SMOKE CONTROL Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 1 Smoke, Not Flame The most significant cause of death in building fires is smoke, which accounted for 73% of fire-related deaths in 1990, according to a 1994 report by the NFPA. However, fires also can cause structural collapse of buildings, and burns cause the remainder of deaths in fire. Larry Gelin, Johns Manville Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 2
Smoke, A BSU Example Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 3 Smoke, A BSU Example repeat after me code = minimum code = minimum code = minimum code = minimum code = minimum Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 4
Smoke, A BSU Example the codes didn t require it the budget wouldn t allow it Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 5 Smoke Is defined (by ASHRAE) as: products of combustion and associated solids, liquids, and gasses. Essentially smoke is anything and everything that becomes airborne as a result of a fire. Smoke is related to fire, but does not behave the same as fire or affect people the same as fire. Fire solutions are not necessarily smoke solutions. Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 6
Smoke Hazards Asphyxiation (lack of oxygen) Toxicity (poisoning) Obscuration (reduced visibility) Psychological disorientation (loss of judgment) Combustibility Building materials damage affects people affects building the bottom line: smoke is dangerous Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 7 Reflecting on Smoke Hazards kills occupants Asphyxiation (a problem for millennia) Toxicity (a more recent problem caused by combustion of plastics) impedes egress Obscuration (a problem for millennia) Psychological disorientation (a more recent problem caused by combustion of plastics) modern construction materials and furnishings have upped the ante Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 8
Smoke Spreads via: Temperature expansion Hot air/gas expands; this action will cause smoke to move in all directions (up, down, sideways away from the source) Stack effect Hot air rises; this action will cause upward smoke movement Air-handling unit Air circulation through action of an AHU; this action supports smoke movement along the HVAC system ductwork paths Wind Causes pressure differences; this action causes smoke movement in unpredictable directions determined by wind direction and window breakage Molecular diffusion Partial-pressure-of-gasses effect; this causes smoke movement away from the source in all directions (a weak, but persistent, action) the bottom line: smoke can move readily Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 9 Smoke Control Rationale Smoke in a building presents numerous hazards, some lethal Smoke in a building, left to its own devices, can easily move up, down, and sideways Such unrestrained flow of a hazardous substance is not a good design scenario Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 10
Smoke Control: Two General Approaches Containment Keep smoke from moving (using air-tight barriers and intentional pressure differences) Usually applied in conjunction with evacuation and/or dilution to protect those in the smoke-producing part of a building Dilution Reduce smoke concentration (through the exhaust of smoke and/or infusion of fresh air) Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 11 Smoke Control: Code Requirements Building code requirements regarding smoke control are generally scattered, occasionally outdated, and now and then conflicting. In most larger buildings, the smoke control system will be custom designed for the building and may require a variance from the building official in charge (the AHJ). All such systems should be fully commissioned. Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 12
Smoke Control: Code Requirements ICC: International Fire Code Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 13 Smoke Control: Code Requirements ICC: International Fire Code Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 14
Smoke Control: Code Requirements ICC: International Fire Code Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 15 building code requirements are of two broad types: prescriptive (do this) and performance (accomplish something) smoke control is performance-based Smoke Control: Code Requirements ICC: International Fire Code the gist of these excerpts is to suggest that smoke control systems are treated differently from most other building systems; that they are customized, and must pass operational verification testing Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 16
Smoke Control: Some Specific Methods Smoke-free stairways (or corridors) Intrinsically protected (open air arrangements) or protected via pressure controls (engineered air supplies) Smoke-free elevators (very, very difficult) Via venting or pressure controls Areas of refuge Via smoke barriers and pressurization Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 17 Smoke Control: Some Specific Methods Smoke-free atria (as part of a means of egress) High-volume exhaust (fans) Large inlet openings (automatic doors often used, or louvers with dampers) Distributed smoke detection (often quite sophisticated) Typically, system effectiveness must be demonstrated to a code official (the AHJ: authority having jurisdiction) before system will be accepted Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 18
Atrium Smoke Control: A Current Topic Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 19 Atrium Smoke Control: A Current Topic ^^ smoke spread scenarios smoke exhaust problems >> ASHRAE Journal, June 2012 Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 20
Testing an Atrium Smoke Control System r e t r o f i t www.haifire.com/images/smoke_control_uc.jpg not looking so good Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 21 Example Area of Refuge Scenario large floor plate supply air return air AHU other core elements: bathroom, fire stair, electric closet, etc. AHU looking at a schematic floor plan, with two air-handling units serving the floor Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 22
A Fire Breaks Out on the Floor without an intentional smoke control response smoke fills the floor and leaks onto adjacent floors supply air return air Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 23 Smoke Control System Response supply air without return/exhaust return/exhaust without supply air closed open closed open the HVAC system, in conjunction with smoke barriers (red lines), establishes an area of refuge on part of the floor by pressurizing (pos) and depressurizing (neg) portions of the floor in order to control and direct smoke flow Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 24
Pressurization r e t r o f i t some serious airflow (into hotel room from a pressurized corridor) Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 25 Smoke Detector in Return Duct smoke detectors are used to control smoke system operation Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 26
Smoke-Free Stairway an interesting concept; but consider the architectural implications vestibule: pressurized or depressurized to space >> << to fire stair Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 27 Smoke-Free Stairway a new construction retrofit lack of stairwell smoke control was caught during construction by the AHJ and a fix was required Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 28
and changing the topic the award for best attempt to hide a supply air register goes to the Austin, TX, convention center Ball State Architecture ENVIRONMENTAL SYSTEMS 2 Grondzik 29