4 Building Systems Flashcards
Convenience stair
Stare that usually connect two floors in a multi story building
Rise
Vertical distance between the treads of a stairway or the height of the entire stairway
Run
Horizontal measurement of a stair tread or the distance of the entire stair line
Means of egress
Save continue this path of travel from any point in a structured to a public way composed of three parts exit access, exit, exit discharge
Straight run stairs
Extend in a straight line for their entire length findings may be found breaking up the stairs vertical travel at intervals
Return stairs
Intermediate landing between floors and reverse direction at that point
Scissors stairs
Two separate sets of stairs constructed in a common shaft, opposing return stairs. May serve opposing floors
Circular stairs
Two levels there is been on with inches stairs that curve
Folding stairs
Folding attic stairs provide access that doesn’t have permanence stairs
Spiral stairs
Allows stairs in a place in a small space. Spiral stairs consists of a series of steps spiraling around a single column
Protected stair closure
Stair with code required fire rated enclosure construction. Intended to protect documents as they make their way through
The only penetrations permitted and protected stairs enclosure are
For light, fire protection, environment control
Exterior stairs
Exterior to a building and opened the air, naturally ventilated or partially enclosed
Fire escape
Open metal stairs and landings attached to the outside of the building
Fire escapes that do exist have been in place for many years because
Codes have not permitted fire escapes in new construction for decades
Smoke proof closure
Stairways that are designed to limit the penetration of smoke and toxic gases from a fire on a floor of a building to the stairway and that serving as part of a means of egress
Minimum requirement of smoke prove stairs in what type of building
Five stories or higher
Smoke proofing may be what two types for stairs
Active or passive
Active smoke proof
Activated by automatic detection equipment there handling unit pressure rises stairwell to Push smoke out
Maximum and minimum allowable pressure differential between their building is in place for what reason
So that the door can be open with a reasonable amount of force
Active smoke proof stairs are entered through
Traditionally straight through the hallway, more recently through pressurized vestibule.
Passive smoke proof enclosure
Accessed using a vestibule or exterior balcony, protect stairwell from smoke by providing a means for smoke to be vented outside before entering stairs
Open stairs
Not enclosed with fire rated construction typically only permitted if connecting two floors
Americans with disabilities act of 1990, public Law 101-336
Federal statute intended to remove barriers physical and otherwise that limit access by individuals with disabilities
Most elevator regulations are based on
ASME/ANSI A17.1 safety code for elevators
Service elevator
Another term used to describe passenger elevators that have been designed to carry freight
Two types of elevators
Passenger and freight
Two most common types of power system for hoisting elevators
hydraulic and electric
Type of elevator that does not have breaks
Hydraulic
Electric elevators are subdivided into
Drum elevators more traction elevators
Drum elevator
Cable is pulled onto a large drum above the elevator shaft, counterweights reduce effort in wasting and lowering car, similar to a winch
traction elevator
Cable from elevator goes straight up and over drive sheave. Traction is produced by counterweight hanging on opposite side of cable. Requires braking system
Traction motor braking system
Drum break located on the shaft of the drive motor
Safety mechanisms for elevators
Terminal device, buffers, speed reducing switch, overspeed switch, car safeties
Terminal device
Electric switch designed to stop in the car by removing power before it reaches the upper and lower limits of hoist way
Buffers
Springs or hydraulic shock absorbers at bottom of elevator shaft only stop in elevator car traveling in the normal rate of speed
Speed reducing switch
Speed governor. Snows drive motor man elevator starts to exceed safe speed. If continues to accelerate, applies car safeties and trips over speed switch
Overspeed switch
Activated it’s been reducing switch fails,
Car safeties
Still jobs that wedged against guard rails and bring elevator to a stop. designed to stop freefalling car
Elevator pit
Extends down for the lowest floor landing to the bottom of the hoistway
Elevator hoistway is located in an atrium are not required to
Not required to be enclosed
Mushrooming
Tendency of heat smoke to rise until they encounter horizontal obstruction. At this point they will spread laterally until they encounter vertical obstruction and begin to bank downward
Elevator hoistway enclosures usually are required to be fire rated with
One or two hour rating depending on situation
building codes require venting at the top of almost every elevator hoistway because
To prevent mushrooming
The building contains three or fewer elevators code permits them to be in one hoistway. When four or more elevators are provided, there must be
A minimum of two separate hoistways
Express elevator hoistway is serving upper floors of tall buildings pertaining to entrances have
No entrances to the hoistway between the main entrance and lowest floor served
Single elevator hoistway that only serve upper levels have access doors for rescue purposes
Every three floors or so in that portion without normal hoistway doors (blind shafts)
In very tall buildings elevators are divided into zones with one zone serving lower floors and another serving upper floors. As own usually serves how many floors
15 through 20 floors
Blind hoistway
Used for express elevators that serves only upper floors of tall buildings. There are no entrances to the shaft on the floor is between the first floor and the lowest floor served
How many doors consist in an elevator door
Two, one for the past in your car, one for the hoistway. Passenger car door automatically opens hoistway doors at same time
Emergency exits on elevator cars
Hatch on the roof of the car, removable panel on the side of the car. Time-consuming only used as a last resort
Top exits are present in which type of elevator
Traction elevators, hydraulic elevators optionally
Some top panels are designed to be opened from inside the elevator but
All can be opened from the outside
In multiple elevator hoistways most elevator cars are equipped with
Side exits to allow passengers to be transferred laterally from a stalled car to functioning car
Older moving stairways or escalators, operate at what speed
90 through 120 ft./m, speeds now have been standardized at 100 ft./m
When serving more than two floors vertical openings created by escalators need to be
Protected. Commonly used with sprinklers and draft stop of 18 inches deep
Types of conveyor systems
Belt, roller, chain, screw, bucket, pneumatic
Utility Chase
Vertical pathway in a building that contains utility services such as plumbing electric telecommunications ductwork HVAC
Pipe chase
Concealed vertical channel and which pipes and other utility conduits are housed
Pipe chases must be surrounded by
Fire resistive construction to ensure fire safety
Refuse chute
Provides for the removal of trash and garbage from upper floors extending through the building with openings on each floor the depositing of trash or linen
Grease duct
Part of exhaust system for commercial cooking appliances that produce grease laden vapors.
