HVAC Systems

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Author:
tonytee
ID:
141421
Filename:
HVAC Systems
Updated:
2012-11-14 16:44:45
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Technical Core HVAC Heating Ventilation Air Cooling
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Description:
HVAC learning 1.Thermodynamics and Properties of Air 2.Hydronic Cooling Systems 3.Air Distribution Systems 4.Direct Expansion Units 5.Heating Systems 6.Automatic Controls 7.Water Treatment Systems
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  1. Module 1: Thermodynamics and Properties of Air

    1. Consider air in a boiler's combustion chamber. The air closest to the heat source receives heat, becomes less dense, and rises. The surrounding, denser cool air then moves to replace the heated air.

    a. Conduction

    b. Radiation

    c. Convection
    c. Convection
  2. Module 1: Thermodynamics and Properties of Air

    2. Cooling coils rely on temperature differentials to transfer heat from the return air, through the coil and to the chilled water.

    a. Conduction

    b. Radiation

    c. Convection
    a. Conduction
  3. Module 1: Thermodynamics and Properties of Air

    3. The solar load on a building is a significant contributor to the building's heat gain during the cooling season.

    a. Conduction

    b. Radiation

    c. Convection
    b. Radiation
  4. Module 1: Thermodynamics and Properties of Air

    4. Which pressure/temperature relationship explains why hot water heating systems often include an expansion tank on each loop?

    a. If volume decreases, temperature decreases

    b. If temperature increases, pressure increases

    c. If pressure increases, volume decreases

    d. None of the above

    b. If temperature increases, pressure increases
  5. Module 1: Thermodynamics and Properties of Air

    5. A temperature change that comes unaccompanied by a change in air humidity is know as a change in the substance's _________.

    a. Specific heat capacity

    b. Enthalpy

    c. Latent heat

    d. Sensible heat
    d. Sensible heat
  6. Module 1: Thermodynamics and Properties of Air

    6. How many BTUs'hr are needed to raise the temperature of 15 lbs of water from 60F to 88F?

    a. 15lbs * 1.085 * (88F - 60F) =455.7 BTUs/hr

    b. 15lbs * 1 * 88F = 1320 BTUs/hr

    c. 15lbs * 1 * (88F - 60F) = 420 BTUs/hr

    d. None of the above
    6. 15lbs * 1 * (88F - 60F) = 420 BTUs/hr
  7. Module 1: Thermodynamics and Properties of Air

    7. If an air handling unit cools 7,000 cfm of 78F-air to 58F, how many BTUs/hr does the AHU remove from the air:

    a. 7,000 cfm * 1.085 * (78F - 58F) = 151,900 BTUs/hr

    b. 7,000 cfm * 1 * (78F - 58F) = 140,000BTUs/hr

    c. 7,000 cfm * 1.085* 58F = 440,510 BTUs/hr

    d. None of the above
    a. 7,000 cfm * 1.085 * (78F - 58F) = 151,900 BTUs/hr
  8. Module 1: Thermodynamics and Properties of Air

    8. Achange in a substance's latent heat results in temperature change.

    True or False
    False
  9. Module 1: Thermodynamics and Properties of Air

    9. In refrigeration, one ton of cooling is equal to _________.

    a. The amount of latent heat energy required to melt 2,000 lbs (i.e.,one ton) of ice at 32F over a 24-hour period

    b. 288,000 BTUs/ day

    c. 12,00BTUs/hr

    d. All of the above
    d. All of the above
  10. Module 1: Thermodynamics and Properties of Air

    10. If one ton-hour of refrigeration removes 12,000BTus/hr from a space, determine the minimem amount of refrigeration repquired to remove a sensible heat gain of 6,000,000 BTUs/hr from a space.

