Smoke and Heat Venting in Sprinklered Facilities Dr. Craig Beyler

Value of S&HV’s in Sprinklered Facilities Improved visibility (and reduced heat and toxic gases) life safety/egress firefighter access Eliminates the need for manual venting by the fire department Reduced heat and smoke damage

Concerns with S&HV’s in Sprinklered Facilities Potential negative impact on sprinkler performance Cost effectiveness

Smoke and Heat Venting

Sprinklers Alone

Combined Sprinklers and Vents: Ideal Scenario

State of Knowledge S&HV’s in Sprinklered Facilities 1950’s to the present Full-scale fire tests Reduced-scale fire tests Mathematical modeling

Sprinkler/Vent Fire Tests Armor Research Foundation reduced scale testing (1:8), pool fires FM, 120’ X 60’, spray fires 3.UL 1964, wood cribs, cardboard, and plastics FM Reduced Scale (1:12.5), 20’ X 16’, vertical tri-wall cardboard array, ganged spray nozzles

Sprinkler/Vent Fire Tests IITRI, 75’ X 25’, pallet fires FRS/Colt, 150’ X 60’, controlled pool fire (Ghent) (ganged vent ops) NFPA RF, 100’ X 100’, UL ventilated facility, - spray fires (growing fires up to 10 MW) - rack commodity fires (20’ high Group A Plastics in double row racks)

Findings 1.Vents improve visibility and reduce exposure to smoke and heat (1-6) 2.Thermally activated vents do not open in large numbers so that manual operation of vents by FD is generally needed as well (3- 5, 7) 3.Venting does not interfere with sprinkler performance (2-7) 4.Full scale sprinkler tests with suppressible fuels are not reproducible (5,7) 5.FDS can predict well the thermo-fluidic environment and sprinkler operation, but not suppression (7)

FDS Prediction of Sprinkler Operations First ring operation time: ±15% Second ring operation time: ±25%

FDS Simulations of Performance of S&HV’s in Sprinklered Facilities Goal: Evaluate venting performance and effect on sprinkler operations Findings: 1. Venting had no effect on sprinkler operations 2. Venting improved smoke conditions 3. Additional vent area is beneficial

Plan View of the Modeled Building

No Smoke and Heat Vents Visibility Distance at 600 sec.

Four S & HV’s Operating Visibility Distance at 600 sec.

16 S & HV’s Operating Visibility Distance at 600 sec.

Ganged Vent Operation Concept Operate all vents within a sprinkler system area (~40,000 sq ft) one minute after first sprinkler operation using a water flow alarm device Approach supports remote manual operation of vents by FD as well Model with FDS to evaluate system performance

Computational Domain (two 40,000 sq ft sprinkler systems)

Smoke Remaining in the Building No S&HV, No DC S&HV, No DC S&HC, with DC S&HV, with DC (Beams ) No S&HV, No DC S&HV, No DC S&HC, with DC

Visibility Distance (ft) at 10 Minutes Without smoke and heat vents and without draft curtains With smoke and heat vents and without draft curtains

Visibility Distance (ft) at 15 Minutes Without smoke and heat vents and without draft curtains With smoke and heat vents and without draft curtains

FDS Modeling Findings Ganged vent operation concept is highly effective in mitigating heat and smoke hazards Ganged vent operation has no impact on sprinkler effectiveness

Path Forward Incorporate new findings in NFPA 204, Standard for Smoke and Heat Venting in Fall 2009 cycle Propose adoption of NFPA 204 in IBC in next edition (as has already been done with NFPA 92B (atria etc.))