BOC Cheat Sheet 2026

The 30 highest-yield BOC facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. In a BAS, what does a DDC controller stand for? → Direct Digital Control
2. What inspection procedure is essential for safety procedures? → Systematic inspection following established checklists and standards
3. What is the main goal of a root cause analysis after a repeated equipment failure? → To find the underlying cause so the failure does not happen again
4. Under NFPA 101, how long must battery-powered emergency lighting operate during the annual functional test? → 90 minutes
5. Which NFPA standard covers inspection, testing, and maintenance of water-based fire protection systems such as sprinklers and standpipes? → NFPA 25
6. What code compliance requirement applies to material selection? → All work must comply with applicable local, state, and national codes
7. A demand-controlled ventilation (DCV) system typically adjusts outdoor air intake based on which measurement? → Space CO2 concentration
8. What is an 'alarm management' feature in a BAS used for? → Notifying operators when a monitored point exceeds normal operating limits
9. Occupants report a sewer gas odor near a rarely used floor drain. What is the most likely cause and fix? → A dry P-trap; refill it with water or install a trap primer
10. An enthalpy economizer differs from a dry-bulb economizer because it considers: → Both temperature and moisture content of the air
11. An air-side economizer in fixed dry-bulb mode should use outdoor air for free cooling when: → Outdoor air temperature is below the changeover setpoint and cooling is needed
12. How should hazardous conditions be handled during maintenance protocols work? → Stop work, secure the area, report the hazard, and follow safety protocols
13. What is the primary purpose of a freezestat on an air handling unit? → To shut down the fan or close outdoor dampers when air entering the coil nears freezing
14. A steam trap stuck open on a 100 psig line causes energy loss mainly by: → Allowing live steam to pass into the condensate system
15. What environmental protection measure applies to quality inspection? → Proper handling, storage, and disposal of materials according to environmental regulations
16. Which bacteria is of greatest concern in a building's hot water and cooling tower systems due to risk of Legionnaires' disease? → Legionella pneumophila
17. The minimum outdoor air damper setting on an air handler exists primarily to: → Provide required ventilation air for occupants
18. What inspection procedure is essential for material selection? → Systematic inspection following established checklists and standards
19. What minimum hot water storage temperature does ASHRAE 188 recommend to control Legionella growth? → 140°F (60°C)
20. What environmental protection measure applies to technical measurements? → Proper handling, storage, and disposal of materials according to environmental regulations
21. A fire door is found propped open with a wedge. What is the code compliance issue? → Fire doors must be self-closing and latching and must not be blocked open
22. How often does NFPA 101 require a functional test of battery-powered emergency lights lasting at least 30 seconds? → Monthly
23. Which test is used to check a sanitary drain system for leaks before walls are closed during construction or renovation? → Hydrostatic pressure test
24. In a VAV system, the duct static pressure sensor that controls the supply fan is typically located: → About two-thirds of the way down the longest main supply duct
25. Testable backflow prevention assemblies such as reduced pressure zone (RPZ) valves are typically required to be tested how often? → At least annually
26. What is the purpose of a feedwater economizer in a boiler system? → To preheat feedwater using waste heat from flue gases
27. What inspection procedure is essential for code compliance? → Systematic inspection following established checklists and standards
28. What is the most critical safety requirement in quality inspection? → Following all applicable safety regulations and wearing required PPE
29. A boiler's Hartford Loop is designed to protect against: → Siphoning of water out of the boiler
30. A lamp rated at a correlated color temperature of 2700 K will appear: → Warm, with a yellowish-white tone