Appendix 1: Self-Tests

This chapter contains all of the Self-Tests in a text format. Answers can be found in Appendix 2: Self-Test Answer Keys.

Competency B1, Self-Test 1

Found in Competency B1, Learning Task 1.

Self-Test 1

  1. The appliance shut-off valve is typically located just inside the appliance service cover, were it can be easily reached.
    1. True
    2. False
  2. Most gas shut-off applications will require the use of a manual valve that will fully open or close with a quarter-turn of the handle
    1. True
    2. False
  3. A valves Water, Oil and Gas (WOG) pressure rating includes the maximum approved pressure for use on fuel gas applications.
    1. True
    2. False
  4. A threaded brass ball valve has the following markings: 600 WOG, 150 WSP,1/2 G, 5G, CGA 3.16. what is the maximum certified pressure rating for combustible gas applications?
    1. ½ psig
    2. 5 psig
    3. 125 psig
    4. 600 psig
  5. A standard port ball valve has an opening through the ball that is one pipe size smaller than the valves’ connection size.
    1. True
    2. False
  6. A Luboseal™ gas valve must be shut off in order to be relubricated.
    1. True
    2. False
  7. Butterfly, globe and needle valves are commonly used as appliance shut-off valve.
    1. True
    2. False
  8. What is the colour of the valve handles on approved gas valves?
    1. Red
    2. Blue
    3. Yellow
    4. Any of the choices

Check your answers using the Self-Test Answer Keys in Appendix 2.

B1 Self-Test 2

Found in Competency B1, Self-Test 2.

Self-Test 2

  1. Where is the appliance regulator located in relation to the automatic gas valve?
    1. On the pilot line
    2. Upstream of the automatic gas valve
    3. Downstream of the automatic gas valve
    4. Upstream of the appliance manual shut-off valve
  2. The A-Cock is a manual shut-off valve used to adjust the pilot burner.
    1. True
    2. False
  3. Which gas code contains the requirements for the field assembly of gas valve trains?
    1. CSA B149.1
    2. CSA B149.2
    3. CSA B149.3
    4. CSA B149.5
  4. What is the name of the systems were the automatic safety shut-off valve stops the gas flow to both the main burner and the pilot burner?
    1. 80% safe
    2. Wild pilot
    3. 100% safe
    4. Non-100% safe
  5. An electric automatic gas valve is normally operated by 120 VAC.
    1. True
    2. False

Check your answers using the Self-Test Answer Keys in Appendix 2.

B1, Self-Test 3

Found in Competency B1, Learning Task 3.

