NISTIR 7468 

Evaluating Positive Pressure Ventilation In Large Structures: 

High-Rise Fire Experiments 

Stephen Kerber 

Daniel Madrzykowski 

U.S. Department of Commerce 

Building and Fire Research Laboratory 

National Institute of Standards 

and Technology 

Gaithersburg, MD 20899 
NISTIR 7468 

Evaluating Positive Pressure Ventilation In Large 

Structures: High-Rise Fire Experiments 

Stephen Kerber 

Daniel Madrzykowski 

U.S. Department of Commerce 

Building and Fire Research Laboratory 

National Institute of Standards 

and Technology 

Gaithersburg, MD 20899

November 2007 

 - - iii

Department of Homeland Security 

Michael Chertoff, Secretary 

Federal Emergency Management Association 

R. David Paulison, Administrator

United States Fire Administration 

Gregory B. Cade, Assistant Administrator

U.S. Department of Commerce 

Carolos M. Gutierrez, Secretary

National Institute of Standards and 

Technology 

James M. Turner, Acting Director
Table of Contents 

Abstract............................................................................................ 2 

Introduction..................................................................................... 3 

Experimental Configuration .......................................................... 5 

Furnishings............................................................................................7

Fans.....................................................................................................11

Instrumentation ...................................................................................12

Experimental Procedure............................................................... 14 

Results............................................................................................ 15 

Experiment Timelines.........................................................................15

Pressure Data.......................................................................................24

Temperature Data................................................................................34

Heat Flux Data ....................................................................................42

Carbon Monoxide Data.......................................................................44

Weather Data.......................................................................................45

Observations (Video and Thermal Imaging Recording Data)............46

Uncertainty Analysis..................................................................... 64 

Discussion....................................................................................... 66 

Conclusions.................................................................................... 72 

Acknowledgements........................................................................ 73 

References...................................................................................... 73 

Appendix A ..................................................................................A-1 

Appendix B .................................................................................. B-1 

Appendix C ..................................................................................C-1 

Appendix D ..................................................................................D-1 

Appendix E .................................................................................. E-1 

Appendix F................................................................................... F-1 

Appendix G..................................................................................G-1 

Appendix H..................................................................................H-1 

1
Evaluating Positive Pressure Ventilation In Large Structures: 

High-Rise Fire Experiments 

Stephen Kerber 

Daniel Madrzykowski 

Building and Fire Research Laboratory 

National Institute of Standards and Technology 

Abstract 

A series of six experiments was conducted in a high-rise apartment building in Chicago, Illinois 

during November 2006. Experiments on each of the fire floors utilized portable fans and another 

utilized a large truck or trailer mounted fan. Two experiments on the third floor examined the 

effects of wind driven fire conditions. All of the experiments created high temperatures and 

dense smoke conditions in the hallway. Numerous configurations were used during the 

experiments and the ability of the fans to keep smoke and heat out of the stairwell was analyzed. 

The minimum design pressures of NFPA 92A were used as baselines to compare to the actual 

pressures measured. 

In this limited set of experiments, portable fans and mounted fans were able to quickly clear the 

stairwell of smoke and maintain a pressure high enough to prevent smoke infiltration into the 

stairwell. Positive pressure ventilation (PPV) fans utilized correctly can increase the 

effectiveness and safety of fire fighters and survivability of occupants in high-rise buildings. 

When configured properly, PPV fans can meet or exceed previously established performance 

criteria for fixed smoke control systems. 

The primary objective of this report is to present the reduced data generated by the experiments. 

More detailed analyses will be included in subsequent publications. 

Disclaimer 

Certain trade names and company products are mentioned in the text or identified in an 

illustration in order to specify adequately the experimental procedure and equipment used. In no 

case does such identification imply recommendation or endorsement by the National Institute of 

Standards and Technology, nor does it imply that the products are necessarily the best available 

for the purpose. 

2
Introduction 

Between 1985 and 2002, there have been approximately 385 000 fires in high-rise buildings 

greater than seven stories. These fires resulted in 1600 civilian deaths and more than 20 000 

civilian injuries [1]. Smoke movement in high-rise buildings poses serious challenges for the 

fire service. Attempting to control the smoke movement is difficult because fire fighting 

operations require opening potential smoke barriers between the source of water and the fire. 

Buoyancy of hot gases and stack effecti due to temperature differences between the inside and 

outside of the building cause smokeii travel in high-rise buildings. This smoke enters vertical 

shafts in the building such as stairwells, and can block evacuation of occupants and can hinder 

fire fighting operations. 

It is common for the fire service to encounter smoke filled stairwells upon their arrival at an 

apartment fire scene. If the stairwells are not smoke-filled, they soon become smoke filled once 

fire department operations begin. Dividing the stairwells in a high-rise building into attack and 

evacuation stairwells is a common tactic. This tactic entails the fire service utilizing one 

stairwell for fire attack and allowing smoke to flow into the stairwell as hose lines are stretched 

onto the fire floor and another stairwell for evacuation in which the stairwell is not opened onto 

the fire floor in an attempt to keep it as free of smoke as possible. However, the tactic may not 

keep the evacuation stairwell free of smoke. Stairwell door assemblies have been observed to 

leak and it is possible to have smoke enter the stairwells without ever opening a stairwell door. 

Under normal fire fighting operating conditions, the attack stairwell door to the fire floor is 

opened and the stairwell becomes completely filled with smoke above the fire floor. Typically, 

the fire department will open the bulkhead door or vent at the top of the stairwell to remove the 

smoke on the fire floor. This does not always accomplish the desired effect. While it allows the 

smoke to exit the structure; the stairwell is now the flow path for the fire gases. The flow of hot 

gases through stairwell doorways can create extreme hazards for fire fighters. Safe operations 

above the fire floor in the attack stairwell are now limited because the stairwell is full of smoke 

and hot gases. 

In order for the fire department to operate safely above the fire floor, the evacuation stairwell 

must be utilized. Unfortunately, the evacuation stair may be contaminated as well, due to smoke 

infiltration through the cracks of the doorway to the fire floor. The pressure created by the fire 

causes the hot gases and smoke to flow into the stairwell even with the door completely closed. 

This assumes that the evacuation stairwell door is never opened by occupants attempting to 

evacuate or a team of fire fighters attempting to enter the fire floor to perform search operations 

or stretch a back-up attack line from a different location. 

During a fire on the third floor of a 16-story building, it is very possible that there will be 13-

stories of stairwell that are contaminated with smoke. The fire department needs to search this 

area for occupants that may have attempted to escape, but were overcome by smoke on the way 

 

i

Stack Effect – The vertical airflow within buildings caused by the temperature-created density differences between 

the building interior and exterior or between two interior spaces. 

ii Smoke – The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or 

combustion, together with the quantity of air that is entrained or otherwise mixed into the mass. 

3
out. A difficulty arises in that fire fighters may not have enough air in their Self Contained 

Breathing Apparatus (SCBA) to make it up to the top and back down, potentially leaving them 

trapped on an upper floor. The option exists to carry extra SCBA cylinders, but that adds more 

weight to an already heavily equipped fire fighter. 

Another serious situation that can occur in high-rise buildings is a wind driven fire. The hazards 

of smoke and heat in the public halls and stairwells are similar, but the time frame in which it 

occurs can be catastrophic. Changes in building ventilation or presence of an external wind can 

increase the energy release of a fire. This can also increase the spread of fire gases through a 

building, placing building occupants and fire fighters in an environment that changes rapidly and 

may not be survivable. The trigger of this event could be as fast as a window failing or a door 

being opened. Several documented wind driven fires have resulted in fire fighter injuries and 

fatalities [2-4]. 

Different tactics need to be utilized to keep stairwells free of smoke, to increase the ability of 

occupants to egress and for fire fighters to operate. One possible solution is the proper use of 

positive pressure ventilation. National Fire Protection Agency (NFPA) 5000 requires that 

stairwells in current high-rise buildings be smoke proof [5]. NFPA allows three means to 

accomplish this, natural ventilation, mechanical ventilation incorporating a vestibule; and 

pressurizing the enclosure. This requirement, along with research and improved technology has 

led to an increase in the number of buildings that have stairwell pressurization systems. The 

research that has been done examining these systems suggests that if a pressure difference across 

the doorways is not less than 12.5 Pa (0.05 in. water column) in sprinklered buildings or 25 Pa 

(0.10 in. water column) in nonsprinklered buildings under likely conditions of stack effect or 

wind, then smoke will not infiltrate into the stairwells [6]. While these systems have proven to 

be effective and have been installed in many newer buildings, there are still a majority of highrise buildings without these systems to protect stairwells. 

The stairwell pressurization systems installed today are usually one of two types: single injection 

systems or multiple injection systems. The single injection systems have a blower installed in 

either the top or bottom of a stairwell to provide pressurization. The multiple injection systems 

have blowers that supply air at a number of floors over the height of the stairwell. The capacity 

of the blowers used and the number of blowers varies greatly dependent upon the height of the 

stairwell. Blower capacity can range from 850 m3

/h (500 ft3/min) to as high as 170 000 m3/h 

(100 000 ft3/min) in some systems. 

Technology in the fire service has increased greatly in the past 20 years, especially with regards 

to positive pressure ventilation (PPV) fans. Fans have been engineered and manufactured to 

provide flow capacities comparable to those specified for fixed or mounted stairwell 

pressurizations systems. 

Typically, a PPV fan is placed about 1.2 m to 3.0 m (4 ft to 10 ft) outside the doorway of the 

structure [7]. It is positioned so that the “cone of air” produced by the fan extends beyond the 

boundaries of the opening. With the doorway within the cone of air, pressure inside the structure 

increases. An exhaust opening in the structure, such as an opening in the roof or an open 

window, allows the flow to escape due to the difference between the inside and outside air 

4
pressure. Smoke, heat and other combustion products are pushed out of the structure and 

replaced with ambient air. 

In order for the fire service to provide the same level of protection that a fixed stairwell 

pressurizations system does, it requires thinking beyond the current PPV use in ventilation. 

Examination of the ability to pressurize is also needed. When a structure is pressurized and a 

vent is provided, the PPV fan creates a residual pressure inside the structure that is higher, 

forcing the flow to the lower pressure outside. The increased pressure provided by the fan works 

with the increased pressure created by the fire and combines the natural and mechanical 

ventilation forces to speed up the ventilation process. 

This same principle can be used to ventilate a stairwell, but it leaves the section of the stairwell 

between the fire floor and the top of the stairwell full of smoke and hot gases until the fire has 

been extinguished. During the ventilation process, the residual pressure provided by the PPV fan 

slows the amount of smoke coming into the stairwell. Because there is less of a pressure 

gradient leading into the stairwell, it is possible that smoke and hot gases are still entering the 

stairwell. Fresh air forced in by the fan mixes with the smoke and hot gases as it travels past the 

fire floor and out of the vent at the top of the stairs. This reduces the concentration of the toxic 

smoke and cools the hot gases, but does not entirely eliminate the problem of a contaminated 

stairwell. 

PPV fans that are utilized without a vent are able to create an elevated static pressure. The static 

pressure can be used to counter the increased pressure created by the fire. The fire naturally 

causes ventilation out of the fire floor and into the stairwell, which has a lower pressure. If the 

static pressure created by the fan is greater than the pressure created by the fire, then the smoke 

will be prevented from flowing into the stairwell. 

The experiments that are summarized in this report examine the use of PPV fans to both ventilate 

and pressurize in coordination with door openings consistent with fire department high-rise 

operations during room fires in a residential apartment building. The fan size and placement was 

determined based on previous pressure experiments conducted in a 30-story high-rise in Toledo, 

Ohio [8]. 

Experimental Configuration 

The experiments were conducted in a condemned 16-story high-rise apartment building. The 

building was constructed of poured concrete floors and ceiling deck with concrete block corridor 

walls and gypsum board interior walls. The overall building dimensions were 75.6 m wide by 

20.8 m deep by 46.9 m tall. The left half of the building was utilized for the experiments. The 

door from the center stairwell to the right side of the building was sealed on every floor. The 

four sides of the building are depicted in Figures 1 through 4. 

The corridors from the second to sixteenth floors were open air, only covered with an expanded 

metal screen on the front side. This is not representative of a typical high-rise structure, so the 

corridors on floors 3, 10 and 15 were enclosed with metal studs and two layers of gypsum board. 

This created four floors (1, 3, 10 and 15) and two stairwells (south and center) that were enclosed 

5
to create the experimental volume (Figure 5). There were no vents out of either of the stairwells, 

so the door to the 16th floor was used as the vent to the outside, similar to a bulkhead door, due to 

the lack of an enclosed corridor on the top floor. 

The experimental series was comprised of 6 independent apartment fires with the apartment door 

to the corridor left open in order for smoke and heat to travel into the corridors and stairwells of 

the building. Floor 15 and floor 10 utilized a furnished living room in apartment 3 and apartment 

5. Floor 3 included a furnished living room in apartment 3 and a furnished bedroom and living 

room in apartment 4 (Figure 6).

Figure 1. East or Front (Side A) Figure 2. North or Left (Side B)

Figure 3. West or Rear (Side C) Figure 4. South or Right (Side D) 

6
15

10

3

Figure 5. Experimental site outlined in red 

 NORTH 

South Stairwell 

Center Stairwell 

Figure 6. Floor Plan typical of floors 3, 10 and 15 (Left Half of Building) 

Furnishings 

The fuel load for the experiments was designed to simulate a common living room

configuration. The purpose of the fuel load was to create high heat and dense smoke 

conditions in the apartment of origin and the common corridor. The overall dimensions 

and weights of the furnishings are listed in Table 1. 

7
8

Table 1. Furnishings (Uncertainty ± 6%) 

Item Width (m) Depth (m) Height (m) Weight (kg) 

Chair 0.58 0.61 0.76 14.9 

End Table 0.46 0.61 0.41 8.7 

Twin Mattress 0.90 2.03 0.25 36.3 

Dresser 1.37 0.51 0.61 56.7 

Coffee Table 0.71 0.46 0.41 8.1 

Sofa w/ Cushions 1.98 0.86 0.84 40.5 

Sofa Mattress 1.83 1.35 0.11 17.0 

Small Sofa w/ Cushions 1.24 0.64 0.84 26.7 

Small Sofa Mattress 1.1 1.2 0.11 11.2 

Stuffed Chair 0.64 0.91 0.84 20.3 

Carpet (per m2) 1.0 1.0 0.007 2.5 

Padding (per m2) 1.0 1.0 0.001 4.2 

Each of the living rooms had the floor covered with high density cellular rubber carpet 

padding topped with a polypropylene backed nylon carpet. The living rooms on floors 10 

and 15 were furnished similarly. Each contained a sleeper sofa, two chairs, two end 

tables, a coffee table and a lamp. The experiment in apartment 303 included the addition 

of a second sleeper sofa, a third chair and a stuffed chair. Apartment 304 had a furnished 

bedroom in addition to the living room. The bedroom furnishings included a twin bunk 

bed set, a chair, two dressers and a coffee table. 

The sleeper sofa had a wood frame covered in upholstery (Figure 7). The metal sleeper 

frame was removed but the inner-spring mattress was folded and placed under the two 

polyurethane core seat cushions (Figure 8). The ignition point was located on the left 

side of the sofa in every experiment (Figure 9) with the exception of the experiment in 

apartment 304, where the ignition took place on the bunk bed. 

The chairs included an upholstered wood frame and a 0.08 m (3.0 in) thick polyurethane 

core cushion (Figure 10). The stuffed chair and the small sofa were a narrower version of 

the sofa (Figures 11, 12). The small sofa had a mattress and the stuffed chair did not. 

The end tables, coffee tables and dressers were made of pressed wood board (Figures 13-

15). The bunk beds were framed out with 0.038 m x 0.089 m (1.5 in x 3.5 in) pine boards 

(Figure 16). The twin mattresses were covered in cotton bedding consisting of flat 

sheets, pillows and pillow cases. The lamps were made of metal and had a small plastic 

shade and did not contribute significantly to the fire load. 
Figure 7. 30 kg sleeper sofa in living room Figure 8. 10 kg inner-spring mattress 

Figure 9. 40 kg sofa with ignition point in rear left 

corner 

 Figure 10. 20 kg chair in living 

 room 

Figure 11. 20 kg stuffed chair 

in living room 

 Figure 12. 40 kg small sofa w/ mattress in living room

9
Figure 13. 3 kg wood end table 

in living room 

 Figure 14. 8 kg wood coffee table in living room

Figure 15. 60 kg wood dresser in bedroom Figure 16. Bunk beds with 40 kg twin 

mattresses in bedroom

10
Fans 

Four different fan types were used during this set of experiments (Table 2). Two 

different truck or trailer mounted fans and two different portable fans were used in 

various capacities (Figures 17-20). Each of the mounted fans was used to pressurize the 

stairwells as well as to create simulated wind conditions. The portable fans were placed 

inside the structure to pressurize both the south and center stairwells. 