    a. 6,000,000 BTUs/hr divided 12,000BTus/hr = 500 tons of refrigeration

    b. 6,000,000 BTUs/hr times 12,000 BTUs/hr = 72,000,000,000 tons of refrigeration

    c. 6,000,000 divided 288,000 BTUs/day = 20.83 tons of refrigeration

    d. None of the above
    a. 6,000,000 BTUs/hr divided 12,000 BTUs/hr = 500 tons of refrigeration
  11. Module 1: Thermodynamics and Properties Of Air

    11. The process of heating a gas beyond its vaporization temperature is know as __________.

    a. Evaporation

    b. Metering

    c. Subcooling

    d. Superheating
    d. Superheating
  12. Module 1: Thermodynamics and Properties of Air

    12. The process of cooling a liquid below its condensing temperature is known as _______.

    a. Condensation

    b. Metering

    c. Subcooling

    d. Superheating
    c. Subcooling
  13. Module 2: Hydronic Cooling Systems

    1. As air passes through chilled water cooling coils on its way to occupied spaces, heat is transferred from the _____.

    a. Chilled water to the air

    b. Air to the chilled water

    c. Chilled water to the refrigerant

    d. Air to the refrigerant
    b. Air to the chilled water
  14. Module 2: Hydronic Cooling Systems

    2. In the cooling tower, heat is transferred from the _____.

    a. Condenser water to the atmosphere

    b. Atmosphere to the condenser water

    c. Refrigerant to the condenser water

    d. All of the above
    a. Condenser water to the atmosphere
  15. Module 2: Hydronic Cooling Systems

    3. Once the chilled water releases its heat in the evaporator, it returns to the _____ to absorb more heat from the air.

    a. Air handling unit cooling coils

    b. Condenser water loop

    c. Economizer

    d. Metering device
    a. Air handling unit cooling coils
  16. Module 2: Hydronic Cooling Systems

    4. The ______ is a vapor pump that increases the pressure and temperature of the refrigerant vapor.

    a. Metering device

    b. Economizer

    c. Condenser

    d. Compressor
    d. Compressor
  17. Module 2: Hydronic Cooling Systems

    5. Refigerant vapor rises to the top of the evaporator shell where it is drawn into the _____.

    a. Metering device

    b. Economizer

    c. Compressor

    d. Condenser
    d. Compressor
  18. Module 2: Hydronic Cooling Systems

    6. In the condenser, ______ accepts heat from the compressed refrigerant gas.

    a. Liquid refrigerant

    b. Return chilled water

    c. Condenser water

    d. None of the above
    c. Condenser water
  19. Module 2: Hydronic Cooling Systems

    7. Since the temperature of the condenser water is lower than the temperature of the refrigerant vapor, heat flows from the refrigerant to the condenser water.

    True or False
    True
  20. Module 2: Hydronic Cooling Systems

    8. The _______ distributes liquid refrigerant into the evaporator at a rate that matches the amount of refrigerant leaving the evaporator.

    a. Evaporator

    b. Metering device

    c. Condenser

    d. Economizer
    b. Metering device
  21. Module 2: Hydronic Cooling Systems

    9. The flash economizer helps to improve the evviciency of the chiller.

    True or False
    True
  22. Module 2: Hydronic Cooling Systems

    10. The _______ prevents the chiller from starting if its oil pressure is too low.

    a. Oil heater thermostat

    b. Low oil pressure cutout

    c. Condenser high pressure cutout

    d. Evaporator low pressure cutout
    b. Low oil pressure cutout
  23. Module 2: Hydronic Cooling Systems

    11. A _______ chiller uses impellers and high rotational speeds to increase vapor pressure.

    a. Absorption

    b. Rotary screw

    c. Centrifugal compression

    d. None of the above
    c. Centrifugal compression
  24. Module 2: Hydronic Cooling Systems