Self-Test 3

  1. What is the restricting element of a regulator?
    1. Spring
    2. Valve disc
    3. Diaphragm
    4. Atmospheric vent
  2. What is the measuring element of a regulator?
    1. Spring
    2. Valve disc
    3. Diaphragm
    4. Atmospheric vent
  3. What is the loading element of a regulator?
    1. Spring
    2. Valve disc
    3. Diaphragm
    4. Atmospheric vent
  4. What is the purpose of a gas pressure regulator?
    1. To keep the colour of the flame constant
    2. To maintain even outlet heated air temperatures
    3. To maintain a constant gas pressure at the gas valve inlet
    4. To increase and maintain higher pressures as the load increases
  5. In a gas pressure regulator, how is the closing force is created?
    1. Decreased flow velocity
    2. The inlet pressure to the regulator
    3. The outlet pressure under the diaphragm
    4. The adjustable spring above the diaphragm
  6. In a gas pressure regulator, how is the opening force is created?
    1. Increased flow velocity
    2. The inlet pressure to the regulator
    3. The pressure under the diaphragm
    4. The adjustable spring above the diaphragm
  7. How is the downstream pressure of the regulator increased?
    1. The orifice size is changed
    2. The adjusting screw is screwed out
    3. The adjusting screw is screwed down
    4. Replace the restricting disc and the spring
  8. What is the purpose of the regulator atmospheric vent?
    1. Allow gas to escape
    2. Sense downstream pressure
    3. Allow the regulator to breath
    4. Allow a connection for a secondary pilot
  9. When is a pressure regulator said to be in equilibrium?
    1. Opening force of the diaphragm is equal to the closing force of the orifice
    2. Opening force of the diaphragm is equal to the closing force of the spring
    3. Opening force of the spring is equal to the closing force of the upstream pressure
    4. Opening force of the spring is equal to the closing force of the downstream pressure
  10. What term describes the condition when the outlet pressure is lower than set point pressure during flow conditions?
    1. Rise
    2. Boost
    3. Droop
    4. Lockup
  11. If a regulator is installed backwards in a piping system, what is the most likely result?
    1. The regulator will open completely
    2. The regulator will close completely
    3. Pressure downstream will rise above set point
    4. No difference – they are non-directional valves
  12. What is the purpose of a pitot tube in a regulator?
    1. Provide mechanical advantage for positive shut-off
    2. Relieve unwanted gases when overpressure occurs
    3. Increase upstream pressure during static conditions
    4. Keep downstream pressure closer to set point during flow conditions
  13. What is the purpose of the addition of a lever in a regulator?
    1. Provide mechanical advantage for positive shut-off
    2. Relieve unwanted gases when overpressure occurs
    3. Increase upstream pressure during static conditions
    4. Keep downstream pressure closer to set point during flow conditions
  14. When flow rate increases through a regulator, what happens to the downstream pressure?
    1. It increases
    2. It decreases
    3. It cycles/hunts
    4. It stays the same
  15. Which category of gas pressure regulators are used to reduce the service line pressure to building line pressure at the gas meter set?
    1. Service regulators
    2. Appliance regulators
    3. First-stage regulators
    4. Line pressure regulators
  16. What is the most likely result of a partially restricted regulator vent?
    1. Pilot safety to fail
    2. Restricting element to stay fully open
    3. Restricting element to say fully closed
    4. Regulator to respond slow or sluggish
  17. What is “lockup pressure”?
    1. The pressure downstream of a regulator under no flow conditions
    2. The pressure downstream of a regulator under full flow conditions
    3. The pressure downstream of a regulator during full relief conditions
    4. The pressure downstream of a regulator which activates the internal relief valve
  18. What is the maximum allowed propane pressure in a single-family dwelling?
    1. 7” WC
    2. 14” WC
    3. 2 psig
    4. 5 psig
  19. What type of regulator arrangement is required in all permanent propane installations?
    1. Two stage regulation
    2. Proportioning regulation
    3. Zero governor regulation
    4. Balance diagram regulation
  20. What are the typical setpoints for a two-stage propane regulator?
    1. First stage 14” wc, Second stage 7” wc
    2. First stage 2 psig, Second stage 14” wc
    3. First stage 5 psig, Second stage 2 psig
    4. First stage 10 psig, Second stage 11” wc
  21. What units are usually used to express the rate of flow for a regulator?
    1. SCFH
    2. BTUH
    3. MBH
    4. KWH
  22. When installing an appliance regulator the vent opening is completely blocked. This will cause the regulator to:
    1. remain permanently open
    2. go into a hunting condition
    3. remain permanently closed
    4. regulate the gas flow at the correct pressure
  23. What is the purpose of a pitot tube in a regulator?
    1. to provide mechanical advantage for positive shut-off
    2. to relieve unwanted gases when overpressure occurs
    3. to increase upstream pressure during static conditions
    4. to keep downstream pressure closer to set point during flow conditions.
  24. What position is the valve seat of a zero govern/ratio regulator when deenergized.
    1. Normally open
    2. Normally closed

Check your answers using the Self-Test Answer Keys in Appendix 2.

B1, Self-Test 4

Found in Competency B1, Learning Task 4.