Table 2. Fan Details 

Experiment 

(apartment) 

Number 

of Fans 

Identifier Fan Shroud 

Size 

Motor 

1503 1 MVU 1.2 m (48 in) Hydraulic (Truck Mounted) 

1505 2 27 0.7 m (27 in) Gasoline (9.0 hp) 

1003 2 

2 

27 

24 

0.7 m (27 in) 

0.6 m (24 in) 

Gasoline (9.0 hp) 

Gasoline (9.0 hp) 

1005 1 SVU 1.3 m (50 in) Gasoline (Trailer Mounted) 

303 2 

2 

27 

24 

0.7 m (27 in) 

0.6 m (24 in) 

Gasoline (9.0 hp) 

Gasoline (9.0 hp) 

303 (Wind) 1 SVU 1.3 m (50 in) Gasoline (Trailer Mounted) 

304 1 SVU 1.3 m (50 in) Gasoline (Trailer Mounted) 

304 (Wind) 1 MVU 1.2 m (48 in) Hydraulic (Truck Mounted) 

Figure 17. SVU [9] Figure 18. MVU [10] Figure 19. 0.7 m (27 in) fan 

Figure 20. 0.6 m (24 in) fan 

11
Instrumentation 

The data collected during the experiments included differential pressure, gas temperature, 

heat flux, carbon monoxide, meteorological data, video, thermal imaging and sound 

levels. The uncertainty associated with these measurements is located in Table 17. Unit 

conversions and reference values for this data is located in Appendix H. A differential 

pressure transducer and thermocouple were located on the door knob of every floor in the 

south stairwell (Figure 21). The door knobs were approximately 1.0 m (3.3 ft) above 

the floor. A small diameter tube was run through the door to the opposite door knob to 

reference the pressure readings to the floor side. The thermocouples were bare-bead, 

type K, with a 0.5 mm (0.02 in) nominal diameter. 

Thermocouples were also located in the fire apartments and corridors to provide 

temperatures for the environment that building occupants and fire fighters may encounter 

and to measure the thermal effects of ventilation (Figure 22). Each living room had a 

vertical array of 8 thermocouples located near the center of the room with measurement 

locations of 0.025 m, 0.30 m, 0.61 m, 0.91 m, 1.22 m,1.52 m, 1.83 m and 2.13 m (1 in, 

1 ft, 2 ft, 3 ft, 4 ft, 5 ft, 6 ft and 7 ft) below the ceiling. Thermocouple arrays were also 

placed in the corridor adjacent to the south stair, center stair and in the middle of the 

corridor. The experiment in apartment 304 had a similar thermocouple array in each of 

the two bedrooms. 

Schmidt-Boelter heat flux gauges were placed on the fire floors in the potential paths of 

fire fighters advancing on the fire. All of the gauges were located 1.0 m (3.3 ft) above 

the floor. Each location had two gauges, one mounted horizontally facing the fire and 

one mounted vertically facing the ceiling (Figure 23). The heat flux gauges were colocated with the thermocouple arrays, in the fire apartment and in the corridor. The 

corridor had heat flux gauges located adjacent to the south stairwell, center stairwell and 

in the middle of the corridor. 

Carbon monoxide was measured in both stairwells as well as in the corridor. The carbon 

monoxide meters were co-located with the heat flux gauges. Measurements were made 

using a portable chemical cell monitor with built-in sample pump (Figure 24). The 

monitors were also located on the stairwell side of the door handle on their respective 

floors. The CO meters were the same models as those typically available for fire 

department use. The sensors had a maximum upper limit that was less than the range of 

CO created during the experiments. The calibrated range of the CO meters was 0 ppm 

(0 %) to 750 ppm (0.0075 %). At values above 750 ppm (0.0075 %), the chemical 

sensors were saturated and the reported values probably under-report actual gas 

concentrations. 

Weather was monitored and recorded during each of the experiments using two portable 

weather stations. Average temperature, average wind speed and average wind direction 

were recorded continuously. One weather station was located 15.2 m (50 ft) from the 

centerline of the main entrance, 2.5 m (8 ft) above the ground (Figure 25). The second 

12
weather station was located on the roof between the south and center stairwells, 2.5 m (8 

ft) above the ground (Figure 26). 

Video cameras and thermal imaging cameras were placed inside and outside the building 

to monitor both smoke and heat conditions throughout each test. As many as six video 

camera views and two thermal imaging views were recorded during each test (Figures 27, 

28). Internal camera locations included the fire apartment, south stairwell, center 

stairwell, and the middle and ends of the corridor. 

Sound measurements were taken with an analog sound meter at various locations 

including next to the fan and inside the structure to analyze any potential impact on fire 

ground communications. The meter had an operating range of 40 dBA to 120 dBA 

(Figure 29). 

Figure 21. Pressure transducer Figure 22. Thermocouple tree in hallway

Figure 23. Heat flux gauge Figure 24. CO meter

13
Figure 25. Ground weather station Figure 26. Roof weather station

Figure 27. Video camera in stairwell Figure 28. Protected IR 

camera on tripod in the 

hallway 

Figure 29. 

Sound Meter

Experimental Procedure 

Prior to ignition in each experiment, a computerized data acquisition system was started. 

Data were collected from each instrument every 6 s. Video cameras recording the 

experiment were also started at this time. After at least 180 s of background data were 

collected, a remote matchbook ignition was used to ignite the left, rear corner of the sofa 

cushion in each experiment with the exception of the experiment in apartment 304. This 

experiment was ignited on the pillow of the lower bunk of the bunk beds. 

After ignition, the fire was allowed to grow until the living room reached flashover 

conditions and visibility from the video camera output became limited in both the 

apartment and corridor. As smoke began to leak into the stairwell, the effect of different 

ventilation tactics were tested. Ventilation tactics included the use of compartment sized 

fans and larger mounted fans. The compartment size fans were positioned inside the 

structure both at the base of the stairwell and two floors below the fire floor. The larger 

mounted fans were placed at the front entrance (East side) to the building. 

Additional doors and ventilation points were utilized to simulate conditions such as fire 

fighters operating and occupants leaving the building. The 16th floor doorway was used 

for vertical ventilation and the fire floor door was opened to simulate fire fighters 

entering the floor. 

14
During the experiments on the third floor, apartment 303 and apartment 304, the larger 

mounted fans were used to simulate a wind condition by blowing in through an apartment 

window (Figure 30). Air velocity measurements were made with a hand-held 

anemometer from inside the window prior to each experiment. Both fans were throttled 

up to the engine speed that created an average velocity of approximately 11 m/s 

(25 mi/h). The same engine speed was utilized during each of the experiments. A fire 

blanket was also deployed during the experiment in apartment 303 to determine its effect 

on the wind and fire conditions. 

A fire blanket is a tool that is available to the fire department that is made of fire resistive 

materials and can be deployed from the floor above the fire. The blanket is deployed 

from the windows above and adjacent to the window that the wind is entering the fire 

apartment (figure 30). The blanket is dropped over the window and secured on the floor 

below the fire floor, covering the window and greatly reducing the wind flow into the fire 

apartment. Hand-held anemometer measurements inside the apartment prior to the 

experiments yielded wind velocities of less than 0.4 m/s (1 mi/h) through the fire blanket. 

Experiments were run until the fire burned down and smoke production was minimal. 

The experimental duration varied between 10 min and 50 min depending on the 

ventilation and fuel available during each experiment. Detailed tables of the 

experimental event changes are included in the results section. 

 Figure 30. Trailer and truck mounted fans in position to create simulated wind 

Results 

The results of the experiments include experiment timelines, photographs, videos, and 

pressure, temperature, heat flux, carbon monoxide, and weather measurements. 

Experiment Timelines 

The timelines were developed from observations made during the experiment, review of 

the video, and the data. The timelines for the six experiments are given in Tables 3 

through 8. Photographs before, during and after each experiment are presented in Figures 

31 through 51.

15
Table 3. Timeline for experiment in apartment 1503 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed 

0 Ignition 

465 Stair door on floor 15 open 

582 Stair door on floor 16 open (exterior vent) 

845 Stair door on floor 16 closed 

870 Stair door on floor 15 closed 

875 Stair door on floor 16 open 

895 MVU started 

938 MVU up to speed (1800 rpm) 

960 Stair door on floor 16 closed 

1025 Stair door on floor 15 opened 0.08 m (3 in) 

1068 Stair door on floor 15 open 

1475 FF crew moves down hallway 

1485 FF crew removes gypsum board blocking rear of apartment 

1580 Two chairs placed on sofa 

1640 MVU turned off 

1788 MVU turned on (1800 rpm) 

3184 Experiment Terminated 

Figure 31. 1503 - Prior to ignition Figure 32. 1503 – Smoke from hallway leaks

Figure 33. 1503 – Post test (Same view as figure 31)

16
Table 4. Timeline for experiment in apartment 1505 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed 

0 Ignition 

340 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

392 Stair door on floor 16 open 

411 Stair door on floor 13 opened 

416 0.7 m (27 in.) fan turned on at floor 13 [1.2 m (4 ft.) 80 degrees] 

442 Stair door on floor 16 closed 

469 Stair door on floor 15 opened 0.08 m (3 in) 

489 Stair door on floor 15 opened 

808 Stair door on floor 14 open 

838 Stair door on floor 14 closed 

1074 Both fans turned off 

1148 Stair door on floor 1 closed 

1162 Stair door on floor 13 opened 

1167 0.7 m (27 in.) fan turned on at floor 13 [1.2 m (4 ft.) 80 degrees] 

1241 0.7 m (27 in.) fan turned off at floor 13 

1250 Stair door on floor 13 closed 

1329 Stair door on floor 1 open 

1545 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

1717 Stair door on floor 13 opened 

1722 0.7 m (27 in.) fan turned on at floor 13 [1.2 m (4 ft.) 80 degrees] 

2172 Experiment Terminated 

Figure 34. 1505 - Prior to ignition 

 

Figure 35. 1505 – Smoke from bedroom

17
Figure 36. 1505 – Post test (Same view as figure 34) 

Table 5. Timeline for experiment in apartment 1003 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed 

0 Ignition 

223 Stair door on floor 10 open 

248 Stair door on floor 16 open 

297 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

317 Stair door on floor 8 open 

322 0.7 m (27 in.) fan turned on at floor 8 [1.2 m (4 ft.) 80 degrees] 

346 Stair door on floor 16 closed 

480 Stair door on floor 1 open (center stairwell) 

491 0.6 m (24 in.) fan turned on at floor 1 center stairwell [1.2 m (4 ft.) 80 deg] 

528 Stair door on floor 9 open (center stairwell) 

533 0.6 m (24 in.) fan turned on at floor 9 center stairwell [1.2 m (4 ft.) 80 deg] 

593 Stair door on floor 16 open (center stairwell) 

803 0.7 m (27 in.) fan turned off at floor 1 

803 0.6 m (24 in.) fan turned off at floor 1 (center stairwell) 

803 0.6 m (24 in.) fan turned off at floor 9 (center stairwell) 

810 Stair door on floor 9 closed (center stairwell) 

891 0.7 m (27 in.) fan turned off at floor 8 

896 Stair door on floor 8 closed 

1093 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

1235 Stair door on floor 16 open 

1300 Overhaul initiated 

1480 Experiment Terminated 

18
Figure 37. 1003 - Prior to ignition Figure 38. 1003 – Smoke from bedroom

Figure 39. 1003 – Post test (same view as figure 37) 

Table 6. Timeline for experiment in apartment 1005 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed 

0 Ignition 

221 Stair door on floor 10 open 

276 Stair door on floor 16 open 

336 SVU turned on (3600 rpm) 

351 Stair door on floor 16 closed 

626 Stair door on floor 1 open (center stairwell) 

661 Stair door on floor 16 open (center stairwell) 

896 Stair door on floor 16 closed (center stairwell) 

973 SVU turned down to idle 

1328 SVU turned up (3600 rpm) 

1396 Stair door on floor 1 closed (center stairwell) 

1506 Overhaul begins 

1626 Experiment Terminated 

19
Figure 40. 1005 - Prior to ignition Figure 41. 1005 – Smoke from bedroom

Figure 42. 1005 – Post test (same view as figure 40) 

20
Table 7. Timeline for experiment in apartment 303 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed 

0 Ignition 

264 SVU turned on (Simulated wind) 

278 SVU at full throttle (4300 rpm) 

339 Stair door on floor 3 open 

349 Stair door on floor 16 open 

444 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

444 0.7 m (27 in.) fan turned on at floor 1 (Center Stairwell) [1.2 m (4 ft.) 80 deg] 

584 0.6 m (24 in.) fan turned on at floor 5 [1.2 m (4 ft.) 80 degrees] 

589 Stair door on floor 5 open 

668 0.6 m (24 in.) fan turned off at floor 5 

687 0.7 m (27 in.) fan turned off at floor 1 

687 0.7 m (27 in.) fan turned off at floor 1 (Center Stairwell) 

719 0.7 m (27 in.) fan turned on at floor 1 (Center Stairwell) [1.2 m (4 ft.) 80 deg] 

747 Fire Blanket Deployed on Bedroom Window 

789 Stair door on floor 3 open (1/2) 

806 Stair door on floor 3 closed 

844 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

873 Stair door on floor 16 open 

1016 Stair door on floor 3 opened 0.08 m (3 in) 

1027 Stair door on floor 3 closed 

1061 Stair door on floor 16 closed 

1066 Stair door on floor 3 opened 0.08 m (3 in) 

1071 Stair door on floor 3 closed 

1092 Stair door on floor 16 open 

1130 Stair door on 16 closed 

1146 Stair door on floor 5 open 

1151 0.6 m (24 in.) fan turned on at floor 5 [1.2 m (4 ft.) 80 degrees] 

1158 Stair door on floor 3 opened 0.08 m (3 in) 

1207 0.6 m (24 in.) fan turned off at floor 5 

1212 Stair door on floor 5 closed 

1218 Stair door on floor 3 open 

1278 0.7 m (27 in.) fan turned off at floor 1 

1379 SVU turned off 

1461 Fire Blanket Removed From Window 

1520 0.7 m (27 in.) fan turned on at floor 1 [1.2 m (4 ft.) 80 degrees] 

1994 Stair door on floor 5 open 

1999 0.6 m (24 in.) fan turned on at floor 5 [1.2 m (4 ft.) 80 degrees] 

2279 Experiment Terminated 

21
Figure 43. 303 - Prior to ignition Figure 44. 303 – Smoke prior to wind

Figure 45. 303 – Smoke during wind Figure 46. 303 – Fire blanket deployed

Table 8. Timeline for experiment in apartment 304 

Time (s) Event 

Background 

Base of south stair and front door open, Center stair closed, 304 Bedroom 

Window Open 

0 Ignition 

138 MVU turned on 

151 MVU (1200 rpm) Simulated 20-25 mph wind 

160 Stair door on floor 3 open 1/2 (Center Stairwell) 

189 Stair door on floor 3 open 0.08 m (3 in) to 0.2 m (8 in) 

214 Stair door on floor 16 open 

279 Stair door on floor 3 closed 

304 SVU turned on (3800 rpm) 

430 Stair door on floor 16 closed 

513 MVU turned off 

513 SVU turned off 

629 Experiment Terminated 

22
Figure 47. 304 – Living room prior to ignition Figure 48. 304 – Bedroom prior to ignition 

Figure 49. 304 – Smoke prior to wind Figure 50. 304 – Fire during wind

Figure 51. 304 – Post test looking 

back to the bedroom 

23
Pressure Data 

The pressure measurements versus time graphs are located in the appendices B through 

G. The experiment time lines are integrated into the graphs to display the pressure 

changes after the configuration changes. The pressures were quasi-steady for the 

different configurations. These pressures are graphed versus the floor number for the 

different configurations in Figures 52 through 57 for the six experiments. Detailed lines 

are located at the NFPA minimum design pressures. Floors that are missing a data point 

had a malfunctioning pressure transducer or the door was open providing no differential 

pressure. 

Average pressures during the different configurations during the experiment in apartment 

1503 are in Figure 52 and Table 9. Ambient differential pressures were below 5 Pa 

before the experiment began and late in the experiment when the MVU was turned off. 

Pressures were mostly above 80 Pa in the stairwell with all of the doors closed and the 

MVU pressurizing 7.6 m (25 ft) from the front door. When the door on floor 15 was 

opened 0.08 m (3 in), the pressures dropped throughout the stairwell but remained above 

50 Pa. Pressures with one door open, either on the 16th floor or on the 15th floor, dropped 

significantly, but remained above 25 Pa below the 11th floor. The upper floors remained 

above 12.5 Pa with the exception of the 15th floor, while the 16th floor was open. 

The experiment in apartment 1505 utilized portable fans to pressurize the south stairwell. 

Average pressures during the experiment are in Figure 53 and Table 10. Ambient 

pressures during this experiment also remained below 5 Pa. Placing a 0.7 m (27 in) fan at 

the base of the south stairwell, setback 1.2 m (4 ft) and angled up to 80 degrees (i.e. 10 

degrees back from vertical), increased the stairwell pressures by 9 Pa to 14 Pa. Opening 

a single door on the 15th floor or the 16th floor decreased the stairwell pressures to 9 Pa to 

11 Pa at the bottom of the stairwell to approximately ambient towards the top of the 

stairwell. A single 0.7 m (27 in) fan at the 13th floor with all other doors closed created 

increased pressures in the entire stairwell with the exception of the 2nd floor as compared 

to the single fan at the base of the stairwell. Pressurizing the stairwell with two 0.7 m 

(27 in) fans, one at the 1st floor and one at the 13th floor, resulted in pressures ranging 

from 16 Pa to 21 Pa independent of the doors opened on the upper floors. With no doors 

opened the pressures reached as high as 26 Pa, while opening two doors on the 14th and 

15th floors decreased the pressures as low as 7 Pa. 

