How do sprinklers work, and what differentiates the following types?
Wet Pipe
Dry Pipe
Pre-Action
Deluge
Metal bulb with a low melting point that bursts and activates when the area is hot enough.
Wet Pipe: Most common type
Dry Pipe: Used in cold, unconditioned spaces, where the first portion of the pipe is filled with gas to keep water in warmer areas to avoid freezing.
Pre-Action: Gives warning before sprinklers activate, allowing time to prevent them coming on (used in sensitive spaces like museums)
Deluge: Best sprinkler type for high hazard areas.
Fire-Protection Rating
The period of time an opening protective assembly can maintain its integrity during a fire test.
Standpipes (note typical materials and differentiate their classes)
Required where a hose from a fire hydrant would have a hard time reaching, like large floor plates or multi-stories.
Materials: cast iron, Type K copper, Steel
Class I: 2-1/2” pipe, no hose
Class II: 1-1/2” pipe, hose in cabinet
Class III: Both 2-1/2” and 1-1/2” pipe with hose in cabinet
Differentiate the following:
Heat Detectors
Ionization Smoke detector
Photoelectric Smoke detector
Combination ionization/photoelectric Smoke detector
Heat detectors: less effective at fire detection than smoke detectors.
Ionization Smoke detector: Passes an electrical current back and forth and trips if the path is interrupted by smoke; quickest to catch a fast fire.
Photoelectric Smoke detector: Passes light to a sensor and trips if smoke interrupts the path; best for slow, smoldering fires.
Combination ionization/photoelectric Smoke detector: The best type of smoke alarm, combining both ionization and photoelectric sensors.
Automatic ventilating hatches
Needed in places that could burn very hot or have a very large internal volume like an atrium
Smoke Baffle
A vertical panel extending 24 inches down from the ceiling adjacent to an atrium to help track and manage smoke movement.
Hydraulic Elevator
Slow, inefficient, and inexpensive to install but uses a piston drilled into the earth and can leak oil into the ground.
Traction Elevator
Faster elevator that travels further distances.
Tankless Toilet
Only possible in buildings with high water pressure, featuring a loud flush.
Tank Toilet
Makes up for lower water pressure and is typical in residential buildings.
Closed contact Security system
Trips when pieces are opened, like a typical door sensor.
Mechanical Security system
Spring loaded system that is prone to false alarms from other vibrations.
Photoelectric Security system
Laser or light fence that doesn’t work well outside.
Passive infrared presence detector security system
Detects rapid change in heat from skin, and can be tripped by HVAC systems.
Motion sensor
Uses micro or infrared frequencies and is most effective with movement toward or away from the sensor.
Acoustic detectors
Tuned to the specific sounds of forced entry.
Delayed egress locking
Keeps perpetrators inside for law enforcement.
Visible Transmittance (VT)
Descriptor of glass ranging from 0 to 1, where 1 means all visible light comes through.