    12. A ________ chiller uses pistons, crankshafts, suction valves, and discharge valves to increase vapor pressure.

    a. Absorption

    b. Centrifugal

    c. Rotary screw

    d. Reciprocating
    d. Reciprocating
  25. Module 2: Hydronic Cooling Systems

    13. Rotary screw and reciprocating chillers use positive displacement to increase vapor pressure.

    True or False
    True
  26. Module 2: Hydronic Cooling Systems

    14. A _________ chiller uses a salt/water solution rather than CFC or HCFC refrigerants in the refrigeration process.

    a. Absorption

    b. Centrifugal

    c. Rotary screw

    d. Reciprocating
    a. Absorption
  27. Module 2: Hydronic Cooling Systems

    15. The chilled water loop runs between the chiller and the cooling coils located in the air handling.

    True or False
    True
  28. Module 2: Hydronic Cooling Systems

    16. The _______ runs between the chillers and the cooling tower.

    a. Chilled water loop

    b. Condenser water loop

    c. Economizer piping

    d. Utility vessel
    b. Condenser water loop
  29. Module 2: Hydronic Cooling Systems

    17. Flow through the cooling tower bypass is achieved by the condenser water bypass valve.

    True or False
    True
  30. Module 2: Hydronic Cooling Systems

    18. The cooling tower removes heat from the building by the process of __________.

    a. Subcooling

    b. Heat transfer in the evaporator

    c. Condensation

    d. Evaporation
    d. Evaporation
  31. Module 2: Hydronic cooling Systems

    19. To maximize evaporative efficiency, cooling towers are designed to distribute condenser water into smaller droplets, which increases the __________ of the water.

    a. Surface tension

    b. Flow rate

    c. Surface area

    d. Density
    c. Surface area
  32. Module 2: Hydronic cooling Systems

    20. In _______ cooling towers, the air moves horizontally through the fill, perpendicular to the downward flow of the condenser water.

    a. Counter-flow

    b. Cross-flow

    c. Drift-eliminator

    d. None of the above
    b. Cross-flow
  33. Module 2: Hydronic cooling Systems

    21. In counter-flow cooling towers, air moves vertically through the fill, counter to the downward flow of the condenser water.

    True or False
    True
  34. Module 2: Hydronic Cooling Systems

    22. The difference in temperature between the water leaving the cooling tower and the ambient air (wet bulb) temperature is referred to as the __________.

    a. Cooling tower return temperature

    b. Cooling tower approach temperature

    c. Fan temperature

    d. Condenser water temperature
    b. Cooling tower approach temperature
  35. Module 2: Hydronic Cooling Systems

    23. Cooling tower cells have ________ to control the flow of water to each cell.

    a. Variable frequency drives

    b. Multi-speed fan motors

    c. Balancing valves

    d. Vibration switches
    c. Balancing valves
  36. Module 2: Hydronic Cooling Systems

    24. An ice plant is a colling system that generates ice, which is used to provide cooling instead of or in conjunction with the chiller.

    True or False
    True
  37. Module 3: Air Distribution Systems

    1. A ________ air conditioning system meets cooling and heating needs by varying the temperature of the air supplied to occupied spaces.

    a. Constant air volume

    b. Variable air volume

    c. All of the above

    d. None of the above
    a. Constant air volume
  38. Module 3: Air Distribution Systems

    2. A _______ air conditioning system increases of decreases the flow of air and changes the temperature of the air to meet cooling and heating needs.

    a. Constant air volume

    b. Variable air volume

    c. All of the above

    d. None of the above
    b. Variable air volume
  39. Module 3: Air Distribution Systems

    3. Which style of air conditioning system distributes conditioned air from a central air handling unit to several different floors?

    a. Parallel-flow

    b. Dual duct

    c. Floor-by-floor

    d. Built-up
    d. Built-up
  40. Module 3: Air Distribution Systems

    4. To maintain the building in a positive pressurized state, exhaust air systems remove the same amount (cfm) of air as the outside air system brings into the building.

