase airflow, and shorten runtimes.
B)
Lengthen run times and slow evaporator air flow.
C)
Oversize the unit for the square footage.
D)
Shorten run times and increase airflow.
Answer:
B
Explanation:
A)
B)
C)
D)
86)
86)
Air leaking into a building is called:
A)
Infiltration.
B)
Exfiltration.
C)
Ventilation.
D)
Exhaust.
Answer:
A
Explanation:
A)
B)
C)
D)
87)
87)
A whole-house dehumidifier:
A)
Requires that a plastic bucket be emptied twice a day.
B)
Can connect to ductwork to dehumidify the air in the entire house.
C)
Is installed in an existing air handler, replacing the evaporator coil.
D)
Normally conditions one room at a time.
Answer:
B
Explanation:
A)
B)
C)
D)
88)
88)
Humidity in the air represents heat that makes humans uncomfortable in hot weather. What
causes this heat factor present in humidity?
A)
Sunlight
B)
Lack of proper airflow
C)
Latent heat in the water vapor
D)
Hot air coming down from the attic
Answer:
C
Explanation:
A)
B)
C)
D)
23
89)
89)
Air leaking out of a building is called:
A)
Infiltration.
B)
Exfiltration.
C)
Ventilation.
D)
Exhaust.
Answer:
B
Explanation:
A)
B)
C)
D)
90)
90)
Window unit air conditioners are designed primarily to supply cool air to:
A)
One room.
B)
Unconditioned attic space.
C)
Unconditioned basements.
D)
Several rooms in a small house.
Answer:
A
Explanation:
A)
B)
C)
D)
91)
91)
A typical residential split-system air conditioner has the evaporator located indoors and the
condenser and compressor located:
A)
Outdoors.
B)
Next to the evaporator in the attic.
C)
In the mechanical room.
D)
In the basement.
Answer:
A
Explanation:
A)
B)
C)
D)
92)
92)
Why were split systems developed?
A)
Splitting the refrigerant flow between two systems reduces line size.
B)
It is not always practical to have all the components of a large air-cooled system located in a
single box.
C)
Splitting the controls into two panels provides redundancy.
D)
Splitting the airflow between two pieces allows for more airflow.
Answer:
B
Explanation:
A)
B)
C)
D)
24
93)
93)
The system used to measure the efficiency of room air conditioners is:
A)
EER - energy efficiency ratio.
B)
CSPF - cooling seasonal performance factor.
C)
AFUE - annual fuel utilization efficiency.
D)
SEER - seasonal energy efficiency ratio.
Answer:
A
Explanation:
A)
B)
C)
D)
94)
94)
The primary advantages of room air conditioners include:
A)
Can be used for improving indoor air quality using HEPA filters.
B)
Relatively low cost and ease of installation.
C)
Can be used with ductwork to distribute air to several rooms.
D)
High efficiency and quiet operation.
Answer:
B
Explanation:
A)
B)
C)
D)
95)
95)
Primary disadvantages of room air conditioners include:
A)
Difficult installation requiring high levels of training.
B)
They block part of the window area and produce operating noise.
C)
They are more expensive than central systems.
D)
They are only available in limited quantities.
Answer:
B
Explanation:
A)
B)
C)
D)
25
96)
96)
How many blower motors does a window air conditioner have?
A)
None - window air conditioners do not require a blower motor because they are not
connected to a duct system.
B)
Two - an evaporator fan motor and a condenser fan motor.
C)
Two - a low-speed blower motor and a high-speed blower motor.
D)
One - a single double-shafted blower motor is used for both the evaporator and condenser
fans.
Answer:
D
Explanation:
A)
B)
C)
D)
97)
97)
What types of systems are particularly well suited to split system design?
A)
Large chillers
B)
Small systems for hotel rooms
C)
Residential air-conditioning systems with air-cooled condensers
D)
Systems with water-cooled condensers
Answer:
C
Explanation:
A)
B)
C)
D)
98)
98)
A residential A/C system that cools in summer and heats in winter by reversing the flow of
refrigerant is called a:
A)
PTAC system.
B)
Heat pump.
C)
Stand-alone A/C system.
D)
Window unit.
Answer:
B
Explanation:
A)
B)
C)
D)
99)
99)
PTAC and window-unit air conditioners often use rotary compressors, which are effective but
susceptible to failure due to high head pressure. What is the most common cause of high head
pressure in these units?
