This article is about HVAC QC Inspector Interview Questions designed for ARAMCO projects in Saudi Arabia. Now a days Aramco CBT Test for QCs is conducted before posting to sites. These HVAC Questions will be helpful for HVAC engineers and QCs. All answers are given below at the end of page.
HVAC QC Inspector Interview Questions
- What is VFD? (WHAT IS VFD AND ITS PRINCIPLE, WHY VFD IS USED)
a. Vent Floor Drain b. Ventilator Fixing Diagram c. Variable frequency drive d. Valued frequency drive e. None of the above
2. What is the device arranged to seal-off airflow automatically through a part of an air duct system so as to restrict the passage of smoke?
a. Fire Damper b. Volume Damper c. Back draft Damper d. Smoke damper e. None of the above
3. When does a rectangular elbow of low velocity duct system do not require to have vanes?
a. If throat radius is equal to duct width b. Throat radius is greater than width of the duct c. Throat radius is less than width of the duct d. Throat radius is twice the width of the duct
e. None of the above
4. A non-woven geo textile with a unit weight of at least of…………..
a. 100 g/m b. 120 g/m c. 90 g/m d. 140 g/m e. None of the above
5 The surface slope to catch basin shall be not less than of………… %
a. 2∙5% b. 1∙5%
c. 1∙0% d. 2∙00% e. None of the above
6. Plastics pipe shall be supported at each story or a minimum interval of……..
| a. | 10ft | b. | 6ft |
| c. | 8ft | d. | 2m |
7. Which type of joints is approved for cpvc pipes?
| a. | Mechanical joints | b. | Solvent cemented joints |
| c. | Welded joints | d. | Brazed joints |
8. For approval of leak test for Sewer line above the ground shall be watertight for a period of
a. 1 hour b. 4 hours
c. 12 hours d. 24 hours e. 48 hours
9. Unless otherwise specified steel sheet and strip used for duct and connectors have the Minimum yield strength of…….
| a. | 28,000 psi | b. | 40,000 psi |
| c. | 35,000 psi | d. | 30,000 psi |
10. Up to 120 in. (3048 mm) width ties shall be spaced at even intervals of duct width not exceeding
a. 1254 mm b. 1524 mm c. 1542 mm d. 1624 mm e. None of the above
11. Which are automatically shut down in the event of a fire or for air transfer openings in walls or partitions
| a. | Fire Wall | b. | Fire dampers |
| c. e. | Draft Stop None of the above | d. | Heat Stop |
12. Dampers can be installed in exhaust duct systems
| a. | TRUE, | b. | FALSE, |
| c. | None of the above | d. | 0 |
13. Where lead flashing material is used, it shall be a minimum of …..
a. two (2) pounds per square foot b. four (4) pounds per square foot
c. six (6) pounds per square foot d. three (3) pounds per square foot
e. None of the above
14. Solvent cement and primer for thermoplastic piping shall be stored temperature of……. %
a. 25∙70% b. 26∙70%
c. 27∙70% d. 28∙70%
e. None of the above
15. PVC pipe and fittings shall be used for cold water distribution systems outside the building shall be not used for water above of…………
| a. | 80C | b. | 48.8C |
| c. | 92C | d. | 110C |
16. Cpvc pipes and fittings are used for
| a. | Cold water system out side the building | b. | Only for hot water system |
| c. | For both hot and cold water system | d. | Not permitted for use |
17. The maximum force required to open a stair door under maxi- mum stair pressure conditions should be limited to …
| a. | 80 lbf | b. | 20 lbf |
| c. | 30 lbf | d. | 40 lbf |
18. Grills are only 2way and 4way type ???
| a. | FALSE, | b. | TRUE, |
| c. | None of the above | d. | 0 |
19. What is the part on the refrigeration system that is designed to liquefy refrigerant vapour by the removal of heat??
| a. | Expansion Valve | b. | Compressor |
| c. | Condenser | d. | Evaporator |
20. What is a full-radius or long sweep elbow?
| a. | Inside radius is less than width of the duct | b. | Inside radius is greater than width of the duct |
| c. | Inside radius is equal to the width of the duct | d. | Inside radius is twice the width of the duct |
21. Gasket, O-Rings and lacking keys be stored flat on racks below of………….
a. 32C b. 38C
c. 35C d. 23C
e. None of the above
22. The maximum drove of catch basin from high point of paving shall be……..
| a. | 200mm | b. | 250mm |
| c. | 150mm | d. | 300mm |
23. Fasteners used on steel duct shall be ………………….
a. COPPER b. STEEL
c. ALUMINIUM d. GALVANIZED
e. None of the above
24. Ducts with interior widths of …………. or less do not require mechanical fasteners in addition to adhesive
a. 453mm b. 303mm c. 203mm d. 243mm e. None of the above
25. Hot and cold water supply it shall be tested under pressure of………
a. 150psi b. 180psi c. 150bar d. 158psi e. None of the above
26. A device or means to prevent backflow into the potable water system.
| a. | Back flow connection | b. | Backflow preventer |
| c. | back-pressure backflow | d. | back-siphon age |
27. For approval of leak test for Sewer line that had been backfilled shall be watertight for a period of
a. 1 hour b. 4 hours c. 12 hours d. 24 hours e. 48 hours
28. A continuous membrane used to subdi- vide a concealed space to restrict the passage of smoke, heat, and flames
a. Draft Stop b. Area Separation Wall
c. Fire wall d. Fire Stoper
e. None of the above
29. Duct systems can be interconnected with any other building ventilation or exhaust system
a. TRUE b. FALSE c. None of the above d. 0
e.
