Archive for September 2018

Chain blocks are designed

Chain blocks are designed



a) for mainly horizontal use
b) with the top hook strongest
c) with a very low mechanical advantage
d) with the bottom hook strongest
e) for lifting very long objects


Answer: B

Prior to hoisting an object it is best to

Prior to hoisting an object it is best to



a) know the route required
b) know or calculate the mass
c) measure its length
d) attach at least two slings
e) measure the width


Answer: B

A single pole scaffold

A single pole scaffold



a) is free standing from the building
b) places no load on the building
c) is partially supported by the building
d) is always made of metal
e) must be made of pipe


Answer: C

A single pole scaffold

A single pole scaffold



a) should not be used
b) must be constructed of metal only
c) is partially supported by a building
d) must have supporting rigging attached to it
e) need not be plumb, only level


Answer: C

A scaffold should always be erected

A scaffold should always be erected



a) by the user only
b) plumb
c) by a contractor
d) plumb and level
e) level


Answer: D

A rung ladder should

A rung ladder should



a) never be able to conduct electricity
b) not be equipped with rubber feet, only metal ones
c) be inclined with a 5:1 slope
d) always have at least one rail touching the support
e) be inclined with a 4:1 slope


Answer: E

When using a step ladder it is best to

When using a step ladder it is best to



a) not work higher than the top three rungs
b) have a 4:1 slope on the rung side
c) have two co-workers hold the ladder steady
d) secure the ladder with a rope
e) place both feet on the top platform if extra height is required


Answer: A

When working on a platform it is important to

When working on a platform it is important to



a) always wear a lifeline harness
b) ensure it is equipped with a full guard railing
c) construct it yourself
d) warn people on the ground of hazards
e) notify the applicable government agency of usage


Answer: D

A government agency which covers several aspects of work platforms is the

A government agency which covers several aspects of work platforms is the



a) Boilers and Pressure Vessels Branch
b) Workers' Compensation Board Accident Prevention Regulations
c) Hoisting and Rigging Regulations
d) Industrial Accident Prevention Association
e) Hoisting and Elevator Regulations


Answer: B

When storing a hacksaw

When storing a hacksaw



a) the blade should be removed
b) the saw should be stored in a protective sheath
c) strain should be removed by loosening the blade
d) it should be hung rather than laid in with other tools
e) none of the above are applicable


Answer: C

Hand taps are usually made in sets of three called

Hand taps are usually made in sets of three called



a) SAE, ISO, and metric
b) warding, mill, and bastard
c) rough, coarse, and fine
d) plug, taper, and bottoming
e) primary, secondary, and finishing


Answer: D

Micrometers are available in a variety of types and are used mainly for the measurement of

Micrometers are available in a variety of types and are used mainly for the measurement of



a) length, width, and thickness of the boiler house structure
b) vertical, perpendicular and parallel distances in assembly of power plant machines
c) outside, inside and depth dimensions of relatively small openings of objects
d) the density of the boiler flue gases for pollution control
e) dissolved solids in boiler water


Answer: C

Flutes are found on

Flutes are found on



a) the inside edges of thread dies
b) the body of a twist drill bit
c) the point of a twist drill bit
d) thread taps
e) scribers


Answer: B

A dressing tool is used to

A dressing tool is used to



a) square the edges of a grinding wheel
b) clean the measuring contact surfaces of a micrometer
c) clean the grooves of a file
d) fit a new handle into a hammer head
e) re-set the teeth of a saw


Answer: A

Copper sulphate may be used

Copper sulphate may be used



a) as a thread cutting fluid
b) for lubricating very fine threads such as those in a micrometer
c) for coating tools in order to prevent rusting
d) to free nuts which are corroded to bolts
e) as a marking material


Answer: E

A collet is

A collet is



a) a type of hole punch
b) used to make a square hole in a piece of plate
c) the moving part of a micrometer
d) a type of face spanner wrench
e) a holder for a thread die


Answer: E

A file which is always single cut is the

A file which is always single cut is the



a) hand file
b) mill file
c) warding file
d) knife file
e) pillar file


Answer: B

Damaged tools

Damaged tools



a) are best disposed of or properly repaired
b) must be used carefully and cautiously if injury is to be prevented
c) should be kept in a special tool box
d) should be of no concern to the user
e) should be replaced under their "Lifetime" warranty


Answer: A

Relative to plant maintenance, a power engineer should have easy access to

Relative to plant maintenance, a power engineer should have easy access to



a) all ASME codes
b) the Chief Inspector
c) the Workers' Compensation Board Accident Prevention Regulations
d) all plant maintenance records and schedules
e) equipment suppliers


Answer: E

Heat lost from a building is

Heat lost from a building is



a) dependent on the shape of the openings in a building
b) is not affected by wind speed
c) affected by wind speed
d) independent of outside temperature
e) not affected by the density of the air


Answer: C

Heat is lost from a building in the following ways:

Heat is lost from a building in the following ways:



a) convection, evaporation, and radiation
b) infiltration, condensation, and conduction
c) evaporation, conduction, and radiation
d) conduction, radiation, and convection
e) infiltration, evaporation, and convection


Answer: D

If exhaust fans are used over cooking only

If exhaust fans are used over cooking only



a) 10% of the heat gain is used in calculations
b) 25% of the heat gain is used in calculations
c) 50% of the heat gain is used in calculations
d) 60% of the heat gain is used in calculations
e) 75% of the heat gain is used in calculations


Answer: C

Electric motors give off _________ while running.

Electric motors give off _________ while running.



a) sensible heat
b) latent heat
c) latent and sensible heat
d) no heat to the atmosphere
e) solar heat


Answer: A

Heat load from people in a room is mostly affected by

Heat load from people in a room is mostly affected by



a) the size of the people
b) smoking
c) the number of people
d) the activity of the people
e) none of the above


Answer: D

Air ventilation is based on the larger of these two requirements:

Air ventilation is based on the larger of these two requirements:



a) solar heat rate and CFM rate per person
b) conduction rate per person and solar heat rate
c) CFM rate and conduction rate per person
d) infiltration rate and CFM rate per person
e) none of the above


Answer: D

In calculating air infiltration the quickest method is

In calculating air infiltration the quickest method is



a) the air change method
b) the crack method
c) the solar method
d) the conduction method
e) none of the above


Answer: A

Two methods of calculating air infiltration into a building are

Two methods of calculating air infiltration into a building are



a) the crack and solar method
b) the air change and solar method
c) the crack and conduction method
d) the air change and crack method
e) the conduction and solar method


Answer: D

Conduction heat gains are calculated on the assumption that

Conduction heat gains are calculated on the assumption that



a) solar heat varies from hour to hour as sun changes position
b) solar heat gains are not included
c) construction details are unimportant
d) the "u" value is not used
e) solar heat gains are included


Answer: B

To control static pressure in the air ducts a differential pressure controller is installed. How does the controller control static pressure?

