WorksheetsBSE UNIT 12 LESSON 1 Quiz on Air Conditioning (AC) in Buildings
Total questions: 68
Worksheet time: 34mins
What is one of the objectives learners should achieve by the end of the session on air conditioning (AC) in buildings?
Calculate the energy consumption of AC systems
List the reasons why AC is provided in buildings
Design a new AC system
Compare AC systems with traditional cooling methods
Which of the following is an objective for learners studying AC systems in buildings?
Evaluate the cost-effectiveness of AC systems
Draw the layout of a central plant AC system
Analyze the environmental impact of AC systems
Invent a new type of AC system
What should learners be able to describe regarding AC systems by the end of the session?
The color coding of AC system components
The operation of two types of AC systems
The marketing strategies for AC systems
The installation process of AC systems in high-rise buildings
By the end of the session, learners should be able to explain which aspects of AC systems?
The historical development of AC systems
The electrical circuits used in AC systems
The advantages and disadvantages of various AC systems
The warranty terms for different AC systems
What is the primary function of air conditioning (AC) in buildings?
To provide lighting to the building
To supply adequate oxygen, comfortable temperature, and remove CO2 and odours
To supply internet connectivity
To provide structural support to the building
What does air conditioning (AC) control in addition to heating and cooling a building?
The color of the walls
The humidity of the air
The electrical systems
The plumbing systems
What is the effect of the air being conditioned in central plant AC systems before being distributed?
The effect varies significantly from room to room.
The effect will be identical throughout the building.
The air quality is reduced.
The system only cools the air without conditioning it.
How can the effect of the conditioned air be changed in central plant AC systems?
By increasing the speed of the supply fan.
By opening the windows in each room.
By reducing the off-coil temperature.
By adjusting the return air fan speed.
What is the purpose of the reheat battery in central plant AC systems?
To cool the supply air before it enters the room.
To reheat the supply air before it enters the room.
To filter the supply air before it enters the room.
To humidify the supply air before it enters the room.
What is the purpose of the preheater battery in central plant components?
To cool the air before it enters the room
To heat fresh air to 70°C in the winter cycle to prevent filters from freezing
To mix fresh air with recirculated air
To create positive air pressure in the room
What percentage of room air can be mixed with fresh air through the recirculation duct?
10%
25%
50%
75%
What is the 'duty' of a supply fan in central plant components?
To create negative air pressure in the room
To cool the air using chilled water or a refrigerant gas
To heat the air to the supply air temperature
To provide the air volume and static pressure required to overcome system resistances
How does the cooling coil function in central plant components?
By heating the air using chilled water
By cooling the air using chilled water or a refrigerant gas and removing moisture through dehumidification
By mixing the air with a refrigerant gas to create positive pressure
By recirculating the air to increase humidity
What is the role of the reheater battery in central plant components?
To cool the air to a comfortable temperature
To remove moisture from the air
To heat the air to the supply air temperature (34°C) for comfort and to compensate for heat loss throughout the building
To mix the air with refrigerant gas
What does CAV stand for in the context of building services engineering?
Constant Air Velocity
Central Air Ventilation
Constant Air Volume
Controlled Air Vacuum
What is the main advantage of a VAV system according to the text?
It provides a constant temperature throughout the building.
It can meet the comfort requirements of different zones in a building without heating and cooling at the same time.
It uses less energy than traditional heating and cooling systems.
It allows for individual temperature control in each room.
What is the role of the air handling unit (AHU) in a VAV system?
It cools the air before it is supplied to the rooms.
It heats the air as it is returned from the rooms.
It 'dumps' dirty air or recycles clean air.
It regulates the temperature of the air in each zone.
What is the function of the economizer damper in a Variable Air Volume (VAV) system?
To control the temperature in small zones
To filter the return air
To allow outside air to enter the system
To reduce the noise from the air ducts
What is the purpose of coils in a VAV system?
To control airflow direction
To heat or cool the air
To reduce air pressure
To measure the temperature
What type of fan is suggested for use in a VAV system for high efficiency?
Axial fan
Centrifugal fan
Fan with variable speed drive
Static fan
What is the purpose of the large low-pressure oval/round static regain ducting in a VAV system?
