NIST Technical Note 1938 

Impact of Hose Streams on Air Flows 

Inside a Structure 

Joseph M. Willi 

Daniel Madrzykowski 

Craig G. Weinschenk 

This publication is available free of charge from: 

http://dx.doi.org/10.6028/NIST.TN.1938 

NIST Technical Note 1938 

Impact of Hose Streams on Air Flows

Inside a Structure 

Joseph M. Willi 

Daniel Madrzykowski∗

Craig G. Weinschenk+

Fire Research Division

Engineering Laboratory

This publication is available free of charge from: 

http://dx.doi.org/10.6028/NIST.TN.1938 

October 2016 

∗Currently with UL FSRI

+Currently with JENSEN HUGHES

UNITED STATES OF AMERICA

DEPARTMENT OF COMMERCE

U.S. Department of Commerce 

Penny Pritzker, Secretary

National Institute of Standards and Technology 

Willie May, Under Secretary of Commerce for Standards and Technology and Acting Director
Certain commercial entities, equipment, or materials may be identified in this 

document in order to describe an experimental procedure or concept adequately. 

Such identification is not intended to imply recommendation or endorsement by the 

National Institute of Standards and Technology, nor is it intended to imply that the 

entities, materials, or equipment are necessarily the best available for the purpose. 

Regarding Non-Metric Units: The policy of the National Institute of Standards and 

Technology is to use metric units in all its published materials. To aid the understanding of 

this report, in most cases, measurements are reported in both metric and U.S. customary units. 

There are instances in this study where only the U.S. customary units are used as they relate to 

specific equipment or common fire service vernacular 

National Institute of Standards and Technology Technical Note 1938

Natl. Inst. Stand. Technol. Tech. Note 1938, 43 pages (October 2016)

CODEN: NTNOEF 

This publication is available free of charge from: 

http://dx.doi.org/10.6028/NIST.TN.1938 
Contents 

Contents i
 

List of Figures ii
 

List of Tables iv
 

List of Acronyms v
 

1 Introduction 1
 

1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
 

1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
 

2 Experimental Overview 4
 

2.1 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
 

2.1.1 Test Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
 

2.1.2 Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
 

2.1.3 Uncertainty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
 

2.2 Experimental Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
 

2.2.1 Monitor Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
 

2.2.2 Handline Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
 

3 Results and Discussion 25
 

3.1 Monitor Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
 

3.2 Handline Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
 

4 Summary 32
 

5 Acknowledgments 34
 

References 35
 

A Dimensioned Floor Plans 36
 

B Monitor Test Plots 38
 

C Handline Test Plots 42
 

i
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
List of Figures 

1.1	 Hose stream patterns used during experiments. . . . . . . . . . . . . . . . . . . . . 3
 

2.1	 North side of the Single Story and Two Story Structures. . . . . . . . . . . . . . . 5
 

2.2	 TJI-constructed ceiling support of the Two Story Structure. . . . . . . . . . . . . . 6
 

2.3	 Simple floor plan of the Single Story Structure. . . . . . . . . . . . . . . . . . . . 7
 

2.4	 Simple floor plan of the first and second floors of the Two Story Structure. . . . . . 8
 

2.5	 Array of bi-directional probes at interior doorway in Single Story Structure. . . . . 10
 

2.6	 Flow meter used to measure flow rate during experiments. . . . . . . . . . . . . . . 12
 

2.7	 Monitor and handline equipped with a combination nozzle. . . . . . . . . . . . . . 14
 

2.8	 Plan view of the Single Story Structure setup for Tests 1 and 5. . . . . . . . . . . . 15
 

2.9	 Plan view of the Two Story Structure setup for Tests 2 and 6. . . . . . . . . . . . . 16
 

2.10 Plan view of the Two Story Structure setup for Tests 3 and 7. . . . . . . . . . . . . 17
 

2.11 Straight stream, narrow fog stream, and wide fog stream during Test 1. . . . . . . . 19
 

2.12 Straight stream, narrow fog stream, and wide fog stream aimed at the near and far
 

targets in the Two Story Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . 20
 