A)
Dirty evaporator
B)
Metering device failure
C)
Dirty condenser
D)
Incorrect charge
Answer:
C
Explanation:
A)
B)
C)
D)
26
100)
100)
How is the energy efficiency ratio (EER) calculated?
A)
The output in Btuh is divided by the input in watts.
B)
The output in Btuh is multiplied by the input in watts.
C)
The input in watts is added to the output in Btuh.
D)
The input in watts is divided by the output in Btuh.
Answer:
A
Explanation:
A)
B)
C)
D)
101)
101)
Where is the condensing unit of a split system located?
A)
Either inside or outside
B)
Outside
C)
Inside in a basement, crawlspace, attic, or closet
Answer:
B
Explanation:
A)
B)
C)
102)
102)
A common problem with larger window air-conditioning units used in older homes is:
A)
Nuisance circuit breaker trips due to inadequate electrical service.
B)
Overcooling the home.
C)
Older-style window framing will not support the weight of a window unit.
D)
Restrictive neighborhood covenants, which prohibit window units.
Answer:
A
Explanation:
A)
B)
C)
D)
103)
103)
What type of fan is used in most air-cooled condensing units?
A)
A blow-through centrifugal fan
B)
A draw-through centrifugal fan
C)
A draw-through propeller fan
D)
No fanmost condensing units are natural draft.
Answer:
C
Explanation:
A)
B)
C)
D)
27
104)
104)
The most likely result of field design modifications to equipment is:
A)
Lower operating cost.
B)
Increased equipment life.
C)
Improved performance and efficiency.
D)
Reduced performance.
Answer:
D
Explanation:
A)
B)
C)
D)
105)
105)
Typical condenser fan motor speeds are about:
A)
800 rpm or 1,000 rpm.
B)
500 rpm or 800 rpm.
C)
1,000 rpm or 1,600 rpm.
D)
1,600 rpm or 3,400 rpm.
Answer:
A
Explanation:
A)
B)
C)
D)
106)
106)
The terms upflow, horizontal, and downflow refer to the direction of:
A)
Refrigerant flow through air-conditioning evaporator coils.
B)
Airflow through split-system air-conditioning evaporator coils.
C)
Electrical current flow through the evaporator fan motor.
D)
Heat flow through air-conditioning evaporator coils.
Answer:
B
Explanation:
A)
B)
C)
D)
107)
107)
What is the major advantage of mini-split air-conditioning systems?
A)
Lower cost
B)
Air ducting is not necessary.
C)
Higher efficiency
D)
Shorter line sets
Answer:
B
Explanation:
A)
B)
C)
D)
28
108)
108)
Where is the split-system evaporator coil located?
A)
Outside
B)
Inside the conditioned space
C)
Either inside or outside
Answer:
B
Explanation:
A)
B)
C)
109)
109)
When the temperature of the rejected condenser air is much warmer than usual, it can be an
indication that:
A)
The condenser coil is dirty.
B)
The compressor is dirty.
C)
The filter is dirty.
D)
The evaporator coil is dirty.
Answer:
A
Explanation:
A)
B)
C)
D)
110)
110)
The outdoor air-cooled condensing unit consists of:
A)
A compressor, condenser coil, a condenser fan, evaporator coil, and the necessary electrical
control box assembly.
B)
A compressor, condenser coil, a condenser fan, and the necessary electrical control box
assembly.
C)
Copper tubing surrounded by aluminum fins and a condenser fan, and the necessary
electrical control box assembly.
D)
Copper tubing surrounded by aluminum fins and a condenser fan, a refrigerant expansion
device, and the necessary electrical control box assembly.
Answer:
B
Explanation:
A)
B)
C)
D)
111)
111)
Most systems can operate with up to ________ feet of lines and a maximum of ________ feet
vertical distance between the indoor and outdoor units.
A)
100, 30
B)
75, 15
C)
50, 10
D)
90, 20
Answer:
C
Explanation:
A)
B)
C)
D)
29
112)
112)
Some codes limit refrigerant 410A to 25 pounds per 1000 cubic feet of space. This works out to 40
cubic feet per pound of refrigerant. The limit is lower, ________ cubic feet per pound of refrigerant
for 24 hour care facilities such as hospitals and nursing homes.