Average pressures for the experiment in apartment 1003 created by portable fans are in 

Figure 54 and Table 11. The ambient pressures prior to the experiment were at or below 

5 Pa with a transient increase to 9 Pa on floor 13. The single 0.7 m (27 in) fan on the 1st

floor and with the fire floor door open and the 16th floor door open, raised pressures 

lower in the building as high as 17 Pa, but pressures above the 8th floor fell below 

ambient. A single 0.7 m (27 in) fan on floor 8 with the 10th floor open, kept pressures in 

the entire stairwell above 12.5 Pa except for floor 2. Utilizing both fans was effective at 

keeping stairwell pressures up to the 7th floor above 25 Pa regardless of ventilation 

opening above the 9th floor. All pressures remained above 12.5 Pa except when the 10th

and 16th floor doors were both open. 

24
The average pressures for the configurations during the experiment in apartment 1005 are 

in Figure 55 and Table 12. Ambient pressures prior to the experiment ranged from 0 Pa 

to 11 Pa in the stairwell. Pressures up to 64 Pa were recorded with the SVU running and 

the fire floor door open on the 10th floor. The same configuration had pressures as low as 

21 Pa above the fire floor. When the center stairwell was opened in addition to the south 

stairwell, the pressures declined to 13 Pa to 40 Pa below the fire floor and 10 Pa to 15 Pa 

above the fire floor. 

The experiment in apartment 303 had pressures created by a simulated wind as well as by 

portable fans. The average pressures for this experiment are in Figure 56 and Table 13. 

The ambient stairwell pressures for this experiment were impacted by a natural wind. 

The fire floors (3, 10, 15) were enclosed, therefore creating an interior stairwell. The 

wind was able to reach the low side of the pressure transducers on the non-fire floors 

lowering the pressures, while the leakage into the stairwell caused a slight increase in 

pressure on the fire floors. This wind effect remained constant through the experiment so 

the impact of the fans can be determined by the change in differential pressure. The 

ambient pressure on the fire floors was approximately 11 Pa and the ambient pressure on 

all other floors was zero. 

The simulated wind created by the SVU blowing into the third floor caused the pressure 

on floor 3 to drop to zero and caused an increase of approximately 1 Pa throughout the 

rest of the stairwell. The third floor pressure may have been negative, but the pressure 

transducer was unidirectional and did not have the range to measure negative pressures. 

When the third floor door was opened, the pressure on floors 5 through 10 increased to 

10 Pa. Above floor 10, there was a minimal impact. With floor 3 and 16 open, the 

impact of the wind on the upper floor pressures was greater. A fire blanket was deployed 

over the fire apartment window that the simulated wind was being introduced. This fire 

blanket prevented any pressure impact created by the wind in the south stairwell. While 

the fire blanket was deployed, portable fans were used to pressurize the south stairwell. 

Single fans at the base of the stairwell increased the pressure above 14 Pa in most of the 

stairwell. Multiple fans, one at the base of the stair and one on the 5th floor, increased the 

pressure above 25 Pa and as high as 37 Pa in the stairwell. 

Average pressures from the configurations during the experiment in apartment 304 are 

shown in Figure 57 and Table 14. This experiment also had a simulated wind, but it was 

created by the MVU instead of the SVU used for the experiment in apartment 303. The 

SVU was used at the front door to pressurize the stairwell against the effects of the 

simulated wind on the fire. Ambient differential pressures were approximately 10 Pa to 

12 Pa on the enclosed floors and less than 5 Pa on the other floors before the experiment 

began. The addition of the wind through the fire apartment decreased the third floor 

pressure to zero and increased the rest of the stairwell by 3 Pa to 5 Pa. The third floor 

door was opened allowing the wind to flow into the stairwell and the pressures increased 

as much as 20 Pa on the fifth floor. With the simulated wind still impacting the fire 

apartment, the SVU was activated at the front door. With the SVU running and the 16th

floor door open, pressures increased to above 10 Pa throughout the stairwell. After the 

16th floor door was closed, the pressures increased to above 33 Pa. 

25
0 20 40 60 80 100 120

0

2

4

6

8

10

12

14

16

Ambient

MVU (16 Open)

MVU (16 Closed)

MVU (15 Open 3 in.)

MVU (15 Open)

MVU Off

MVU (15 Open) [2]

Pressure (Pa)

Floor

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

Figure 52. Pressure vs. Floor with MVU at front door for fire in apartment 1503 (Uncertainty ±10%) 

Table 9. Average stairwell pressure during events for fire in apartment 1503 (Uncertainty ±10%) 

Ambient MVU 

(16 Open) 

MVU 

(16 Closed) 

MVU 

(15 Open 3 in.) 

MVU 

(15 Open) 

MVU Off MVU 

(15 Open) Floor Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

16 No Data Open No Data No Data No Data No Data No Data 

15 1 15 20 Open 13 6 13 

14 2 52 80 55 18 3 19 

13 2 53 84 67 26 3 26 

12 1 53 82 60 24 2 25 

11 3 53 89 75 33 3 33 

10 7 60 87 72 37 6 34 

9 3 61 92 81 38 3 40 

8 3 60 85 72 47 3 43 

7 3 68 97 88 48 3 47 

6 3 67 87 83 60 3 58 

5 3 70 96 95 69 3 51 

4 3 71 101 101 70 3 72 

3 1 64 98 99 85 1 60 

2 2 69 102 102 98 1 79 

1 Open Open Open Open Open Open Open 

26
0 5 10 15 20 25 30 35 40

0

2

4

6

8

10

12

14

16

Ambient

27 on Floor 1

27 on Floor 1 (16 open)

27 on Floors 1 and 13 (16 open)

27 on Floors 1 and 13

27 on Floors 1 and 13 (15 open 0.08 m (3 in))

27 on Floors 1 and 13 (15 open)

27 on Floors 1 and 13 (15 and 14 open)

Fans off

27 on Floor 13 (1 closed)

27 on Floor 1 (15 Open)

27 on Floors 1 and 13 (15 Open)

Pressure (Pa)

Floor

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

Figure 53. Pressure vs. Floor with 0.7 m (27 in.) fan for fire in apartment 1505 (Uncertainty ±10%) 

Table 10. Average stairwell pressure during events for fire in apartment 1505 (Uncertainty ±10%) 

Ambient 27 on Floor 

1 27 on Floor 

1 (16 open) 

27 on Floors 

1 and 13 

(16 open) 

27 on Floors 

1 and 13 

27 on Floors 1 and 13 

(15 open 0.08 m (3 in)) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

16 5 14 Open Open 26 18 

15 No Data No Data No Data No Data No Data No Data 

14 3 9 3 8 17 14 

13 3 12 4 Fan (Open) Fan (Open) Fan (Open) 

12 2 10 3 15 20 19 

11 3 11 5 17 21 22 

10 5 12 7 18 22 22 

9 4 12 7 17 21 21 

8 4 11 8 17 20 21 

7 4 12 9 17 20 21 

6 4 12 10 17 19 21 

5 4 12 11 17 20 22 

4 3 13 11 17 20 21 

3 3 11 8 15 17 19 

2 2 12 11 15 17 21 

1 2 Fan (Open) Fan (Open) Fan (Open) Fan (Open) Fan (Open) 

27
Table 10 (cont.) 

27 on Floors 1 

and 13 

(15 open) 

27 on Floors 1 

and 13 (15 and 

14 open) 

Fans off 27 on Floor 

13 (1 closed) 

27 on Floor 1 

(15 Open) 

27 on Floors 1 

and 13 

(15 Open) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

 (Pa)

Pressure 

(Pa)

16 16 7 7 16 6 15 

15 Open Open Open Open Open Open 

14 12 Open 3 12 4 12 

13 Fan (Open) Fan (Open) 2 Fan (Open) 5 Fan (Open) 

12 19 14 1 15 4 18 

11 21 15 2 16 5 20 

10 22 17 3 16 7 21 

9 21 16 2 14 7 20 

8 21 16 2 14 7 19 

7 21 17 2 14 7 19 

6 20 16 3 13 8 18 

5 20 16 3 13 8 18 

4 21 17 3 13 9 19 

3 19 14 2 11 8 16 

2 20 15 2 11 9 17 

1 Fan (Open) Fan (Open) Open 12 Fan (Open) Fan (Open) 

28
0 5 10 15 20 25 30 35 40

0

2

4

6

8

10

12

14

16

Ambient

27 on Floor 1 (10 and 16 Open)

27 on Floors 1 and 8 (10 and 16 Open)

27 on Floors 1 and 8 (10 Open)

27 on Floors 1 and 8 (10 Open, CS Pressurized)

27 on Floor 8 (10 Open)

Pressure (Pa)

Floor

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

Figure 54. Pressure vs. Floor with 0.7 m (27 in.) fan for fire in apartment 1003 (Uncertainty ±10%) 

Table 11. Average stairwell pressure during events for fire in apartment 1003 (Uncertainty ±10%) 

Ambient 

27 on Floor 1 

(10 and 16 

Open) 

27 on Floors 1 

and 8 (10 and 

16 Open) 

27 on Floors 

1 and 8 (10 

Open) 

27 on Floors 1 and 

8 (10 Open, CS 

Pressurized) 

27 on Floor 

8 (10 Open) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

16 5 Open Open 19 22 16 

15 5 3 3 18 23 17 

14 4 2 2 15 20 15 

13 9 6 6 18 21 17 

12 3 1 1 13 19 14 

11 3 1 5 14 20 15 

10 5 Open Open Open Open Open 

9 6 5 15 19 26 20 

8 3 4 Fan (Open) Fan (Open) Fan (Open) 10 

7 2 10 25 29 28 19 

6 2 11 25 29 27 17 

5 3 13 27 29 28 17 

4 3 15 27 28 29 15 

3 2 15 26 28 26 13 

2 1 18 25 28 26 11 

1 Open Fan (Open) Fan (Open) Fan (Open) Open Open 

29
0 10 20 30 40 50 60 70 80

0

2

4

6

8

10

12

14

16

Ambient

SVU (10 and 16 Open)

SVU (10 Open)

SVU [10 and 1(CS) Open]

SVU [10,1(CS),16(CS) Open]

SVU idle

SVU [10 and 1(CS) Open]

Pressure (Pa)

Floor

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

Figure 55. Pressure vs. Floor with SVU at front door for fire in apartment 1003 (Uncertainty ±10%) 

Table 12. Average stairwell pressure during events for fire in apartment 1005 (Uncertainty ±10%) 

Ambient SVU (10 

and 16 

Open) 

SVU (10 

Open) 

SVU [10 and 

1(CS) Open] 

SVU 

[10,1(CS),16

(CS) Open] 

SVU 

idle 

SVU [10 

and 1(CS) 

Open] 

SVU (10 

Open) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

16 6 Open 25 19 15 7 16 18 

15 7 5 26 20 16 8 16 19 

14 4 2 23 18 13 6 14 17 

13 8 6 25 18 15 9 17 19 

12 2 1 21 15 12 4 11 14 

11 2 4 22 15 12 4 10 15 

10 11 Open Open Open Open Open Open Open 

9 2 19 31 21 17 4 16 24 

8 2 24 35 23 19 2 18 28 

7 1 26 37 24 21 2 21 31 

6 2 35 44 27 25 2 26 38 

5 2 42 51 31 30 3 32 47 

4 3 48 55 34 31 3 35 51 

3 0 60 63 36 36 4 39 58 

2 No Data No Data No Data No Data No Data No Data No Data No Data

1 Open Open Open Open Open Open Open Open 

30
0 10 20 30 40 50

0

2

4

6

8

10

12

14

16

Ambient

Wind

Wind (3 Open)

Wind (3 and 16 Open)

27 on Floor 1 (Wind)

27 on Floors 1 and 5 (Wind)

Fans Off (Wind)

Fire Blanket Deployed

3 Open (Fire Blanket)

27 on Floor 1 (16 Open)

27 on Floor 1 (16 Open, 3 Open 0.08m)

27 on Floor 1 (16 Open) [2]

27 on Floor 1 [2]

27 on Floor 1 (3 Open 0.08m)

27 on Floor 1 [3]

27 on Floor 1 (16 Open) [3]

27 on Floors 1 and 5 

27 on Floors 1 and 5 (3 Open 0.08m)

27 on Floor 1 (3 Open)

Pressure (Pa)

Floor

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

Figure 56. Pressure vs. Floor with 0.7 m (27 in.) fan and SVU simulated wind for fire in apt. 303 

(Uncertainty ±10%) 

Table 13. Average stairwell pressure during events for fire in apartment 303 (Uncertainty ±10%) 

Ambient Wind Wind 

(3 Open) 

Wind 

(3 and 16 

Open) 

27 on Floor 1 

(Wind) 

27 on Floors 1 

and 5 (Wind) 

Fans Off 

(Wind) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

 (Pa)

Pressure 

(Pa)

16 1 4 2 Open 2 3 2 

15 11 12 15 14 10 11 7 

14 0 2 1 3 3 3 2 

13 0 2 1 3 4 5 2 

12 0 1 0 4 3 4 0 

11 0 1 1 8 5 7 0 

10 11 13 20 22 15 19 8 

9 No Data No Data No Data No Data No Data No Data No Data

8 0 2 7 12 10 14 1 

7 0 2 8 12 10 15 0 

6 0 3 9 11 12 18 1 

5 0 5 10 11 14 Fan (Open) 1 

4 No Data No Data No Data No Data No Data No Data No Data

3 12 0 Open Open 2 5 0 

2 0 1 1 3 18 27 0 

1 Open Open Open Open Fan (Open) Fan (Open) Open 

31
Table 13 (cont.) 

Fire Blanket 

Deployed 

3 Open (Fire 

Blanket) 

27 on Floor 

1 (16 

Open) 

27 on Floor 1 

(16 Open, 3 

Open 0.08m) 

27 on Floor 

1 (16 Open) 

[2] 

27 on Floor 

1 [2] 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

16 2 2 Open 2 Open 24 

15 10 12 11 15 14 33 

14 0 0 2 1 2 20 

13 1 1 3 0 2 20 

12 0 0 2 0 1 18 

11 0 0 4 0 2 20 

10 10 12 16 21 18 31 

9 No Data No Data No Data No Data No Data No Data

8 1 0 10 8 7 22 

7 0 0 9 5 8 20 

6 1 1 12 7 9 19 

5 0 1 15 9 12 20 

4 No Data No Data No Data No Data No Data No Data

3 0 Open 11 2 9 2 

2 0 0 15 12 14 20 

1 Open Open Fan (Open) Fan (Open) Fan (Open) Fan (Open) 

Table 13 (cont.) 

27 on Floor 

1 (3 Open 

0.08m) 

27 on 

Floor 1 [3] 

27 on Floor 1 

(16 Open) [3] 

27 on Floors 1 

and 5 (Wind) 

27 on Floors 1 

and 5 (3 Open 

0.08m) 

27 on Floor 1 (3 

Open) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure (Pa)

16 22 23 Open 28 27 22 

15 29 35 12 33 34 30 

14 17 20 2 25 26 20 

13 17 18 2 26 25 19 

12 15 15 2 25 22 18 

11 16 16 4 27 23 18 

10 30 32 18 37 33 30 

9 No Data No Data No Data No Data No Data No Data

8 22 19 8 31 24 20 

7 21 18 8 32 23 19 

6 21 18 9 32 24 20 

5 23 21 12 Fan (Open) Fan (Open) 21 

4 No Data No Data No Data No Data No Data No Data

3 6 11 5 37 3 1 

2 17 18 16 30 25 19 

1 Fan (Open) 

Fan 

(Open) Fan (Open) Fan (Open) Fan (Open) Fan (Open) 

32
0 10 20 30 40 50

0

2

4

6

8

10

12

14

16

Ambient

Wind

Wind (3 Open)

Wind (3 and 16 Open)

Wind (16 Open)

SVU (Wind and 16 Open)

SVU (Wind)

Pressure (Pa)

Floor

NFPA 92A

Sprinklered Bldg.

Min. Design Pressure

NFPA 92A

Nonsprinklered Bldg.

Min. Design Pressure

Figure 57. Pressure vs. Floor with SVU at front door and MVU simulated wind fore fire in apt. 304 

(Uncertainty ±10%) 

Table 14. Average stairwell pressure during events for fire in apartment 304 (Uncertainty ±10%) 

Ambient Wind 

Wind 

(3 Open) 

Wind (3 and 

16 Open) 

Wind 

(16 Open) 

SVU (Wind and 

16 Open) 

SVU 

(Wind) 

Floor 

Pressure 

(Pa) 

Pressure 

(Pa) 

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa)

Pressure 

(Pa) 

16 5 8 21 Open Open Open No Data 

15 12 15 29 9 No Data No Data No Data 

14 2 7 10 6 No Data No Data No Data 

13 1 5 9 8 3 10 45 

12 0 4 7 11 No Data No Data No Data 

11 1 4 8 16 3 12 43 

10 12 14 18 22 No Data No Data No Data 

9 2 4 5 6 No Data No Data No Data 

8 1 4 9 15 0 18 43 

7 1 4 7 15 No Data No Data No Data 

6 1 4 10 12 0 17 34 

5 1 4 23 7 No Data No Data No Data 

4 No Data No Data No Data No Data No Data No Data No Data

3 9 0 Open Open No Data No Data No Data

2 No Data No Data No Data No Data No Data No Data No Data 

1 Open Open Open Open Open Open Open 

33
Temperature Data 

Temperature measurements at each of the instrument locations are graphed versus time in 

the appendix. These graphs include lines to detail the events and configuration changes 

that occurred during the experiments. The thermocouple locations that correspond to 

those in the graphs are shown in Figure 58. The temperatures for each of the 

thermocouple locations at the ceiling and at 0.9 m (3 ft) from the floor are shown for each 

of the six experiments in Figures 59 through 70. The largest observed temperatures were 

typically located at the ceiling, while temperatures at 0.9 m (3 ft) would be more 

representative of what a fire fighter experiences. Table 15 shows the maximum 

temperatures at the ceiling and at 0.9 m (3 ft) for each experiment. 

