BC Ch. 7 Non-Fire Building Systems

Electrical Systems

• Conductors primarily distribute electricity throughout buildings, utilizing materials like copper or aluminum for efficiency.
• American Wiring Gauge (AWG) measures conductor size, critical for ensuring appropriate current flow.
• Insulation on electrical wiring prevents electrical shock and fire hazards, serving as a protective barrier.
• Fuses are single-use devices that stop electrical flow during excessive current; unlike circuit breakers that can be reset.
• Overcurrent protection devices prevent fires caused by excessive electrical current, crucial for system safety.
• Electrical service panels are typically located in utility rooms or basements to centralize electricity distribution.
• Transformers change voltage for efficient electricity transfer, safeguarding wiring against overload.
• Emergency generators provide backup power during outages, ensuring that critical systems remain functional.

HVAC Systems

• Furnaces transfer heat from combustion chambers to air or water, playing a pivotal role in heating systems.
• Condensing furnaces have secondary heat exchangers that enhance efficiency by extracting extra heat from exhaust gases.
• Air Handling Units (AHUs) distribute climate-controlled air, ensuring even temperature throughout buildings.
• Ductwork distributes climate-controlled air to and from AHUs, vital for maintaining indoor comfort.
• Air-cooled chillers use fans to blow air across water pipes, creating cool air for effective air conditioning.
• During the evaporator stage of refrigeration, the refrigerant absorbs heat, cooling the surrounding environment.
• Smoke circulation poses risks in fires, as it can spread smoke throughout buildings, increasing danger and damage.
• Fire sprinkler systems, commonly found in cooling towers, play a critical role in fire prevention.
• Heating output is measured in British Thermal Units (Btu), essential for assessing system capacity.
• Dampers control airflow by regulating openings in ductwork, allowing for efficient temperature management.

Plumbing Systems

• The main control valve in water supply systems regulates flow, allowing for quick shutoff during emergencies or leaks.
• Backflow preventers are critical for preventing contaminated water from re-entering public water supplies, ensuring safety.
• Gravity-controlled drainage systems efficiently remove wastewater, keeping plumbing systems functional and clean.
• Traps block sewer gases from entering occupied spaces, contributing to indoor air quality and safety.
• Vent stacks balance air pressure in drainage systems, crucial for preventing backflow and ensuring proper drainage function.
• Plastic or copper is typically used for water distribution piping due to durability and corrosion resistance.
• Gas leaks require immediate action to shut off the gas supply to prevent hazards and ensure safety.
• Mercaptan, added to natural gas, provides a distinct odor for detecting leaks, enhancing safety measures.
• Domestic water pumps ensure adequate water pressure reaches upper floors of tall buildings, essential for operational efficiency.
• Shut-off valves are crucial in medical gas systems to isolate sections during emergencies for safety compliance.

Elevators and Escalators

• Traction elevators use steel cables and are commonly found in taller buildings for efficient vertical transport.
• Governors in elevator systems control speed, enhancing safety during operation.
• Door restrictors prevent elevator doors from opening when the car is in transit between floors, reducing accident risks.
• Phase I elevator operation during fires automatically recalls elevators to safe floors, ensuring user safety.
• Older escalators with wooden steps can pose significant fire risks, highlighting safety concerns in maintenance.
• Main disconnect switches for escalators are located near motors for quick access during emergencies.
• The King's Cross Fire exemplifies the severe risks associated with escalator fires, emphasizing the need for stringent safety measures.

Refrigeration Systems

• The refrigerant classification A3 indicates low toxicity but high flammability, requiring careful handling.
• The condenser in refrigeration systems releases heat, initiating the liquefaction of refrigerant, essential for cooling processes.
• Ammonia's high toxicity and flammability pose significant risks as a refrigerant, necessitating strict regulations and safety measures.