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CMC Test Preperation > Mechanical Code > Flashcards

Mechanical Code Flashcards

0
Q

Desiccants are used in…

A

Driers

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1
Q

Which of the following is true? Stud wall cavity is proposed to be used as supply air plenum.

A

Not allowed by code

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2
Q

Air to air heat pump in the heating mode, the heating capacity will increase or decease as the outside temperature rises?

A

Increase

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3
Q

For condensation disposal on fuel burning appliances, every foot of a horizontal run shall slope… ____”

A

1/8”

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4
Q

Vent of appliance is prohibited from going through (attic, crawl, air duct)

A

Air duct

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5
Q

Outside or return air shall be a minimum of how many feet from vent?

A

10’

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6
Q

A plume discharge from a cooling tower must be a minimum of how many feet above ventilation inlet to a building? (3, 5, 8, 10)

A

5 ft

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7
Q

A thermostat wire passes through an air duct plenum. How must the wire be rated?

A

plenum

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8
Q

What is the maximum temperature exposure for non-metallic ducts such as duct board?

A

250 degrees

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9
Q

When insulating duct, when can the service opening be covered?

A

When the exact location of the opening is properly identified

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10
Q

Minimum size letters to mark access locations of smoke and fire detectors in an air duct system?

A

1/2 inch

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11
Q

What is the net free area of 12x12 metal louver in a combustion air opening? (36, 72, 108, 144)

A

108

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12
Q

A 120,000 BTU furnace is located in a confined space. All air is taken from inside. What is the minimum free area from all vents. (100, 120, 240, or 300 square inches)

A

240 square inches

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13
Q

In confined space, duct from combustion air must be a maximum of how many inches from floor?

A

12”

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14
Q

A 50,000 Btu furnace installed in a residential room with normal infiltration. The room is 20x20 and a 9’ ceiling. Not usually tight construction. What is the minimum size for combustion air opening- not required.

A

72 Cubic Feet per 1000 Btu

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15
Q

Residential gas fired fuel appliance is 80,000 Btu. Combustion air through vertical duct to outdoors. What is the minimum free area for openings? (25”, 20”, 18” or 16”)

A

20”

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16
Q

Minimum number of openings communicating with outside required to ventilate a confined space where a gas appliance has a clearance of one inch on it’s sides and 6” on front. (1, 2, 3, 4)

A

2

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17
Q

Minimum cross section of combustion air duct is ____ inches

A

3”

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18
Q

Minimum size mesh for combustion air openings for fuel burning appliances is ______”

A

1/4”

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19
Q

Which of the following is a metal sleeve with fabric connected and used to reduce noise in an exhaust system?

A

Vibration insulator

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20
Q

A boiler that furnishes water at 225 degrees and 150 psi is classified as a ______-____________ boiler.

A

low pressure

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21
Q

Where do steam traps discharge to?

A

Boiler

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22
Q

What type of refrigerant can be tested with air?

A

R717

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23
Q

What is the minimum distance a refrigeration fusible plug or purge system must vent above grade level from a mechanical room. (15, 20, 25, 30)

A

15’

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24
Q

What is the maximum size annealed temper copper tube that can be used for refrigerant piping?

A

2”

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25
Q

What is the maximum size outside diameter for annealed temper copper tubing in a refrigeration system that is permitted to have a flared fitting?

A

7/8

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26
Q

After piping a refrigeration system, pipes shall be tested at what minimum pressure?

A

Not less than the lower of the design pressure or setting of the relief device

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27
Q

What is the maximum smoke developed rating for hydronic pipe insulation? (50, 75, 100, 125)

A

50

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28
Q

Minimum clearance for hydronic piping at 250 degrees from combustibles is…

A

1”

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29
Q

Horizontal steam lines should slope so that condensation flows away from OR back towards the boiler?

A

Back towards the boiler

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30
Q

Minimum test pressure for “slab on grade” hydronic piping is ____ psi?

A

100 psi

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31
Q

Minimum test time for hydronic piping is ______ minutes?

A

15 minutes

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32
Q

What type of joint is used for copper hydronic piping installed in concrete slab?

A

Silver brazed

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33
Q

Where do you install an oil trap on a suction line riser?

A

At the “Base” of the vertical suction line

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34
Q

Liquid refrigerant entering the evaporator is suddenly at a Lower Pressure OR Higher Pressure?

A

Lower Pressure

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35
Q

Maximum flame spread for adhesive duct liner is… (15, 25, 30 50)

A

25

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36
Q

What joint or seam of a metal duct must be sealed as directed by sealing requirements of class C duct? (Helical, Longitudinal, Transverse)

A

Transverse

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37
Q

The maximum distance for supports on horizontal sheet metal duct is…

A

10ft

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38
Q

When is duct type smoke detectors required?

