4 - Building Systems

High voltage

600 volts or more !

Circular stairs

Grand stairs or convenience stairs Only serves 2 levels Minimum width of run is 10" Small radius of full circle is greater than or equal to twice the widest part of the stair tread

Refrigerants

Halogenated refrigerants banned. Butane and propane used instead.

HVAC systems in many complex buildings

Has become a life support system.

Folding stairs

Ladders used to provide attic access Most common in residential and added after construction. Located away from functional spaces 3 wooden sections - main section hinges from frame - 2 articulating sections -coil -gas springs(strut) -counterbalance Springs lose tension when exposed to heat Strut can fail with explosive force in a fire Fixed ladders(ship's ladders) may be used in similar application such as - - mechanical spaces - roof hatches at the top of stairways - between roof levels with portions at different elevations

Air cooled transformer

"Dry" transformer Fins, heat sinks, and vents Used throughout building to step down 480v to 120v.

Two most common types of power for elevators-

- Hydraulic - Electric

4 common styles of elevators

-Drum elevators, intended for passenger use -Traction elevator, intended for passenger use -Machine room less (MRL),intended for passenger use -Dumbwaiters, intended for cargo use All for passenger use except dumbwaiter

Elevators can be classified according to their use-

-Passenger elevators carry people -Freight elevators carry resources that may be bulky or heavy -Service elevators are passenger elevators designed to also carry freight(may deliver to a small range of floors)

Vent hazards

-Thermoplastic dome vents melt and fall -Metal vents spring open -Oversensitive smoke detector opens vent in nonfire condition. -When manually activating, must select correct vent.

Elevator doors

1. When the elevator stops at correct level, driving vane attached to the car door holds the door open 2. As the car door opens, the vane strikes a roller that releases the hoistway door lock 3. The car doors then push the hoistway doors completely open 4. When the controller signals the doors to close, a weight forces the hoistway doors closed, the driving vane moves away from the roller, and hoistway doors are relocked. Passenger cars use the power of an electric motor mounted on top of car. The car door does not have locks and can be pushed opened at any time. Interlocks will not allow the car to move and will immediately stop the car. When the doors are closed most elevators will start to move again. Some will not until reset.

Duct detectors are typically provided for fans with capacities exceeding

2,000 cubic feet per minute to stop these systems under fire conditions and minimize unwanted smoke movement

Most common voltage delivered via transformers to medium to large buildings is carried via

3 phase 208/120 transformers

Buffers

Large spring, hydraulic cylinders, or pistons located at bottom of hoistway Act as shock absorber if terminal switch fails Cannot stop free falling car. Only stops car traveling at normal speed.

Maintenance and emergency access side doors

May be equipped with electronic locks and minimal inside handle.

Heated or cooled air

May be provided without the use of a duct system using interstitial spaces. Return air plenums in suspended ceilings Supply air from under floor

Elevator keys

May be secured in a lock box. Location determined by codes or AHJ.

Active smokeproof enclosure

Mechanical pressurization - fan located at top Codes specify minimum and maximum pressure differentials. Codes require dedicated, pressurized stairway solely for FF access. Newer codes require vestibules and fire doors

NFPA 92A - standard for smoke control systems utilizing barriers and pressure differences

Minimum pressure differences via water gauge across a smoke barrier in a sprinkled building.

Protected stairs

Must resist effects of products of combustion. -Limited penetrations in the enclosure for light, fire protection and environmental control -Self or automatic closing fire rated doors -Separation from the rest of building -Stairway vestibules

HVAC ducts

NFPA 90A standard for the installation of air conditioning and ventilation Enclosure rated at 1 hour for buildings less than 4 stories in height and 2 hours for building 4 stories or more. !

Heating fuel

Natural gas Oil Other types use - -Electricity -Steam

Exterior stairs

Naturally ventilated on one or more sides Limited or protected openings in the buildings outside wall near the stairs.