To control static pressure in the air ducts a differential pressure controller is installed. How does the controller control static pressure?



a) By increasing air temperature
b) By decreasing air temperature
c) By modulating the damper on the suction side of the fan
d) By modulating the damper on the discharge side of the fan
e) By grounding the ductwork and carrying the charge to a battery


Answer: C

To prevent too frequent starting and stopping of the compressor in a cooling system what should be done?

To prevent too frequent starting and stopping of the compressor in a cooling system what should be done?



a) Regulate the operation of the compressor with a set point thermostat
b) Turn off the compressor when temperatures required for conditioning are reached
c) Run the compressor continuously and vent any excess cold air
d) Run the main fan only
e) Run the compressor continuously and modulate refrigerant flow


Answer: E

Dehumidification is achieved by

Dehumidification is achieved by



a) absorbing the moisture with a sponge filter
b) absorbing moisture with a chemical drying agent
c) cooling the air to a corresponding dew point temperature
d) heating air to a corresponding wet bulb temperature
e) saturating the air until the precipitation point at room temperature is reached


Answer: C

A main advantage of steam type humidifiers over pan type humidifiers is that

A main advantage of steam type humidifiers over pan type humidifiers is that



a) steam type humidifiers are inexpensive
b) there is minimal time lag with steam type humidifiers
c) steam types can achieve higher relative humidity
d) steam types do not require a humidistat
e) steam type humidifiers require less space


Answer: B

Air conditioning with respect to heating coils is achieved in which of the following ways?

Air conditioning with respect to heating coils is achieved in which of the following ways?



a) A combination of tempering control functions
b) The selected mixing of warm return air and cooler outside air
c) Selective heating by passing air through the heating coils
d) Proportioning the amount of air flow through the face damper for heat addition, or through the bypass dampers for no heat addition.
e) All of the above


Answer: E

Which of the following is not a correct method of heat regulation?

Which of the following is not a correct method of heat regulation?



a) Direct modulation of the control valve on the steam or hot water to the heating coil
b) Modulating the position of a 3-way mixing valve on the hot/cold water line into the coil
c) Modulating the relative positions of face and bypass dampers controlling air flow across the coils
d) Modulating the actuators or the steam or water supply in conjunction with the coil bypass damper
e) Modulating the valve and the face and the bypass damper 30 degrees out of phase.


Answer: E

In severely cold weather what adjustment must be made to properly preheat the outside air?

In severely cold weather what adjustment must be made to properly preheat the outside air?



a) The temperature controller's throttling range must be increased
b) The outdoor damper should be closed
c) Two separate preheater coils should be installed
d) Damper must be heated
e) Preheat coil temperature should be increased


Answer: C

When the outdoor air damper increases the flow of fresh air, which of the following is true?

When the outdoor air damper increases the flow of fresh air, which of the following is true?



a) The return air damper throttles up to reduce the volume of recirculated air.
b) The return air damper throttles up to increase the volume of returned air.
c) The return air damper is not affected.
d) The return air damper throttles down to reduce the volume of returned air.
e) The return air damper throttles up to increase the volume of returned air.


Answer: D

When is the capacity of a heat pipe at a maximum?

When is the capacity of a heat pipe at a maximum?



a) When the system is level
b) When the evaporator is raised above the horizontal
c) When the system is placed vertically with the evaporator on top
d) When the system is placed vertically with the condenser on top
e) When the evaporator is lowered below the horizontal


Answer: E

Which of the following is not an advantage for a runaround system?

Which of the following is not an advantage for a runaround system?



a) Installation costs are comparatively low.
b) The system is readily adaptable to retrofit applications.
c) Piping is not required in the system.
d) The exhaust and ventilation streams can be remote.
e) Maintenance is relatively simple.


Answer: C

A system consists of two finned tube heat exchangers. Where is the preconditioning coil of this system located?

A system consists of two finned tube heat exchangers. Where is the preconditioning coil of this system located?



a) On the suction side of the pump
b) On the discharge side of the 3-way mixing valve
c) In the duct work handling the ventilation into the process
d) At the end of the charging unit
e) In the ductwork handling exhaust air


Answer: C

The recovery system which employs a single exchange unit consisting of a casing split into two sections and a segmented rotating wheel 300 mm (12 in) thick and 1 to 3.7 m (3 to 12 ft) in diameter is called a

The recovery system which employs a single exchange unit consisting of a casing split into two sections and a segmented rotating wheel 300 mm (12 in) thick and 1 to 3.7 m (3 to 12 ft) in diameter is called a



a) runaround system
b) thermal wheel
c) heat pipe
d) heat valve
e) heat pump


Answer: B

When looking at building function to select a system which of the following factors are considered?

When looking at building function to select a system which of the following factors are considered?



i) Physical size of the building
ii) Climatic conditions
iii) Amount of zoning required
iv) Funds available for the system
v) Occupancy periods
vi) Need to operate certain areas off-hours


a) i, ii, and vi
b) iii, v, and vi
c) i, iii, iv, v, and vi
d) ii, v, and iv
e) i, iii, iv, and vi


Answer: B

If operating personnel from an old building are going to be transferred to the new building the system installed in the new building will be the same as in the older building because all the personnel are familiar with that system. This type of system selection is based mainly on which of the following factors?

If operating personnel from an old building are going to be transferred to the new building the system installed in the new building will be the same as in the older building because all the personnel are familiar with that system. This type of system selection is based mainly on which of the following factors?



a) Building owner's considerations
b) Geographical location
c) Building layout
d) Operating costs
e) Maintenance requirements


Answer: A

A system which provides cooling and heating all year round is highly energy efficient but has a high initial cost. The system consists of two separate supply and return piping systems which are connected to separate coils. Which of the following systems fits this description?

A system which provides cooling and heating all year round is highly energy efficient but has a high initial cost. The system consists of two separate supply and return piping systems which are connected to separate coils. Which of the following systems fits this description?



a) A single pipe system
b) A four pipe system
c) A hydronic heat pump system
d) A three pipe system
e) A two pipe system


Answer: B

Which of the following statements about two-pipe arrangements is false?

Which of the following statements about two-pipe arrangements is false?



a) The arrangement is the least costly.
b) Piping is connected to the boiler during winter.
c) Piping is connected to the chiller during summer.
d) The arrangement is made up of a supply and return connection to a single coil.
e) The system can heat and cool at the same time.