Self-Test 4

  1. The rod and tube actuator operates on which principle?
    1. Electro-magnetism
    2. Thermoelectric effect
    3. Thermal expansion of solids
    4. Thermal expansion of liquids
  2. Sealed bellows actuator operates on which principle?
    1. Electro-magnetism
    2. Thermoelectric effect
    3. Thermal expansion of solids
    4. Thermal expansion of liquids
  3. Solenoids operate on which principle?
    1. Electro-magnetism
    2. Thermoelectric effect
    3. Thermal expansion of solids
    4. Thermal expansion of liquids
  4. What control components produce electricity when heated?
    1. Transistor
    2. Thermistor
    3. Thermocouple
    4. Bimetallic strip
  5. On what type of gas appliance would a rod and Tube (Unitrol) valve typically be installed?
    1. Gas range
    2. Gas boiler
    3. Gas Furnace
    4. Gas water heater
  6. In a Unitrol gas-fired water heater control, what is the purpose of the snap operating mechanism?
    1. To prevent override
    2. To prevent undershoot
    3. To open or close the valve seat faster
    4. To shut down the burner in an unsafe condition
  7. Pilot operated solenoid valves use pressure differential to assist the plunger in opening and closing the main valve.
    1. True
    2. False
  8. The servo regulator built into a combination gas valve serves as which type of gas pressure regulator?
    1. System regulator
    2. Service regulator
    3. Appliance regulator
    4. Over pressure protection regulator
  9. What is the name of the backup safety designed to shut off the burner if the temperature of the water in the heater exceeds 2000 F?
    1. T&P
    2. ECO
    3. TCO
    4. FVIR
  10. What feature acts as extra protection on a redundant gas valve?
    1. On-off switch
    2. Pilot adjustment
    3. Servo regulator
    4. A second automatic shutoff valve seat
  11. How have redundant combination gas valves been adapted to give them modulating operation?
    1. WiFi-enabled
    2. Servo regulated
    3. Electric Stepper motor
    4. Electro hydraulic actuator
  12. On an electric oven safety valve, the HSI must warm up sufficiently before enough electricity can pass to open the gas valve.
    1. True
    2. False
  13. A seismic valve will reset automatically once the vibration stops.
    1. True
    2. False
  14. Cable release fire suppression gas valves can only be activated manually.
    1. True
    2. False
  15. What are the typical manifold pressure ranges from a two stage gas valve supplying CH4?
    1. Low Fire 1 in. WC,  High Fire 1.5 in. WC
    2. Low Fire 1 – 1.5 in. WC, High Fire 3 – 4 in. WC.
    3. Low Fire 3 in. WC, High Fire 4 in. WC
    4. Low Fire 3 –4 in. WC, High Fire 10 – 11 in. WC.
  16. On a “Call for Heat” condition with a rod and tube control valve, which of the following statements is correct?
    1. The copper tube has expanded and the gas valve is open.
    2. The Invar rod has expanded and the gas valve is closed.
    3. The copper tube has contracted and the Invar rod has opened the gas valve.
    4. The Invar rod has expanded and the copper tube has opened the gas valve.
  17. A solenoid gas valve is in the open position when:
    1. the coil is energized
    2. the valve is pressurized
    3. the coil is not energized
    4. the valve is not pressurized
  18. Which of the following voltages would not be used to energize a diaphragm gas valve?
    1. 30 MV
    2. 750 MV
    3. 24 V
    4. 120 V
  19. Which of the following voltages could be used to energize a solenoid gas valve?
    1. 10 MV
    2. 30 MV
    3. 750 MV
    4. 24 V
  20. A solenoid gas valve would be installed:
    1. upstream of the safety valve
    2. downstream of the safety valve
    3. upstream of the pilot connection
    4. upstream of the appliance regulator
  21. The closing force of a diaphragm gas valve is:
    1. outlet gas pressure and total force
    2. inlet gas pressure and spring pressure
    3. outlet gas pressure and spring pressure
    4. inlet gas pressure and electro-magnetism
  22. A servo pressure regulator controls:
    1. the pressure to the pilot burner
    2. the pressure to the main burner
    3. the pressure to the SSOV (safety shut-off valve)
    4. the pressure to both the main burner and the pilot burner
  23. Which of the following valves would never require electricity to operate?
    1. Seismic valve
    2. Solenoid gas valve
    3. Diaphragm gas valve
    4. Redundant gas valve
  24. Which of the following valves would be used with an intermittent pilot system?
    1. Solenoid gas valve
    2. Safety shut-off valve
    3. Diaphragm gas valve
    4. Redundant gas valve
  25. A solenoid gas valve installed upside down may:
    1. remain fully open and never close
    2. open very slowly causing flashback
    3. open very quickly causing flame lift off
    4. stay closed when the valve is energized
  26. The safety shut-off valve is held open by:
    1. spring pressure
    2. a thermocouple
    3. atmospheric pressure
    4. gas pressure under the diaphragm
  27. A FV sensor reacts to the ignition of flammable vapours in the combustion chamber.
    1. True
    2. False
  28. How does a modulating hydraulic gas valve react on an initial call for heat?
    1. Snaps open to fully open position
    2. Snaps open to modulated input
    3. Snaps open to a pre-set minimum input
    4. Slowly opens to the proportional modulated position