Draft curtains

Not less than 20% of ceiling height Spaced no further apart than 8x ceiling height

Fire escapes

Not permitted in new construction and cannot be considered safe for use today. Attached to outside of building. Usually an interior or exterior stairway or slide, independently supported, fire-resistive material. ?

Oil cooled transformers

Older transformers containing PCB are required to be labeled Oil conducts heat away from core and insulates If inside building, room or vault - -3 hour fire rated if no sprinklers or -1 hour rated with sprinklers.

Open stairs

Only allowed to connect two adjacent floors above basement level

Elevator evacuation

Only trained personnel should attempt ASME Standard A17.4 guide for emergency personnel - contains procedures to follow

Car safeties

Tapered pairs of steel jaws that wedge against the guide rails and bring elevator to a stop. Designed to stop free falling car

Buildings 4 or more stories may require one stairway

That extends to roof and is identified by signage in the stairway. (Does not indicate that where it must start, or if part of egress)

Some hoistway are not required to be enclosed, such as

Those located in atriums

Emergency exits in elevators

Top exit is provided on all electric traction elevators. ! On hydraulic elevators, a top exit may be provided depending on whether the system is equipped with a manual lowering valve. The valve permits lowering the car in event of a malfunction. A top exit is optional otherwise. (top exit provided with no valve? optional if valve present??) Some top panels are designed to be opened from inside, but all can be opened from outside and all open outward. Interlock may stop car from moving when top panel opened but not required.!!

Stairs

Tread - horizontal Riser - vertical (Run and rise) Rise - vertical distance between treads or height of entire stairway Run - horizontal measurement of a stair tread or the entire stair length

Double deck elevator

Two cars stacked vertically. Bottom car serves odd floors, top serves even.

Scissor stairs

Two separate sets of stairs in a common shaft. Cheaper and efficient. Assembly occupancies with large floor to ceiling height Positions standpipe on same stair side at each floor Ingress/egress at each floor Additional exit capacity Older scissor stairs may return to every second floor

ADA requires either

A ramp or elevator access within multistory buildings

Cupola

A rooftop projection historically used for lighting and ventilation. Modernly used for aesthetics (aka monitor??)

Door clutch

A safety measure to prevent the elevator car from operating if all systems are not working correctly.

Elevator regulations

ASME/ANSI A17.1 safety code for elevators

Active vs Passive fire protection

Active - uses moving mechanical or electrical parts that work as a system and require a power source for operation. Passive - relies on building construction and materials to contain fire or products of combustion.

Speed reducing switch

Aka - "speed governor" Slows drive motor when car starts to exceed safe speed If car continues to accelerate, the switch trips the overspeed switch and applies car safeties

Rooftop smoke and heat vents

Allows for faster FF attack and dissipates some thermal energy of the fire. NFPA 204 standard for smoke and heat venting Found in large area buildings and buildings with few windows Small area hatchways with single or double leaf metal lids, or plastic domes designed to open manually or automatically. Open minimum 4' either direction (which direction?) Used in conjunction with draft curtain to increase effectiveness and speed of operation of the vent. Size and spacing depend on floor to ceiling height and nature of contents. Vent area determined by analysis of heat release rate of fuel, ceiling height, and depth of curtain boards !!! Less effective when used in conjunction with sprinkler systems due to loss of buoyancy or air when cooled. Roof vents in sprinklered buildings are of max value in the final or overhaul stages of a fire. !!

Automatic smoke control

Always takes priority over normal operations. Can signal HVAC to transfer to smoke control mode - - Smoke detectors - Heat detectors - Sprinkler waterflow switches Advantage - fast activation Disadvantage - the number of elements that must be coordinated (Manual control takes priority over automatic control, and automatic control takes priority over normal operations)

Cooling equipment hazards

Are limited mainly to hazards associated with the refrigerant and electrical equipment.

