2024 Commercial Mechanical Inspector – Practice Exam

1. For smoke barriers in non-sprinklered buildings using the pressurization method, the pressure difference across the smoke barrier must be not less than what value relative to the maximum calculated pressure difference produced by the design fire?

2. When entering an occupied structure or premises for inspection, the code official must first present credentials to the occupant and do what?

3. Where two or more appliances are connected to a vertical vent or chimney, the smaller connector shall enter at the highest level consistent with available headroom or clearance to combustible material.

4. What type of concentration is the Occupational Exposure Limit (OEL) based on?

5. Openings into fire-resistance-rated construction for exit enclosure ventilation systems shall be limited to those needed for maintenance and operation and protected by what?

6. Before a permit is issued, the code official is authorized to inspect and evaluate the systems, equipment, buildings, devices, premises and spaces or areas to be used in a procedure known as a:

7. Ozone gas generators having a maximum ozone-generating capacity of 1/2 pound (0.23 kg) or more over a 24-hour period must be mechanically ventilated at a rate of not less than how many air changes per hour?

8. Commercial-industrial-type incinerators shall be constructed and installed in accordance with which NFPA standard?

9. What must be provided prior to placing a gaseous hydrogen system into operation to displace the air in the piping system?

10. For an Elevator car in public spaces, what is the required Exhaust Airflow Rate in CFM/ft squared?

11. Which category of condensing appliances must be provided with an auxiliary drain pan where damage to any building component will occur as a result of a stoppage?

12. Duct smoke detectors must report only as a supervisory signal, not as a fire alarm, in facilities required to be monitored by what location?

13. Storage tanks and heating equipment installed in outdoor locations must be designed for what specific condition?

14. For compensating hoods with makeup air supplied only from the front face discharge and side face discharge openings, what labeling information is NOT required?

15. What is the minimum clearance required above an appliance or horizontal connector where the original required clearance was 36 inches, and the protection is 0.024-inch sheet metal with ventilated airspace?

16. Commercial refrigerators, freezers, beverage coolers, and walk-in coolers must be tested in accordance with UL 471 or which other standard?

17. What must failure of the exhaust ventilation system cause in a repair garage for lighter-than-air fuels?

18. Vented gas fireplace heaters shall be listed in accordance with which ANSI/CSA standard?

19. Approved plastic pipe or tubing for heating panels embedded in concrete must be rated at 100 psi (689 kPa) at what specific temperature?

20. Boilers shall be mounted on floors of noncombustible construction, unless what condition is met?

21. Gas-fired appliances shall be vented in accordance with which other code?

22. Unless otherwise approved, pressure vessels must be constructed and certified in accordance with which standard?

23. Commercial electric cooking appliances must be listed and labeled in accordance with which UL standard?

24. Required ventilation systems for dip tank operations shall be arranged such that the failure of any ventilating fan will automatically stop what component?

25. For piping materials other than steel pipe and CSST, exposed piping must be identified by a yellow label marked “Gas” in black letters at intervals not exceeding what distance?

26. For a Nail salon, each manicure and pedicure station shall be provided with a source capture system capable of exhausting not less than how many CFM per station?

27. Where ducts used for cooling are externally insulated, the insulation must be covered with a vapor retarder having a maximum permeance of what value, unless the insulation itself meets this standard?

28. Mechanical systems shall not be located in which specific building element?

29. For horizontal terminations of mechanical draft systems adjacent to walkways, what is the minimum required height above the walkway level?

30. An appliance vented by natural draft shall not be connected into a vent, chimney, or vent connector on which side of a mechanical flue exhauster?

31. The interlock requirement for dampers in combustion air openings serves to prevent operation of any appliance that draws combustion air from the room or space when what condition is true?

32. Where single-wall metal pipe passes through a combustible exterior wall serving a listed appliance with a draft hood, the ventilated metal thimble must be not less than 4 inches larger in diameter than the metal pipe, unless a minimum horizontal pipe run of 6 feet is provided in the open, in which case the thimble can be not less than how much larger in diameter than the metal pipe?

33. What is the capacity in cfh for 1 1/4-inch nominal Schedule 40 metallic pipe at 100 feet in length, with an initial supply pressure of 8.0 in. w.c. or greater and a 3.0 in. w.c. pressure drop?

34. Relief valve discharge piping must terminate not more than how many inches above the floor or flood level rim of the waste receptor?

35. Truss members and components shall not be cut, drilled, notched, spliced, or otherwise altered without whose written concurrence and approval?

36. Where the duct is constructed of steel not less than 0.019 inch in thickness and there are no openings serving the corridor, smoke dampers are not required at which penetrations?

37. In industrial occupancies and refrigerated rooms, where a machinery room would otherwise be required, refrigerant detectors are not required in unoccupied areas that contain only what type of piping?

38. Hearth extensions of approved factory-built fireplaces must be installed in accordance with the listing and must comply with which UL standard?

39. Fuel oil piping and equipment located in flood hazard areas must be capable of resisting hydrostatic and hydrodynamic loads and stresses, including what specific effect?

40. A timer provided to control main burner operation of a sauna heater shall have a maximum operating time of what duration?

41. For a Kitchen (cooking) in a food and beverage service occupancy, what is the required Exhaust Airflow Rate in CFM/ft squared?

42. For a round galvanized steel duct with a diameter of 18 inches operating at 1-inch water gauge static pressure in a single dwelling unit, what is the minimum sheet metal thickness required?

43. A sediment trap must be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical, except for which common appliance?

44. Full-face flange gaskets must be used with all flanges made of which type of material?

45. For kitchens in Group R-2, R-3, and R-4 occupancies, what is the required intermittent exhaust rate capacity?

46. What is the minimum clearance required to a mechanical air supply inlet (Clearance I) for a vent terminal?

47. A masonry chimney flue cleanout opening must have a minimum height of 6 inches and its upper edge must be located not less than what vertical distance below the lowest chimney inlet opening?

48. Factory-built chimneys for building heating appliances producing flue gases having a temperature not greater than 1,000°F must be listed and labeled in accordance with which UL standard?

49. The board of appeals shall not have the authority to:

50. Mechanical ventilation systems for enclosed parking garages shall operate continuously or shall be automatically operated by means of carbon monoxide detectors applied in conjunction with what other detector type?