 NORTH 

Figure 58. Thermocouple tree locations 

Experimental temperatures in apartment 1503’s living room reached 800 o

C (1470 oF) at 

the ceiling and 500 oC (930 oF) at 0.9 m (3 ft) from the floor. The fire became ventilation 

limited at approximately 850 s based on the video and infrared views and the temperature 

fell to between 150 oC (300 oF) and 250 oC (480 oF). The MVU was turned on and the 

16th floor was opened to vent the stairwell. The temperatures in the stairwell of up to 

100 oC (210 oF) decreased down to near ambient. Later in the experiment, the rear of the 

apartment was ventilated and two chairs were added to the burning sofa. The MVU was 

turned off and the temperatures in the hallway and stairwell climbed back up to near 

200 o

C (390 oF). The MVU was turned on again with the fire floor door open and the 

temperatures declined rapidly. 

The living room ceiling temperatures during the experiment in apartment 1505 reached 

800 o

C (1470 oF), then the room became ventilation limited and the temperature 

decreased to 200 o

C (390 oF). The stairwell door was opened and the temperatures 

recovered to 850 o

C (1560 oF). Hallway temperatures reached a maximum of 250 oC 

(480 o

F) and stairwell temperatures remained below 100 oC (210 oF). The use of the fans 

34
lowered the stairwell temperatures by as much as 50 o

C (120 oF) and it recovered by the 

same amount when the fans were turned off. 

Experimental temperatures in apartment 1003’s living room reached 800 o

C (1470 oF) at 

the ceiling and 600 o

C (1110 oF) at 0.9 m (3 ft) from the floor. More oxygen was 

available from a window on the rear of the apartment, so this experiment was likely less 

ventilation limited as compared to the prior experiments. Hallway ceiling temperatures 

reached 250 oC (480 oF) near the south stairwell and declined with the use of portable 

fans. The stairwell temperatures remained near ambient and were cooled by the fan air 

flow when they increased. 

The living room ceiling temperatures during the experiment in apartment 1005 reached 

800 oC (1470 oF). Temperatures 0.9 m (3 ft) from the floor peaked at 850 oC (1560 oF). 

This experiment also did not see large temperature drops due to limited oxygen. Hallway 

ceiling temperatures reached 225 oC (440 oF) throughout the hallway and declined with 

the use of the SVU. The stairwell temperatures remained near ambient and were cooled 

by the fan air flow when the fan was turned on at 340 s and 1330 s. 

Temperatures during the experiment in Apartment 303 were greatly influenced by 

ventilation. A simulated wind was introduced through a bedroom window which caused 

temperatures to reach as high as 900 o

C (1650 oF) in the living room. Temperatures as 

high as 600 oC (1110 oF) were reached in the hallway and the temperature in the stairwell 

peaked at 250 oC (480 o

F) on the floor above the fire floor. A fire blanket was deployed 

to block the effects of the wind and the temperatures were held below 200 oC (390 oF) 

everywhere on the floor until the blanket was removed. The remaining fuel in the room 

began to burn causing temperatures to rise back up to 800 oC (1470 oF). 

Temperatures during the experiment in apartment 304 were also greatly influenced by the 

simulated wind into the bedroom window. The bedroom and living room were furnished, 

which also played a role in the increased temperatures. Temperatures throughout the fire 

apartment and entire hallway reached 800 o

C (1470 oF) to 900 oC (1650 oF). Some of the 

temperatures increased over 500 o

C (930 oF) in less than 30 s. Temperatures in the 

stairwell on the floor above the fire increased from 35 o

C (95 oF) to over 180 oC (360 oF) 

in less than 20 s. The reliability of temperatures after 400 s is not certain because the 

corridor lost integrity creating holes and thermocouple extension wires were damaged by 

thermal exposure. 

Table 15. Maximum temperature readings (Uncertainty ± 15%) 

Experiment Living Room (°C) Hall SS (°C) Hall Mid (°C) Hall CS (°C) 

Ceiling 0.9 m (3 ft) Ceiling 0.9 m (3 ft) Ceiling 0.9 m (3 ft) Ceiling 0.9 m (3 ft) 

1503 800 500 250 150 225 125 150 150 

1505 850 525 150 100 200 100 250 100 

1003 800 600 250 100 175 75 125 100 

1005 825 850 175 100 200 75 225 75 

303 900 900 575 400 450 250 250 250 

304 800 850 850 850 650 650 650 700 

35
0

200

400

600

800

1000

0 500 1000 1500 2000 2500 3000 3500

1503 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor16

Temperature (

oC)

Time (s)

Figure 59. Gas temperatures at ceiling during apartment 1503 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 500 1000 1500 2000 2500 3000 3500

1503 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor15

TCFloor14

Temperature (

oC)

Time (s)

Figure 60. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 1503 experiment 

(Uncertainty ± 15%) 

36
0

200

400

600

800

1000

0 500 1000 1500 2000 2500

1505 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor16

Temperature (

oC)

Time (s)

Figure 61. Gas temperatures at ceiling during apartment 1505 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 500 1000 1500 2000 2500

1505 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor15

TCFloor14

Temperature (

oC)

Time (s)

Figure 62. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 1505 experiment 

(Uncertainty ± 15%) 

37
0

200

400

600

800

1000

0 500 1000 1500

1003 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor11

TCFloor16

Temperature (

oC)

Time (s)

Figure 63. Gas temperatures at ceiling during apartment 1003 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 500 1000 1500

1003 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor10

TCFloor9

Temperature (

oC)

Time (s)

Figure 64. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 1003 experiment 

(Uncertainty ± 15%) 

38
0

200

400

600

800

1000

0 500 1000 1500 2000

1005 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor11

TCFloor16

Temperature (

oC)

Time (s)

Figure 65. Gas temperatures at ceiling during apartment 1005 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 500 1000 1500 2000

1005 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor10

TCFloor9

Temperature (

oC)

Time (s)

Figure 66. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 1005 experiment 

(Uncertainty ± 15%) 

39
0

200

400

600

800

1000

0 500 1000 1500 2000 2500 3000 3500

303 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor4

TCFloor16

Temperature (

oC)

Time (s)

Figure 67. Gas temperatures at ceiling during apartment 303 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 500 1000 1500 2000 2500 3000 3500

303 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor3

TCFloor2

Temperature (

oC)

Time (s)

Figure 68. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 303 experiment 

(Uncertainty ± 15%) 

40
0

200

400

600

800

1000

0 200 400 600 800 1000

304 0.03 m

304 BR 0.03 m

Hall SS 0.03 m

Hall Mid 0.03 m

Hall CS 0.03 m

TCFloor4

TCFloor16

Temperature (

oC)

Time (s)

Figure 69. Gas temperatures at ceiling during apartment 304 experiment (Uncertainty ± 15%) 

0

200

400

600

800

1000

0 200 400 600 800 1000

304 1.52 m

304 BR 1.52 m

Hall SS 1.52 m

Hall Mid 1.52 m

Hall CS 1.52 m

TCFloor3

TCFloor2

Temperature (

oC)

Time (s)

Figure 70. Gas temperatures at 1.2 m (3 ft.) above floor during apartment 304 experiment 

(Uncertainty ± 15%) 

41
Heat Flux Data 

The maximum heat fluxes observed during each experiment are in Table 15. Heat flux 

measurements at each of the instrument locations are graphed versus time in the appendix 

Figures. These graphs include lines to detail the events and configuration changes of the 

experiments. The heat flux gauge locations that correspond to those in the graphs are in 

Figure 71. 

 NORTH 

Figure 71. Heat flux gauge locations 

The heat flux gauges placed in each of the fire rooms achieved heat fluxes that are 

consistent with flashover. The heat flux gauge located near the south stairwell in the 

horizontal orientation malfunctioned (Table 16). Heat flux gauges were not placed in the 

fire apartment for the experiment in apartment 304, due to the expected extreme heat flux 

conditions. 

The experiment in Apartment 1503 exhibited a maximum fire room horizontal flux of 

30.9 kW/m2

 and a vertical flux of 19.8 kW/m2. These fluxes occurred after the fire was 

manually ventilated by removing the gypsum board blocking the rear of the apartment 

and additional fuel was added to the diminishing fire. The heat flux gauges in the 

hallway locations did not exceed 4.8 kW/m2 at any of the locations. 

The maximum heat fluxes in the experiment in Apartment 1505 were similar to those in 

the previous experiment on the 15th floor. The maximum heat flux in the living room of 

fire origin was 40.6 kW/m

2

. The fluxes in the hallway locations did not exceed 

6.3 kW/m

2

. 

The experiment in Apartment 1003 had a maximum fire room horizontal flux of 

36.2 kW/m

2

 and a vertical flux of 28.7 kW/m2. The fire room maximum heat fluxes 

42
occurred after numerous ventilation actions had taken place. The heat flux gauges in the 

hallway locations did not exceed 4.2 kW/m2 at any of the locations. The peaks for these 

heat flux gauges occurred during initial fire growth prior to complete smoke obscuration 

in the hallway. 

Maximum heat fluxes in the living room of the experiment in apartment 1005 were 

approximately 80 kW/m2 in both the horizontal and vertical orientations. These 

maximums occurred after forced ventilation from the SVU was allowed to flow through 

the fire apartment. The heat flux gauges in the hallway locations did not exceed 

8.4 kW/m2 at any of the locations. The peaks for the heat flux gauges located near the 

center stairwell occurred after ventilation and the other hallway heat flux gauges occurred 

during initial fire growth prior to complete smoke obscuration in the hallway. 

The experiment in apartment 303 had a maximum fire room horizontal flux of 

216.8 kW/m2 and a vertical flux of 95.0 kW/m2. These extreme heat fluxes occurred 

after the introduction of a simulated wind blowing through the bedroom in the rear of the 

fire apartment. Prior to the introduction of the wind the heat fluxes in the fire apartment 

exceeded 20 kW/m2

, consistent with flashover. The heat flux in the hallway near the 

south stair reached 23.2 kW/m2 prior to stairwell pressurization. The heat flux in the 

middle of the hallway peaked at 13.3 kW/m2 and the heat flux in the hallway near the 

center stairwell peaked at approximately 8.4 kW/m2

. 

The experiment in apartment 304 had a higher magnitude simulated wind introduced 

through the rear bedroom by the MVU. In this experiment the fire began in the bedroom 

and was blown through the furnished living room. There was no heat flux gauge in the 

fire apartment. The heat flux in the hallway near the south stair reached 15.8 kW/m2. 

The heat flux in the middle of the hallway near the fire apartment peaked at 45.4 kW/m2

and the heat flux in the hallway near the center stairwell peaked at approximately 

30.1 kW/m2. The peak heat fluxes after 300 s were disregarded due to steam in the 

radiometer coolant lines. 

Table 16. Maximum heat flux readings (Uncertainty -24% to +13%) 

Experiment FireVert 

(kW/m2)

FireHorz 

(kW/m2)

Hall SS 

Vert 

(kW/m2)

Hall SS 

Horz 

(kW/m2)

Hall Mid 

Vert 

(kW/m2)

Hall Mid 

Horz 

(kW/m2)

Hall CS 

Vert 

(kW/m2)

Hall CS 

Horz 

(kW/m2)

1503 19.8 30.9 4.4 NA 3.7 4.8 4.1 4.5 

1505 40.6 32.9 6.3 NA 3.0 2.9 4.5 4.9 

1003 28.7 36.2 4.2 NA 2.0 1.9 2.6 3.0 

1005 81.0 76.2 5.5 NA 1.9 1.7 5.0 8.4 

303 95.0 216.8 23.2 NA 10.1 13.3 7.5 8.3 

304 NA NA 15.8 NA 33.5 45.4 29.6 30.1 

43
Carbon Monoxide Data 

Carbon monoxide (CO) measurements at each of the instrument locations are graphed 

versus time in the appendix of each respective experiment. These graphs include lines to 

detail the events and configuration changes of the experiments. The CO meter locations 

that correspond to those in the graphs are in Figure 72. The CO meters were the same 

models as those typically available for fire department use. The sensors had a maximum 

upper limit that was less than the range of CO created during the experiments. The 

calibrated range of the CO meters was 0 ppm (0 %) to 750 ppm (0.075 %). At values 

above 750 ppm (0.075 %), the chemical sensors were saturated and the reported values 

probably under-report actual gas concentrations. All of the graphs have values above the 

maximum that the meters can read and are depicted as a flat line. 

 NORTH 

Figure 72. Carbon monoxide meter locations

CO readings in the hallway during the experiment in Apartment 1503 quickly reached a 

maximum value above 800 ppm (0.08 %) and remained there until the fire burned out and 

the fans ventilated the hallway. Prior to ventilation of the stairwell, the stairwell CO 

values exceeded 800 ppm (0.08 %), on both the 15th and 16th floors. During ventilation 

of the stairwell CO levels dropped below 200 ppm (0.02 %) and recovered to above 800 

ppm (0.08 %) when the fan was turned off. Towards the end of the experiment, the levels 

dropped rapidly with ventilation by the MVU. 

The experiment in Apartment 1505 also created CO levels in the hallway above the 

maximum range of the meters. The CO meter in the center stairwell peaked at 250 ppm 

(0.025 %) during the experiment. The center stairwell was not ventilated; the doors at the 

base of the stairwell, on the fire floor and bulkhead were closed. The CO concentration 

on the 16th floor in the south stairwell were decreased from 800 ppm (0.08 %) to 350 ppm

(0.035 %) temporarily during ventilation. The CO concentration on the 15th floor in the 

44
south stairwell decreased from 800 ppm (0.08 %) to 100 ppm (0.01 %) temporarily 

t. 

ter 

 the south stairwell on the 10 floor reached as high as 200 ppm (0.02 %) when the fire 

h 

10 floor reached as high as 180 ppm (0.018 %) when the fire floor door 

as opened, but declined to below 50 ppm (0.005 %) during ventilation until it also 

out of 

r 

e fans were used to ventilate the center stairwell. 

e CO readings decreased throughout the fire floor once the wind was stopped and the 

fire had consumed most of the fuel. 

ation were 

milar as compared to the ground data. Therefore the ground data can be used as an 

7 C (63 F). The outside temperatures 

mained constant during the experiments and were comparable to the interior stairwell 

e 

e 

during ventilation and returned to 800 ppm (0.08 %) when the fans were turned off. 

The experiment in Apartment 1003 had a number of CO meters fail to operate properly

early in the experiment. Two meters functioned as intended during the entire experimen

The CO level in the hallway reached the maximum of 750 ppm (0.075 %) early in the 

experiment and remained at the maximum during the entire experiment. The CO me

th in

floor door was opened, but declined to below 100 ppm (0.01 %) during ventilation. 

The experiment in Apartment 1005 also had similar CO meter malfunctions. The CO 

level in the hallway reached the maximum of 750 ppm (0.075 %) early in the experiment 

and remained at the maximum for most of the experiment. The CO meter in the sout

stairwell on the th

w

failed at 660 s. 

The experiment in Apartment 303 created CO levels in the hallway above the maximum 

of the meters. The CO reading in the south stairwell was above the maximum read

850 ppm (0.085 %) within seconds after the simulated wind was started. The CO mete

in the center stairwell peaked at 950 ppm (0.095 %) approximately 400 s into the 

experiment, but decreased as portabl

Th

 

Weather Data 

Average temperature, average wind speed and average wind direction for the weather 

stations on the ground and the roof were averaged over the duration of each of the 

experiments as shown in Table 17. The data from the roof weather station during the 

experiments in apartments 1003 and 1005 were missed due to issues with the power 

supply to the weather station. The weather conditions at the roof weather st

si

approximation to the overall weather conditions during those experiments. 

The average temperatures remained fairly constant during all of the experiments. 

Temperatures ranged between 11 o

C (52 oF) and 1 o o

re

temperatures, which minimized the stack effect. 