    True or False
    False
  41. Module 3: Air Distribution Systems

    5. The air-side economizer function of an outside air handling unit typically operates during ________.

    a. The cooling season when the outside air and dew point temperatures are higher than return air temperatures

    b. The heating season when the outside air and dew point temperatures are lower than return air temperatures

    c. The cooling season when the outside air and dew point temperatures are lower than return air temperatures

    d. All of the above
    c. The cooling season when the outside air and dew point temperatures are lower than return air temperatures
  42. Module 3: Air Distribution Systems

    6. A pad-type air filter is a deep filter containing a high proportion of surface are relative to its outside dimension.

    True or False
    False
  43. Module 3: Air Distribution Systems

    7. An air handling unit with a draw-through design will have a fan positioned dwnstream of the conditioning coils so that it pulls air through the coils.

    True or False
    True
  44. Module 3: Air Distribution Systems

    8. A building with air handling units that feature the air-side economizing capability will also have a relief air system.

    True or False
    True
  45. Module 3: Air Distribution Systems

    9. Which is a key indicator of an air filter's filtration efficiency?

    a. MERV rating

    b. MERL rating

    c. MERL-11

    d. All of the above
    a. MERV rating
  46. Modle 3: Air Distribution Systems

    10. The fins surrounding copper cooling coil tubes ______.

    a. Help to hold the tubing in place

    b. Disperse water flow through the coil

    c. Increase the surface aria for heat transfer

    d. Reduce pressure losses that occur when air flow is forced to change direction
    c. Increase the surface area for heat transfer
  47. Module 3: Air Distribution Systems

    11. The cooling capacity of hydronic air handling units is typically controlled by modulation the amount of chilled water flowing through the cooling coils.

    True or False
    True
  48. Module 3: Air Distribution Systems

    12. A ________ is an air duct that penetrates the floor slab.

    a. Air shaft or air chase

    b. Branch duct

    c. Plenum space

    d. All of the above
    a. Air shaft or air chase
  49. Module 3: Air Distribution Systems

    13. Air shafts can deliver ________.

    a. Outside air to air handling units

    b. Conditioned supply air to branch ductwork

    c. Exhaust air to the outside

    d. All of the above
    d. All of the above
  50. Module 3: Air Distribution Systems

    14. Plenum space is often used as a pathway for return air to travel back to the air handling unit and as the space through which supply air duct routed.

    True or False
    True
  51. Module 3: Air Distribution Systems

    15. When a multi-zone air handling unit's face damper is fully open and its bypass damper is closed, the unit is likely _______.

    a. Operating in economizer mode

    b. Working to satisfy a demand for full cooling

    c. Reacting to a decrease in the cooling load

    d. None of the ablove
    b. Working to satisfy a demand for full cooling
  52. Module 3: Air Distribution Systems

    16. One type of fan powered terminal unit satisfies zone temperature requirements by regulating the temperature of the discharge air while maintaning a constant volume of airflow to the zone.

    True or False
    True
  53. Module 3: Air Distribution Systems

    17. In _______ terminal units, the fan is located outside the central variable volume air supply and activated only when the cooling load decreases.

    a. VAV box

    b. Mixing box

    c. Series-flow

    d. Parallel-flow
    d. Parallel-flow
  54. Module 3: Air Distribution Systems

    18. A series-flow terminal unit has a fan that operates continuously.

    True or False
    True
  55. Module 3: Air Distribution Systems

    19. Which unit is least likely to contain a fan?

    a. Parallel-flow terminal unit

    b. Series-flow terminal unit

    c. VAV box

    d. None of the above
    c. VAV box
  56. Module 3: Air Distribution Systems

    20. Linear slot diffusers are low-visibility diffusers installed on tip of 2 by 4 fluorescent light fixtures.

    True or False
    False
  57. Module 4: Direct Expansion Units

    1. The evaporator/cooling coil in a DX unit uses chilled water to remove heat from the air.

    True or False
    False
  58. Module 4: Direct Espansion Units

    2. In a DX unit, the compressor _________.

    a. IIncreases the pressure of the cooling medium

    b. Increases the cooling medium,s saturation temperature and boiling point

    c. Pumps the cooling medium to the condenser

    d. All of the above
    d. All of the above
  59. Module 4: Direct Expansion Units

