IFSTA, Building Construction Related to the Fire Service Chapter 4 questions and answers

Building systems Systems utilized to address convenience, comfort, access, efficiency, and life safety of occupants Stairs Enable access to multiple levels of a structure and serve as a basic component of building egress during an emergency Convenience stairs Stairs that usually connects two floors in a multistory building Tread Horizontal face of a step, flat portion Riser Vertical part of a stair step Run Horizontal measurement of a stair tread or distance of the entire stair length Rise Vertical distance between the treads of a stairway or height of entire stairwell 6 common types of stairs Straight run, landing, return, scissor, circular, spiral, folding Straight run stairs Extend in one direction for their entire length, may have a landing between sections Landing stairs Horizontal platform where a flight of stairs begins or ends Return stairs Intermediate landing between floors where stairs reverse direction of travel, common in modern construction Scissor stairs 2 separate sets of stairs constructed in a common shaft, helix pattern, more space-efficient and cheaper, often used in airport terminals, convention centers, malls, and cinema complexes Circular stairs Often found as grand stairs or convenience stairs only serving two floors, minimum width of the run is usually 10 inches, special requirement that a small radius of the full circle is greater than or equal to twice the widest part of the stair tread Spiral stairs Series of steps spiraling around a single column to fit in a very small space, each tread connects to center column called the baluster Baluster Center column in a spiral staircase Folding stairs Ladders used to provide access to an attic space that does not have a permanent access stair, made up of 3 sections that unfold as the stair is lowered Gas springs Aka struts, increasingly used with the hinge in folding stairs to replace coil springs, are cheap and function more efficiently and quietly, **Sudden exposure to fire temperatures or compression leads to explosive failure Stairs for egress (Must meet strict requirements to ensure safe passage during evacuation) - Fire-resistance rating of the enclosure - Separation when exterior stairs are utilized - Features to ensure safety during (non)emergency use *Exit stairs often only allow exit for security reasons Protected stairs Stairs that must resist the effects of the products of combustion building codes to protect stair enclosures Protected stairs guidelines - Limited penetrations in the enclosure for light, fire protection, and environmental control - Required self or automatic-closing fire rated doors - Separation from the rest of building - Stairway vestibules Exterior stairs Stairs separated from the interior of a building by walls Fire escapes Means of escape from a building in case of fire, usually an interior or exterior stairway or slide, independently supported and made of fire-resistive material, must be regularly maintained and inspected Fire escape failure Anchor points may fail from freeze-thaw cycle, corrosion, or inadequate mortar holding the anchors Smokeproof stair enclosures Stairway that are designed to limit the penetration of products of combustion into a stairway enclosure that serves as part of a means of egress Passive Smoke Control Smoke control strategies that incorporate fixed components that provide protection against the spread of smoke and fire, fire doors, walls, and stopping of barrier penetration Active fire protection Uses moving mechanical or electrical parts, work as a system, requires power while passive fire protection do not require system activation or movement Pressurized stairwell Uses a ventilation system to maintain a higher air pressure in the stairwell than on individual floors, prevents smoke from entering stairwell Passive smokeproof enclosures Protect the stairway enclosure and provide a means of smoke ventilation before the smoke enters the enclosure Open stairs Connect different levels of a building without compartmentation from the building Escalator Belt-driven moving stairs that move in one direction at a fixed rate (90 to 120 ft per minute) continuous handrails move at same speed as steps Elevators Vertical traveling mechanical system used to transport people and items in a multistory building, serve 2 or more landings, include hoisting and lowering mechanisms, use a car or platform that moves along guide rails 3 types of elevators Passenger, Freight, Service (Passenger that can also carry freight) Hydraulic elevators Operate via fluid forced under pressure into a cylinder containing a piston or ram, practical limit of 6 stories and requires a deep well in order for ram to extend low enough to allow the car to reach the lowest floor Electric elevators Elevators that use AC or DC power and use a hoist cable and drum, wires or flat polyethylene-coated steel belts Drum elevator Cable wound around a drum located in the motor room directly over hoistway, utilize counter weights, old school Traction elevator Most common type of elevator in buildings 6+ stories, cable does not wind around drive sheave but passes through it, operate on AC or DC currents Machine-Room Less (MRL) elevator Hoistway includes all components, elevator controls located remotely from system Dumbwaiters Used for lifting cargo, smaller