Nfpa 90a
Standard for the installation of air conditioning and ventilation systems
Hvac ducts often travel vertically through multistory buildings. with few minor exceptions the code requires hvac duct to be
Enclosed in fire rated shaft
Nfpa 90a requires hvac ducts be in an enclosure rated at
1 hr for les than four story building, 2 hr for higher buildings.
True, false. Hvac systems cannot distribute products of combustion throughout the structure.
False. Hvac can spread combustion products
Duct
Channel or enclosure , sheet metal, used to move heat and cooling through a building. Hollow pathways used to move air from one area to another in ventilation system
Interstitial space.
In building construction, refers to generally inaccessible spaces between layers of building materials. May be large enough to spread fire.
Duct detectors are provided for fans with capacities exceeding
2000 cubic feet per min
Natural gas collects in what parts of buildings
Upper parts, it’s lighter so it rises.
Log, propane, collects in what part of buildings
Lower parts, it’s heavier so it sinks.
Sometimes interstitial spaces are used as what for hvac
Return air plenum. Instead of duct work, though limited by code
Smoke control system
Engineered system designed to control smoke by using the mechanical fans to produce air flows and pressure differences across smoke barriers to limit and direct smoke movement
Automatic smoke control
Smoke control systems in hvac disengaged to be automatically initiated by fire protection detection sensors, actuating dampers or venting smoke outside.
Automatic smoke control requires careful coordination of fire protection sensors because
Improper coordination of sensors and false activations can cause automatic smoke control to mitigate the wrong area.
Advantage of manual smoke control system
Elimination of system disruption from false alarms. Specific control of system through firefighter smoke control station, manual takes priority over automatic.
Disadvantage to manual smoke control
Delay in mitigating smoke in building, potentially allowing fire headway
Smoke control system should not be activated using
The manual pull stations to avoid pull stations being activated in area other than fire and improperly activating system in wrong area
Two methods to protect stairwells from smoke
Smoke proof tower. Stairwell pressurization
Smoke proof tower
Smoke proof enclosure that makes use of vestibule between corridor and the stairwell that is open to outside air, isolating stairs from interior of building.
Pressurized stairwell
Blower or fan pressurizes stairs to keep smoke out
Nfpa 92a
Standard for smoke control systems utilizing barriers and pressure differences.
Stairwell pressurization method where fan supplies air at a single point
Single injection method, can cause loss of pressure if door opened close to fan
Stairwell Multiple injection system
Air forced into stairwells at multiple levels through ducts to overcome limitations of single method.
Compensated pressurized stairwell
Air pressure is adjusted based on pressure detected in stairwell, adjusting as doors open an close
Stairwell pressurization, over pressure relief
Weighted dampers to outside forced open if stairwell is over pressurized. Automatic dampers opened by pressure switches. P
Smoke and heat vent minimum size for small hatchways
4 feet
Curtain boards
Vertical boards, fire resistive half walls, that extend down from the underside of a roof underneath and ceasing the opening for roof vent, intended to limit spread of fire and smoke
Curtain boards are designed to reduce fire spread and increase efficiency of fire and heat vents, minimum depth of boards is
No less than 20% of the ceiling height.
Voltage
The electrical force that causes a charge (electrons) to move through a conductor. Sometimes called electromotive force, EMF
High voltage electrical equipment is defined as operating at
600 volts or higher
Low voltage equipment operates at
Less than 600 volts
Transformers
Used to convert high voltage service to manageable voltage for building use.
Transformers may be high or low voltage, their cooling method is one of two
Air or oil
Dielectric
Nonconductor of direct electrical current.
Older transformers carry what type of oil
High in PCBs, and must be labelled. Flammable.
Transformers located inside buildings must be enclosed in
3 hour rated transformer rooms if unsprinklered. Sprinklers present then 1 hr room
Diesel fuel power generator is most common type because
Gasoline is more hazardous and natural gas may be lost during power outages.
Generators may be located outside or on roofs for ventilation and cooling. If stored inside what is required.
Installed in fire rated room with fuel spill control
Day tanks are located in either the same room or on the generator and is typically limited in capacity by code to
60 gallons of diesel, usually kept full pumped by main tank
Lead acid batteries contain
Lead and sulfuric acid,
During charging, sulfuric acid releases
Hydrogen gas
Thermal runaway
Battery fire
Lead acid batteries are also known as
Wet cell Gel cell Starved electrolyte cell Sealed cell Maintenance free cell Flooded cell
Firefighting gear is not designed to be exposed to what concerning batteries
Acid
Small uninterruptible power supplies, UPS, containing lead acid batteries are found near
Fire a,arm control panels, under desks, next to computers.
When more than one elevator hoistway is provided, up to how many elevators may be located in one hoistway
Up to 4