A)
50
B)
15
C)
30
D)
20
Answer:
D
Explanation:
A)
B)
C)
D)
113)
113)
Wiring for a four-port multisplit system runs:
A)
Four wires to each indoor unit.
B)
Two wires to each indoor unit.
C)
One wire to each indoor unit.
D)
Three wires to each indoor unit.
Answer:
A
Explanation:
A)
B)
C)
D)
114)
114)
What type of refrigerant line connections are used on multisplit systems?
A)
Multiple connections on the outdoor unit
B)
Single set of connections on the outdoor unit
C)
A refrigeration network similar to a heat recovery system
D)
Both A and B could be used.
Answer:
D
Explanation:
A)
B)
C)
D)
115)
115)
VRF systems use a refrigeration network of:
A)
Headers and branch joints.
B)
Wyes and tees.
C)
Both aA and B.
D)
None of the above.
Answer:
A
Explanation:
A)
B)
C)
D)
30
116)
116)
While multisplit units are limited to a single outdoor unit, large VRF systems can combine as
many as ________ outdoor units manifolded together to increase overall system capacity.
A)
five
B)
two
C)
three
D)
four
Answer:
C
Explanation:
A)
B)
C)
D)
117)
117)
Multisplit manufacturer's installation instructions will specify the maximum total installed piping
length which can be supported by the charge shipped in the unit. If additional piping is installed
the only correct way to charge the system is to:
A)
Add the specified amount of refrigerant for each additional foot of refrigerant line.
B)
Charge the system to the required subcooling.
C)
Charge the system to the required superheat.
D)
None of the above.
Answer:
A
Explanation:
A)
B)
C)
D)
118)
118)
Branch selectors are boxes in heat recovery VRF systems that allow:
A)
Multiple refrigerant lines to feed a single indoor unit.
B)
One refrigerant line to feed multiple indoor units.
C)
One refrigerant line to feed a single indoor unit.
D)
Multiple refrigerant lines to feed multiple indoor units.
Answer:
B
Explanation:
A)
B)
C)
D)
119)
119)
A type system that allows simultaneous heating and cooling to different parts of a building is the:
A)
Heat pump variable refrigerant flow system.
B)
Heat recovery system.
C)
Multisplit system.
D)
All of the above.
Answer:
B
Explanation:
A)
B)
C)
D)
31
120)
120)
On heat recovery systems:
A)
One indoor unit can be in heating mode while others are in cooling mode at the same time.
B)
It is required that all indoor units be in cooling mode.
C)
It is required that all indoor units be in heating mode.
D)
Both A and B.
Answer:
A
Explanation:
A)
B)
C)
D)
121)
121)
Which of the following mini-split system indoor units requires a condensate pump because
gravity condensate draining is never feasible for this type of installation?
A)
Ceiling suspended
B)
Wall mount
C)
Floor mount
D)
All of these
Answer:
A
Explanation:
A)
B)
C)
D)
122)
122)
On mini-split systems both refrigerant lines must be insulated because they are both:
A)
Low pressure and low temperature in the heating and cooling mode.
B)
Low pressure and high temperature in the cooling mode.
C)
Low pressure and low temperature in the cooling mode.
D)
Low pressure and low temperature in the heating mode.
Answer:
C
Explanation:
A)
B)
C)
D)
123)
123)
Most manufacturer's joints work well when the inlet and both outlet branches are installed:
A)
In the same horizontal plane and parallel.
B)
In the same vertical plane as the ground.
C)
Either the same vertical or horizontal plane.
Answer:
A
Explanation:
A)
B)
C)
32
124)
124)
Mechanical codes limit the amount of refrigerant a system can contain if it is located in an
occupied space. Because VRF systems are connected to one large refrigerant network that would
release the entire charge in case of a leak, some codes limit refrigerant 410A charge to ________
pounds per 1,000 cubic feet of space.
A)
25
B)
15
C)
50
D)
30
Answer:
A
Explanation:
A)
B)
C)
D)
125)
125)
Designing a heating and cooling system to accommodate load shifts:
A)
Improves comfort.
B)
Allows buildings to operate with less installed capacity and still meet the demand.
C)
Improves efficiency.
D)
All of the above.