    3. In a DX unit, refrigerant changes from a vapor to a liquid form in the _______.

    a. Evaporator coil

    b. Compressor

    c. Condenser

    d. Metering device
    c. Condenser
  60. Module 4: Direct Expansion Units

    4. In a DX unit, the metering device _________.

    a. Is typically located between the condenser and the compressor

    b. Meters the cooling medium into the compressor based on the temperature of the vapor leaving the evaporator coil

    c. Decreases the cooling medium,s saturation temperature and boiling point

    d. All of the above
    c. Decreases the cooling medium's saturation temperature and boiling point
  61. Module 4: Direct Exspansion Units

    5. Reducing the pressure of the cooling medium increases its capacity to absorb heat.

    True or False
    True
  62. Module 4: Direct Exspansion Units

    6. Split system DX units are commonly used in commercial office buildings for base building cooling.

    True or False
    False
  63. Module 4: Direct Expansion Units

    7. The refrigerant in an air-cooled DX unit rejects heat to condenser water that then travels to the cooling tower where the heat is rejected to the atmosphere through the process of evaporation.

    True or False
    False
  64. Module 4: Direct Expansion Units

    8. When the reversing valve is in the de-energized state, the DX unit will provide _________.

    a. Cooling

    b. Heating

    c. both cooling and heating

    d. None of the above
    b. Heating
  65. Module 4: Direct Expansion Units

    9. DX units meet cooling requirements by controlling the operation of the ________.

    a. Dampers

    b. Compressor

    c. Condenser fan

    d. All of the above
    b. Compressor
  66. Module 4: Direct Expansion Units

    10. In a DX unit, compressor operation is controlled based on outside air temperature.

    True or False
    False
  67. Module 4: Direct Expansion Units

    11. Heat pumps can provide either cooling or heating because they have _________.

    a. Areversing valve that controls the direction of refrigerant flow

    b. A combination of normal refrigeration equipment and an electric or gas heating element

    c. Two fan assembles that are controlled to reject or recover heat as neede

    d. All of the above
    a. A reversing valve that controls the direction of refrigerant flow
  68. Module 4: Direct Exspansion Units

    12. Heat pumps systems use heat recovered from the outside air and/ or condenser water to provide heat to conditioned spaces.

    True or False
    True
  69. Module 4: Direct Exspansion Units

    13. Heat pumps operate more evviciently in temperate climates than in cold-weather climates because _______.

    a. The stack effect is more pronounced in cold-weather climates

    b. The medium that facilitates the heat transfer has a greezing point of 42 degrees F

    c. Absorbing heat from outside air becomes increasingly difficult as the outside air temperature drops

    d. None of the above; climate does not affect heat pump operation
    c. Absorbing heat from outside air becomes increasingly difficult as the outside air temperature drops.
  70. Module 4: Direct Exspansion Units

    14. When a heat pump operates in heating mode, the condenser/ outside coil acts as the __________.

    a. Metering device

    b. Heat source

    c. Compressor

    d. Evaporator
    d. Evaporator
  71. Module 5: Heating Systems

    1. Fire tube boilers produce steam; water tube boilers produce hot water.

    True or False
    False
  72. Module 5: Heating Systems

    2. The amount of steam produced by a steam boiler is controlled by modulating __________.

    a. The amount of air supplied to the combustion chamber

    b. The amount of fuel supplied to the combustion chamber

    c. The amount of air and fuel supplied to the boiler

    d. None of the above
    c. The amount of air and fuel supplied to the boiler
  73. Module 5: Heating Systems