To provide structural support to the VAV boxes
To distribute air to different floors
To control the volume of air supplied to different zones
To maintain a consistent air pressure throughout the ductwork
What is the purpose of a VAV system in air conditioning?
To maintain a constant supply volume at all times
To condition the air to multiple supply conditions
To reduce or increase the supply volume to condition a room
To filter the air through multiple chambers
What does VAV stand for in the context of the learning material?
Variable Air Volume
Variable Air Velocity
Ventilation Air Volume
Ventilation Air Vent
How does a VAV system adjust the room conditions?
By changing the temperature of the air
By adjusting the amount of air entering the space
By filtering the air more thoroughly
By recirculating the same air within the room
What is the function of the component labeled "Cooling coil" in a VAV air handling unit (AHU)?
To heat the air
To filter the air
To cool the air
To humidify the air
Where is the "Filter" located in relation to the "Centrifugal fan" in a VAV air handling unit (AHU)?
Before the fan
After the fan
Inside the fan
There is no filter in relation to the centrifugal fan
What is the purpose of the "Reheater battery" in a VAV air handling unit (AHU)?
To cool the air before it enters the room
To remove impurities from the air
To reheat the air after cooling has taken place
To propel the air through the system
What is the purpose of the velocity sensor in a VAV terminal unit?
To heat the air entering the space
To eliminate the velocity noise of the air flow
To adjust the volume of air entering the space
To cool the air entering the space
What does an attenuator do in a VAV terminal unit?
Controls the temperature of the air
Eliminates the velocity noise of the air flow
Senses the velocity of the air
Reheats the air if necessary
Can a reheat battery be incorporated into a VAV terminal unit?
Yes, but only if the air velocity is too high
No, because it would interfere with the velocity sensor
Yes, if necessary
No, because it would increase the velocity noise
At what constant air temperature do VAV systems typically vary the airflow?
10°C
13°C
20°C
25°C
What is the purpose of the reheat coil in a VAV terminal box?
To cool down the air
To regulate the airflow
To boost the temperature if necessary
To measure the air temperature
What component in the VAV terminal box is electrically linked to the thermostat?
Actuator
Damper
Reheat coil
VAV terminal
What do pressure sensors in a VAV system link to?
Thermostat
Reheat coil
Variable speed drives/variable frequency drives
Diffuser
What is the function of the actuator and damper in a VAV terminal box?
To measure the air temperature
To regulate the system
To boost the temperature
To link to the thermostat
What do AC induction systems condition the air to before circulating it into the building?
Multiple conditions depending on the room
A single condition
A variable condition based on external temperature
No specific condition, it circulates as is
What is the purpose of room induction units in AC induction systems?
To reduce the air velocity
To filter the air only
To induce and mix room air with fresh, conditioned air
To reheat the air only
Is there return air ductwork for recirculation in AC induction systems?
Yes, it is essential for the system
No, all recirculation takes place within the casing
Yes, but only for heating purposes
No, because it is not needed for cooling
What is a consequence of using heating water to reheat the mixed air in AC induction systems?
It reduces the operational cost of the system
It has no impact on the cost
It decreases the efficiency of the system
It significantly increases the capital cost of the system
What is the purpose of deliberately constricting pipework in induction systems that use the Venturi effect?
To increase fluid pressure and decrease velocity
To reduce fluid pressure and increase velocity
To maintain constant fluid pressure and velocity
To eliminate the need for a vacuum in the system
What is the result of using the Venturi effect in induction systems according to the text?
It stops the recirculation of air from the room
It creates a vacuum that recirculates the air from the room
It heats the air within the pipework
It cools down the air before it enters the room
What is the function of the balancing damper in the diagram?
To control the temperature of the primary air
To regulate the flow of induced air
To recirculate the air from the room
To adjust the pressure and velocity of the air
What is the purpose of a dual duct system in building services engineering?
To provide a single pathway for either heated or chilled air
To distribute air via two ducts: one for chilled air and one for heated air
To filter the outside air only without temperature adjustments
To recirculate the indoor air without any conditioning
What is the function of the dampers in a dual duct system?