Answer:
D
Explanation:
A)
B)
C)
D)
126)
126)
VRF systems are commercial systems. The outdoor units are normally designed to operate on
________ phase power and the indoor units on ________ phase power.
A)
three, single
B)
three, three
C)
single, three
D)
single, single
Answer:
A
Explanation:
A)
B)
C)
D)
127)
127)
When more than one indoor unit is connected an individual branch selection box on a heat
recovery system:
A)
One indoor unit may operate in the heat mode and other(s) may operate in the cooling
mode.
B)
Each indoor unit must operate in the same mode.
Answer:
B
Explanation:
A)
B)
33
128)
128)
Variable refrigerant flow systems use:
A)
Inverter driven systems and electronic expansion valves.
B)
Inverter driven systems and thermostatic expansion valves.
C)
Scroll compressors and thermostatic expansion valves.
D)
Scroll compressors and electronic expansion valves.
Answer:
A
Explanation:
A)
B)
C)
D)
129)
129)
The typical number of wires connecting the outdoor unit to the indoor unit of a mini-split system
is:
A)
Two.
B)
Three.
C)
Four.
D)
Any of the above.
Answer:
C
Explanation:
A)
B)
C)
D)
130)
130)
ACCA's Manual J:
A)
Provides a complete list of board jumper locations.
B)
Is a national best practices overview for system installation.
C)
Is used for determining the heat gain of a residential structure.
D)
Provides detailed procedures for installing air-conditioning equipment.
Answer:
C
Explanation:
A)
B)
C)
D)
131)
131)
The minimum SEER rating for new air-conditioning systems is:
A)
13 SEER.
B)
20 SEER.
C)
10 SEER.
D)
16 SEER.
Answer:
A
Explanation:
A)
B)
C)
D)
34
132)
132)
An efficient and trouble-free air conditioning system installation is more likely if the installation
starts:
A)
With planning the installation.
B)
In the afternoon.
C)
By cutting holes to rough in the ductwork.
D)
By pulling the refrigerant line set.
Answer:
A
Explanation:
A)
B)
C)
D)
133)
133)
How is the refrigerant charge normally checked on air-conditioning systems that use a TEV
expansion device?
A)
Adjust the charge to achieve a 40°F saturated evaporator temperature.
B)
Subcooling
C)
Feel to see if the suction line is cold and the liquid line warm.
D)
Superheat
Answer:
B
Explanation:
A)
B)
C)
D)
134)
134)
The power wire for the condensing unit is sized:
A)
The same wire gauge as the wires inside the unit.
B)
At 115% of the minimum circuit ampacity shown on the nameplate.
C)
By the maximum overcurrent protection (MOP) shown on the nameplate.
D)
By the minimum circuit ampacity (MCA) shown on the name plate.
Answer:
D
Explanation:
A)
B)
C)
D)
35
135)
135)
The circuit breaker for the condensing unit is sized:
A)
By the maximum overcurrent protection (MOP) shown on the nameplate.
B)
The same wire gauge as the wires inside the unit.
C)
At 115% of the minimum circuit ampacity shown on the nameplate.
D)
By the minimum circuit ampacity (MCA) shown on the name plate.
Answer:
A
Explanation:
A)
B)
C)
D)
136)
136)
The most reliable source for information regarding system installation is:
A)
Knowledge gained through installing other systems.
B)
The foreman.
C)
The customer.
D)
The manufacturer's installation manual.
Answer:
D
Explanation:
A)
B)
C)
D)
137)
137)
What is the standard airflow across the evaporator of a 3-ton residential split-system air
conditioner?
A)
800 CFM
B)
1,200 CFM
C)
1,500 CFM
D)
1,000 CFM
Answer:
B
Explanation:
A)
B)
C)
D)
138)
138)
A common problem in split-system installations is improper sizing of the system. When a system
is oversized what is the result?
A)
Lower electric bills
B)
Not enough humidity is removed to keep occupants comfortable.
C)
Occupants are more comfortable due to more cooling capacity.
D)
Abnormally loud fan noise
Answer:
B
Explanation:
A)
B)
C)
D)
36
139)
139)
What procedure should be used to size air-conditioning equipment?
A)
Perform a load study using ACCA Manual J.
B)
Divide the house square footage by 600 and round up to the nearest whole number to arrive
at the unit capacity in tons.