Check your answers using the Self-Test Answer Keys in Appendix 2.

B2, Self-Test 1

Found in Competency B2, Learning Task 1.

Self-Test 1

  1. The Water, Oil and Gas (WOG) pressure rating covers flammable gas applications.
    1. True
    2. False
  2. Ball valves with a 5G rating are good for up to 5 psi gas installations indoors and outdoors
    1. True
    2. False
  3. Repair or replacement of two-piece ball valves internal parts is not recommended.
    1. True
    2. False
  4. How can a ball valve stem leak be fixed?
    1. Lubricate the ball valve
    2. Tighten the handle nut
    3. Remove the handle and tighten the packing nut
    4. Use two wrenches to tighten the two halves of the valve body
  5. Lubricated gas vales are equipped with a SAE standard grease fitting.
    1. True
    2. False
  6. Lubricated gas valves require monthly relubrication.
    1. True
    2. False
  7. How are button head grease couplers are installed onto the fitting?
    1. Push onto the fitting
    2. Pulls onto the fitting
    3. Screw into the fitting
    4. Push and ¼ turn twist action

Check your answers using the Self-Test Answer Keys in Appendix 2.

B2, Self-Test 2

Found in Competency B2, Learning Task 2.

Self-Test 2

  1. Any gas piping passing through a wall is defined as concealed piping
    1. True
    2. False
  2. The gas code stipulates that, a line pressure or high pressure regulator must be provide with OPP when installed, with a supply pressure greater than what?
    1. ½ psig
    2. 2 psig
    3. 5 psig
    4. 10 psig
  3. What is the maximum allowable pressure downstream of a pressure controlling device?
    1. 2 psig
    2. 5 psig
    3. Lowest maximum pressure rating of any downstream components
    4. Highest maximum pressure rating of any downstream components
  4. Direct operated relief valves are supplied in the normally open position.
    1. True
    2. False
  5. A direct operated relief valve looks like an ordinary direct-operated regulator except that it senses upstream pressure rather than downstream pressure.
    1. True
    2. False
  6. An overpressure shut-off (OPSO) will automatically reset.
    1. True
    2. False
  7. The vent limiting orifice has a very small orifice opening that will restrict the air flow which will delay the regulators reaction time.
    1. True
    2. False
  8. When using a regulator with a ball check leak limiters what must you ensure?
    1. It is not installed outdoors
    2. The leak limiting device must be in the vertical position
    3. The regulator is installed in a ventilated space
    4. All of the above
  9. If a 5 psig line pressure regulator has a ¾ inch vent tapping and the vent line must run 65 feet, what must be done?
    1. Use ¾ inch pipe for the first 20 feet, then increase to 1 inch
    2. Use ¾ inch pipe for the first 50 feet, then increase to 1 inch
    3. Use ¾ inch pipe for the entire length – you may not change sizes
    4. Use 1 inch pipe for the entire length – make the change at the vent tapping
  10. Too many fittings on a vent line could cause:
    1. the regulator to “hunt”
    2. the regulator to lock-up
    3. the restricting element to fully close
    4. the restricting element to fully open
  11. If a 5 psig line-pressure regulator (with internal relief) was installed in a boiler room, which of the following would be required?
    1. A bypass shall be installed
    2. It shall be of negative shut-down type
    3. The vent must be piped to a safe location outdoors
    4. All downstream piping must be Type “K” copper tubing
  12. A line pressure regulator operating at 2 psig or less shall be exempt from the requirements of Clause 5.2.1.7 (B) when equipped with which of the following?
    1. A vent leak-limiting system
    2. An internal relief valve spring
    3. A union on the downstream piping
    4. A pitot tube and balancing diaphragm
  13. The arrow on a regulator body should point upstream.
    1. True
    2. False
  14. What is the minimum clearance from a regulator vent termination to a mechanical air intake?
    1. 1 ft
    2. 3 ft
    3. 10 ft
    4. 15 ft
  15. What is the minimum clearance from a regulator vent termination to an electrical outlet?
    1. 1 ft
    2. 3 ft
    3. 10 ft
    4. 15 ft