    3. Which boiler component is considered part of the draft system?

    a. Fan

    b. stack

    c. chimmey

    d. All of the above
    d. All of the above
  74. Module 5: Heating Systems

    4. What is the most commonly used fuel source for combustion boilers?

    a. Coal

    b. Natural gas

    c. Fuel oil

    d. Diesel
    b. Natural gas
  75. Module 5: Heating Systems

    5. Which system supplies domestic water to the boiler to replace water lost during the heating process?

    a. Makeup water system

    b. Blow-down system

    c. Expansion tank system

    d. All of the above
    a. Makeup water system
  76. Module 5: Heating Systems

    6. Which system uses condensate as a source of makeup water for the boiler?

    a. Makeup water system

    b. Feedwater system

    c. Blow-down system

    d. Expansion tank system
    b. Feedwater system
  77. Module 5: Heating Systems

    7. Some boilers have both a makeup water system and a feedwater system.

    True or False
    True
  78. Module 5: Heating Systems

    8. What is the function of a blow-down valve?

    a. To allow domestic water to be added to the boiler

    b. To release excess pressure from the boiler

    c. To prevent water from carrying over into the steam lines and causing water hammer or ruptured pipes

    d. To allow for sediment to be removed regularly.
    d. To allow for sediment to be removed regularly.
  79. Module 5: Heating Systems

    9. What is the primary means of cooling boiler blow-down to a temperature that meets code requirements for discharge into sewer systems?

    a. Mixing the blow-down water with domestic water

    b. Using a heat exchanger to transfer heat from the boiler blow-off to domestic hot water

    c. Boiler blow-off is not discharged into sewer systems.

    d. None of the above
    a. Mixing the blow-down water with domestic water
  80. Module 5: Heating Systems

    10. What is the primary purpose of a water column?

    a. To introduce makeup water into the boiler

    b. To equalize the pressure on both sides of the low-water fuel cutoff device

    c. To reduce water movement so the water level in the boiler can be physically verified

    d. To reduce the temperature of the blow-down water before it is released to the sewer line
    c. To reduce water movement so the water level in the boiler can be physically verified
  81. Module 5: Heating Systems

    11. Which device opens to release excess pressure when the boiler pressure exceeds its MAWP (maximum allowable working pressure)?

    a. Main steam stop valve

    b. Safety valve

    c. Pressure gauge

    d. MAWP fitting
    b. Safety valve
  82. Module 5: Heating Systems

    12. Which device stops the flow of fuel to the boiler when the water level falls below the NOWL (normal operating water level)?

    a. Main steam stop valve

    b. Safety valve

    c. Fusible plug

    d. Low-water fuel cutoff
    d. Low-water fuel cutoff
  83. Module 5: Heating Systems

    13. Thermal efficiency is a measure of the amount of unburned fuel and excess air in the boiler exhaust.

    True or False
    False
  84. Module 5: Heating Systems

    14. A boiler's thermal efficiency can be increased by:

    a. Following a good water treatment program

    b. Regular blow-down practices

    c. The use of turbulators

    d. All of the above
    d. All of the above
  85. Module 5: Heating Systems

    15. What is the function of an expansion tank?

    a. To improve a boiler's combustion efficiency

    b. To preheat boiler makeup water

    c. To provide a place for excess pressure in the hot water heating system

    d. To reduce the temperature of the blow-down water before it is released to the sewer line
    c. To provide a place for excess pressure in the hot water heating system
  86. Module 5: Heating Systems

    16. In a building with a two-loop heating system, a _______ is used to transfer heat from the primary loop to the secondary loop.

    a. Boiler

    b. Heat exchanger

    c. Terminal unit

    d. Feedwater system
    b. Heat exchanger
  87. Module 5: Heating Systems

    17. A hot water heating coil is a type of heat exchanger.

    True or False
    True
  88. Module 5: Heating Systems

    18. Electric heating elements are the only source of heat for some buildings.

    True or False
    True
  89. Module 5: Heating Systems

    19. The substance in a heat exchanger do not mix.

    True or False
    True
  90. Module 5: Heating Systems

    20. The operation of electric duct heaters is controlled based on __________.

    a. Outside air temperature

    b. Return air temperature

    c. Discharge air temperature

    d. Occupied space temperature
    d. Occupied space temperature
  91. Module 6: Automatic Controls