C)
Divide the house volume by 15 to arrive at air changes and then divide that answer by 400
to get the unit capacity in tons.
D)
Multiply the rooms by 120 to get the system airflow, then divide that answer by 400 to get
the unit capacity in tons.
Answer:
A
Explanation:
A)
B)
C)
D)
140)
140)
Where should the thermostat be mounted?
A)
52 to 60 in above the floor on an inside wall
B)
36 to 48 in above the floor on an outside wall
C)
52 to 60 in above the floor on an outside wall
D)
36 to 48 in above the floor on an inside wall
Answer:
A
Explanation:
A)
B)
C)
D)
141)
141)
What is a whip?
A)
A watertight, flexible electrical cable connecting the system's disconnect to the condensing
unit
B)
The control wire between an air conditioner and the remote control
C)
A flexible wire on the evaporator fan, which helps remove condensate water
D)
The refrigerant line set installed between the condensing unit and the evaporator
Answer:
A
Explanation:
A)
B)
C)
D)
37
142)
142)
Where is solid 18 gauge copper wire typically used in residential air-conditioning installation?
A)
Inside the equipment supplying power to the major loads
B)
The power wire to the indoor unit
C)
The power wire to the condensing unit
D)
The thermostat control wire
Answer:
D
Explanation:
A)
B)
C)
D)
143)
143)
An industry rule-of-thumb concerning airflow is that there should be what CFM of airflow per
ton across the evaporator?
A)
100
B)
1,000
C)
200
D)
400
Answer:
D
Explanation:
A)
B)
C)
D)
144)
144)
The condensate line from the drain pan of the evaporator is normally:
A)
3/4 in galvanized iron pipe.
B)
1/2 in galvanized iron pipe.
C)
3/4 in PVC.
D)
1/2 in PVC.
Answer:
C
Explanation:
A)
B)
C)
D)
145)
145)
Which is the best location for an outdoor condensing unit?
A)
Under a deck
B)
Under a bedroom window
C)
On the back side of a house away from windows and overhangs
D)
Under a roof overhang
Answer:
C
Explanation:
A)
B)
C)
D)
38
146)
146)
What is the most common deep vacuum level required by manufacturers?
A)
100 microns
B)
500 microns
C)
5,000 microns
D)
1,000 microns
Answer:
B
Explanation:
A)
B)
C)
D)
147)
147)
Fiberboard duct is joined:
A)
With tape and mastic.
B)
Using the mechanically self-sealing joints formed on the end of the duct.
C)
With sheet metal screws and mastic.
D)
With staples and UL 181A tape.
Answer:
D
Explanation:
A)
B)
C)
D)
148)
148)
For maximum efficiency, the duct system should be located within the building's:
A)
Insulation envelope.
B)
Interior walls.
C)
Mechanical room.
D)
Basement.
Answer:
A
Explanation:
A)
B)
C)
D)
149)
149)
Flex duct is easy to install and quiet but has higher ________ than all other forms of duct material.
A)
resistance to airflow
B)
efficiency ratings
C)
energy loss
D)
installation cost
Answer:
A
Explanation:
A)
B)
C)
D)
39
150)
150)
Round sheet metal ductwork should be:
A)
Fastened with sheet metal screws and sealed with mastic.
B)
Fastened and sealed with mastic.
C)
Fastened with duct tape and sealed with mastic.
D)
Fastened and sealed with duct tape.
Answer:
A
Explanation:
A)
B)
C)
D)
151)
151)
Duct leakage area calculates:
A)
Which assigned duct leak category the leak falls into.
B)
Duct leakage correction factors based on the area of the country.
C)
The size of the hole if all the leaks were combined into one.
D)
The area where leaks are occurring in the duct systems.
Answer:
C
Explanation:
A)
B)
C)
D)
152)
152)
When comparing duct materials, none have a lower friction rate or are as durable as:
A)
Ductboard.
B)
Fiberboard.
C)
Sheet metal.
D)
Flex duct.
Answer:
C
Explanation:
A)
B)
C)
D)
153)
153)
Underwriters Laboratories standard 181 A covers:
A)
Methods of connecting and sealing metal duct.
B)
Methods of connecting and sealing flexible duct.
C)
Methods of connecting and sealing all types of duct.
D)
Methods of connecting and sealing ductboard.
Answer:
D
Explanation:
A)
B)
C)
D)
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