Check your answers using the Self-Test Answer Keys in Appendix 2.

B3, Self-Test 1

Found in Competency B3, Learning Task 1.

Self-Test 1

  1. System pressure tests can be performed with compressed Oxygen.
    1. True
    2. False
  2. What are is the minimum pressure test requirements for the unconnected (stage 1) test, of a 5 psi system 70 meter in length.
    1. 15 psi for 15 minutes
    2. 15 psi for 60 minutes
    3. 50 psi for 60 minutes
    4. 50 psi for 180 minutes
  3. A 3” pressure gauge with a 50 psi maximum range and 1 psi pressure increments would be acceptable to use for a 15 psi pressure test.
    1. True
    2. False
  4. Line pressure (system) regulators should be installed for the Stage 1 pressure test.
    1. True
    2. False
  5. What is the purpose of the valve seepage test?
    1. To verify that the supply valve is closed tight
    2. To verify there are no open ends in the system
    3. To verify the appliance control valve is closing tight
    4. To verify the regulator is closing tight at positive lockup pressure
  6. A partially full nitrogen cylinder has 800 psig it has an internal volume of 1.77 ft3 (50 L). How much gas will be available for a 50 psig pressure test?
    1. 8.1 ft3 (230 L)
    2. 22.28 ft3 (630.5 L)
    3. 28.32 ft3(801.5 L)
    4. 632.5 ft3 (1789 L)

Check your answers using the Self-Test Answer Keys in Appendix 2.

B3, Self-Test 2

Found in Competency B2, Learning Task 2.

Self-Test 2

  1. As per the gas code a 2 psig 3” NPS natural gas pipeline that is 40 ft in length must first be purged with inert gas and then purged with the fuel gas.
    1. True
    2. False
  2. The purging of gas system supplying a 500000 Btu/h appliance ca be performed and or supervised by a class B gas fitter.
    1. True
    2. False
  3. Purging is done before the line have been pressure tested.
    1. True
    2. False
  4. If you have a gas range the entire piping system can be purged indoors using one of the ranges open burners.
    1. True
    2. False
  5. As per the Gas Code what is the maximum gas system pressure that may be purged using the indoor hose purge assembly method?
    1. 7” wc
    2. 11” wc
    3. 2 psi
    4. 5 psi
  6. As per the Gas Code what is the maximum pipe size that may be purged using the indoor hose purge assembly method?
    1. ½” NPS
    2. ¾” NPS
    3. 1” NPS
    4. 4” NPS
  7. As per the Gas Code what is the maximum length of piping that may be purged using the indoor hose purge assembly method?
    1. 50 ft
    2. 100 ft
    3. 200 ft
    4. No maximum length

Check your answers using the Self-Test Answer Keys in Appendix 2.

B4, Self-Test 1

Found in Competency B4, Learning Task 1.

Self-Test 1

  1. What term describes the unintentional act of air entering through the building envelope?
    1. Infiltration
    2. Exfiltration
    3. Stack effect
    4. Distribution effect
  2. Pressure induced backdrafting is the reversal of the flow of flue gases out of the building caused by negative pressure in the building.
    1. True
    2. False
  3. What is the maximum house depressurization limit (HDL) that a natural draft vented appliance should be exposed to?
    1. 1 Pa (.004” wc)
    2. 5 Pa (.02” wc)
    3. 10 Pa (.04” wc)
    4. 15 Pa (.06” wc)
  4. What are the two common methods of delivering the air supply requirements to a gas appliance?
    1. Induced and Forced draft
    2. Direct vent and room air systems
    3. Primary and secondary
    4. Make-up and ventilation air
  5. When installing a twin pipe direct vent appliance the air supply must be sized and installed according to the requirements of the B149.1 Gas code.
    1. True
    2. False

Check your answers using the Self-Test Answer Keys in Appendix 2.