Answer: E

An induction system gets its name from which property of the system?

An induction system gets its name from which property of the system?



a) The way air in the room is circulated
b) The type of units in each zone
c) The type of air handling unit
d) The air used in the central element of the system
e) The volume of air conditioned


Answer: A

Which of the following statements about fan coil units makeup air systems is false?

Which of the following statements about fan coil units makeup air systems is false?



a) The units include a disposable filter, fan, and heating/cooling coil.
b) Ventilation is provided by a 100% outside air system.
c) The air handling unit includes filters, heating coil, cooling coil, humidifier, and supply fan.
d) Fan coil units are installed in each room.
e) Humidity is controlled by the fan coil units.


Answer: E

A system used extensively in hotels and motels due to its minimal space requirement, relatively low initial cost, and high degree of individual zone control is called

A system used extensively in hotels and motels due to its minimal space requirement, relatively low initial cost, and high degree of individual zone control is called



a) a hydronic heat pump system
b) an induction system
c) a variable volume system with perimeter heating
d) a fan coil unit with make up air system
e) a compartmental atomizing system


Answer: D


In a constant air volume system with perimeter heating which of the following elements are fluids in the air handling unit?

In a constant air volume system with perimeter heating which of the following elements are fluids in the air handling unit?



i) Heating coils
ii) Cooling coils
iii) An air mixing section
iv) Filters
v) A humidifier
vi) A dehumidifier


a) i, ii, iii, and iv
b) i, ii, v, and vi
c) ii, iii, iv, and v
d) i, iii, and v
e) iii only


Answer: C

Which of the following statements about multi zone systems is true?

Which of the following statements about multi zone systems is true?



a) The cooling coils are installed in-line
b) The dampers are out of phase by 10 degrees
c) When the hot deck is fully opened the cold deck is fully closed
d) The system cannot operate a humidifier
e) All of the above


Answer: C

The most common system installed in most residences where the furnace is located in the basement and provides conditioned air via ducts to each room is called

The most common system installed in most residences where the furnace is located in the basement and provides conditioned air via ducts to each room is called



a) a forced air system
b) a single zone, constant air volume system
c) a low velocity terminal reheat system
d) a multizone system
e) a unit ventilator


Answer: A

Which of the following statements about central air conditioning systems is false?

Which of the following statements about central air conditioning systems is false?



a) Central systems are used in large buildings.
b) All the major equipment in central systems is located in a central mechanical room in the building.
c) Air is conditioned in the main mechanical room and distributed by duct work.
d) The central system is able to utilize large central equipment with high efficiency and low initial cost.
e) Unitary systems are able to control noise and vibration better than central systems.


Answer: E

Which of the following statements about the unit ventilators is false?

Which of the following statements about the unit ventilators is false?



a) The units are used in areas with limited available floor space
b) The units provide individual room temperature control
c) The units provide cooling only
d) The units provide heating
e) Room air is mixed with outside air


Answer: C

The unitary air conditioning system which uses a direct expansion refrigeration system to provide cooling and dehumidification in a local area without ductwork is called

The unitary air conditioning system which uses a direct expansion refrigeration system to provide cooling and dehumidification in a local area without ductwork is called



a) a unit ventilator
b) a rooftop unit
c) a window air conditioner
d) a high velocity terminal reheat system
e) a multi zone system


Answer: C

Which of the following statements about air handling units is true?

Which of the following statements about air handling units is true?



a) In any system the air is mainly conditioned in the units
b) The units can only heat air
c) The units only circulate
d) For each function there needs to be a separate air handling unit
e) None of the above


Answer: A

Steam grid humidifiers used in air conditioning systems achieve humidification by

Steam grid humidifiers used in air conditioning systems achieve humidification by



a) the installation of a steam coil in the entering air stream
b) the installation of a water coil in the entering air stream
c) injecting steam in the supply air stream
d) injecting steam into the spray water of an air washer
e) injecting steam directly into the rooms to be humidified


Answer: C

Which is not a method employed to maintain the desired temperature of the spray water in air washers used in air conditioning systems?

Which is not a method employed to maintain the desired temperature of the spray water in air washers used in air conditioning systems?



a) an electric heater and fan
b) part of the spray water is recirculated and hot or cold water is added as required
c) the spray water if recirculated through a heat exchanger and is cooled by chilled water
d) the spray water is recirculated through a heat exchanger and is heated by hot water
e) a heating or cooling coil is directly mounted in the sump of the washer



Answer: A

Air washers used in air conditioning systems achieve cooling and dehumidification by

Air washers used in air conditioning systems achieve cooling and dehumidification by



a) heating the spray water to a temperature above the dry bulb temperature of the entering air
b) cooling the spray water to a temperature below the dew point temperature of the entering air
c) cooling the entering air below its dry bulb temperature
d) heating the entering air above its dry bulb temperature
e) heating the spray water to a temperature above the dew point temperature of the entering air


Answer: B

Air washers used in air conditioning systems achieve heating and humidification by

Air washers used in air conditioning systems achieve heating and humidification by



a) cooling the spray water to a temperature below the dew point of the entering air
b) cooling the spray water to a temperature below the dry bulb temperature
c) heating the spray water to a temperature above the dry bulb temperature of the entering air
d) heating the entering air above its dry bulb temperature
e) cooling the entering air below its dry bulb temperature


Answer: C

Air washers used in air conditioning systems

Air washers used in air conditioning systems



a) only clean the air
b) only clean and cool the air
c) only humidify and dehumidify the air
d) humidify, heat, cool, dehumidify, and clean the air
e) only humidify, cool, and clean the air


Answer: D

A disadvantage of the atomizing humidifier is

A disadvantage of the atomizing humidifier is



a) it has a lower humidification rate than the pan type humidifier
b) its evaporation plates clog up due to the salt left behind after evaporation
c) it can be used only as an individual area or room humidifier
d) its evaporation plates have to be replaced regularly
e) the salts that were in the water before atomization and evaporation settle as white dust in rooms and ducts


Answer: E

Atomizing humidifiers

Atomizing humidifiers



a) break up the water for humidification into small particles by either a spinning disc or spray nozzle and are placed either in the warm air supply duct or in the area to be humidified
b) spray water through plates to atomize the water
c) spray water through rotating pads to atomize the water
d) can be either the power type or the bypass type
e) have a lower humidification rate than the pan type humidifiers


Answer: A

Wetted element humidifiers

Wetted element humidifiers



a) are the same as pan type humidifiers
b) can be either the power type or the bypass type
c) have stationary plates placed in a tray and placed in individual rooms
d) have a lower humidification rate than the pan type Atomizing humidifiers