Wind speed has the potential to greatly impact the effectiveness of PPV. The averag

wind speed for each experiment remained below 3.6 m/s (8.0 mph) and was typically 

below 2.0 m/s (4.5 mph) during the experiments. The wind had little impact on th

experimental results. If there was wind, there were no gusts that would be expected to 

significantly impact any single experiment. The average wind direction was also 

45
examined to determine if the wind was into or out of one of the inlets or vents. The wind

shifted over the course of the experimental series, but remained fairly constant during 

each of the individual experiments. The wind was mainly out of the south (180°) wh

had little impact of the flows into the ground floor

ich 

 or out of the vent which were both 

cated on the east side of the building. The south stairwell was also interior to the 

Tabl e Weat rtai

Average Outside 

Temperature (°C) 

Average Wind 

Speed (m/s) 

Average irection 

(degrees from north) 

lo

building, which lessened the impact of any wind. 

e 17. Averag her Conditions (Unce nty ± 6 %) 

Experiment 

(location) 

Wind D

1503 (Roof) 11.6 1.7 202.3 

1503 (Ground) 12.2 0.7 146.2 

1505 (Roof) 12.3 2.0 169.8 

1505 (Ground) 12.7 1.1 156.1 

1003 (Ground) 11.5 0.2 320.6 

1005 (Ground) 11.0 0.7 307.3 

303 (Roof) 17.1 3.6 236.8 

303 (Ground) 17.2 0.5 115.5 

304 (Roof) 13.3 2.1 83.7 

304 (Ground) 13.3 1.3 309.0 

Observations (Video and Thermal Imaging Recording Data) 

A video camera and a thermal imaging camera were co-located in the south stairwell w

views of the fire floor doorway. These cameras recorded during each of the experiments 

to determine when smoke and heat entered the stairwe

ith 

ll. When the video camera was 

ompletely obscured by smoke, the thermal imaging camera was used to determine if 

shairs 

ing objects: painted concrete block, painted 

eel door and door jam, and fire fighter turnout gear. All of these materials have 

of 

 the 

c

heated gases and smoke were entering the stairwell. 

The temperature displayed in the top right view of the Figures is the average surface 

temperature of the object or objects within the crosshairs in the center of the image. The 

camera has a fixed emissivity of 0.95 [11] which is representative of most surfaces found 

in the field of view of the thermal imaging camera. In the stairwell views, the cros

of the thermal imaging camera had the follow

st

emissivities in the range of 0.95 ± 0.05 [11]. 

The Figures captured from the video of the experiment in apartment 1503 show important

times during the numerous events that took place. Figure 73-a shows the camera view 

the south stairwell prior to ignition. Figure 73-b shows total smoke obscuration after

door to the fire floor is opened. After the door to the 16th floor was opened the smoke 

layer lifted and reached an equilibrium height as shown in Figure 73-c. Figure 73-d 

shows the smoke layer quickly dropped after the 16th floor door was closed. Less than 

30 s later the fire floor door was closed, the 16th floor door was reopened and the MVU 

was started. The stairwell is quickly cleared of smoke (Figure 73-e). Once the smoke 

46
47

onds after the 

VU was turned off and the smoke quickly refilled the stairwell. The MVU was turned 

 at 

n was turned off (Figure 73-m) and back on (Figure 73-n). 

he heat was held at the fire floor doorway and the stairwell wall was cooled from 31 o

C 

(84 oF) to 23 oC (73 oF). 

was cleared the 16th floor door was closed and the fire floor door was opened. No smoke

was entering the stairwell with the MVU running (Figure 73-f). The smoke churned at 

the doorway, but did not enter the stairwell. Figure 73-g was taken 15 sec

M

back on and the smoke was forced back onto the fire floor (Figure 73-h). 

The thermal imaging Figures were captured during the same events as the video views

similar times. Figure 73-i shows the view prior to ignition with an ambient wall 

temperature of 16 o

C (60 oF). As the heat filled the hallway, the door became heated 

around the edges and heat began to flow into the south stairwell (Figure 73-j). 

Figure 73-k was captured when the fire floor door was opened and the hot gases were 

able to flow up the stairwell. The fire fighter is blocking the crosshairs of the camera, so

the estimated temperature in the field of view was that of his turnout gear. The MVU 

was started and the heat was forced out of the top of the stairwell and back onto the fire 

floor (Figure 73-l). The fa

T

Figure 73-a Figure 73-b

Figure 73-c Figure 73-d
Figure 73-e Figure 73-f

Figure 73-g Figure 73-h

Figure 73-i Figure 73-j

48
Figure 73-k Figure 73-l

Figure 73-m Figure 73-n

Figure 73. Visual and thermal imaging images captured during the experiment in apartment 1503. 

The video frame captured in the south stairwell before ignition of the experiment in 

apartment 1505 is in Figure 74-a. Smoke leaked around the door with one 0.7 m (27 in) 

fan placed at the base of the stairwell (Figure 74-b). A second 0.7 m (27 in) fan was 

added at the 13th floor and the smoke was vented out of the 16th floor doorway (Figure 

74-c). Figure 74-d shows that with two portable fans running the smoke was kept out of 

the stairwell with the fire floor door open 0.08 m (3 in). The door was then opened 

completely and the smoke was still kept out of the stairwell. The wall of smoke at the 

doorway is shown in fire 74-e. The door to floor 14 was opened and a little bit of smoke 

can be seen intermittently flowing into the stairwell (Figure 74-f). The smoke flow into 

the stairwell seen in Figure 74-g is a result of turning both fans off. Figure 74-h was 

captured 20 seconds after the fan on floor 13 was turned back on. The fan was turned off 

and the stairwell quickly filled with smoke again (Figure 74-i). Both fans were turned 

back on and the smoke was pushed back into the fire floor (Figure 74-j). 

The thermal imaging frames in Figures 74-k through 74-p show similar trends as the 

visual views. When the fans were on, the heat was kept out of the stairwell. When they 

were turned off, the heat flowed into the stairwell. The temperature of the concrete block 

wall did not change significantly during the experiment. 

49
Figure 74-a Figure 74-b

Figure 74-c Figure 74-d

Figure 74-e Figure 74-f

50
Figure 74-g Figure 74-h

Figure 74-i Figure 74-j

Figure 74-k Figure 74-l

51
Figure 74-m Figure 74-n

Figure 74-o Figure 74-p

Figure 74. Visual and thermal imaging images captured during the experiment in apartment 1505. 

Figure 75-a shows the doorway to the fire floor prior to ignition of the experiment in 

apartment 1003. After ignition but prior to the door being opened, the smoke enters the 

stairwell around the cracks of the door and a layer begins to form (Figure 75-b). The 

door on floor 10 was opened and the black smoke quickly began to fill the stairwell 

(Figure 75-c). The 16th floor door was opened and two 0.7 m (27 in) fans were turned on 

at floors 1 and 8. After less than 60 s, the stairwell was cleared of any smoke 

(Figure 75-d). The fans were turned off (Figure 75-e) and the smoke entered the 

stairwell. The fans were turned back on and the smoke was vented again. After 

ventilation the 16th floor door was closed, the fans were able to maintain a stairwell free 

of smoke (Figure 75-f). 

Figure 75-g was captured from the thermal imaging camera prior to ignition. Figure 75-h 

shows the heat layer developed after the fire floor doorway was opened. After one fan 

was turned on, the heat layer lifted slightly (Figure 75-i), but the heat flow into the 

stairwell stopped with the use of two fans (Figure 75-j). The fans were turned off in 

Figure 75-k. Both fans were turned back on and Figure 75-l was captured 10 s after they 

were turned on. This demonstrated how quickly the addition of pressure can stop the 

flow of heated gases into the stairwell. 

52
Figure 75-a Figure 75-b

Figure 75-c Figure 75-d

Figure 75-e Figure 75-f

53
Figure 75-g Figure 75-h

Figure 75-i Figure 75-j

Figure 75-k Figure 75-l

Figure 75. Visual and thermal imaging images captured during the experiment in apartment 1003. 

The Figures captured below were from the experiment in apartment 1005. Figure 76-a 

was captured prior to ignition. Figure 76-b shows the dense smoke conditions created by 

opening the fire floor door. The following frame shows the effect that the SVU had on 

the smoke flow. The 16th floor door was opened; therefore the smoke in the stairwell was 

forced up and out of the stairwell while the smoke on the fire floor was kept from 

entering the stairwell (Figure 76-c). Figure 76-d shows that the smoke barrier maintained 

well and prevented smoke from entering the stairwell through the rest of the experiment. 

The SVU was turned off and the smoke flowed back into the stairwell (Figure 76-e). 

54
Once the fire burned-down significantly, the SVU was turned back on and it was able to 

clear the hallway, all the way down to the fire apartment (Figure 76-f). 

The thermal imaging camera images were captured during the same events as the video 

views at similar times. Figure 76-g shows the conditions prior to ignition with an 

ambient wall temperature of 18 oC (64 oF). Figure 76-h was captured when the fire floor 

door was opened and the hot gases were able to flow up the stairwell. The thermal 

imaging temperature of the wall increased to 25 o

C (77 oF). The SVU was started and the 

heat was stopped from entering the stairwell (Figure 76-i). The fan was turned off 

(Figure 76-j) and back on (Figure 76-k). The heat was held at the fire floor doorway and 

the stairwell remained smoke-free and cool. 

Figure 76-a Figure 76-b

Figure 76-c Figure 76-d

55
Figure 76-e Figure 76-f

Figure 76-g Figure 76-h

Figure 76-i Figure 76-j

56
Figure 76-k 

Figure 76. Visual and thermal imaging images captured during the experiment in apartment 1005. 

Figure 77-a was captured prior to ignition of the experiment in apartment 303. Once the 

simulated wind was started utilizing the SVU smoke was forced into the stairwell through 

the cracks around and especially under the door (Figure 77-b). Even with the door closed 

visibility was greatly reduced in a matter of seconds (Figure 77-c). Figure 77-d was 

captured just after the door to the 3rd floor was opened. Figure 77-e shows the stairwell 

clearing of smoke with a fan on at floor 1 and at floor 5. The stairwell is actually cleared 

out but appears hazy due to the soot deposition on the camera lens. The camera lens was 

wiped off and then the fire floor doorway was opened 0.08 m (3 in) with one fan on at the 

base of the stairwell. This slowed the smoke flow into the stairwell down but did not 

completely stop it (Figure 77-f). A second fan was turned on at the 5th floor and the 

smoke was completely stopped (Figure 77-g). Figure 77-h shows the smoke flow into the 

stairwell with one fan on at the base of the south stairwell and the door to the fire floor 

completely open with a simulated wind condition through the fire apartment. Figure 77-i 

has the same setup but without the fan at the base of the stair turned on. Finally, Figure 

77-j shows the stairwell clear of smoke again after turning both portable fans back on. 

The thermal imaging Figures were captured during the same events as the video views at 

similar times. Figure 77-k shows the view prior to ignition with an ambient wall 

temperature of 17 o

C (62 oF). The SVU was turned on to simulate the wind condition and 

heat was flowing into the stairwell around all for sides of the door (Figure 77-l). Figure 

77-m was captured one second after the fire floor door was opened and the hot gases 

were able to flow into the stairwell. Figure 77-n was captured 5s after the door was 

opened and the heat quickly entered the stairwell, increasing temperatures. The door was 

opened halfway and the amount of heat entering the stairwell due to the wind forced flow 

caused the thermal image to become mostly white with little detail of the stairwell 

(Figure 77-o). The increase in temperature from 34 o

C (93 oF) to 181 oC (357 oF) was 

mainly due to the thermal imaging camera crosshairs aimed on the brick wall in the 

hallway once the door was opened half way. Conditions quickly changed once the door 

to the hallway was closed (Figure 77-p). One portable fan was turned on and the heat 

flow into the stairwell around the cracks of the door was slowed down, but was not 

completely stopped due to the wind pressures being greater (Figure 77-q). However, 

when two fans were turned on the heat was held completely on the fire floor (Figure 77-

57
r). With the fans off and the fire blanket deployed over the window, the heat flow into 

the stairwell decreased greatly (Figure 77-s). Figure 77-t shows two fans running and the 

fire blanket deployed. The combination of these two tactics forced the heat down the 

hallway toward the fire room. 

303

Figure 77-a Figure 77-b

Figure 77-c Figure 77-d

Figure 77-e Figure 77-f

58
Figure 77-g Figure 77-h

Figure 77-i Figure 77-j

Figure 77-k Figure 77-l

59
Figure 77-m Figure 77-n

Figure 77-o Figure 77-p

Figure 77-q Figure 77-r

60
Figure 77-s Figure 77-t

Figure 77. Visual and thermal imaging images captured during the experiment in apartment 303. 

Figures 78-a through 78-d show the visual video view during the experiment in apartment 

304. Figure 78-a shows the south stairwell fire floor doorway prior to ignition. After the 

simulated wind was started smoke was forced under the doorway (Figure 78-b). The fire 

floor door was opened 0.08 m (3 in) and seconds later the camera view was completely 

obscured (Figure 78-c). Once the door was closed, the SVU was started to ventilate and 

pressurize the south stairwell. The SVU was able to clear the stairwell and keep it clear, 

but this could not be visualized, because the video camera lens melted and left the view 

blurry (Figure 78-d). 

Figure 78-e was captured from the thermal imaging camera prior to ignition. Figure 78-f 

shows the heat being forced around the cracks of the doorway once the simulated wind 

was started. The door was opened slightly for one second and the heat poured into the 

stairwell (Figure 78-g). Ten seconds later the heat is flowing into the stairwell and the 

door jamb temperature increased from 55 oC (131 oF) to 145 oC (293 oF) (Figure 78h). 

Figure 78-i was captured seconds before the door was closed and Figure 78-j was 

captured seconds after the door was closed. This showed the importance of controlling 

the stairwell door under wind driven conditions in order to keep smoke and heat from 

entering the stairwell. Once the stairwell door was closed, the SVU was turned on at the 

front of the building and was able to keep the heat from the wind driven fire out of the 

stairwell (Figure 78-k). 

304

Figure 78-a Figure 78-b

61
Figure 78-c Figure 78-d

Figure 78-e Figure 78-f

Figure 78-g Figure 78-h

62
Figure 78-i Figure 78-j

Figure 78-k 

Figure 78. Visual and thermal imaging images captured during the experiment in apartment 304. 

63
Uncertainty Analysis 

There are different components of uncertainty in the length, differential pressure, gas 

temperature, heat flux, metrological, and carbon monoxide data reported here. 

Uncertainties are grouped into two categories according to the method used to estimate 

them. Type A uncertainties are those which are evaluated by statistical methods, and 

Type B are those which are evaluated by other means [12]. Type B analysis of 

systematic uncertainties involves estimating the upper (+ a) and lower (- a) limits for the 

quantity in question such that the probability that the value would be in the interval (± a) 

is essentially 100 %. After estimating uncertainties by either Type A or B analysis, the 

uncertainties are combined in quadrature to yield the combined standard uncertainty. 

Multiplying the combined standard uncertainty by a coverage factor of two results in the 

expanded uncertainty which corresponds to a 95 % confidence interval (2σ). 

Components of uncertainty are tabulated in Table 18. Some of these components, such as 

the zero and calibration elements, are derived from instrument specifications. Other 

components, such as differential pressure, include past experience with the instruments. 

Each length measurement was taken carefully. However due to some issues, such as 

obstructions and unleveled terrain there was a total expanded uncertainty of ± 6 % 

associated with the measurements. 

Differential pressure reading uncertainty components are derived from pressure 

transducer instrument specifications. The transducers were factory calibrated and the 

zero and span of each was checked in the laboratory prior to the experiments. 

The uncertainty in the gas temperature measurements includes radiative cooling in the 

each of the tests series, but also includes radiative heating for thermocouple located in the 

lower layer of the full-scale tests. Small diameter thermocouples were used to limit the 

impact of radiative heating and cooling. This resulted in an estimate of ±15 % total 

expanded uncertainty.

The potential for soot deposition on the face of the water-cooled total heat flux gauges 

contributed significant uncertainty to the heat flux measurements. Calibration of heat flux 

gauges was completed at lower fluxes and then extrapolated to higher values and this 

resulted in a higher uncertainty in the flux measurement. Combining all of component 

uncertainties for total heat flux resulted in a total expanded uncertainty of 

– 24 % to + 13 % for the flux measurements.

Weather, carbon monoxide and sound measurement uncertainty was referenced to each of 

their published user’s manuals. Weather and CO instruments have calibration certificates 

that are traceable to NIST standards. The carbon monoxide meters were factory 

calibrated prior to the experiments. The sound meter had a self-calibration setting. 

64
Table 18. Uncertainty Analysis 

Component 

Standard 

Uncertainty 

Combined 

Standard 

Uncertainty 

Total 

Expanded 

Uncertainty 

Length Measurements 

 Instrumentation 

 Locations 

 Fan Location 

 Building Dimensions 

 Repeatability1

 Random1

± 1 % 

± 1 % 

± 1 % 

± 2 % 

± 2 % 

± 3 % ± 6 % 

Differential Pressure 

 Calibration [13] 

 Accuracy [13] 

 Repeatability 1

 Random 1

± 2 % 

± 1 % 

± 3 % 

± 3 % 

± 5 % ± 10 % 

Gas Temperature – 

Lower Layer 

 Calibration[14] 

 Radiative Cooling 

 Radiative Heating 

 Repeatability 1 

 Random 1 

± 1 % 

- 5 % to + 0 % 

- 0 % to + 5 % 

± 5 % 

± 3 % 

± 8 % ± 15 % 

Total Heat Flux 

 Calibration 

 Zero 

 Soot Deposition 

 Repeatability 1 

 Random 1 

± 3 % 

± 2 % 

- 10% to + 0 % 

± 5 % 

± 3 % 

- 12 % to + 7 % - 24 % to + 13 %

Weather Measurements 

 Temperature[15] 

 Relative Humidity 

 Average Wind Speed 

 Wind Direction 

 Barometric Pressure 

 Repeatability1

 Random1

± 2 % 

± 2 % 

± 1 % 

± 1 % 

± 0.003 % 

± 1 % 

± 1 % 

± 3 % ± 6 % 

Carbon Monoxide 

Measurements 

 Calibration[16] 

 Accuracy[16] 

 Repeatability1

 Random1

± 1 % 

± 0.002 % 

± 2 % 

± 2 % 

± 2 % ± 4 % 

65
Sound Measurements 

 Calibration[17] 

 Accuracy[17] 

 Repeatability1

 Random1

± 1 % 

± 3 % 

± 2 % 

± 2 % 

± 4 % ± 8 % 

Notes: 1. Random and repeatability evaluated as Type A, other components as Type B. 