weight and capacity Hoistway Vertical shaft in which the elevator car travels, includes elevator pit AC Circuit Electrical circuit where current can flow in both directions, constantly reversing DC Circuit Electrical current moves through the circuit in only one direction Elevator safety features - Strict regulation of equipment - Rigorous engineering - Safety devices Terminal device Electric switch that terminates power before the car reaches upper or lower limits of the hoistway Buffers Large springs or hydraulic cylinders and pistons at bottom of elevator pit that act as shock absorbers if terminal switch fails, can NOT stop a car in free fall Speed-reducing switch Aka speed governor, slows drive motor when car exceeds safe speed Overspeed switch Connected to speed governor, actives if speed-reducing switch unable to slow car sufficiently Car Safeties Tapered pairs of steel jaws that wedge against the guide rails and bring the elevator to a stop, designed to stop a free-falling car Elevator pit Depression at the base of an elevator hoistway that contains equipment and maintenance access 3 common types of hoistways Single, Multiple, Blind Blind hoistway Two or more shafts that only go to a certain level, serve only upper levels of taller buildings ex. 1-20 and 21-40 floor Shear Wall Wall panels that are braced against lateral loads, can be load and non-load bearing Mushrooming Tendency of heat and products of combustion to rise until they encounter a horizontal obstruction and spread laterally until they cannot and bank downwards Hoistway guidelines A building with 3 or fewer elevators can have only one hoistway, 4+ must have a minimum of 2 separate hoistways Elevator operation sequence Car stops at correct level > drive vane attached to the car door holds door open > Car door opens > Vane strikes a roller that releases the hoistway door lock > Car doors then push the hoistway doors open completely > Controller signals the doors to close > Weight forces the hoistway doors closed > Drive vane moves away from rollers > Hoistway doors are relocked Utility Chase Shaft in a building that contains utility services such as laundry or refuse chutes, and grease ducts Refuse chute Vertical shaft with a self-closing access door on every floor, typically extends from basement to top floor Grease ducts Installed over deep-fat fryers and grills as part of an exhaust system for commercial cooking appliances, often utilize in-line fans or fans on the roof, reduces amount of grease waste deposition Pipe chases Concealed vertical channel in which pipes and other utility conduits are housed, must be properly protected to prevent vertical spread of smoke and fire in a building Pipe chase uses - Hot and cold potable water - Drain lines - Steam - Hot and chilled water for heating and AC - Sprinkler piping HVAC Systems Mechanical systems used to provide environmental control within a structure and equipment that aids its function, can be a single standalone system or individual component systems HVAC uses - Heating and cooling - (De)humidifying - Filtering - Exhausting air - Regulating intake of outdoor air - Recirculating indoor air Cupola A type of rooftop projection historically used for ventilation and lighting, modernly added for aesthetics, permit airflow through a building Air intake position Outside air intake must be positioned in an area that prevents the drawing of combustible, flammable, toxic substances, vehicle exhaust, products of combustion from fires in nearby structures Fans Used to draw supply air in a expel exhaust air, can be dual purpose Air filtration systems Necessary to keep the air free of contaminants, can use filters and, or electrostatic equipment Air cooled chillers Remove heat from piped water system in a building that passes through fan-coil or other air handling equipment Air ducts The distribution component of HVAC systems, deliver heated or chilled air throughout the building Return-Air Plenum Unoccupied space within a building through which air flows back to the HVAC system, typically directly above a ceiling or below an insulated roof or floor above Smoke damper Device that automatically restricts the flow of smoke through all or part of an air handling system, usually activated by building's fire alarm signaling system Fire damper Device that automatically restricts the flow of air through all or part of an air handling system, usually activated by building's fire alarm signaling system or fusible links Exhaust System Ventilation system designed to remove stale air, smoke, vapors or other airborne contaminants from an area Forced-Air System A building heating and cooling system that uses air as the heat transfer medium, recirculates air using fans, filters, heating and cooling coils, vents, and dampers. Includes pathways for communication of heat and smoke, penetrations to fire-rated assemblies, dedicated use of substantial amounts of space. Hydronic System A building heating and cooling system that uses water as the heat-transfer medium Cooling Tower Rooftop or independent unit that ejects waste heat into the atmosphere to lower the temperature in a system, commonly used in HVAC Recirculation Movement of air back into a ventilation system after being ejected Hurricane Glazing Protective treatment for exterior windows designed to withstand hurricane conditions including high wind and impact