B4, Self-Test 2

Found in Competency B4, Learning Task 2.

Self-Test 2

  1. How are air supply requirements for a direct vent appliance determined?
    1. Table 8.1
    2. Table 8.2
    3. Code clause 8.2.6
    4. Manufacturer’s literature
  2. What is the minimum required free area of a square combustion air opening?
    1. 3 in.2
    2. 6 in.2
    3. 9 in.2
    4. 10 in.2
  3. What is the smallest opening dimension in a fixed louvre, grille, or screen?
    1. [latex]\dfrac{1}{8}[/latex]”
    2. [latex]\dfrac{1}{4}[/latex]”
    3. [latex]\dfrac{1}{2}[/latex]”
    4. 1”
  4. Under what conditions can a gas-fired appliance be installed in a building and not have a separate combustion air supply?
    1. Tight building of sufficient volume
    2. Loose building of less than 1000 ft2
    3. Loose building of sufficient volume
    4. Tight building appliance in an enclosure
  5. When compared to the air supply opening, what is the minimum cross-sectional area of the ventilation air opening for an appliance over 400 MBH?
    1. 5% or 5 in.2
    2. 10% or 10 in.2
    3. 20% or 20 in.2
    4. 50% or 50 in.2
  6. A single family dwelling complies with Clause 8.2.1(a) or (b). It has a boiler rated at 200 MBH and a hot water storage tank rated at 110 MBH. Both appliances are equipped with draft control devices. The air supply is brought from outdoors through a duct. Determine the area of air supply duct.
    1. 22 in.2
    2. 25 in.2
    3. 40 in.2
    4. 47 in.2
  7. A structure conforms to Clause 8.2.1(a) or (b). It contains a boiler rated at 65 MBH and a domestic hot water tank rated at 40 MBH. Both appliances are designed for use with no draft control devices and the air supply is brought from outdoors through a duct. Determine the area of air supply duct.
    1. 7 in.2
    2. 9 in.2
    3. 14 in.2
    4. 18 in.2
  8. A single family dwelling conforms to Clause 8.2.1(a) or (b). It has a furnace rated at 80 kW and a hot water tank rated at 30 kW. The furnace is equipped with a barometric draft control and the hot water tank has a draft-hood. The air supply is from outdoors. Determine the area of air supply duct.
    1. 12000 mm2
    2. 14000 mm2
    3. 30000 mm2
    4. 35000 mm2
  9. A structure conforms to Clause 8.2.1(a) or (b). It has a mid-efficient furnace rated at 150 MBH and a hot water tank with an input of 40 MBH. The furnace has no draft control device, but the hot water tank is equipped with a draft-hood. The air supply is from outdoors. Determine the area of air supply duct.
    1. 4 in.2
    2. 14 in.2
    3. 29 in.2
    4. 18 in.2
  10. A structure does not comply with Clause 8.2.1(a) or (b). It is equipped with a boiler rated at 150 MBH and a hot water tank rated at 60 MBH. Both appliances are equipped with draft control devices. The volume of the structure is 8000 cu ft Determine the area of air supply duct.
    1. 16 in.2
    2. 29 in.2
    3. 32 in.2
    4. None required
  11. A structure does not conform to Clause 8.2.1(a) or (b). It is equipped with a boiler rated at 225 MBH and a hot water tank rated at 50 MBH. Both appliances do not use a draft control device and the volume of the structure is 10000 cu ft Determine the area of air supply duct.
    1. 20 in.2
    2. 32 in.2
    3. 40 in.2
    4. None required
  12. A boiler room is located within an enclosure in a structure that does not comply with Clause 8.2.1(a) or (b). The boiler is rated at 200 MBH and a hot water tank is rated at 60 MBH. Both units are equipped with draft-hoods. The volume of the structure is 20000 cu ft and Table 8.3 indicates that the air supply may be taken from the structure. Calculate the area of openings required to be cut into the enclosure.
    1. 20 in.2
    2. 260 in.2 upper and lower
    3. 260 in.2 upper opening only
    4. 260 in.2 lower opening only
  13. A mechanical room is equipped with gas appliances with a total input of 1800 MBH. All appliances are equipped with draft control devices. Determine the free area of air supply opening.
    1. 18 in.2
    2. 60 in.2
    3. 201 in.2
    4. 260 in.2
  14. A structure is equipped with a boiler rated at 400 MBH and a hot water tank rated at 80 MBH. Both pieces of equipment are equipped with draft control devices and the air supply is ducted from outdoors. Determine the free area of ventilation opening
    1. 7 in.2
    2. 10 in.2
    3. 12 in.2
    4. 68 in.2
  15. A structure is equipped with a boiler rated at 1000 kW and has a barometric draft control. The louvered opening has 65% free area. Determine the area of air supply opening.
    1. 70000 mm2
    2. 201500 mm2
    3. 310000 mm2
    4. None required
  16. A structure is equipped with appliances rated at 2000 MBH. None of the appliances are equipped with draft control devices. Determine the free area of air supply opening.
    1. 10 in.2
    2. 67 in.2
    3. 214 in.2
    4. 285 in.2
  17. A structure has a mechanical room into which air must be ducted from outdoors. It contains the following appliances:
    • One boiler rated at 1200 MBH, equipped with a barometric damper.
    • Two duct heaters without draft controls rated at 600 MBH each.
    • Two hot water tanks rated at 300 MBH each. Both tanks are equipped with draft-hoods.