A

When return air is 2000 cfm or higher

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39
Q

A single 16,000 CFM roof top unit serves each floor of a 3 story commercial building. How many smoke detectors are required?

A

3

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40
Q

The net free area of a 12 x 12 metal louver in combustion opening is (36, 72, 108, 144) square inches.

A

108 square inches

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41
Q

What is prohibited from being installed within a plenum?

A

Fuel fired appliances

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42
Q

When a boiler is installed what must be the installer provide to the homeowner? Year end inspection, Control diagram, Warranty)

A

Control diagram

43
Q

What is the maximum temperature in which the fire damper actuating device is engaged”

A

160 Degrees

44
Q

At what height must a type L vent terminate above the roof?

A

4 Feet

45
Q

Schematic of commercial kitchen hood with roof mounted exhaust fan.

A

40”

46
Q

Pipes containing which fluid should be protected with a vapor barrier?

A

Chilled water piping

47
Q

What is the minimum ventilation rate for a 35 square foot public bathroom if there is one water closet and one lavatory?

A

75 CFM

48
Q

In a 3000 square ft crawl space, the exhaust rate must be ____ CFM

A

60 CFM

49
Q

Auditorium exhaust rate needs __________ CFM

A

33,750 CFM

50
Q

Darkroom exhaust rate needs ______ CFM.

A

500 CFM

51
Q

Weight of material x Specific heat value x Temp differential = BTU

20lbs water x 1 Heat Value x 40 degrees = _____ BTU

A

800 BTU

52
Q

What is the velocity air pressure at 2000 Feet Per Minute to a 20x30 duct?

A

.25

53
Q

What is the equivalent Fahrenheit to 49 degrees celcius?

A

120.2

54
Q

What does AFUE stand for?

A

Annual Fuel Utilization Efficiency

55
Q

What is used to determine fuel rating?

A

AFUE

56
Q

What is slugging with regards to a compressor?

A

Liquid enters compressor

57
Q

Ohms Laws says that if you have 9500 watts and 40 amps, the voltage shall be….

A

240 Volts

58
Q

1 watt equals ____ BTUs

A

3.41 BTUs

59
Q

If you have 20 light bulbs that are 60 watt bulbs, what is the BTU rating.

Hint: 1 watt = 3.41 BTUs of heat

A

4092 BTUs

60
Q

Running voltage is always ____% of design voltage

A

90%

61
Q

Equipment and appliances that have an ignition source which is located in a public garage, private garage, etc shall be elevated to what height?

A

18” above floor surface

62
Q

Appliances located in public garages, repair garages and other areas frequented by motor vehicles shall be installed a minimum _____ ft above the floor.

A

8 FT

63
Q

Appliances, Equipment, fans and other components that require roof hatch openings must have guards located within ____ Ft.

A

10 FT

64
Q

Guards for appliances, equipment, fans and other components must be located no less than _____ inches above the elevated surface adjacent to it.

A

42”

65
Q

Appliances in attics must have a passageway no less than ____ inches high, ____ inches wide and not more than _____ feet in length from the opening of the appliance.

A

30” High
22” Wide
20Ft Long

66
Q

The maximum vertical spacing for cast iron piping support is a maximum ____ Ft.

A

15 Ft

67
Q

The maximum horizontal spacing for steel tubing piping support is ____ Ft.

A

8 Ft

68
Q

Equipment and appliances on a roof or elevated structure at a height exceeding ___ Ft shall have a permanent means of access that is grade or floor level and is located on a level service space.

A

16 Ft

69
Q

Condensate waste and drain line size shall be no less than ____ inch.

A

3/4 inch

70
Q

Condensate and auxiliary drain pans must be a minimum ____ inches deep.

A

1.5 Inches

71
Q

Where a source of contaminant is located within 10 ft horizontally of an intake opening, that opening has to be located in minimum of ____ FT below the contaminant source.

A

2 Ft

72
Q

The minimum and maximum size opening sizes in louvers, grilles and screens for intake openings in other than residential occupancies is ____ inch and not ____ inch.

A

1/4 inch and not 1 inch

73
Q

Occupied zones for ventilation shall have boundaries measured at ____ inches and ____ inches above the floor and ____ inches away from enclosing wall.

A

3 inches and 72 inches above floor

24 inches from enclosing walls

74
Q

The mechanical exhaust rate for an uninhabited space such as a crawl space or attic shall be not less than ____ CFM per square ft of horizontal area.

A

0.02 CFM

75
Q

Toilet rooms must have ventilation to the outside at a minimum ____ CFM per water closet or urinal.

A

75 CFM

76
Q

The required outdoor ventilation for an auditorium of 150 people for every 1000 square ft shall be ____ CFM per person.

