Mechanical Code Flashcards
Desiccants are used in…
Driers
Which of the following is true? Stud wall cavity is proposed to be used as supply air plenum.
Not allowed by code
Air to air heat pump in the heating mode, the heating capacity will increase or decease as the outside temperature rises?
Increase
For condensation disposal on fuel burning appliances, every foot of a horizontal run shall slope… ____”
1/8”
Vent of appliance is prohibited from going through (attic, crawl, air duct)
Air duct
Outside or return air shall be a minimum of how many feet from vent?
10’
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)
5 ft
A thermostat wire passes through an air duct plenum. How must the wire be rated?
plenum
What is the maximum temperature exposure for non-metallic ducts such as duct board?
250 degrees
When insulating duct, when can the service opening be covered?
When the exact location of the opening is properly identified
Minimum size letters to mark access locations of smoke and fire detectors in an air duct system?
1/2 inch
What is the net free area of 12x12 metal louver in a combustion air opening? (36, 72, 108, 144)
108
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)
240 square inches
In confined space, duct from combustion air must be a maximum of how many inches from floor?
12”
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.
72 Cubic Feet per 1000 Btu
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”)
20”
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)
2
Minimum cross section of combustion air duct is ____ inches
3”
Minimum size mesh for combustion air openings for fuel burning appliances is ______”
1/4”
Which of the following is a metal sleeve with fabric connected and used to reduce noise in an exhaust system?
Vibration insulator
A boiler that furnishes water at 225 degrees and 150 psi is classified as a ______-____________ boiler.
low pressure
Where do steam traps discharge to?
Boiler
What type of refrigerant can be tested with air?
R717
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)
15’
What is the maximum size annealed temper copper tube that can be used for refrigerant piping?
2”
What is the maximum size outside diameter for annealed temper copper tubing in a refrigeration system that is permitted to have a flared fitting?
7/8
After piping a refrigeration system, pipes shall be tested at what minimum pressure?
Not less than the lower of the design pressure or setting of the relief device
What is the maximum smoke developed rating for hydronic pipe insulation? (50, 75, 100, 125)
50
Minimum clearance for hydronic piping at 250 degrees from combustibles is…
1”
Horizontal steam lines should slope so that condensation flows away from OR back towards the boiler?
Back towards the boiler
Minimum test pressure for “slab on grade” hydronic piping is ____ psi?
100 psi
Minimum test time for hydronic piping is ______ minutes?
15 minutes
What type of joint is used for copper hydronic piping installed in concrete slab?
Silver brazed
Where do you install an oil trap on a suction line riser?
At the “Base” of the vertical suction line
Liquid refrigerant entering the evaporator is suddenly at a Lower Pressure OR Higher Pressure?
Lower Pressure
Maximum flame spread for adhesive duct liner is… (15, 25, 30 50)
25
What joint or seam of a metal duct must be sealed as directed by sealing requirements of class C duct? (Helical, Longitudinal, Transverse)
Transverse
The maximum distance for supports on horizontal sheet metal duct is…
10ft
When is duct type smoke detectors required?
When return air is 2000 cfm or higher
A single 16,000 CFM roof top unit serves each floor of a 3 story commercial building. How many smoke detectors are required?
3
The net free area of a 12 x 12 metal louver in combustion opening is (36, 72, 108, 144) square inches.
108 square inches
What is prohibited from being installed within a plenum?
Fuel fired appliances
When a boiler is installed what must be the installer provide to the homeowner? Year end inspection, Control diagram, Warranty)
Control diagram
What is the maximum temperature in which the fire damper actuating device is engaged”
160 Degrees
At what height must a type L vent terminate above the roof?
4 Feet
Schematic of commercial kitchen hood with roof mounted exhaust fan.
40”
Pipes containing which fluid should be protected with a vapor barrier?
Chilled water piping
What is the minimum ventilation rate for a 35 square foot public bathroom if there is one water closet and one lavatory?
75 CFM
In a 3000 square ft crawl space, the exhaust rate must be ____ CFM
60 CFM
Auditorium exhaust rate needs __________ CFM
33,750 CFM
Darkroom exhaust rate needs ______ CFM.
500 CFM
Weight of material x Specific heat value x Temp differential = BTU
20lbs water x 1 Heat Value x 40 degrees = _____ BTU
800 BTU
What is the velocity air pressure at 2000 Feet Per Minute to a 20x30 duct?