Smoke control mode

Automatically or manually Manual operations take priority over automatic control. Discharges smoke through exhaust fan without returning air to supply fan. Dampers close on fire floor. Open on all others. Continuance of air supply to non fire floors creates a "pressure sandwhich" on floors above and below fire floor reducing movement of smoke into those areas. Uses active and passive devices. (Manual control takes priority over automatic control, and automatic control takes priority over normal operations)

Generators

Buildings with emergency backup generators - - Buildings required to have smoke management systems (highrise) - Occupancies required to maintain full-time access to power (detention facility) - Occupancies that require support for the facility's function (telecommunications) Fuel - - Gas - Diesel - Propane - Natural gas At minimum, it should be able to service all life safety systems plus the critical needs of the occupancy. Code specifies minimum required fuel storage for diesel and gasoline. Amounts are stated in terms of expected duration of operation. Fuel storage should be located separately from generator. (Exception - day tank located in same room or mounted on generator typically limited to 60 gallons of diesel. Usually kept full with fuel pumped from main tank) Transfer switches may be required to be located in a protected room away from main electric panel room. Fire control room should have status panel and possibly a remote start/stop switch.

Elevater and stair shafts are

Built early in the construction process and use shear walls.

Historically, stairs have been the only recognized means of emergency egress,

But in recent years elevators have gained new importance- -Dedicated cars for FF use -Designated means of egress in high rise -Emergency evacuation for disabled

Emergency power batteries

Commonly use lead-acid batteries in a stationary storage battery system. If inside, requires fire rated room and ventilation Areas containing batteries are not usually diked or sealed May be in a dedicated room or a whole floor Types of battery systems- - Small UPS containing lead-acid batteries (near fire alarm system control panels, under desks, next to computers) - Battery charging room for battery powered vehicles (manufacturing or golf clubhouse)(in building or on property) - Cellular equipment with independent battery backup system hosted on taller buildings.

Pipe chase

Concealed vertical channel housing pipes or other utilities through floors Mechanical equipment rooms stacked one above the other on each floor may be used instead of a pipe chase. The walls enclosing these rooms are then treated as shaft walls to separate the utility space from the rest of the building.

Overspeed switch

Connected to speed governor Activated if speed reducing switch fails to slow car sufficiently (applies car safeties??)

Machine room less (MRL) elevators

Controls are remote from elevator. Motors and all other components fit in the hoistway.

Escalators

Conveyor transport device aligned as stairway with electrically powered steps that continuously moves in one direction. Driving machinery is located under an access plate at the upper landing Speed - 100'/minute Older escalator speed - 90-120'/min Belt driven -Each step rides a track -Steps are linked by step chain and move around escalator frame -Continuous handrails move at the same speed as steps Emergency stop switch will set the brake. Vertical penetrations for escalators serving MORE than 2 floors must be protected. Most common form of protection, 18" deep draft stop with row of closely spaced sprinklers on each side. Other options include- - a rolling shutter at the top of the escalator - partial enclosures use separate fire rated enclosures for the up and down escalators.

Express elevators

Divided into zones of 15-20 consecutive floors Upper zone cars operate in express mode and do not stop between first floor and lowest floor of zone. If single elevator hoistway, will have regularly spaced access doors for rescue only. Generally placed every 3 floors.

HVAC systems

Divided into zones of several floors with each zone supplied from a separate equipment room. Controls, intake, and exhaust at the top of building minimizes obstructions to airflow.

Terminal device

Electric switch that terminates power before car reaches upper or lower limits of hoistway

Means of egress consists of 3 parts

Exit access Exit Exit discharge

Elevator pit

Extends down from lower floor landing to bottom of hoistway

Air filtration

Filters and/or electrostatic equipment Filters using liquid adhesives may be a combustible liquid hazard

Sky lobby

Floor used as a common discharge floor for 2 separate elevator systems. (Express elevators) May separate types of occupancies.