Discussion 

For this limited series of experiments, the fans and their locations were determined by the 

previous series of pressure experiments [8]. One experiment on each of the fire floors 

utilized portable fans and the other utilized a large truck (MVU) or trailer mounted 

(SVU) fan. All of the experiments created high temperatures and dense smoke conditions 

in the hallway. Numerous configurations were used during the experiments and the 

ability of the fans to keep smoke out of the stairwell was analyzed. The minimum design 

pressures of NFPA 92A were used as baselines to compare to the actual pressures 

measured. 

This building was unsprinklered, therefore an attempt was made to obtain a minimum 

pressure of 25 Pa in the stairwell, in the area of the fire floor for all the experiments. 

Numerous scenarios were examined by changing fan placement and the location and 

number of open doors (Table 19). The scenarios in gray in Table 2 indicate that smoke 

was visualized entering the stairwell. The other events had no smoke entering the 

stairwell. Fire floor pressures are in brackets and shown in bold. Many configurations 

had the door to the fire floor partially or fully open. In these events, there was no 

differential pressure, so the fire floor pressure was estimated by examining the pressures 

at the floors above and below the fire floor. Many of the configurations that were 

successful in prohibiting smoke infiltration into the stairwell had pressures significantly 

below 25 Pa. The lowest pressure on a fire floor that was able to keep smoke out of the 

stairwell was 9 Pa. The maximum temperatures recorded in the south end of the hallway 

adjacent to the stairwell door ranged between 100 o

C and 300 oC. Utilizing the 100 oC 

and 300 oC gas temperature in the equation provided in NFPA 92A to determine the 

pressure difference due to buoyancy of hot gases yields pressures of 4.1 Pa and 9.3 Pa 

respectively. This limited data from this practical set of configurations suggests that this 

correlation is consistent for estimating the pressure required to stop smoke spread. 

This analysis only focused on the events that had no smoke entering the stairwell. Many 

of the configurations had very little smoke entering the stairwell due to the pressure 

increase. Pressurizing the stairwell always had a positive effect on the conditions in the 

stairwell. If the stairwell was not vented and only pressurized the heat and smoke flow 

into the stairwell was either stopped or at least slowed down improving the conditions in 

the stairwell. The fans never increased the amount of smoke able to flow into the 

stairwell. 

66
Table 19. Experimental Events Indicating when Smoke was in the Stairwell 

Experiment Events 

1503 

MVU (16 Open) 

[>25 Pa]

MVU (16 

Closed) [>25 Pa]

MVU (15 Open 

0.08 m) [>25 Pa]

MVU (15 Open)

[13 Pa] MVU Off [4 Pa]

1503 (Cont.) 

MVU (15 Open) [2] 

[13 Pa] 

1505 

27 on Floor 1 [8 Pa] 27 on Floor 1 

(16 open) [3 Pa]

27 on Floors 1 and 

13 (16 open) [10 

Pa]

27 on Floors 1 and 

13 [21 Pa]

27 on Floors 1 and 13 

(15 open 0.08 m) 

[16 Pa]

1505 (Cont.) 

27 on Floors 1 and 13 

(15 open) [14 Pa]

27 on Floors 1 

and 13 (15 and 

14 open) [7 Pa]

Fans off [3 Pa] 27 on Floor 13 (1 

closed) [12 Pa]

27 on Floor 1 (15 

Open) [4 Pa]

1505 (Cont.) 

27 on Floors 1 and 13 

(15 Open) [13 Pa]

1003 27 on Floor 1 (10 and 

16 Open) [3 Pa]

27 on Floors 1 

and 8 (10 / 16 

Open) [10 Pa]

27 on Floors 1 and 8 

(10 Open, CS 

Press.) [16 Pa]

27 on Floor 8 (10 

Open) 

[22 Pa]

Fans Off [2 Pa]

1005 SVU (10 and 16 Open) 

[11 Pa]

SVU (10 Open) 

[>25 Pa]

SVU (10 and 1(CS) 

Open) [19 Pa]

SVU (10, 

1(CS),16 (CS) 

Open) [13 Pa]

SVU idle [4 Pa]

1005 (Cont.) SVU (10 and 1(CS) 

Open) [12 Pa]

SVU (10 Open) 

[20 Pa]

303 Wind [0 Pa]

Wind (3 Open) 

[0 Pa]

Wind (3 and 16 

Open) [0 Pa]

27 on Floor 1 

(Wind) [2 Pa]

27 on Floors 1 and 5 

(Wind) [5 Pa]

303 (Cont.) Fans Off (Wind) 

[0 Pa]

Fire Blanket 

Deployed [0 Pa]

3 Open (Fire 

Blanket) [0 Pa]

27 on Floor 1 (16 

Open) [11 Pa]

27 on Floor 1 (16 

Open, 3 Open 0.08m) 

[2 Pa]

303 (Cont.) 27 on Floor 1 (16 

Open) [2] [9 Pa]

27 on Floor 1 [2] 

[10 Pa]

27 on Floor 1 (3 

Open 0.08m) 

[15 Pa] 

27 on Floor 1 [3] 

[15 Pa]

27 on Floor 1 (16 

Open) [3] [10 Pa]

303 (Cont.) 

27 on Floors 1 and 5 

[>25 Pa] 

27 on Floors 1 

and 5 (3 Open 

0.08m) [20 Pa]

27 on Floor 1 (3 

Open) 

[18 Pa]

304 Wind [ 0 Pa]

Wind (3 Open) 

[0 Pa]

Wind (3 and 16 

Open) [0 Pa]

Wind (16 Open) 

[0 Pa] 

SVU (Wind and 16 

Open) [8 Pa]

304 (Cont.) SVU (Wind) [>25 Pa]

MVU – 1.2 m hydraulic powered Truck mounted fan, SVU – 1.3 m gasoline powered Trailer mounted fan, 27 – 0.7m portable fan, ( ) – 

indicates door position, [ ] – Fire floor stairwell pressure 

Typically a fixed stairwell pressurization system will only be installed in a building with 

a sprinkler system so that the fire is contained and the introduction of more oxygen will 

have minimal effects. A concern with the use of PPV fans is the ability of the fans to 

provide oxygen to the fire. This is possible but it is also controllable. Initially the 

stairwell can be cleared of smoke by having all of the stairwell doors closed and the roof 

vent or bulkhead door opened (Figure 79a). This tactic provides no fresh air to an 

apartment fire off of the hallway. Once the vent is closed and the stairwell is adequately 

pressurized, no smoke is able to enter the stairwell and the flow from the fan is able to go 

through the cracks around the fire floor doorway but none of the air has enough pressure 

behind it to readily make it all the way to the fire apartment (Figure 79b). Once the door 

to the fire floor is opened by advancing fire fighters a pressure balance or critical air 

velocity to prevent smoke backflow must occur to keep smoke out of the stairwell (Figure 

79c). Ideally this critical air velocity would keep smoke out of the stairwell but not 

supply oxygen to the fire (Figure 79d). The results from these experiments indicate that 

this was achieved by the barriers of smoke that were visualized at the fire floor stairwell 

door and the lack of increase in fire intensity or smoke spread out of the vent window of 

the fire apartment. However more research needs to be conducted to determine the 

impact of diluted smoke being pushed back towards the source of the fire by the fan on 

the fire size (Figure 79e). The effect of fresh air being provided to a fire by PPV fans has 

67
been studied [18] but the introduction of diluted smoke to the fire for a period of time 

prior to the introduction of fresh air needs to be further researched. 

The portable fans were able to vent through the fire apartment but only after the fire had 

burned down significantly allowing the flow to over-pressurize what was created by the 

fire. The mounted fans were able to create a flow through the fire apartment even when 

the fire was at its peak output. This was able to be limited by at least two ways, turn 

down the speed of the fan or allow the fan to pressurize a larger volume. An example of 

the larger volume is opening an additional stairwell or opening a floor below the fire 

floor. An advantage of the larger mounted fan is that it can pressurize multiple stairwells 

from the front of the building whereas two portable fans were required for each stairwell 

that needed to be pressurized. If limiting the air to the fire is not the priority and the 

priority is creating visibility in the hallway to the fire apartment then the larger fans were 

effective at clearing fire gases to the fire apartment door if the fire apartment was vented 

to the outside of the structure. 

Temperatures in the fire apartments peaked at approximately 800 oC. The temperature in 

the entire hallway peaked between 100 o

C and 300 oC at the ceiling level and 100 oC and 

150 oC at 0.91 m above the floor. Heat fluxes in the fire apartment peaked at 

81.0 kW/m2. The peak heat fluxes in the hallway ranged between 1.9 kW/m2 and 

6.3 kW/m2

 depending on the location of the gauges in relation to the fire apartment. The 

CO levels on the fire floors for all of the experiments quickly exceeded the 800 ppm 

(0.008 %) maximum on the gas monitors. Stairwell CO levels dropped below 200 ppm 

(0.002 %) during ventilation. The average temperatures remained fairly constant during 

all of the experiments. Temperatures ranged between 11 oC (52 oF) and 17 oC (63 oF). 

The outside temperatures remained constant during the experiments and were comparable 

to the interior stairwell temperatures which minimized the stack effect. 

Wind speed has the potential to greatly impact the effectiveness of PPV. The average 

wind speed remained below 3.6 m/s (8.0 mph) and was mostly below 2.0 m/s (4.5 mph) 

during the experiments. The wind appeared to have little impact on the experimental 

results. When there was wind there were no gusts that would impact one experiment over 

another experiment. The wind was mainly out of the south which had little impact of the 

flows into the ground floor or out of the vents which were both located on the east side of 

the building. The south stairwell was also interior to the building which lessened the 

impact of any wind. 

One of the main toxic gases in combustion is carbon monoxide (CO). When examining 

PPV and preventing smoke infiltration there are two types of combustion that are 

important, the fire creating the smoke and the internal combustion of the fan motor. Both 

sources of CO must be monitored to maintain a safe environment for occupants as well as 

fire fighters. 

A fire has the potential to produce a very large amount of CO. This amount could be on 

the order of 50,000 ppm (5 %) in an under-ventilated fire [19]. Tenability limits for 

incapacitation and death for a 5 minute exposure are 6000 ppm (0.6 %) to 8000 ppm 

(0.8 %) and 12,000 (1.2 %) to 16,000 ppm (1.6 %) respectively. CO is the ultimate major 

cause of death in fires. Using PPV fans to keep the CO produced by the fire along with 

68
the other harmful combustion products out of the stairwells greatly increases the chances 

of safe evacuation. 

The internal combustion of a gasoline fan engine also produces CO. While the levels are 

much lower than the fire they have to be analyzed. CO meters were placed in both 

stairwells to monitor the fans impact on CO levels. The National Institute of 

Occupational Safety and Health (NIOSH) has established a recommended exposure limit 

for CO of 35 ppm (0.0035 %) as an 8-hour time weighted average (TWA) and 200 ppm 

(0.02 %) as a ceiling exposure [20]. A reading of 1200 ppm (0.12 %) is considered 

immediately dangerous to life and health (IDLH). The National Research Council (NRC) 

also defines emergency exposure guidance levels of, 1500 ppm (0.15 %) for 10 minutes, 

800 ppm (0.08 %) for 30 minutes, 400 ppm (0.04 %) for 60 minutes and 50 ppm (0.005 

%) for 24 hours [21]. 

Without the use of the fans the CO levels in the hallway and in the south stairwell during 

the fire almost always reached above the range of the meters. While this peak was 

around 800 ppm (0.08 %) it is conservative to say that many of the meter locations 

exceeded the IDLH threshold. In most cases, the use of the fans to vent the stairwell and 

to pressurize the stairwell to reduce smoke and CO levels allowed the CO levels to 

decrease from IDLH conditions to less than 200 ppm (0.02 %). Ultimately the CO 

produced by the PPV fans was at least one order of magnitude less than that created by 

the fire. 

Both experiments on the third floor included a wind driven fire. It was quickly observed 

and supported by the data that a wind directed into the window of a fire apartment can 

have a significant impact on the speed and severity of fire growth. Conditions in the 

hallway changed from tenable to untenable so rapidly that a person in the hallway would 

have had trouble escaping the flow path, even in full personal protective equipment. The 

following tactical considerations were identified. 

1) Controlling the door to either the fire apartment or stairwell can provide a safer area 

of refuge out of the direct flow path of fire gases. 

2) A warning sign that a wind driven fire condition exists is the continuous forceful push 

of hot smoke from under the stairwell door at the fire floor. 

3) If visibility is lost and a thermal imaging camera is available and the entire door 

appears hot, then proceed with caution. 

4) If attempting to open the door, fire fighters should make sure that they have the ability 

to close the door quickly if, in fact, there is a wind driven condition. 

5) The use of PPV fans to improve tenability in the stairwell during a wind driven fire 

was also effective but more research is needed to understand the benefits and limitations 

of this approach. 

A fire blanket was used to minimize the impact of the wind on an apartment fire. Prior to 

the use of the blanket during the fire, the simulated wind speed was approximately 11 m/s 

(25 mph). The blanket was deployed over the window and the measurable wind speed 

69
inside the structure decreased to less than 0.4 m/s (1 mph). When used during the fire 

experiment, the fire blanket eliminated the wind driven effects on the fire. While the 

blanket proved to be a viable alternative tactic, more research needs to be conducted on 

its full capabilities. The blankets should be deployed on larger fuel loads, different wind 

speeds and various wind angles to further determine the blanket’s abilities and 

limitations. 

70
a) 

b) 

c) 

d) 

e) 

Figure 79. Diagrams for process of providing oxygen to the fire

71
Conclusions 

This set of experiments examined the impact of positive pressure ventilation on smoke 

and heat spread from a post flashover fire in an apartment with a furnished living room. 

Both the portable fans and the mounted fans were able to create pressures to remove the 

smoke from and keep the target stairwell free of smoke under numerous conditions. The 

pressures measured during these experiments agreed with the correlation provided in 

NFPA 92A for using pressure difference as a smoke barrier. 

The mounted fans positioned at the front of the structure were able to clear the stairwell 

quickly when vented and were able to keep smoke out of the entire stairwell with the fire 

floor door open. The mounted fans were also able to clear the smoke all the way back 

out of the fire apartment past the fire and through an open rear window. This was not the 

intent of the experiments so no measurements were taken on the effect of oxygen 

supplied to the fire or spread to target rooms. In order to keep from over pressurizing and 

flowing air through the fire apartment, a second stairwell was opened and the mounted 

fans were able to keep that second stairwell free of smoke as well. Other successful ways 

to keep the stairwells free of smoke without providing oxygen to the fire apartment were 

to add volume by opening additional floors below the fire floor or to decrease the speed 

of the fan. 

The portable fans were also effective at ventilating the 16-story stairwell and keeping it 

free of smoke while pressurizing. In most cases the single portable fan at the base of the 

stairwell improved conditions in the stairwell. The increased pressures greatly reduced 

the amount of smoke that was able to flow into the stairwell under natural ventilation 

conditions. When a second fan was added two floors below the fire floor smoke was kept 

completely out of the stairwell, even with the fire floor door open or with an additional 

door open. 

The creation of a simulated wind driven fire demonstrated how quickly conditions can 

change and how a room and contents fire can become a “blow torch” out into the public 

hallway and into the stairwells. Fire fighters need to appreciate this potential, especially 

in high-rise buildings because the time to seek an area of refuge is on the order of 

seconds before conditions become untenable. Alternative techniques to prevent a wind 

driven condition or minimize its impact such as PPV and fire blankets, showed excellent 

potential in these experiments. Further experiments and research are needed to confirm 

this for other configurations. 

Positive pressure ventilation fans utilized correctly can increase the effectiveness of fire 

fighters and survivability of occupants in high-rise buildings. In a high-rise building it is 

possible to increase the pressure of a stairwell to prevent the infiltration of smoke, if fire 

crews configure the fans properly. When configured properly PPV fans can meet or 

exceed previously established performance guidelines for fixed smoke control systems. 

Proper configuration requires the user to consider a range of variables, including, fan 

size, set back, and angle, fan position inside or outside of the building, and number and 

alignment of multiple fans. 