A

15 CFM

77
Q

The required outdoor ventilation for a darkroom shall be ____ CFM per person.

A

0.50 CFM

78
Q

A vibration isolation connector for connecting a duct to a fan shall consist of _______________________ packing in a metal sleeve joint of approved design or shall be a coated fabric flexible duct connector listed for the application.

A

non-combustible packing

79
Q

Exhaust outlets that terminate above the roof shall have the discharge opening located not less than ____ inches above the roof surface.

A

40”

80
Q

A type 1 hood shall be installed with a clearance to combustibles of not less than _____ inches.

A

18 inches

81
Q

Type L hoods shall be constructed of a steel material not less than ____ msg in thickness.

A

18 MSG

82
Q

The vertical distance between the front lower lip of a type 1 and type 2 commercial hood and the appliance surface shall not exceed ____ FT.

A

4 ft

83
Q

Metal duct with 9-18” diameter in abrasive material requires No. ____ gage.

A

18 Gage

84
Q

Materials in duct plenums should be non combustible or shall have flame spread index of not more than _____ and a smoke developed index of not more than _____.

A

Flame spread index max 25

Smoke developed index max 50

85
Q

Flexible air connectors shall be limited in length to ____ Ft.

A

14 Ft

86
Q

Ducts shall be supported with approved hangers at intervals not exceeding ____ ft.

A

10 Ft

87
Q

Linings shall be ____________ at the area of operation of a fire damper and at a minimum of 6” upstream and 6” downstream of electric resistance and fuel burning heaters in a duct system.

A

Interrupted

88
Q

Where return air risers serve 2 or more stories and serve any portion of a return air system having a design capacity greater than ____ CFM, smoke detectors shall be installed on each story.

A

15,000 CFM

89
Q

Regarding combustion air, 2 openings shall be provided, 1 within ____ Ft of the ceiling of the room and 1 with ____ Ft of the floor.

A

1 Ft of ceiling

1 Ft of floor

90
Q

Regarding combustion air, the net free area of each opening shall be a minimum of ___ square inch per ______ BTU/h input rating of the fuel burning appliance.

A

1 square inch per 1000 BTU/h

91
Q

Regarding combustion air, the net free area of each direct opening to the outdoors shall be a minimum of ____ square inch per _______ BTU/h of combined input rating of the fuel burning appliance.

A

1 Square inch per 4000 BTU/h

92
Q

Regarding combustion air, the net free area of each horizontal opening connected to the outdoors shall be a minimum ____ square inch per ______ BTU/h of the combined input rating of fuel burning appliances.

A

1 Square inch per 2000 BTU/h

93
Q

Regarding combustion air, the net free area of each vertical opening connected to the outdoors through a vertical duct shall be a minimum _____ square inch per _______ BTU/h of combined input rating of the fuel burning appliance.

A

1 Square inch per 4000 BTU/h

94
Q

Combustion openings covered with metal louvers shall be deemed to have a net free area of ____ % of the area of the opening.

A

75%

95
Q

Type L vents shall terminate not less than _____ft above the highest point of the roof penetration and not less than 2 Ft higher than any portion of the building with 10ft.

A

2 Ft

96
Q

Plume discharges on appliances such as cooling towers and fluid coolers shall be not less than ____ Ft above or 20 Ft away from any ventilation inlet to a building.

A

5 ft

97
Q

Passageways around all sides of boilers shall have an unobstructed width of not more than _____ inches.

A

18 inches

98
Q

Every boiler and modular boiler shall have a shut off valve in the ________ and _________ piping.

A

Supply and Return

99
Q

All steam and hot water boilers shall be protected with a low water ______ _______ control.

A

Cut-off

100
Q

Carbon steel pipe with a wall thickness not less than scheduled _____ shall be used for refrigerant liquid lines for sizes 1.5 inches and smaller.

A

scheduled 80

101
Q

Soldering on the metal portion of the system shall be performed at least ______ inches from a plastic to metal adapter in the same water line.

A

18 Inches

102
Q

Pipe insulation installed in buildings shall have a flame spread index of _____ and a smoke developed index of _____.

A

25 flame spread

450 smoke developed

103
Q

________ piping shall be installed to drain the boiler or the steam trap.

A

Steam piping

104
Q

Provisions shall be made to prevent the formation of _______________ on the exterior of hydronic piping.

A

condensation

105
Q

Hydronic piping systems other than ground source heat pump loop systems shall be tested hydrostatically at 1-1/2 times the maximum design pressure, but not less than _____ PSI. The duration of each test shall be a minimum of _______ minutes.

A

100 PSI

15 Minutes

106
Q

Copper tubing shall be joined by brazing with filler metals having a melting point of not less than _______ fahrenheiht.

A

1000 F

CMC Test Preperation (10 decks)

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