Answer: B

Pan type humidifiers with plates

Pan type humidifiers with plates



a) consist of rotating plates in a pan partially filled with water
b) are placed in individual rooms to humidify the individual rooms
c) consist of a shallow pan, partially filled with water in which absorbent plates are placed and the pan is installed in the supply plenum of smaller warm air furnaces
d) consist of plates in a pan through which water is sprayed by a spinning disc or cone
e) can be a power type or a bypass type


Answer: C

The types of humidifiers used for residential purposes are

The types of humidifiers used for residential purposes are



a) air washers, wetted element, and atomizing
b) pan, atomizing, and air washers
c) pan, hot water, and air washers
d) atomizing, wetted element, and pan
e) pan, steam, and atomizing


Answer: D

Humidifying units which use a small fan to draw warmer air from the furnace plenum or from the room, force the air through the wetted pad, and return the air to the room, are called

Humidifying units which use a small fan to draw warmer air from the furnace plenum or from the room, force the air through the wetted pad, and return the air to the room, are called



a) pan type humidifiers with plates
b) atomizing humidifiers
c) bypass type humidifiers
d) power type wetted element humidifiers
e) industrial pan type steam grid humidifiers


Answer: D

Dehumidification occurs in an Air washer when which of the following occurs?

Dehumidification occurs in an Air washer when which of the following occurs?




a) If the level in the bottom tank drops lower than the minimum level
b) If water temperature is heated above the dry bulb temperature
c) If spray water is cooled to a temperature below the dew point
d) Heating of the spray water
e) None of the above


Answer: C

To keep humidifiers in top condition the plates of plate type units should be cleaned by soaking them in a slightly acidic solution and then washing them in soapy water to

To keep humidifiers in top condition the plates of plate type units should be cleaned by soaking them in a slightly acidic solution and then washing them in soapy water to




a) remove dirt
b) remove grease
c) remove soot
d) remove mineral salts
e) remove corrosion on the plate


Answer: D

Which of the following statements about Air washers is false?

Which of the following statements about Air washers is false?



a) Air washers can cool air.
b) Air washers can remove tobacco smoke.
c) Air washers can dehumidify air.
d) Air washers can heat air.
e) Air washers can clean air.


Answer: B

Which type of humidifier breaks water up into a mist or fog?

Which type of humidifier breaks water up into a mist or fog?



a) A bypass humidifier
b) A welted element humidifier
c) An atomizing humidifier
d) An air washing humidifier
e) A steam grid humidifier


Answer: C

The residential humidifier which is commonly used in the supply plenum of smaller warm air furnaces and consists of a shallow tray partially filled with water is called a

The residential humidifier which is commonly used in the supply plenum of smaller warm air furnaces and consists of a shallow tray partially filled with water is called a



a) bypass humidifier
b) welted element humidifier
c) steam grid humidifier
d) pan type humidifier
e) power type humidifier


Answer: D

Humidification in residences equipped with ducted warm air heating systems

Humidification in residences equipped with ducted warm air heating systems



a) is not necessary because the humidity does not change with heating
b) requires separate humidifiers for each heated area
c) is accomplished by installing a second heating system, such as hot water
d) is supplied sufficiently by normal living processes such as cooking, washing, and breathing
e) is provided for by placing a single humidifier in the furnace plenum or in the warm air duct


Answer: E

Relative humidity

Relative humidity



a) increases when the air temperature is raised without the addition of moisture to the air
b) remains the same when the air temperature is raised
c) decreases when the air temperature is raised without the addition of moisture to the air
d) remains the same when the air temperature is lowered
e) decreases when the air temperature is lowered without the addition of moisture to the air


Answer: C

The purpose of humidification is to

The purpose of humidification is to



a) add humidity to the air during the cooling season
b) add humidity to the air during the heating season
c) remove moisture from the air during the heating season
d) remove moisture from the air during the cooling season
e) add moisture to the air during the cooling season



Answer: B

Relative humidity is the amount of

Relative humidity is the amount of



a) moisture contained in the air compared to the maximum amount of moisture the air is capable of holding at the stated temperature
b) moisture contained in the air compared to the maximum amount of moisture the air is capable of holding, air temperature being irrelevant
c) air contained in the air-moisture mixture compared to the maximum amount of air the air-mixture moisture is capable of holding at the stated temperature
d) air compared to the amount of moisture in the air at any temperature
e) moisture contained in the air at 0 degrees C


Answer: A

Humidity in the air

Humidity in the air



a) increases when the air temperature decreases
b) increases when the air pressure decreases
c) decreases when the air pressure increases
d) decreases when the air temperature decreases
e) remains constant with air temperature changes


Answer: D

The outside temperature 18 - 25 degrees C is saturated (Air at -25 degrees C holds a maximum of 0.0005 kg of moisture/kg of water). This air is drawn into the building and heated to 21 degrees C (air at 21 degrees C holds a maximum of 0.015 kg of moisture/kg of water). What is the relative humidity of the air inside?

The outside temperature 18 - 25 degrees C is saturated (Air at -25 degrees C holds a maximum of 0.0005 kg of moisture/kg of water). This air is drawn into the building and heated to 21 degrees C (air at 21 degrees C holds a maximum of 0.015 kg of moisture/kg of water). What is the relative humidity of the air inside?



a) 3.3%
b) 0.015%
c) 0.5%
d) 10.6%
e) 4.5%


Answer: A

Which of the following is not a result of very low humidity?

Which of the following is not a result of very low humidity?



a) Throat and nose membranes drying up
b) Static electricity build-up
c) Evaporation of moisture on the skin decreases
d) At sufficiently high room temperatures people still feel cool
e) Wood furniture and floor squeaks and cracks


Answer: C

Air vents are

Air vents are



a) not required when an inverted bucket steam trap is used
b) not required on the steam mains if an inverted bucket steam trap is used at the steam coil
c) not required at the steam coil if a float and thermostatic (F & T) trap is used at the steam coil with an atmospheric return and the steam main is adequately vented
d) not required anywhere if a float and thermostatic (F & T) trap is used at the steam coil
e) required only with hot water coils


Answer: C

A modulating control valve

A modulating control valve



a) can be oversized
b) is used for steam coils where the condensate is lifted to an overhead return
c) is used for steam coils when the entering air temperature is below 1.5 degrees C
d) can be used to control steam coils when the entering air temperature is above 1.5 degrees C
e) is not used to control steam coils at any air inlet temperature


Answer: D

The inverted bucket steam trap is

The inverted bucket steam trap is



a) used when the coil steam pressure is higher than 172 kpa or 25 psig
b) used when the flow is modulated
c) used when the coil steam pressure is lower than 172 kpa or 25 psig
d) recommended when condensate flows by gravity into a return main at atmospheric pressure
e) more expensive than the F & T trap


Answer: A

Steam coils

Steam coils



a) should be installed with tubes in a vertical position to ensure positive condensate drainage
b) when installed in the horizontal position, do not have to be pitched toward the return
c) are installed exactly the same as are glycol coils
d) do not require a vacuum breaker
e) do not require air venting


Answer: A

Steam coil piping and trapping

Steam coil piping and trapping



a) is the same as for hot water and glycol coils
b) only handles steam and non-condensable gases
c) differs from the hot water and glycol coil because it carries more fluids: steam, air, water, and non condensable gases
d) are installed in the horizontal position whenever possible
e) can be supported directly by the coils


Answer: C

Which of the following is not an installation recommendation for steam traps?