    Determine the free area of air supply opening:

    1. 80 in.2
    2. 171 in.2
    3. 220 in.2
    4. 240 in.2
  18. Calculate the air requirements supplied from outdoors to a mechanical room equipped with the following appliances:
    • One boiler with a draft control at 200 kW.
    • One boiler with no draft control rated at 100 kW.
    • Two duct heaters with no draft control rated at 50 kW each.
    • Two hot water tanks with draft-hoods at 100 kW each.

    Determine the free area of ventilation opening:

    1. 4200 mm2
    2. 11250 mm2
    3. 12250 mm2
    4. 13950 mm2

Check your answers using the Self-Test Answer Keys in Appendix 2.

B4, Self-Test 3

Found in Competency B4, Learning Task 3.

Self-Test 3

  1. If there is more than one gas appliance in the area, the air supply can be located at any appliance.
    1. True
    2. False
  2. What minimum distance must the air supply opening be located above the finished grade?
    1. 12 in.
    2. 18 in.
    3. 24 in.
    4. 36 in.
  3. What is the maximum vertical distance above the burner level that the air supply can terminate on a low volume installation?
    1. 6 in.
    2. 12 in.
    3. 18 in.
    4. 24 in.
  4. The outside opening for an air supply can not terminate any closer than what distance from a clothes dryer vent?
    1. 12 in.
    2. 18 in.
    3. 24 in.
    4. 36 in.
  5. Mechanical room has one 500 MBH boiler with a draft control device, the air supply can be located anywhere in the mechanical room, provided that it does not interfere with the performance of the ventilation air opening.
    1. True
    2. False
  6. When using the low volume air supply tables, what is the maximum equivalent length if the duct is oversized by one?
    1. 10 ft
    2. 20 ft
    3. 40 ft
    4. 50 ft
  7. When connecting two rectangular ducts the S-cleats are used to joint the two folded (hemmed) edges.
    1. True
    2. False
  8. A combustion air pot is a type of passive air trap designed to to inhibit the unwanted movement of air through the duct.
    1. True
    2. False
  9. What is the minimum clearance requirement from a passive air supply opening to a flue gas vent serving a 100 MBH appliance?
    1. 6 in.
    2. 12 in.
    3. 3 ft
    4. 10 ft

Check your answers using the Self-Test Answer Keys in Appendix 2.

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