    1. A set point is ___________.

    a. The value of a controlled variable after it has been acted upon by a controlled device

    b. The value of a controlled variable as measure by a sensor

    c. The desired value of a controlled variable

    d. The highest possible value a controlled variable can safely obtain within a control loop
    c. The desired value of a controlled variable
  92. Module 6: Automatic Controls

    2. Which of the following is a function of the contol link?

    a. Positioning a damper or actuator

    b. Sending control signals to conrolled devices

    c. Measuring a controlled variable

    d. Comparing controlled variable measurements to a set point
    a. Positioning a damper or actuator
  93. Module 6: Automatic Controls

    3. Which of the following temperature sensors uses a fluid expansion device?

    a. Remote bulb element

    b. Rod and tube element

    c. Pitot tube

    d. Bimetal element
    a. Remote bulb element
  94. Module 6: Automatic Controls

    4. Bimetal temperature sensors are commonly made of ________.

    a. Iron and nickel

    b. Mercury and aluinum

    c. Tin and Zinc

    d. Brass and steel
    d. Brass and steel
  95. Module 6: Automatic Controls

    5. Which of the following sensors is used to measure the flow rate of a liquid or gas?

    a. Bimetal strip

    b. Rod and tube element

    c. Pitot tube

    d. Variable frequency drive
    c. Pitot tube
  96. Module 6: Automatic Controls

    6. Flow rate sensors utilize the relationship between _______.

    a. Velocity pressure and travel speed

    b. Differential pressure and density

    c. Mass and volume

    d. None of the above
    a. Velocity pressure and travel speed
  97. Moduel 6: Automatic Controls

    7. Devices with modulation control are positioned proportionlly t changes in a controlled variable.

    a. True or False
    True
  98. Module 6: Automatic Controls

    8. Controllers that determine control with IF/THEN statements are utilizing __________.

    a. Proportional control

    b. Fuzzy logic control

    c. Proportional plus integral control

    d. Proportional-integral-derivative
    b. Fuzzy logic control
  99. Module 6: Automatic Controls

    9. A single pneumatic controller can act on more than one controlled device.

    True or False
    True
  100. Module 6: Automatic Controls

    10. Electric controllers use electicity, either low- or line-voltage, to achieve control action.

    True or False
    True
  101. Module 6: Automatic Controls

    11. Which statement best describes a pneumatic valve actuator with modulating control?

    a. An actuator consisting of a motor attached to the valve stem through a gear train and linkage

    b. An actuator constisting of a magnetic coil operating a movable plunger

    c. An actuator consisting of a spring-opposed flexible diaphragm or bellows attached to the valve stem

    d. None of the above
    c. An actuator consisting of a spring-opposed flexible diaphragm or bellow attached to the valve stem
  102. Module 6: Automatic Controls

    12. A normally open valve provides full flow when _______.

    a. Actuating force is fully applied

    b. Acturating force is fully removed
    b. Actuating force is fully removed
  103. Module 6: Automatic Controls

    13. Solenoid valves are generally limited in size to less than one inch.

    True or False
    False
  104. Module 6: Automatic Controls

    14. A variable frequency drive (VFD) modulates the speed and output of an electic motor by modulating ________.

    a. The intensity of electrical power

    b. The current strength of electrical power

    c. The voltage of electric power

    d. The frequency of electric power
    d. The frequency of electric power
  105. Module 6: Automatic Controls

    15. Air compressors tpically pressurize air to ______.

    a. 100-150 psig

    b. 200-300 psig

    c. 20-40 psig

    d. 45-55 psig
    a. 100-150 psig
  106. Module 6: Automatic Controls

    16. A system that utilizes both pneumatic and electronic controls may be classified as a _______ system.

    a. Mixed

    b. Doubled

    c. Hybrid

    d. Crossed
    c. Hybrid
  107. Module 6: Automatic Controls

    17. Electric relays are classified as solid state or _________.

    a. Mechanical

    b. Hybrid

    c. Pneumatic

    d. Low-voltage
    a. Mechanical
  108. Module 6: Automatic Controls

    18. A latching relay will open or close a circuit every time power is applied and stay in that position until power is applied again.