.25
What is the equivalent Fahrenheit to 49 degrees celcius?
120.2
What does AFUE stand for?
Annual Fuel Utilization Efficiency
What is used to determine fuel rating?
AFUE
What is slugging with regards to a compressor?
Liquid enters compressor
Ohms Laws says that if you have 9500 watts and 40 amps, the voltage shall be….
240 Volts
1 watt equals ____ BTUs
3.41 BTUs
If you have 20 light bulbs that are 60 watt bulbs, what is the BTU rating.
Hint: 1 watt = 3.41 BTUs of heat
4092 BTUs
Running voltage is always ____% of design voltage
90%
Equipment and appliances that have an ignition source which is located in a public garage, private garage, etc shall be elevated to what height?
18” above floor surface
Appliances located in public garages, repair garages and other areas frequented by motor vehicles shall be installed a minimum _____ ft above the floor.
8 FT
Appliances, Equipment, fans and other components that require roof hatch openings must have guards located within ____ Ft.
10 FT
Guards for appliances, equipment, fans and other components must be located no less than _____ inches above the elevated surface adjacent to it.
42”
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.
30” High
22” Wide
20Ft Long
The maximum vertical spacing for cast iron piping support is a maximum ____ Ft.
15 Ft
The maximum horizontal spacing for steel tubing piping support is ____ Ft.
8 Ft
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.
16 Ft
Condensate waste and drain line size shall be no less than ____ inch.
3/4 inch
Condensate and auxiliary drain pans must be a minimum ____ inches deep.
1.5 Inches
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.
2 Ft
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.
1/4 inch and not 1 inch
Occupied zones for ventilation shall have boundaries measured at ____ inches and ____ inches above the floor and ____ inches away from enclosing wall.
3 inches and 72 inches above floor
24 inches from enclosing walls
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.
0.02 CFM
Toilet rooms must have ventilation to the outside at a minimum ____ CFM per water closet or urinal.
75 CFM
The required outdoor ventilation for an auditorium of 150 people for every 1000 square ft shall be ____ CFM per person.
15 CFM
The required outdoor ventilation for a darkroom shall be ____ CFM per person.
0.50 CFM
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.
non-combustible packing
Exhaust outlets that terminate above the roof shall have the discharge opening located not less than ____ inches above the roof surface.
40”
A type 1 hood shall be installed with a clearance to combustibles of not less than _____ inches.
18 inches
Type L hoods shall be constructed of a steel material not less than ____ msg in thickness.
18 MSG
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.
4 ft
Metal duct with 9-18” diameter in abrasive material requires No. ____ gage.
18 Gage
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 _____.
Flame spread index max 25
Smoke developed index max 50
Flexible air connectors shall be limited in length to ____ Ft.
14 Ft
Ducts shall be supported with approved hangers at intervals not exceeding ____ ft.
10 Ft
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.
Interrupted
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.
15,000 CFM
Regarding combustion air, 2 openings shall be provided, 1 within ____ Ft of the ceiling of the room and 1 with ____ Ft of the floor.
1 Ft of ceiling
1 Ft of floor
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.
1 square inch per 1000 BTU/h
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.
1 Square inch per 4000 BTU/h
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.
1 Square inch per 2000 BTU/h
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.
1 Square inch per 4000 BTU/h
Combustion openings covered with metal louvers shall be deemed to have a net free area of ____ % of the area of the opening.
75%
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.
2 Ft
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.
5 ft
Passageways around all sides of boilers shall have an unobstructed width of not more than _____ inches.
18 inches
Every boiler and modular boiler shall have a shut off valve in the ________ and _________ piping.
Supply and Return
All steam and hot water boilers shall be protected with a low water ______ _______ control.
Cut-off
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.
scheduled 80
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.
18 Inches
Pipe insulation installed in buildings shall have a flame spread index of _____ and a smoke developed index of _____.
25 flame spread
450 smoke developed
________ piping shall be installed to drain the boiler or the steam trap.
Steam piping
Provisions shall be made to prevent the formation of _______________ on the exterior of hydronic piping.
condensation
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.
100 PSI
15 Minutes
Copper tubing shall be joined by brazing with filler metals having a melting point of not less than _______ fahrenheiht.
1000 F