72
Acknowledgements 

The authors would like to thank Roy McLane, Robert Vettori, Nelson Bryner, Jack Lee, 

Jay McElroy, Michael Selepak and Michael Malloy of the Building and Fire Research 

Laboratory for their invaluable support during the preparation and implementation of the 

experimental series. The authors would also like to thank Mayor Richard M. Daley from 

the City of Chicago, Commissioner Ray Orozco, Director of Training Richard 

Edgeworth, Battalion Chief Peter VanDorpe, Lieutenant Patty Lynch and the instructors 

and Firefighter/EMT’s of Candidate Classes May 1, 2006 and August 16, 2006 of the 

Chicago Fire Department for inviting NIST to participate and the endless support they 

provided. Special thanks to Battalion Chief Jerry Tracy, Chief of Training Thomas 

Galvin, Battalion Chief George Healy and Lieutenant John Ceriello from the Fire 

Department of New York, Assistant Chief John Coleman of the Toledo Fire Department 

and Captain Peter McBride of the Ottawa Fire Services for their guidance and assistance 

during the experiments. Appreciation is also extended to Underwriter’s Laboratory, 

Illinois Fire Service Institute and the Bureau of Alcohol Tobacco Fire Arms and 

Explosives for help in performing and documenting the experiments. Tempest, SuperVac 

and Euramco supplied resources and provided technical support in order to make the 

experiments possible. Finally, the authors express gratitude to the Department of 

Homeland Security and Mr. Randall Griffin for their sponsorship and support of this 

important and ongoing research. 

References 

1. Hall Jr., John. High-rise Building Fires. NFPA, Quincy, MA. August 2005. 

2. Daly, James D., Healy, George. “Wind-Driven Queens Fire Provokes Several 

Maydays.” WNYF, 3rd/2006. 

3. “Three fire fighters die in a 10-story high-rise apartment building – New York.” 

National Institute for Occupational Safety and Health, 99-F01. 

4. “High-rise apartment fire claims life of one career fire fighter (Captain) and injures 

another career fire fighter (Captain) – Texas.” National Institute for Occupational 

Safety and Health, F2001-33. 

5. NFPA 5000. Building Construction and Safety Code. 2006 Edition. 

6. NFPA 92A. Standard for Smoke-Control Systems Utilizing Barriers and Pressure 

Differences. 2006 Edition. 

7. Hall, R. and Adams, B., Eds, Essentials of Fire Fighting, 4th ed., Oklahoma State 

University, Stillwater, OK, 1998, 716p. 

73
74

8. Kerber, S., Madrzykowski, D., Stroup, D. “Evaluating Positive Pressure 

Ventilation In Large Structures: High-Rise Pressure Experiments.” National 

Institute of Standards and Technology, NISTIR 7412, 2007. 

9. Super Vacuum Manufacturing Company, Inc, http://www.supervac.com. July 2007. 

10. Tempest Technology Corporation, http://www.tempest-edge.com, January 2003. 

11. ISG Thermal Systems USA, Inc. K1000 ELITE Operating Manual. 2005.

12. Taylor, B. N. and C. E. Kuyatt, Guidelines For Evaluating and Expressing the 

Uncertainty of NIST Measurement Results. National Institute of Standards and 

Technology (U.S.) NIST-TN 1297; September, 20 p. 1994. 

13. Setra Systems, Inc., Installation Guide, Setra Systems Model 264 Differential 

Pressure Transducer. Boxborough, MA., 1999. 

14. Omega Engineering Inc., The Temperature Handbook, Vol. MM, pages Z-39-40, 

Stamford, CT., 2004. 

15. Weatherpak – 2000 User’s Manual. Coastal Environmental Systems. December 9, 

1997. 

16. Q-RAE Multi-gas Monitor. Operational and Maintenance Manual. Document 

No.:027-4001-000, Rev. B. May 2005. 

17. Sound Meter 84005 Instruction Manual. Sper Scientific Ltd. May 11, 2005. 

18. Kerber, S., Walton, D. “Effect of Positive Pressure Ventilation on a Room Fire.” 

National Institute of Standards and Technology, NISTIR 7213, 2005. 

19. Purser, David. “Toxicity Assessment of Combustion Products.” The SFPE 

Handbook of Fire Protection Engineering, National Fire Protection Association, 

Quincy, MA, Third Edition (2002). 

20. NIOSH [1992]. Recommendations for occupational safety and health: Compendium 

of policy documents and statements. Cincinnati, OH: U.S. Department of Health 

and Human Services, Public Health Service, Centers for Disease Control, National 

Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 92-

100. 

21. NRC [1987]. Emergency and continuous exposure guidance levels for selected 

airborne contaminants. Vol. 7. Ammonia, hydrogen chloride, lithium bromide, and 

toluene. Washington, DC: National Academy Press, Committee on Toxicology, 

Board on Toxicology and Environmental Health Hazards, Commission on Life 

Sciences, National Research Council, pp. 17-38. 
Appendix A. Dimensioned Drawings 

Figure 1. Front elevation 

A-1
Figure 2. Overall dimensions with stair detail 

A-2
Figure 3. Structure location and exposures 

A-3
Figure 4. Hallway and stair instrument locations 

IR – Thermal Imaging CameraV – Video Camera HF – Heat Flux Gauge P – Pressure Transducer CO – Carbon Monoxide Meter TC – Thermocouple Array 

A-4
Figure 5. Apartment 1503 dimensions and instrument locations 

A-5
Figure 6. Apartment 1505 dimensions and instrument locations 

A-6
Figure 7. Apartment 1003 dimensions and instrument locations 

A-7
Figure 8. Apartment 1005 dimensions and instrument locations 

A-8
Figure 9. Apartment 303 dimensions and instrument locations 

A-9
Figure 10. Apartment 304 dimensions and instrument locations 

A-10
Appendix B. Detailed Data for Apartment 1503 

0

200400600800

1000

0 500 1000 1500 2000 2500 3000 3500

Figure 1. Detailed temperature vs. time for 1503 living room 1503 2.13 m 1503 1.83 m 1503 1.52 m 1503 1.22 m 1503 0.91 m 1503 0.61 m 1503 0.30 m 1503 0.03 m

Temperature (oC)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-1
0

200400600800

1000

0 500 1000 1500 2000 2500 3000 3500

Figure 2. Detailed temperature vs. time for 1503 hallway adjacent to the south stair Hall SS 2.13 m Hall SS 1.83 m Hall SS 1.52 m Hall SS 1.22 m Hall SS 0.91 m Hall SS 0.61 m Hall SS 0.30 m Hall SS 0.03 m

Temperature (oC)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-2
0

200400600800

1000

0 500 1000 1500 2000 2500 3000 3500

Figure 3. Detailed temperature vs. time for 1503 middle hallway Hall Mid 2.13 m Hall Mid 1.83 m Hall Mid 1.52 m Hall Mid 1.22 m Hall Mid 0.91 m Hall Mid 0.61 m Hall Mid 0.30 m Hall Mid 0.03 m

Temperature (oC)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-3
0

200400600800

1000

0 500 1000 1500 2000 2500 3000 3500

Figure 4. Detailed temperature vs. time for 1503 hallway adjacent to the center stair Hall CS 2.13 m Hall CS 1.83 m Hall CS 1.52 m Hall CS 1.22 m Hall CS 0.91 m Hall CS 0.61 m Hall CS 0.30 m Hall CS 0.03 m

Temperature (oC)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-4
0

50

100150200

0 500 1000 1500 2000 2500 3000 3500

Figure 5. Detailed temperature vs. time for 1503 south stair TCFloor1 TCFloor2 TCFloor3 TCFloor4 TCFloor5 TCFloor6 TCFloor7 TCFloor8 TCFloor9 TCFloor10 TCFloor11 TCFloor12 TCFloor13 TCFloor14 TCFLoor15 TCFloor16

Temperature (oC)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-5
0

50

100150

0 500 1000 1500 2000 2500 3000 3500

Figure 6. Detailed pressure vs. time for 1503 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13 Pressure 14 Pressure 15

Pressure 16

Pressure (Pa)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-6
0

1020304050

0 500 1000 1500 2000 2500 3000 3500

Figure 7. Detailed heat flux vs. time for 1503 Hall CS Horz Hall CS Vert Hall Mid Horz

Hall Mid VertHall SS VertFireHorz

FireVert

Heat Flux (kW/m2)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated

B-7
0

200400600800

1000

0 500 1000 1500 2000 2500 3000 3500

B-8

Figure 8. Detailed carbon monoxide vs. time for 1503 Hall CS Hall Mid Hall SS Floor 16 Stairwell

Floor 15 Stairwell

Carbon Monoxide (ppm)

Time (s)

15 Open

16 Open

FF Crew In

MVU Off

Gyp. Removed

16 Closed

2 Chairs on Sofa

15 Closed

16 Open

MVU Started

MVU 1800 rpm

16 Closed

15 Open (0.08 m)

15 Open

MVU 1800 rpm

Exp. Terminated
Appendix C. Detailed Data for Apartment 1505 

0

200400600800

1000

0 500 1000 1500 2000 2500

Figure 1. Detailed temperature vs. time for 1505 living room 1505 2.13 m 1505 1.83 m 1505 1.52 m 1505 1.22 m 1505 0.91 m 1505 0.61 m 1505 0.30 m 1505 0.03 m

Temperature (oC)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-1
0

200400600800

1000

0 500 1000 1500 2000 2500

Figure 2. Detailed temperature vs. time for 1505 hallway adjacent to the south stair Hall SS 2.13 m Hall SS 1.83 m Hall SS 1.52 m Hall SS 1.22 m Hall SS 0.91 m Hall SS 0.61 m Hall SS 0.30 m Hall SS 0.03 m

Temperature (oC)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-2
0

200400600800

1000

0 500 1000 1500 2000 2500

Figure 3. Detailed temperature vs. time for 1505 middle hallway Hall Mid 2.13 m Hall Mid 1.83 m Hall Mid 1.52 m Hall Mid 1.22 m Hall Mid 0.91 m Hall Mid 0.61 m Hall Mid 0.30 m Hall Mid 0.03 m

Temperature (oC)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-3
0

200400600800

1000

0 500 1000 1500 2000 2500

Figure 4. Detailed temperature vs. time for 1505 hallway adjacent to the center stair Hall CS 2.13 m Hall CS 1.83 m Hall CS 1.52 m Hall CS 1.22 m Hall CS 0.91 m Hall CS 0.61 m Hall CS 0.30 m Hall CS 0.03 m

Temperature (oC)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-4
0

50

100150200

0 500 1000 1500 2000 2500

Figure 5. Detailed temperature vs. time for 1505 south stair TCFloor1 TCFloor2 TCFloor3 TCFloor4 TCFloor5 TCFloor6 TCFloor7 TCFloor8 TCFloor9 TCFloor10 TCFloor11 TCFloor12 TCFloor13 TCFloor14 TCFLoor15 TCFloor16

Temperature (oC)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-5
0

1020304050

0 500 1000 1500 2000 2500

Figure 6. Detailed pressure vs. time for 1505 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13 Pressure 14 Pressure 15

Pressure 16

Pressure (Pa)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-6
0

1020304050

0 500 1000 1500 2000 2500

Figure 7. Detailed heat flux vs. time for 1505 Hall CS Horz Hall CS Vert Hall Mid Horz Hall Mid Vert

Hall SS VertFireHorzFireVert

Heat Flux (kW/m2)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated

C-7
0

200400600800

1000

0 500 1000 1500 2000 2500

C-8

Figure 8. Detailed carbon monoxide vs. time for 1505 Floor 15 Center Stairwell Hall Mid Hall SS Floor 16 Stairwell

Floor 15 Stairwell

Carbon Monoxide (ppm)

Time (s)

16 Open

16 Closed

14 Closed

14 Open

Both Fans Off

1 Closed

15 Open (0.08 m)

15 Open

Fan on @ 13 (27)

Fan on @ 1 (27)

13 Open

13 Open

Fan on @ 13 (27)

Fan off @ 13 

13 Closed

1 Open

Fan on @ 1 (27)

13 Open

Fan on @ 13 (27)

Exp. Terminated
Appendix D. Detailed Data for Apartment 1003 

0

200400600800

1000

0 500 1000 1500

Figure 1. Detailed temperature vs. time for 1003 living room 1003 2.13 m 1003 1.83 m 1003 1.52 m 1003 1.22 m 1003 0.91 m 1003 0.61 m 1003 0.30 m 1003 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-1
0

200400600800

1000

0 500 1000 1500

Figure 2. Detailed temperature vs. time for 1003 hallway adjacent to the south stair Hall SS 2.13 m Hall SS 1.83 m Hall SS 1.52 m Hall SS 1.22 m Hall SS 0.91 m Hall SS 0.61 m Hall SS 0.30 m Hall SS 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-2
0

200400600800

1000

0 500 1000 1500

Figure 3. Detailed temperature vs. time for 1003 middle hallway Hall Mid 2.13 m Hall Mid 1.83 m Hall Mid 1.52 m Hall Mid 1.22 m Hall Mid 0.91 m Hall Mid 0.61 m Hall Mid 0.30 m Hall Mid 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-3
0

200400600800

1000

0 500 1000 1500

Figure 4. Detailed temperature vs. time for 1003 hallway adjacent to the center stair Hall CS 2.13 m Hall CS 1.83 m Hall CS 1.52 m Hall CS 1.22 m Hall CS 0.91 m Hall CS 0.61 m Hall CS 0.30 m Hall CS 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-4
0

50

100150200

0 500 1000 1500

Figure 5. Detailed temperature vs. time for 1003 south stair TCFloor1 TCFloor2 TCFloor3 TCFloor4 TCFloor5 TCFloor6 TCFloor7 TCFloor8 TCFloor9 TCFloor10 TCFloor11 TCFloor12 TCFloor13 TCFloor14 TCFLoor15 TCFloor16

Temperature (oC)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-5
0

1020304050

0 500 1000 1500

Figure 6. Detailed pressure vs. time for 1003 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13 Pressure 14

Pressure 15Pressure 16

Pressure (Pa)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-6
0

1020304050

0 500 1000 1500

Figure 7. Detailed heat flux vs. time for 1003 Hall CS Horz Hall CS Vert Hall Mid Horz

Hall Mid VertHall SS VertFireHorz

FireVert

Heat Flux (kW/m2)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated

D-7
0

200400600800

1000

0 500 1000 1500

D-8

Figure 8. Detailed carbon monoxide vs. time for 1003 Hall Mid

Floor 10 Stairwell

Carbon Monoxide (ppm)

Time (s)

10 Open

16 Open

Fan on @ 1 (27)

8 Open

Fan on @ 8 (27)

16 Closed

1 Open (CS)

Fan on @ 1 (CS) (24)

9 Open (CS)

Fan on @ 9 (CS) (24)

16 Open (CS)

Fan off @ 1 (CS) (24)

Fan off @ 1 (27)

Fan off @ 9 (CS) (24)

9 Closed (CS)

Fan off @ 8 (27)

8 Closed

Fan on @ 1 (27)

16 Open

Overhaul Initiated

Exp. Terminated
Appendix E. Detailed Data for Apartment 1005 

0

200400600800

1000

0 500 1000 1500 2000

Figure 1. Detailed temperature vs. time for 1005 living room 1005 2.13 m 1005 1.83 m 1005 1.52 m 1005 1.22 m 1005 0.91 m 1005 0.61 m 1005 0.30 m

1005 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-1
0

200400600800

1000

0 500 1000 1500 2000

Figure 2. Detailed temperature vs. time for 1005 hallway adjacent to the south stair Hall SS 2.13 m Hall SS 1.83 m Hall SS 1.52 m Hall SS 1.22 m Hall SS 0.91 m Hall SS 0.61 m Hall SS 0.30 m Hall SS 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-2
0

200400600800

1000

0 500 1000 1500 2000

Figure 3. Detailed temperature vs. time for 1005 middle hallway Hall Mid 2.13 m Hall Mid 1.83 m Hall Mid 1.52 m Hall Mid 1.22 m Hall Mid 0.91 m Hall Mid 0.61 m Hall Mid 0.30 m Hall Mid 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-3
0

200400600800

1000

0 500 1000 1500 2000

Figure 4. Detailed temperature vs. time for 1005 hallway adjacent to the center stair Hall CS 2.13 m Hall CS 1.83 m Hall CS 1.52 m Hall CS 1.22 m Hall CS 0.91 m Hall CS 0.61 m Hall CS 0.30 m Hall CS 0.03 m

Temperature (oC)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-4
0

50

100150200

0 500 1000 1500 2000

Figure 5. Detailed temperature vs. time for 1005 south stair TCFloor1 TCFloor2 TCFloor3 TCFloor4 TCFloor5 TCFloor6 TCFloor7 TCFloor8 TCFloor9 TCFloor10 TCFloor11 TCFloor12 TCFloor13 TCFloor14 TCFLoor15

TCFloor16

Temperature (oC)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-5
0

20406080

100

0 500 1000 1500 2000

Figure 6. Detailed pressure vs. time for 1005 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13

Pressure 14Pressure 15

Pressure 16

Pressure (Pa)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-6
0

20406080

100

0 500 1000 1500 2000

Figure 7. Detailed heat flux vs. time for 1005 Hall CS Horz Hall CS Vert Hall Mid Horz

Hall Mid VertHall SS VertFireHorz

FireVert

Heat Flux (kW/m2)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)

E-7
0

200400600800

1000

0 500 1000 1500 2000

E-8

Figure 8. Detailed carbon monoxide vs. time for 1005 Hall Mid Floor 10 Stairwell

Carbon Monoxide (ppm)

Time (s)

10 Open

16 Closed

16 Open (CS)

Exp. Terminated

16 Open

Overhaul

SVU On

1 Open (CS)

16 Closed (CS)

SVU On 

SVU Off 

SVU On 

1 Closed (CS)
Appendix F. Detailed Data for Apartment 303 

Figure 1. Detailed temperature vs. time for 303 living room 

0

200400600800

1000

0 500 1000 1500 2000 2500

303 2.13 m303 1.83 m303 1.52 m303 1.22 m303 0.91 m303 0.61 m303 0.30 m303 0.03 m

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-1
Figure 2. Detailed temperature vs. time for 303 hallway adjacent to the south stair 