Which of the following is not an installation recommendation for steam traps?



a) Base steam trap selection or the pressure difference across the trap and a minimum capacity corresponding to three times the coil condensate rate.
b) Locate the steam trap so that its outlet is at least 30 cm (12 in) above the coil return connection.
c) Trap each coil separately.
d) Install a strainer near the inlet of each trap.
e) Drip the steam supply main through a steam trap into the return condensate main.


Answer: B

The greatest fears in hot water coil installations handling subfreezing air are:

The greatest fears in hot water coil installations handling subfreezing air are:



i) pipe expansivity
ii) outside air temperature being too low
iii) failure of the circulating pipe
iv) water viscosity being too high
v) failure of the heat source


a) i, ii, and iv
b) i, ii, and iii
c) iii only
d) i, iv, and v
e) iii and v


Answer: E

Which of the following statements about vacuum breakers is false?

Which of the following statements about vacuum breakers is false?



a) They are used to prevent freeze-ups caused by negative pressure in the coil.
b) The vacuum breaker must be installed before the control valve and as near as possible to the outlet connection of the coil.
c) Check valves used as vacuum breakers may be left open to the atmosphere.
d) Check valves used as vacuum breakers may be connected to the return header.
e) Vacuum breakers are essential for satisfactory functioning of the steam trap.


Answer: B

A thermostat which is sometimes installed in the return air duct serves which main function?

A thermostat which is sometimes installed in the return air duct serves which main function?



a) To limit temperature of the heated outside air
b) To control the throttle of the steam in the tubes
c) To sense the temperature of the steam in the coils
d) To minimize temperature fluctuations in discharge air
e) To heat recirculated air


Answer: D

Glycol coils using ethylene glycol

Glycol coils using ethylene glycol



a) give reasonable heat transfer efficiency at low glycol velocity
b) are not recommended for use in heating and air conditioning systems in the food industry
c) use direct fired boilers as their heat source
d) do not use steam-glycol converters as their heat source
e) are used only for heating purposes and are not used for cooling purposes


Answer: B

Ethylene glycol used in glycol coils

Ethylene glycol used in glycol coils



a) has a higher heat transfer efficiency than hot water
b) has less friction losses in the coil and piping than hot water
c) requires a smaller pump and less horsepower than hot water
d) has much lower pressure drops through the coil and piping
e) has a lower heat transfer efficiency than hot water


Answer: E

For a glycol system using hot water as its heat source which of the following statements is false?

For a glycol system using hot water as its heat source which of the following statements is false?



a) Valve V-3 will be opened to feed a constant flow of hot water to the converter.
b) Hot water temperature should not exceed 100 degrees C.
c) Temperature controller TC-1 opens V-3 when the temperature outside drops to 10 degrees C.
d) Flow Switch FS automatically starts the glycol pump automatically after V-3 is opened.
e) Provide flanges or unions and manual shutoff valves to facilitate coil removal.


Answer: D

The use of ethylene glycol solution will result in which of the following:

The use of ethylene glycol solution will result in which of the following:



i) Lower heat transfer rate
ii) Better protection against freezing
iii) Increased friction losses in the coil and piping
iv) The requirement of a larger pump with more H.P.


a) i and iv
b) i and iii
c) i and iv
d) iii only
e) i, ii, iii, and iv


Answer: E

The flow arrangement best suited for hot water coils is

The flow arrangement best suited for hot water coils is



a) the counterflow arrangement because it is more efficient
b) the parallel flow arrangement because it gives better protection against freezing
c) one in which the cold air enters the coil where the coldest water is flowing
d) the half serpentine
e) the triple bypass flow arrangement


Answer: B

The purpose of the flow switch or sail switch used with hot water coils is to

The purpose of the flow switch or sail switch used with hot water coils is to



a) stop the fan and close the outside air dampers if the low limit temperature controller malfunctions or the heat source fails
b) open the outside air dampers wide when the outside air temperature rises
c) increase the heat source temperature if the outside air temperature decreases
d) close the outside air dampers and stop the fan if the flow of water is interrupted due to pump failure or closing of the hand valves
e) increase the hot water flow through the coil if the outside air temperature is too low



Answer: D

The purpose of the "freeze-stat" temperature controller used with hot water coils is to

The purpose of the "freeze-stat" temperature controller used with hot water coils is to



a) close the outside air dampers and stop the fan if the heat source fails or the low limit temperature controller malfunctions
b) increase the hot water flow through the coil if outside air temperature is too low
c) increase the heat source temperature if the outside air temperature decreases
d) open the outside air dampers wide when the outside air temperature rises
e) increase the fan output if the return air temperature is too low


Answer: A

Which of the following is not a cause of freezing in hot water coils?

Which of the following is not a cause of freezing in hot water coils?



a) failure of the circulating pump
b) very low circulating water velocity
c) very high circulating water velocity
d) failure of the heat source
e) poor air venting of the coil


Answer: C

In a hot water coil which of the following is not included for providing a good guideline for the correct application of the system with minimal possibility of freeze-up?