30. Lead bends and lead traps shall not be less than ………….. wall thickness
a. 3.2mm b. 4mm
c. 6mm d. 2.5mm
e. None of the above
31. Pipe stored on racks or bearing board the support will be at least ……………
a. 75mm Wide b. 90mm Wide c. 100mm Wide d. 60mm Wide
e. None of the above
32. The minimum height of hanger width for plastic pipe shall be …………
a. 50mm b. 75mm
c. 60mm d. 100mm
e. None of the above
33. What should be the height of header from where water will be filled for drainage leak test?
a. 3m b. 4m c. 3.5m d. 2m e. None of the above
34. In a smoke control system acceptance testing, which one is most important
a. Component testing b. Functional testing c. Performance testing d. Documentation e. All above
35. Bends shall be made with not less than ……………. centerline radius
a. two duct diameter b. one duct diameter
c. half duct diameter d. one and half duct diameter e.
36. Flexible duct shall be supported at the manufacturer’s recommended intervals but at least every ………..
a. 5.5 ft b. 5 ft c. 3 ft d. 4ft e. None of the above
37. Butterfly damper is a fire damper.
| a. | TRUE, | b. | FALSE, |
| c. | None of the above | d. | 0 |
38. What Is The meaning of FAHU?
| a. | Fresh Air Handling Unit | b. | First Air Handling Unit |
| c. | Front Air Handling Unit | d. | None of the above |
39. When does a rectangular radius elbow do not require to have turning vanes?
a. Throat radius is 1-1/2 the duct width b. Gaiter line radius is 1-1/2 the duct width c. Outside radius is l-l/2 the duct width d. None of the above
40. Solvent cement and primer for thermoplastic piping shall be stored temperature of…….
a. 25∙70% b. 26∙70%
c. 27∙70% d. 28∙70%
e. None of the above
41. The minimum surface travel of any liquid to a catch basin should not greater than……
a. 10 meter b. 18 meter c. 15 meter d. 16 meter
e. None of the above
42. The minimum spacing between drainage inlets should not exceed……….
a. 120m b. 90m c. 80m d. 50m
e. None of the above
43. Trap used in pressurized building as described shall have minimum trap seal of….
a. 110mm b. 120mm c. 90mm d. 150mm
e. None of the above
44. Valve which is installed for controlling all outlets at discharge side of water meter is
a. Shut off valve b. Isolating valve c. Pressure regulating valve d. Full way valve e. Solenoid valve
45. A wall of fire-rated construction which serves to divide the floor area of a building into acceptable area limits
a. Fire wall b. Area Separation Wall c. Divider wall d. Breaker Wall e. None of the above
46. Ducts shall not pass through firewalls or fire partitions
a. TRUE, b. FALSE
c. Partially d. None of the above e.
47. Metal drain pans shall be of ………. coated galvanized steel
| a. | G−110 | b. | G−98 |
| c. | G−90 | d. | G−120 |
48. Leakage test pressure should be exceed duct pressure class level
a. TRUE b. FALSE
c. None of the above d. 0
49. Water closet shall have an average consumption of not more than……………..of water per flush
a. 6.1 liters b. 4.5liters c. 6.0 liters d. 5.5 liters e. None of the above
50. What is the appliance receiving, conditioning and delivering air supplied through an air distribution system?
a. Fan Coil Unit b. Air Terminal Unit c. Air filter d. Air Foil
Answers:
| 1 | C |
| 2 | D |
| 3 | A |
| 4 | A |
| 5 | B |
| 6 | A |
| 7 | B |
| 8 | B |
| 9 | D |
| 10 | B |
| 11 | B |
| 12 | B |
| 13 | B |
| 14 | B |
| 15 | B |
| 16 | C |
| 17 | C |
| 18 | A |
| 19 | C |
| 20 | A |
| 21 | B |
| 22 | A |
| 23 | B |
| 24 | C |
| 25 | A |
| 26 | B |
| 27 | D |
| 28 | A |
| 29 | B |
| 30 | A |
| 31 | A |
| 32 | A |
| 33 | A |
| 34 | E |
| 35 | B |
| 36 | B |
| 37 | A |
| 38 | A |
| 39 | B |
| 40 | B |
| 41 | C |
| 42 | B |
| 43 | A |
| 44 | D |
| 45 | B |
| 46 | A |
| 47 | C |
| 48 | B |
| 49 | A |
| 50 | B |
For More QC Knowledge Please Read QC CBT and Interview Preparation.