    True or False
    True
  109. Module 6: Automatic Controls

    19. The typical components of a building automatic control system (BACS) include the front end or server, communication trunk, controllers, and ______.

    a. Control links

    b. Relays

    c. Thermostats

    d. Workstations
    d. Workstations
  110. Module 6: Automatic Controls

    20. The typical output signal for a building automatic control system (BACS) is 10-50 volts or 40-80 milliamps.

    True or False
    False
  111. Module 7: Water Treatment Systems

    1. Which condition listed below is least likely to accelerate mineral scale formation on HVAC components?

    a. An increase in the velocity of water flow

    b. A pH above 7

    c. An increase in water temperature

    d. H high mineral concentration in the water
    a. An increase in the velocity of water flow
  112. Module 7: Water Treatment Systems

    2. Water velocity that is too high can cause an erosion type of corrosion.

    True or False
    True
  113. Module 7: Water Treatment Systems

    3. Fouling is prevented by _________.

    a. Proper corrosion, scale, and microbiological control

    b. Limiting the accumilation of debris in the cooling tower basin

    c. The installation of side-stream filters

    d. All of the above
    d. All of the above
  114. Module 7: Water Treatment Systems

    4. Microbiological growth in the cooling system can be prevented by ________.

    a. Exposing the cooling tower to sunlight to destroy microbiological growth

    b. Introducing iron-depositing bacteria into the system

    c. Maintaining water quality by removing organic contaminants such as oil, dirt, and leaves from the cooling tower basins and tower decks.

    d. All of the above
    c. Maintaining water quality by removing organic contaminants such as oil, dirt, and leaves from the cooling tower basins and tower decks.
  115. Module 7: Water Treatment Systems

    5. When would a pressure-reducing station and a booster pump be used in conjunction with a chemical controller:

    a. When a brominator is un use

    b. When the controller is used to monitor halgens and biocides

    c. When the controller's pressure rating is lessthan the normal operating pressure of the condenser water system

    d. When biodispersants are used to control microbiological growth
    c. When the controller's pressure rating is less than the normal operating pressure of the condenser water system
  116. Module 7: Water Treatment Systems

    6. Chemical injection points should be located upstream of the chemical controller to allow for proper circulation of the chemicals in the system prior to sampling.

    True or False
    False
  117. Module 7: Water Treatment Systems

    7. Some chemicals are not to be added within close proximity to other chemicals due to the potential for a chemical reaction.

    True or False
    True
  118. Module 7: Water Treatment Systems

    8. A chemical injection ________ is a section of pipe where most or all chemical injection points are consolidated for spill and leak containment purposes.

    a. Pot feeder

    b. Coil

    c. Quill

    d. Header
    d. Header
  119. Module 7: Water Treatment Systems

    9. A ________ is a side-stream device used to feed solid chemicals (tablet chlorine) into a condenser water system. A _________ is a side-stream device used to introduce liquid chemicals into a closed loop system without taking the system offline.

    a. Chlorine pump, brominator

    b. Brominator, pot feeder

    c. Injection feeder, direct feeder

    d. Pot feeder, chlorine pump
    b. Brominator, pot feeder
  120. Module 7: Water Treatment Systems

    10. When taking a sample from the condenser water loop, allow the sample stream to run long enough to flush the pipe so that you obtain a representative sample.

    True or False
    True
  121. Module 7: Water Treatment Systems

    11. Because these materials are found in most HVAC systems, the two most common types of corrosion coupons in each coupon rack are _________ and _________ .

    a. Brass, copper

    b. Mild steel, brass

    c. Brass, aluminum

    d. Copper, mild steel
    d. Copper, mild steel
  122. Module 7: Water Treatment Systems

    12. Condenser water coupon racks in low-pressure systems are typically made out of _________.

    a. Copper

    b. PVC

    c. Brass

    d. Wood
    b. PVC

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