Question 1

By utilizing a strategy called demand control ventilation, DCV, the amount of outside air being brought into the building can be varied based on the actual occupancy level in the structure.

Accepted Answer

By utilizing demand control ventilation, the amount of outside air can be adjusted based on the occupancy level in the building, allowing for more efficient and cost-effective ventilation.

Question 2

The term enthalpy refers to the total heat content in the air, which accounts for both the temperature (sensible heat portion) and the moisture content (latent heat portion) of the air.

Accepted Answer

Enthalpy is the total heat content of the air, including both sensible heat (temperature) and latent heat (moisture content).

Question 3

In order to deliver different volumes of air to various areas in an occupied space, the blowers used on VAV systems must be able to modulate their openings to accommodate the changing needs of the system.

Accepted Answer

Variable Air Volume (VAV) systems primarily modulate the volume of air delivered to different areas by adjusting the position of dampers in the ductwork, not by changing the blower openings. The blower typically runs at a constant speed, and the airflow is regulated by the dampers.

Question 4

Rooftop units are often positioned ____ the space that is to be served by the equipment.
A) directly below
B) directly behind
C) directly adjacent
D) directly above

Accepted Answer

Rooftop units are designed to be installed directly above the space that they are meant to serve. This allows for better air distribution and circulation throughout the building. Additionally, positioning the unit on the roof saves valuable indoor space and reduces noise within the building.

Question 5

It is good field practice to double-check and possibly triple-check the ____ decision, since the cost of repairing an improperly cut roof can be very high.
A) location
B) size
C) capacity
D) operational

Accepted Answer

The location of a cut on a roof is crucial, as an incorrect location can lead to significant structural issues and costly repairs.

Question 6

The rooftop unit houses the fans and blowers that move air through the heating and cooling portions of the unit but not through the condenser.

Accepted Answer

The rooftop unit typically includes fans and blowers that move air through all parts of the unit, including the condenser, to facilitate heat exchange.

Question 7

If the curb is mounted as part of a new construction process, it can be assembled and installed as soon as the ____ support system is in place.
A) walls
B) ceiling
C) roof
D) utility

Accepted Answer

The curb is typically installed as part of the roof structure, so it can be assembled and installed once the roof support system is in place.

Question 8

The fans that move air through the air-cooled condensers are of the ____-type.
A) propeller
B) squirrel
C) cage
D) push

Accepted Answer

The propeller-type fans are commonly used in air-cooled condensers. These fans have blades that are curved in such a way that they move the air efficiently and create a high airflow rate. They are also designed to run at a high speed to provide the necessary cooling for the condenser coils.

Question 9

The unit's location should be carefully selected so the system's operation is not adversely affected by air being able to ____ the condenser coil.
A) bypass
B) circulate back through
C) recirculate
D) induce cooling in

Accepted Answer

The answer of The unit's location should be carefully selected...

Question 10

Gasketing materials and foam panels that are shipped with the curb are not part of the curb and should be discarded.

Accepted Answer

Gasketing materials and foam panels should not be discarded as they are important for proper installation and sealing of the curb. They should be used according to the manufacturer's instructions.

Question 11

Some roofs are bonded, which are roofs that carry a written warranty or insurance policy that protects the building owner in the event damage from leaks occurs.

Accepted Answer

Bonded roofs are roofs that come with a warranty or insurance policy to protect the building owner in case of leak damage.

Question 12

The curb's cross braces are intended to support the duct connections to the unit, but not the entire air distribution system.

Accepted Answer

The statement is true. The cross braces on the curb are only meant to support the duct connections, not the entire air distribution system.

Question 13

It should be noted that, in most cases, the supply and return ductwork must be attached to the ____ before the unit is set in place.
A) boom
B) package
C) load
D) curb

Accepted Answer

The supply and return ductwork must be attached to the curb before the unit is set in place. The curb is a raised platform installed on the roof, and it provides a base for supporting and securing the HVAC unit.

Question 14

Be sure to provide proper and adequate support for the duct system according to ____.
A) installation instructions
B) local building codes
C) state building rules
D) environmental regulations

Accepted Answer

Local building codes dictate the proper and adequate support for the duct system. State building rules and environmental regulations may have some impact, but local building codes are the primary authority on this matter. Installation instructions may also provide guidance, but they should be in line with local building codes.

Question 15

Improper clearances do not affect the ability of service personnel to perform their jobs adequately.

Accepted Answer

Improper clearances can cause safety hazards and affect the ability of service personnel to perform their jobs adequately.

Question 16

Package units are factory-assembled, factory-charged, self-contained systems that have all of the major system components contained in a single housing.

Accepted Answer

Package units are designed to be a self-contained HVAC system in which all components including the heating and cooling elements, controls, and fan are contained within a single package.

Question 17

By raising the forearm in the air, index finger pointing upward and holding the hands straight, the operator will know to raise the cable on the crane.

Accepted Answer

The answer of By raising the forearm in the air,...

Question 18

Curbs can be prefabricated, but many larger curbs are shipped unassembled.

Accepted Answer

Prefabricated curbs are made in a factory and shipped as a single unit, while larger curbs may be shipped unassembled and assembled on site.

Question 19

Although packaged air-conditioning equipment comes precharged with refrigerant and no field piping must be done, the installation of a rooftop package unit involves many steps and can be very dangerous.

Accepted Answer

While packaged air-conditioning equipment comes precharged with refrigerant and no field piping must be done, the installation of a rooftop package unit involves many steps and can be very dangerous. It requires working at heights, electrical wiring, and handling heavy equipment. It should only be done by trained professionals with proper safety equipment and precautions.

Question 20

The amount of refrigerant indicated on the ____ is the total refrigerant charge for the unit, not simply a holding charge as in the case of a split-type system.
A) bill of lading
B) compressor
C) nameplate
D) blower

Accepted Answer

The nameplate on a unit will indicate its total refrigerant charge, which is not just a holding charge. The bill of lading may indicate the amount of refrigerant shipped but may not be accurate to the specific unit, while the compressor and blower do not typically directly indicate the refrigerant charge.

Quiz 50: Commercial Rooftop, Packaged, Variable Refrigerant Flow, and Variable Air Volume Systems

By utilizing a strategy called demand control ventilation, DCV, the amount of outside air being brought into the building can be varied based on the actual occupancy level in the structure.

The term enthalpy refers to the total heat content in the air, which accounts for both the temperature (sensible heat portion) and the moisture content (latent heat portion) of the air.

In order to deliver different volumes of air to various areas in an occupied space, the blowers used on VAV systems must be able to modulate their openings to accommodate the changing needs of the system.

Rooftop units are often positioned ____ the space that is to be served by the equipment.

It is good field practice to double-check and possibly triple-check the ____ decision, since the cost of repairing an improperly cut roof can be very high.

The rooftop unit houses the fans and blowers that move air through the heating and cooling portions of the unit but not through the condenser.

If the curb is mounted as part of a new construction process, it can be assembled and installed as soon as the ____ support system is in place.

The fans that move air through the air-cooled condensers are of the ____-type.

The unit's location should be carefully selected so the system's operation is not adversely affected by air being able to ____ the condenser coil.