In a hot water coil which of the following is not included for providing a good guideline for the correct application of the system with minimal possibility of freeze-up?



a) Positive air venting of the coil is essential
b) The air velocity should exceed 10 m/s
c) A constant flow of water should be fed to the coil
d) The water velocity should exceed 0.8 m/s
e) The water temperature should be maintained at a reasonable preset temperature


Answer: B

The purpose of a vacuum breaker used with steam coils is to

The purpose of a vacuum breaker used with steam coils is to



a) ensure positive air pressure in the conditioned space
b) ensure negative air pressure in the conditioned space
c) prevent excessive temperatures within the steam coil
d) prevent possible freezing caused by a vacuum or negative pressure in the steam coil
e) ensure proper operation of the steam control valve


Answer: D

It is good design practice to select a steam coil size

It is good design practice to select a steam coil size



a) so that 100% of the coil capacity is needed when the air temperature entering the coil is -1 degrees C
b) so that at least 40% of the coil capacity is needed when the air temperature entering the coil is -1 degree C
c) so that at least 80% of the coil capacity is needed when the air temperature at the coil inlet is -1 degree C
d) so that at least 10% of the coil capacity is needed when the air temperature at the coil inlet is -5 degrees C
e) so that it is twice the size that is required to handle the heating load


Answer: B

To prevent freezing of the steam coil when steam pressure at the coil inlet is too low or is lost

To prevent freezing of the steam coil when steam pressure at the coil inlet is too low or is lost



a) a second preheat coil is installed at the outside air inlet
b) a modulating steam control valve is installed at the coil inlet
c) a two-position steam control valve is installed at the coil inlet
d) the fan output is increased
e) provisions are made to stop the fan and close the outdoor air dampers


Answer: E

Freezing problems in steam coils with long tube lengths, handling a large amount of low temperature outside air

Freezing problems in steam coils with long tube lengths, handling a large amount of low temperature outside air



a) are minimized by using preheat coils controlled by an outdoor temperature controller
b) are minimized by using modulating control valves to control the steam heating coil output
c) are best minimized by using a two-position control valve to control coil output
d) are minimized by using an oversized coil
e) are minimized by using an oversized control valve


Answer: A

Steam coils with long tube lengths

Steam coils with long tube lengths



a) have the greatest freezing problems at extremely low temperatures such as -35° C
b) have the greatest freezing problems at temperatures of about -2 to -1° C
c) have freezing problems at any temperature
d) are not likely to freeze at any temperature
e) are less likely to freeze than steam coils with short tube lengths


Answer: B

Steam coils with a short tube length of 1.1 m or less

Steam coils with a short tube length of 1.1 m or less



a) are more likely to freeze, even if the steam trap is properly chosen
b) are not recommended because they are more likely to freeze
c) are more likely to freeze, even if the coil is properly piped and sloped
d) are less likely to freeze if the steam trap is properly chosen and the coil is properly piped
e) are less likely to freeze regardless of steam trap choice and coil piping


Answer: D

It is good practice to select steam coils which require at least 40% of coil capacity when air temperature is 1 degree C for which of the following reasons?

It is good practice to select steam coils which require at least 40% of coil capacity when air temperature is 1 degree C for which of the following reasons?




a) Steam flow is high enough at high temperature and prevents build-up and freezing of condensate
b) The load on the circulating fan is kept from overheating
c) The mixing valve will never cut out if capacity stays above 40%
d) To avoid hot condensate splashing
e) None of the above


Answer: A

Face velocity is the

Face velocity is the



a) velocity of the supply water to the coil
b) velocity of the air before it enters the coil
c) velocity of the air after it leaves the coil
d) average velocity of the air flowing over the face area of the fin surface
e) velocity of the return water from the coil


Answer: D

Rippled-finned surface type coils

Rippled-finned surface type coils



a) are often used for low temperature application where ice may form
b) decrease the heat transfer efficiency
c) increase the heat transfer efficiency by creating more turbulence at fin surfaces
d) have no effect on heat transfer efficiency
e) are not used in air handling systems


Answer: C

Flat-finned surface type coils are normally used for

Flat-finned surface type coils are normally used for



a) steam heating purposes
b) water heating purposes
c) high temperature application
d) low temperature application where ice may form
e) greater turbulence of air at the fin surface


Answer: D

Two types of modern coils used for heating and cooling services in air handling systems are

Two types of modern coils used for heating and cooling services in air handling systems are



a) the continuous-plate finned surface and the spiral finned surface
b) the bare tube and the spiral-finned surface
c) the continuous-plate finned surface and the bare tube
d) the bare tube and the insulated tube
e) none of the above


Answer: A

Fin surface area is called

Fin surface area is called



a) primary surface area
b) secondary surface area
c) tube surface area
d) heater surface area
e) none of the above


Answer: B

Which of the following statements about coil surfaces is false?

Which of the following statements about coil surfaces is false?



a) Air flows across the fins
b) Finned coils are more compact than smooth tube coils of the same capacity
c) Fins increase the contact surface area between the airstream and the tubes
d) All fins must be crimped
e) Finned coils are less expensive than smooth coils of the same capacity


Answer: D

Which one of the following methods is not a method of ensuring uniform steam distribution in steam coils?

Which one of the following methods is not a method of ensuring uniform steam distribution in steam coils?



a) installation of distributing plates within the steam header
b) "steam distributing" coils
c) installation of individual orifices into the supply end of each tube
d) once called "non-freeze coils"
e) controlling the face velocity of the air flowing over coils


Answer: E

To assure proper air venting, the

To assure proper air venting, the



a) return water connection should be at the bottom of the coil
b) supply water connection should be at the bottom of the coil
c) supply water connection should be at the top of the coil
d) vent should be located at the lowest points of the supply and return lines, and of the coils
e) double serpentine water coil circuit should be used


Answer: B

Half serpentine water coil circuiting is used

Half serpentine water coil circuiting is used



a) in applications requiring high water velocities and low water pressure drops
b) where the water velocity in the tubes is more than 2.4 m/s
c) where the water velocity in the tubes is between 0.3 and 2.4 m/s
d) for any water velocity in the tubes
e) where the water velocity in the tubes is less than 0.3 m/s


Answer: E

Double serpentine water coil circuiting is used

Double serpentine water coil circuiting is used



a) where the water velocity in the tubes is less than 0.3 m/s
b) where the water velocity in the tubes is more than 2.4 m/s
c) for any water velocity in the tubes
d) where the water velocity in the tubes is between 0.3 and 2.4 m/s
e) in applications requiring low water velocities and low water pressure drops


Answer: B

Single serpentine water coil circuiting is used

Single serpentine water coil circuiting is used



a) where the water velocity in the tubes is less than 0.3 m/s
b) where the water velocity in the tubes is more than 2.4 m/s
c) for any water velocity in the tubes
d) where the water velocity in the tubes is between 0.3 and 2.4 m/s
e) in applications requiring high water velocities and low water pressure drops


Answer: D

The most commonly used types of water coil circuiting are

The most commonly used types of water coil circuiting are



a) single serpentine, double serpentine, and half serpentine
b) full circuit, double circuit, and triple circuit
c) single serpentine, double serpentine, and triple serpentine
d) parallel and serpentine
e) parallel, counterflow, and serpentine


Answer: A

With counterflow arrangement of air and water

With counterflow arrangement of air and water



a) the water supply connection is on the same side as the entering air
b) it decreases the heat transfer efficiency
c) the water supply connection is on the same side as the leaving air
d) the water return connection is on the same side as the leaving air
e) the heat transfer efficiency is the same as with parallel arrangement of air and water


Answer: C

Proper performance of heating and cooling water coils depends on

Proper performance of heating and cooling water coils depends on



a) adequate air velocity over the finned surface
b) counterflow arrangement of air and water
c) air venting from the system and the coil
d) tube circuiting and finning
e) all of the above


Answer: E

A factor limiting the number of fins that can be used on coils is

A factor limiting the number of fins that can be used on coils is



a) the diameter of the tube
b) the temperature of the fluid in the tube
c) the material that the tube is made of
d) the resistance to airflow
e) the direction the fluid is flowing in the tube


Answer: D

Which of the following statements about water coils is false?