Smoke tower

Fully enclosed escape stairway that exits directly onto public way Mechanically pressurized or requires user to exit building onto outside balcony before entering Aka - "smokeproof enclosure" or "stairway" May be a stairway that is seperated from a building corridor by a vestibule that is open to the atmosphere. Requires- - Location at periphery of floor plan - Dedicated floor space in the building - Corridor access to the stairwell

Prefabricated stairs using lightweight materials are

Held together using metal gussets that are known to fail under specific conditions. No credible source indicates that these stairs are more likely to fail at a rate higher than heavier types of construction.

Transformers

High or low voltage Oil or air cooled Built in cooling method is the biggest hazard

Blind hoistways

If stopped in a blind hoistway, the emergency exits must be used. 2 types of emergency exits in blind hoistways- -Hinged access hatch through top -Hinged or removable panel on side of car Last resort

Side exits

In multiple elevator hoistway, most cars are equipped with side exits. Car to car exit. Can be opened from outside hoistway where a permanent handle is provided. Some panels are locked from the inside and cannot be opened without a special key or handle. Required to have interlock to prevent movement when opened. !! May not be provided in hydraulic elevator where a manual lowering valve is provided.

Emergency and standby power supplies

Indicated by opeartional needs or by codes. Generators, batteries or combination.

Drum elevator

Intended for Passenger use Use a hoisting cable wound on a drum located in motor room directly over the hoistway. Car is connected to set of counterweights to reduce effort the motor must produce to raise the car.. Height limitations because size of drum increases with lifting distance. Obsolete and found only in very old structures or in use as freight elevators

Traction elevators

Intended for passenger use Most common elevator in buildings over 6 stories Fast No height limitations Machine room directly over hoistway Uses counterweights to reduce amount of energy needed to raise. Hoisting cables attached to elevator car run up and over drive sheave at top of hoistway and then down the back wall of the hoistway to connect to the moveable counterweights. Hoist cables do not wind around drive sheave, they merely pass over it. Friction between cable and sheave hold cable in place. Drive motors may be DC or AC and require up to 500 volts. Braking system operates during normal operations and malfunctions. Brake drum is located on the shaft of drive motor Under normal conditions, spring operated brake shoes hold magnets away from the drum. AC motors - brakes aid in stopping the car at the correct floor (Remember by - AC motor & Brakes = ABC) DC Motors - brakes play no part in stopping the car. The motor stops the car then brakes are applied. In event of power failure, electromagnets release and brake shoes are forced against the drum.

Firefighter smoke control station (FSCS)

Interface between the smoke management system and the FD. Required to have status indicators and switches for all fans and dampers serving a smoke control function. Should also contain diagram that indicates type and location of components.

Return stairs

Intermediate landing between floors and reverse direction at that point. May have more than one landing between floors.

The building design team

Is responsible to ensure the necessary building systems initially provide the intended level of fire and life safety. Subsequently, the building owner and/or management must maintain these systems over time.

Hydraulic elevators

Operate via fluid, forced under pressure, into a cylinder containing a piston or ram. Pumping in fluid raises the ram. Draining fluid lowers car by gravity. No brakes. Controlled through the flow of hydraulic fluid. Single stage ram, or Multi-stage hydraulic cylinder, reducing the overall length of the cylinder. Historically limited to 6 stories Requires a well for the ram to extend into the ground

Grease ducts

Over deep fat fryers and grills. Travel vertically, using inline fans or fans on the roof. No dips or horizontal runs that will collect grease. Some designs use horizontal ducts. They use a grease removal system. Fire resistive construction.

Passive smokeproof enclosure

Protect the stairway enclosure and provide a means of smoke ventilation before the smoke enters the stair enclosure. Accessed through a vestibule or balcony.

Rooms or vaults that contain electrical gear or transformers should be

Protected with sprinklers if the building has an automatic sprinkler. In cases where power utility company do not allow sprinkler protection for their equipment, the utilities may permit carbon dioxide detection systems.!

In emergency use

Recall elevator to lobby Open door from level above recalled elevator to check the shaft for smoke

Air cooled chillers

Remove heat from a piped water system in a building that passes through a fan-coil or other air handling equipment.