0

200400600800

1000

0 500 1000 1500 2000 2500

303 BR 2.13 m303 BR 1.83 m303 BR 1.52 m303 BR 1.22 m303 BR 0.91 m303 BR 0.61 m303 BR 0.30 m

303 BR 0.03 m

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-2
Figure 3. Detailed temperature vs. time for 303 hallway adjacent to the south stair 

0

200400600800

1000

0 500 1000 1500 2000 2500

Hall SS 2.13 mHall SS 1.83 mHall SS 1.52 mHall SS 1.22 mHall SS 0.91 mHall SS 0.61 mHall SS 0.30 m

Hall SS 0.03 m

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-3
Figure 4. Detailed temperature vs. time for 303 middle hallway 

0

200400600800

1000

0 500 1000 1500 2000 2500

Hall Mid 2.13 mHall Mid 1.83 mHall Mid 1.52 mHall Mid 1.22 mHall Mid 0.91 mHall Mid 0.61 mHall Mid 0.30 m

Hall Mid 0.03 m

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-4
Figure 5. Detailed temperature vs. time for 303 hallway adjacent to the center stair 

0

200400600800

1000

0 500 1000 1500 2000 2500

Hall CS 2.13 mHall CS 1.83 mHall CS 1.52 mHall CS 1.22 mHall CS 0.91 mHall CS 0.61 mHall CS 0.30 m

Hall CS 0.03 m

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-5
Figure 6. Detailed temperature vs. time for 303 south stair 

0

50

100150200250300

0 500 1000 1500 2000 2500

TCFloor1TCFloor2TCFloor3TCFloor4TCFloor5TCFloor6TCFloor7TCFloor8TCFloor9TCFloor10TCFloor11TCFloor12TCFloor13TCFloor14TCFLoor15

TCFloor16

Temperature (oC)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-6
0

1020304050

0 500 1000 1500 2000 2500

Figure 7. Detailed pressure vs. time for 303 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13 Pressure 14 Pressure 15 Pressure 16

Pressure (Pa)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-7
Figure 8. Detailed heat flux vs. time for 303 

0

50

100150200250

0 500 1000 1500 2000 2500

Hall CS HorzHall CS VertHall Mid HorzHall Mid VertHall SS VertFireHorz

FireVert

Heat Flux (kW/m2)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)

F-8
F-9

Figure 9. Detailed carbon monoxide vs. time for 303 

0

200400600800

1000

0 500 1000 1500 2000 2500

Hall CSFloor 3 Center StairwellHall MidHall SSFloor 3 Stairwell

Carbon Monoxide (ppm)

Time (s)

3 Open

Fire Blanket Deployed

SVU on (Wind)

3 Open (1/2)

Fan on @ 1 (27)

Exp. Terminated

SVU on 4300 rpm

16 Open

Fan on @ 5 (24)

Fan off @ 5

Fan off @ 1 

3 Closed

Fan on @ 1 (27)

16 Open

3 Open (0.08 m)

3 Closed

16 Closed

3 Open (0.08 m)

3 Closed

16 Open

16 Closed

Fan on @ 5 (24)

3 Open (0.08 m)

Fan off @ 5

3 Open

Fan off @ 1 

SVU off

Fire Blanket Removed

Fan on @ 1 (27)

Fan on @ 5 (24)
Appendix G. Detailed Data for Apartment 304 

0

200400600800

1000

0 100 200 300 400 500 600 700

Figure 1. Detailed temperature vs. time for 304 bedroom 304 BR 2.13 m 304 BR 1.83 m 304 BR 1.52 m 304 BR 1.22 m 304 BR 0.91 m 304 BR 0.61 m 304 BR 0.30 m 304 BR 0.03 m

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-1
0

200400600800

1000

0 100 200 300 400 500 600 700

Figure 2. Detailed temperature vs. time for 304 living room 304 2.13 m 304 1.83 m 304 1.52 m 304 1.22 m 304 0.91 m 304 0.61 m 304 0.30 m 304 0.03 m

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-2
0

200400600800

1000

0 100 200 300 400 500 600 700

Figure 3. Detailed temperature vs. time for 304 hallway adjacent to the south stair Hall SS 2.13 m Hall SS 1.83 m Hall SS 1.52 m Hall SS 1.22 m Hall SS 0.91 m Hall SS 0.61 m Hall SS 0.30 m Hall SS 0.03 m

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-3
0

200400600800

1000

0 100 200 300 400 500 600 700

Figure 4. Detailed temperature vs. time for 304 middle hallway Hall Mid 2.13 m Hall Mid 1.83 m Hall Mid 1.52 m Hall Mid 1.22 m Hall Mid 0.91 m Hall Mid 0.61 m Hall Mid 0.30 m Hall Mid 0.03 m

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-4
0

200400600800

1000

0 100 200 300 400 500 600 700

Figure 5. Detailed temperature vs. time for 304 hallway adjacent to the center stair Hall CS 2.13 m Hall CS 1.83 m Hall CS 1.52 m Hall CS 1.22 m Hall CS 0.91 m Hall CS 0.61 m Hall CS 0.30 m Hall CS 0.03 m

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-5
0

50

100150200250300350400

0 100 200 300 400 500 600 700

Figure 6. Detailed temperature vs. time for 304 south stair TCFloor1 TCFloor2 TCFloor3 TCFloor4 TCFloor5 TCFloor6 TCFloor7 TCFloor8 TCFloor9 TCFloor10 TCFloor11 TCFloor12 TCFloor13 TCFloor14 TCFLoor15 TCFloor16

Temperature (oC)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-6
0

20406080

100

0 100 200 300 400 500 600 700

Figure 7. Detailed pressure vs. time for 304 south stair Pressure 1 Pressure 2 Pressure 3 Pressure 4 Pressure 5 Pressure 6 Pressure 7 Pressure 8 Pressure 9 Pressure 10 Pressure 11 Pressure 12 Pressure 13 Pressure 14 Pressure 15

Pressure 16

Pressure (Pa)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated

G-7
0

102030405060

0 100 200 300 400 500 600 700

G-8

Figure 8. Detailed heat flux vs. time for 304 Hall CS Horz Hall CS Vert

Hall Mid HorzHall Mid Vert

Hall SS Vert

Heat Flux (kW/m2)

Time (s)

3 Open

MVU On (Wind)

16 Open

MVU 1200 rpm

3 Closed

SVU On 3800 rpm

16 Closed

SVU Off

MVU Off

Exp. Terminated
Appendix H. Unit Conversions and Reference Scales 

 For Fire Fighters 

Unit Conversions 

Property To convert from to Multiply by 

Length Foot (ft) Meter (m) 0.3048 

Mass Pound (lb) Kilogram (kg) 0.4536 

Time Second (s) Second (s) 1.0 

Area Square foot (ft 2) Square meter (m2) 0.0929 

Volume Cubic foot (ft 3) Cubic meter (m3) 0.0283 

Energy, work, 

quantity of heat 

British Thermal Unit 

(Btu) 

Joule (J) 1055.0 

Power, heat release 

rate 

British Thermal Unit 

per minute (Btu/min) 

Watt (W) = J/s 17.573 

Heat Flux British Thermal unit 

per square foot minute 

(Btu/ (ft2

 min)) 

Watts per square 

meter (W/m2) 

 189.15 

Pressure Pascal (Pa) Pound per square 

inch (lb/in2

) 

0.000145 

Carbon Monoxide Parts per million (ppm) Percentage (%) 0.0001 

With the exception of the kilogram (kg), the conversions given above are to base units 

such as a Joule (J) or a Watt (W). In the scope of a fire within a building these units are 

small, so the values would be reported as kilo-Joules (kJ) or kilo-Watt (kW). The kilo 

prefix means multiply the base unit by 1000. Another prefix that may be used is Mega 

This prefix means multiply the base unit by 100,000. 

Temperature Conversions: 

Degree Fahrenheit (°F) = (Degree Celsius (°C) X 1.8) + 32 

Kelvin (K) = Degree Celsius (°C) + 273.15 

Reference: NIST Special Publication 811, Guide for the Use of the International System 

of Units (SI), National Institute of Standards and Technology, Gaithersburg, MD, April 

1995. 

H-1 
Reference Scales for Fire Fighters

Temperature

This table provides a set of temperatures commonly experienced during firefighting 

operations and information on the human and equipment response.

Temperature Response 

37 °C (98.6 °F) Normal human oral/body temperature 1

44 °C (111 °F) Human skin begins to feel pain 2

48 °C (118 °F) Human skin receives a first degree burn injury 2

55 °C (131 °F) Human skin receives a second degree burn injury 2

62 °C (140 °F) A phase where burned human tissue becomes numb 2

72 °C (162 °F) Human skin is instantly destroyed 2

100 °C (212 °F) Water boils and produces steam 3

140 °C (284 °F) Glass transition temperature of polycarbonate 4

230 °C (446 °F) Melting temperature of polycarbonate 5

250 °C (482 °F) Charring of natural cotton begins 6

>300 °C (>572 °F) Charring of modern protective clothing fabrics begins 6

>600 °C (1112 °F) Temperatures inside a post-flashover room fire7, 8

References: 

1. Klinghoffer, Max, M.D., “Triage Emergency Care Handbook,” Technomic Publishing Company, Inc., 

Lancaster, PA, 1985. 

2. American Society for Testing and Materials, ASTM C1055, Standard Guide for Heated Systems Surface 

Conditions That Produce Contact Burn Injuries, 4:6, ASTM West Conshohocken, PA, 1997. 

3. Shugar, G.J., Shugar, R.A., Lawrence, B., “Chemical Technicians’ Ready Reference Handbook,” 

McGraw-Hill Book Company, New York, 1973. 

4. Quintiere, J., “Radiative and Convective Heating of a Clear Plastic Fireman’s Face Shield”, National 

Bureau of Standards (currently NIST), Gaithersburg, MD, NBS Report 10-855, March 1972. 

5. Askeland, Donald R., “The Science and Engineering of Materials”, Wadsworth, Inc., Belmont, CA., 

1984. 

6. Krasny, John F., Sello, Stephen B., “Fibers and Textiles, Fire Protection Handbook,” 16th Edition, 1986. 

NFPA, pp.5-27. 

7. Fang, J.B., and Breese, J.N., “Fire Development in Residential Basement Rooms,” National Bureau of 

Standards (currently NIST), Gaithersburg, MD, NBSIR 80-2120, 1980. 

8 Drysdale, D., “An Introduction to Fire Dynamics”, 2nd Edition, John Wiley & Sons, New York, 1999. 

H-2 
Heat Flux

This table provides heat (exposure) flux levels commonly experienced during firefighting 

operations and information on the human response to the heat flux levels or conditions 

associated with the given heat flux.

Heat Flux Response 

~1.0 kW/m2 A typical solar flux during the summer 1

2.5 kW/m2 Typical fire fighter exposure and working environment 2

4.5 kW/m2 Unprotected human skin will receive a second degree burn injury in 

about 30 seconds 3

 

10 kW/m2 Unprotected human skin will receive a second degree burn injury in 

about 10 seconds 3 

20 kW/m2 Heat flux in a room at the floor level at the beginning of flashover 4

80 kW/m2 Unprotected human skin will receive an instant second degree burn 

injury, flashover is established in a room 3

84 kW/m2 Heat flux specified in the NFPA 1971 test for Thermal Protective 

Performance (TPP) to evaluate fire fighter’s thermal protective 

clothing 3 Firefighter in full PPE protected from burn injury for 

17 seconds or less at this heat flux 5 

170 kW/m2 Maximum heat flux level measured by NIST with a post-flashover 

fire inside a burning room 4

 

References: 

1. Young, H.D., and Freedman, R.A., “University Physics”, 9th Edition. Addison-Wesley, Reading, MA., 

1996. 

2. Donnelly, M.K., Davis, W.D, Lawson, J.R., Selepak, M.J., “Thermal Environment for Electronic 

Equipment Used by First Responders, NIST Technical Note 1474, 2006. 

3. NFPA 1971, Standard on Protective Ensembles for Structural Fire Fighting and Proximity Fire Fighting 

2007 Edition, National Fire Protection Association, Quincy, MA 2007 

4. Fang, J.B., and Breese, J.N., “Fire Development in Residential Basement Rooms,” national Bureau of 

Standards (currently NIST), NBSIR 80-2120, Gaithersburg, MD, 1980 

5. Peacock, R.D., Krasny, J.F., Rockett, J.A., Huang, D., “Protecting Fire Fighters Exposed in Room 

Fires, Part 2: Performance of Turnout Coat Materials Under Actual Fire Conditions”, Fire 

Technology, August 1990. 

H-3 
Carbon Monoxide

This table provides common symptoms from carbon monoxide exposures of a given 

duration to a particular concentration. There are number of variables that could cause an 

individual to respond differently.

Concentration Common Symptoms Duration of Exposure

35 ppm None <= 8 hours 

150 ppm Mild headache 2 – 3 hours 

400 ppm Headache/nausea 1 – 2 hours 

800 ppm Headache/nausea/dizziness 

Progressing to unconsciousness 

45 minutes 

2 hours 

6400 ppm Headache/nausea/dizziness 1 – 2 minutes 

12800 ppm Immediately dangerous to life and 

health (IDLH) 

1 – 2 minutes 

References: 

1. Delagi, Robert, “A CO Emergency: Whose Call Is It, Anyway?”, Fire Engineering Magazine, October 

2007. 

2. Henry CR, Satran D, Lindgren B, Adkinson C, Nicholson CI, Henry TD, MD (2006). "Myocardial 

Injury and Long-term Mortality Following Moderate to Severe Carbon Monoxide Poisoning". 

JAMA 295: 398-402. 

3. Raub JA, Mathieu-Nolf M, Hampson NB, Thom SR. (2000). "Carbon monoxide poisoning-a public 

health perspective". Toxicology 145 (1): 1-14. 

Pressure 

This table provides a range of pressures used during firefighting operations. 

Pressure Situation 

12.5 Pa (0.0018 psi) Suggested pressure difference to inhibit smoke flow across a 

doorway in a sprinklered building 1

25 Pa (0.0036 psi) Suggested pressure difference to inhibit smoke flow across a 

doorway in a non-sprinklered building 1

2990 Pa (0.434 psi) 1 foot of water head 2

101,000 Pa (14.7 psi) Atmospheric pressure at sea level 3

240,000 Pa (35 psi) Solid stream nozzle operating pressure 2

690,000 Pa (100 psi) Fog nozzle operating pressure 2

References: 

1. NFPA 92A. Standard for Smoke-Control Systems Utilizing Barriers and Pressure Differences. 2006 

Edition. 

2. Hall, R. and Adams, B., Eds, Essentials of Fire Fighting, 4th ed., Oklahoma State 

University, Stillwater, OK, 1998, 716p. 

3. U.S. Standard Atmosphere, 1976, U.S. Government Printing Office, Washington, D.C., 1976. 

H-4 
Heat Release Rate

This table provides a list of common items and their associated approximate peak heat 

release rates.

Approximate Peak Heat Release Rate Item 

5 W 1

Burning cigarette 

80 W 1,2

Burning match or candle 

50 to 300 kW 3

Small Trash Can, Trash Bag Fires 

80 kW to 2.5 MW 4,5

Burning Upholstered Chair 

3,000 kW or 3 MW 6

Burning Upholstered Sofa 

1.6 MW to 5.2 MW 7

Burning Christmas Tree 

5.3 MW 8

Base Design Fire 

Approximately 10 to 40 GW/acre 9

Forest Fire – Timber w/understory 

References: 

1. Babrauskas,V. and Krasny, J., Fire Behavior of Upholstered Furniture, NBS 

Monograph 173, Nat. Bur. Stds (Currently Nat. Inst. of Stds & Tech.), Gaithersburg, MD., Nov. 

1985, p57. 

2. Hamins, Anthony, Bundy, Matthew, and Dillon, Scott, Characterization of Candle 

Flames, Journal of Fire Protection Engineering, Vol 15, November 2005. 

3. Babrauskas, V., Burning Rates, The SFPE Fire Protection Engineering Handbook, 2nd 

ed., Society of Fire Protection Engineers, Quincy, MA., 1995 

4. Stroup, DW, Delauter,L., Lee, J. and Upholstered Chair Fire Test Using a California 

TB 133 Burner Ignition Source, Report of Test FR 4012, National Institute of Standards and 

Technology, Gaithersburg, MD, December 2001. 

5. Technical Bulletin 133, Flammability Test Procedure for Seating Furniture for Use in 

Public Occupanices, State of California, Department of Consumer Affairs, Bureau of Home 

Furnishings and Thermal Insulation, North Highlands, CA, January 1991. 

6. Peacock, R., Portier, R. & Reneke, P., FASTDATA – NIST Standard Reference 

Database Number 75, National Institute of Standards & Technology, Gaithersburg, MD, January 

1999. 

7. Stroup, D.W., DeLauter, L., Lee, J., and Roadarmel, G., Scotch Pine Christmas Tree 

Fire Tests, Report of Test FR 4010, National Institute of Standards and Technology, Gaithersburg, 

MD, December 1999. 

8. International Building Code®, Section 909.9 

9. U.S. Forest Service 

H-5