Which of the following statements about water coils is false?



a) Coils should be hooked up in a counterflow arrangement.
b) Coils need to be able to vent air.
c) Adequate air velocity over the finned surface must be maintained.
d) Circuiting should minimize the performance of the water flow versus the pressure drop through the coil.
e) The bottom connection should always be the water inlet.


Answer: D

To obtain full rated capacity of water coils what should be done?

To obtain full rated capacity of water coils what should be done?



a) Connect the water supply for counterflow
b) Connect the water supply for parallel flow
c) Decrease the number of fins per unit length of coil
d) Connect the coils with a staggered tube design
e) Increase face velocity


Answer: A

Which of the following statements about steam distributing coils is true?

Which of the following statements about steam distributing coils is true?



a) The coils never freeze
b) The coils distribute steam evenly over the entire coil
c) The coils are used when steam cannot be throttled
d) The coils cannot be used where freezing air temperatures are frequently encountered over the coil
e) The coils can only have same end connections


Answer: B

In order to provide uniform steam distribution to the individual tubes, which of the above design parameters is/are true?

Steam Coils must be designed to:
i) constantly eliminate air
ii) constantly eliminate condensate
iii) constantly eliminate noncondensable gases
iv) constantly maintain face velocity
v) constantly eliminate air venting

In order to provide uniform steam distribution to the individual tubes, which of the above design parameters is/are true?



a) ii, iii, and v
b) iii only
c) ii and iv
d) i, iii, iv, and v
e) i, ii, and iii


Answer: E

Air venting is required for which of the following reasons?

Air venting is required for which of the following reasons?



a) To assure adequate water distribution in supply and return lines
b) To assure adequate air distribution in supply lines
c) To assure adequate air distribution in return lines
d) To maintain face velocity
e) All of the above


Answer: A

Functions of terminal air distribution devices are accomplished

Functions of terminal air distribution devices are accomplished



a) only by diffusion
b) only by diffusion and aspiration
c) by aspiration, entrainment, induction, and diffusion
d) only by entrainment and diffusion
e) only by entrainment and aspiration


Answer: C

Which of the following is not a function of terminal air distribution devices?

Which of the following is not a function of terminal air distribution devices?



a) provide uniform space temperatures
b) provide adequate air motion to prevent local still pockets of air without excess drafts
c) maintain comfortable conditions mainly along the ceiling and outside walls within the occupied zone
d) distribute the air to the spaces
e) control or counteract the effects of conduction, radiation, and convection


Answer: C

Which of the following is NOT a function of terminal air distribution devices?

Which of the following is NOT a function of terminal air distribution devices?



a) Distribute the air to the spaces
b) Provide uniform space temperatures
c) Control or counteract the effects of conduction, convection, and radiation
d) Provide adequate air motion
e) Create local still pockets of air


Answer: E

Air louvers

Air louvers



a) are often used for mixing boxes
b) are always used for fire and smoke dampers
c) are suited for two position damper operation
d) are used in fresh air intake openings to minimize the amount of water and snow entering the air handling system
e) are used as relief dampers


Answer: D

Parallel blade dampers

Parallel blade dampers



a) are used only in small sizes with low velocity air
b) are used when modulation of air flow is required
c) have blades linked so adjacent blades rotate in opposite directions
d) are often used on mixing boxes where two sets of dampers are mounted with blades direct
e) are not suited for two position damper operation


Answer: D

Damper designs include

Damper designs include



a) only parallel blade types
b) only single blade types
c) opposed blade, parallel blade, and single blade types
d) only opposed blade types
e) none of the above


Answer: C

Relief dampers

Relief dampers



a) allow air flow in both directions
b) allow air flow in one direction only
c) allow air mixing
d) are the same as bypass dampers
e) are the same as face dampers


Answer: B

Modulating dampers in air handling systems are used

Modulating dampers in air handling systems are used



a) as mixing boxes to proportion the amounts of two different air flows such as outdoor air and recirculated air
b) to modulate the volume of conditioned air needed to meet load requirements
c) as face dampers to modulate the volume of air that goes through a cooling or heating coil
d) as bypass dampers to throttle the balance of the constant total air flow around a heating or cooling coil
e) all of the above


Answer: E

Dampers in air handling systems

Dampers in air handling systems



a) may only be manual and modulating
b) may only be modulating
c) may be modulating, manual, or two position
d) may only be manual and two position
e) may only be two position


Answer: C

The purpose of dampers in an air handling system is

The purpose of dampers in an air handling system is



a) to control the flow of air
b) to regulate refrigeration compressor speed
c) to control the flow of water in a hot water heating system
d) to regulate the fire in heating boilers
e) to control the flow of water in a water cooling system

Answer: A

Duct liners

Duct liners



a) eliminate corrosion
b) reduce the noise level of air flowing in the duct system
c) reduce fire hazard
d) increase erosion to the duct
e) increase the pressure


Answer: B

Return air duct leakage calculations include

Return air duct leakage calculations include



a) 3% seepage if the return air duct is outside the conditioned space
b) 3% seepage if the return air duct is both inside and outside the conditioned space
c) 10% leakage if the return air duct is inside the conditioned space
d) 3% leakage if the return air duct is inside the conditioned space
e) 5% seepage if the return air duct is outside the conditioned space


Answer: A

Supply air duct leakage loss calculations include

Supply air duct leakage loss calculations include



a) 20% leakage loss when all the supply air duct is outside the conditioned space
b) losses from bare supply air ducts within the conditioned space
c) 10% leakage loss when all the supply air duct is outside the conditioned space
d) 5% leakage loss when all the supply air duct is outside the conditioned space
e) 10% leakage loss when some of the supply air duct is outside the conditioned space and some inside


Answer: C

When all supply air duct is outside the conditioned space there is a certain leakage. This leakage must be calculated how?