To cool and heat the air
To filter the air
To control the flow of air into the hot and cold ducts
To recirculate the air
Why are the two ducts in a dual duct system insulated?
To prevent the chilled air from absorbing warmer ambient temperatures
To make the system more compact
To reduce the noise produced by the system
To filter the air more efficiently
What is the first step in the process of air distribution in a dual duct system?
The air is split into hot and cold
The air is passed through a cooler and heater
The incoming fresh air is preconditioned before entering the fan suction chamber
The air is discharged into the environment
What is the function of terminal boxes in a dual duct system?
To filter the outside air only
To mix the chilled and heated air before discharging it into the room
To control the temperature of the outside air
To cool the exhaust air before it is released outside
What is the temperature of the hot deck in the diagram?
75°F
55°F
95°F
85°F
What is the temperature of the cold deck in the diagram?
75°F
55°F
95°F
85°F
What is the temperature of the return air in the diagram?
75°F
55°F
95°F
85°F
What are compression cycle refrigeration circuits known as?
Constant refrigerant volume (CRV) systems
Variable refrigerant volume (VRV) systems
Fixed refrigerant volume (FRV) systems
Adjustable refrigerant volume (ARV) systems
Where are VRV systems typically used?
Where extensive ductwork is required
Where no ductwork is possible or needed
Where only natural ventilation is allowed
Where refrigeration is not required
What is the purpose of the main refrigeration unit in a VRV system?
To cool multiple buildings simultaneously
To provide refrigeration to the entire city block
To feed a single storey of a building
To distribute refrigerant to other systems
How many pipes does the VRV system's distribution system have?
Two
Three
Four
Five
What capability do individual room units in a VRV system have?
They can only cool the room using the same refrigerant.
They can only heat the room using a different refrigerant.
They are capable of reversing the flow of refrigerant to heat or cool the room using the same refrigerant.
They can remove condensate when heating.
What additional feature do room units in a VRV system have for cooling?
A heating system to warm up the condensate
A drainage system to remove condensate
An extra refrigerant storage tank
A secondary refrigeration unit
What does a single outdoor condensing unit connect to in a VRV system?
Multiple indoor condensing units
One or more air handlers
A central heating system
An external thermostat
How is refrigerant used in a VRV system?
It is used to generate electricity for heating and cooling.
It is cycled through an outdoor unit to distribute heat or cooled air.
It is permanently stored in each room/zone's thermostat.
It is only used to provide cooling to the building.
What allows heating and cooling to occur at the same time in different rooms in a VRV system?
A central control unit
Individual thermostats in each room/zone
A single thermostat for the entire building
Separate outdoor units for each room/zone
What is a significant energy advantage of VRV systems compared to forced air systems?
VRV systems require additional insulation.
VRV systems use water as a refrigerant.
VRV systems incur minimal energy loss.
VRV systems require a back-up heat source.
What is the function of the evaporator in a split system air conditioner?
It condenses the refrigerant gas.
It draws outside air across the heat exchanger.
It evaporates the refrigerant liquid, removing heat from the room air.
It enables the refrigerant to flow between the two units.
Which component of a split system air conditioner is responsible for drawing outside air across the heat exchanger?
Evaporator
Condenser
Propeller fan
Expansion valve
What connects the internal and external units of a split system air conditioner to allow refrigerant flow?
Steel tubing
Copper tubing
Plastic piping
Aluminum ducts
Where are the compressor and expansion valve located in a split system air conditioner?
Within the internal unit
Within the external unit
Outside both units
Within the copper tubing
What is the function of the internal evaporator coil in a split system air conditioner for a single room?
To compress the refrigerant
To expel the hot air outside
To cool down the air inside the room
To expand the refrigerant
Where is the condenser coil located in a split system air conditioner?
Inside the room
In the compressor
Outside the room
In the expansion valve
What is the role of the compressor in a split system air conditioner?
To cool the air
To circulate the refrigerant between the evaporator and condenser coils
To filter the air
To control the temperature of the air
What does the expansion valve do in a split system air conditioner?
It heats up the air
It removes humidity from the air
It compresses the refrigerant
It regulates the flow of refrigerant into the evaporator