Smokeproof stair enclosure

Required in - -Stairs serving buildings 5 stories or higher!!! -Stairs serving floor levels more than 30' below level of exit discharge. Smoke control can be active or passive. Typically located on exterior perimeter of building and are entered through ventilated vestibules or an open exterior balcony.

Refuse chute

Required to be constructed of noncombustible material with rated doors and a fire rated shaft enclosure. Sprinkler head at top of chute and in its termination room Code requires the access opening for chutes to be in separate room from the corridor

Stairs as part of the means of egress

Requirements- -Fire resistance rating of enclosure -Separation when exterior stairs utilized -Features to ensure safety May only provide egress, but not access.

Conveyer systems

Screw or pneumatic systems work in enclosed compartments. Fire barrier penetrations protected by- - fire doors - shutters - water spray fixed fire suppression systems Primary safety hazard - incomplete door or shutter closure Safeguards against incomplete closure- - automatic stop controls - breaks in the conveyor - multiple layers of doors or shutters

Lock-out/tag-out procedures

Should be identified and followed when working with electrical and mechanical equipment. Call utility company if electrical hazards are a substantial concern.

Manual pull stations

Should only activate the fire alarm, not the smoke control system.

Pressurized stairwell

Single injection system - if door opened at point close to air supply, all air pressure can flow directly out of stairwell Multiple-injection system - several discharge points along air supply shaft running parallel to stairwell from supply fan. More uniform flow Compensated system - adjusts airflow based on number of open doors. (modulated or vented) Overpressure options- -Dampers open when pressure in the stairwell is high enough to push open dampers that are equipped with counterweights. -Motor operated dampers sense pressure level and trigger a switch

Dumbwaiters

Small freight elevators Transport items of small weight size between floors Found in modern buildings & have electric motors. Historically drawn with ropes to move food from kitchen

Smoke damper vs fire damper

Smoke damper- - restricts flow of smoke - activated by fire alarm signaling system Fire damper- - restricts flow of air - activated by - -- fire alarm signaling system OR -- fusible links

Theaters are required to have

Smoke vents above the stage

Spiral stairs

Spiral around single column to fit in small space. Each tread is tapered Not enclosed Primarily residential Only allowed as means of egress at residences Sometimes used for access to permit required confined space, such as a dry-well in a sewage pumping station, and in industrial applications.

Convenience stairs

Stairs that are not part of egress Typically open and only connects two levels

6 common types of stairs

Straight run stairs Return stairs Scissor stairs Circular stairs Folding stairs Spiral stairs

Manual smoke control

Takes priority over automatic control. Disadvantage - -slower activation Activation usually occurs after arrival of FD. Advantages - -eliminates false alarms -more specific system control. Controlled from - -dedicated control panel, -the buildings main control room, or -fire fighters smoke control station(FSCS)

Electric elevators

Use a hoisting cable and drum Modern elevator cables are flat polyethylene coated steel belts that increase energy efficiency. Historically cables have been conventional wire cables.

Blind hoistway

Used for express elevators. No openings on some floors.

Forced air system

Uses air as heat transfer medium. Air forced through ductwork.

Hydronic system

Uses water as the heat transfer medium.

Hoistway construction

Usually required to be fire rated assembly with 1-2 hour rating, depending on height of building. Only elevator required wiring, ducts, pipes in hoistway. Low rise - may consist of gypsum cement block or other easily penetrated material In tall buildings of reinforced concrete construction, hoistway may be enclosed on 3 sides with poured concrete, with only the wall that faces the car door built of block. This serves to harden against wind load. Vent required at top to prevent mushrooming Code also requires fire rated vestibules or equivalent at each floor Building with 3 or fewer elevators may all be contained in a single hoistway. 4 or more elevators must have a minimum of 2 separate hoistway. When more than 1 hoistway provided, up to 4 elevators in single hoistway.

Shear wall

Wall panels that are braced against lateral loads. May be load bearing or non load bearing.