When all supply air duct is outside the conditioned space there is a certain leakage. This leakage must be calculated how?



a) It must be added to the calculated room sensible heat load.
b) It need not be considered in loss calculation.
c) It must be subtracted from the return air duct leakage.
d) It must be added to the return air duct leakage.
e) It must be added to the calculated room specific latent humidity load.


Answer: A

Seepage in return air ducts turned within the conditioned space may have what kind of effect?

Seepage in return air ducts turned within the conditioned space may have what kind of effect?



a) It will add to the amount of air needed to supply the cooled space.
b) It will ruin the duct's insulation.
c) It will increase the load on the air system in terms of volumes of air.
d) It will increase the load on the air system in terms of pressure.
e) It will create a loss of cooling effect.


Answer: C

Which of the following statements about duct leakage losses is true?

Which of the following statements about duct leakage losses is true?



a) The effects of air leakage in supply air ducts are the same as those in return ducts.
b) Air leakage varies from 40% to 45%.
c) Leakage inspection can only be done after the duct is covered in insulation.
d) Losses from bare supply air ducts within the conditioned space have a substantial impact on loss calculations.
e) Losses due to air leakage from furred supply air ducts within the conditioned space can only be evaluated on the basis of judgement.



Answer: E

Ducts are fabricated of

Ducts are fabricated of



a) sheet metal
b) cement asbestos
c) plastic
d) fibreglass
e) all of the above


Answer: E

Materials used in sheet metal ducts are

Materials used in sheet metal ducts are



a) only copper
b) only aluminum
c) only stainless steel
d) galvanized or black steel, aluminum, copper, and stainless steel
e) only galvanized or black steel


Answer: D

Fibreglass ducts are used

Fibreglass ducts are used



a) in high pressure systems
b) to handle air with high moisture levels or oil and grease
c) where its heavy weight is not a problem
d) where high strength is required
e) in some low pressure systems


Answer: E

Medium and high pressure duct systems require less space than low pressure duct systems, but this feature is partly offset by

Medium and high pressure duct systems require less space than low pressure duct systems, but this feature is partly offset by



a) higher operating cost and higher initial cost of air handling apparatus
b) costly special control devices and costly noise suppressing devices
c) higher first cost for special equipment required to reduce the air velocity before distribution to the air space
d) more costly fabrication and installation of ductwork
e) all of the above


Answer: E

Classifications of air conditioning ducts include

Classifications of air conditioning ducts include



a) low pressure and medium pressure
b) low pressure, medium pressure, and high pressure
c) medium pressure and high pressure
d) absorption and compression
e) heating and cooling


Answer: B

The main function of an air conditioning duct system is

The main function of an air conditioning duct system is



a) to only transmit return air from the space to be conditioned
b) to only transmit supply air from the air handling apparatus
c) to only transmit air to the refrigeration compressor
d) to transmit supply and return air between the air handling apparatus and the space to be conditioned
e) to transmit air from the refrigeration compressor to the condenser


Answer: D

Short radius elbows should be provided with

Short radius elbows should be provided with



a) stiffeners
b) turning vanes
c) mitre elbows
d) positive lock dampers
e) flexible connections


Answer: B

Ducts of large dimensions must be diagonally creased to

Ducts of large dimensions must be diagonally creased to



a) provide stiffness
b) allow gradual duct size change
c) decrease duct weight
d) increase air velocity
e) decrease air friction in the duct work


Answer: A

Total pressure exerted by the air is the sum of

Total pressure exerted by the air is the sum of



a) suction pressure and velocity pressure
b) head pressure and suction pressure
c) head pressure and velocity pressure
d) static pressure and velocity pressure
e) head pressure, suction pressure, and velocity pressure


Answer: D

Velocity pressure exerted by the air is measured by connecting a

Velocity pressure exerted by the air is measured by connecting a



a) manometer at right angles to the air duct
b) manometer with the opening facing the air flow in the air duct
c) manometer to the fan
d) bourdon tube pressure gage to the air duct
e) pressure gage at right angles to the air duct


Answer: B

Static pressure exerted by air is measured by connecting

Static pressure exerted by air is measured by connecting



a) a manometer at right angles to the air duct
b) a bourdon tube pressure gage to the air duct
c) a pressure gage with the opening facing air flow
d) a manometer with the opening facing the air flow
e) a manometer to the fan


Answer: A

What are the three different kinds of pressure developed by a fan?

What are the three different kinds of pressure developed by a fan?



a) static pressure, head pressure, suction pressure
b) velocity pressure, head pressure, suction pressure
c) static pressure, velocity pressure, total pressure
d) head pressure, suction pressure, total pressure
e) static pressure, head pressure, total pressure


Answer: C

Axial flow fans

Axial flow fans



a) have maximum horsepower requirements at maximum or free air delivery
b) have minimum horsepower at maximum or free air delivery
c) are quieter than centrifugal fans
d) are the least economical fans used to produce high capacity, low pressure air movements
e) are not the logical choice to move large volumes of air at low pressures


Answer: B

The tube axial flow fan

The tube axial flow fan



a) has higher friction losses in ducts than the straight air flow of a centrifugal fan
b) has lower friction losses in ducts than the centrifugal fan
c) is quiet in operation
d) produces lower pressure than the propeller fan
e) is not suitable for duct mounting


Answer: A

The propeller axial flow fan

The propeller axial flow fan



a) is the least economical fan used to produce high capacity, low pressure air movements
b) is used in ducted air distribution systems
c) is used in commercial air conditioning ducting
d) requires the least power at minimum air delivery
e) finds application in unit heaters, air-cooled condensers, and as an exhaust fan for ventilation purposes


Answer: E

The propeller axial flow fan is used

The propeller axial flow fan is used



a) for low capacity, high pressure applications
b) for low capacity, low pressure applications
c) for high capacity, high pressure applications
d) for high capacity, low pressure applications
e) in ducted air distribution systems


Answer: D

Forward curved fans

Forward curved fans



a) require larger size shafts than backward inclined fans
b) are desirable when air handling units have two or more fans mounted on a common shaft
c) operate at higher speeds than backward inclined fans
d) are quieter than backward inclined fans
e) are more desirable for large fans


Answer: B

Backward inclined airfoil fans

Backward inclined airfoil fans



a) are mostly used for low capacity, high pressure applications
b) are mostly used for high capacity, low pressure applications
c) are mostly used for high capacity, high pressure applications
d) have a lower initial cost than the plain backward inclined fan
e) are less efficient than the plain backward inclined fan


Answer: C

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