2.13 Straight stream from combination nozzle and solid stream from smooth bore nozzle
 

with 1 in. tip during Test 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
 

2.14 Straight stream, narrow fog stream, and wide fog stream during Test 5. . . . . . . . 23
 

2.15 North side of Two Story Structure containing a fully established flow path during
 

Test 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
 

3.1	 Average gas velocity through the interior stairwell door during Test 2 for the three
 

hose stream patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
 

3.2	 Average gas velocity through the interior stairwell door during Test 6 for the three
 

hose stream patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
 

A.1	 Dimensioned floor plan of the Single Story Structure. . . . . . . . . . . . . . . . . 36
 

A.2	 Dimensioned floor plan of the first and second floors of the Two Story Structure. . . 37
 

B.1	 Average gas velocity through the interior doorway during Test 1 for the three hose
 

stream patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
 

B.2	 Average gas velocity through the interior stairwell door during Test 3 for the three
 

hose stream patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
 

B.3	 Average gas velocity through the interior stairwell door during Test 4 for the straight
 

stream and smooth bore stream patterns. . . . . . . . . . . . . . . . . . . . . . . . 41
 

C.1	 Average velocity through stairwell door during Test 5 for the three hose stream
 

patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
 

ii
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
C.2 Average velocity through stairwell door during Test 7 for the three hose stream
 

patterns. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
 

iii
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
List of Tables 

2.1 Summary of the seven experimental test series . . . . . . . . . . . . . . . . . . . . 13
 

3.1 Average gas velocity and airflow rate [±18 %] through interior doorway when flow
 

path was fully established for each monitor experiment . . . . . . . . . . . . . . . . 26
 

3.2 Average gas velocity and airflow rate [±18 %] through interior doorway when flow
 

path was fully established for Test 5 . . . . . . . . . . . . . . . . . . . . . . . . . . 29
 

3.3 Average gas velocity and airflow rate [±18 %] through interior doorway when flow
 

path was fully established for Tests 6 and 7 . . . . . . . . . . . . . . . . . . . . . . 30
 

iv
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
List of Acronyms
 

NF Narrow Fog Stream 

NIST National Institute of Standards and Technology 

OSB Oriented Strand Board 

SB Smooth Bore Stream 

SS Straight Stream 

TJI Truss Joist I-beams 

UL FSRI Underwriters Laboratories Firefighter Safety Research Institute 

WF Wide Fog Stream 

v
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Abstract
 

Fire suppression tactics using hose streams can affect ventilation in a structure and may impact the 

movement of smoke and heat through a structure. Seven experimental series containing a total of 

154 configurations were conducted to study the impact of different hose stream and nozzle movement pattern combinations on air movement within residential scale structures. The experiments 

studied four different hose streams: a straight stream, narrow fog stream, and a wide fog stream 

from a combination nozzle and a solid stream from a smooth bore nozzle. The streams were applied 

from a static, or fixed, position; by moving the hoseline left-to-right across the room in a sweeping motion; and by rotating the hoseline in both the clockwise and counterclockwise directions. 

Gas velocity was measured at different locations in the structure during the experiments. The wide 

fog stream caused the most air movement out of any of the tested streams, reaching a maximum 

velocity of 2.6 m/s (5.8 mph) and maximum air flow rate of approximately 4.8 m3/s (10250 cfm), 

followed by the narrow fog stream, and then the straight stream and solid stream from the smooth 

bore nozzle, which both caused approximately the same amount of air movement through the 

structure. The data were consistent with a straight stream only causing air movement through the 

structure when it was applied in a moving pattern. Furthermore, there were no statistically significant differences in the average measured air velocity between the clockwise and counterclockwise 

nozzle movement patterns. It was determined that the type of hose stream and manner in which 

it is applied dictates the extent to which a stream impacts the ventilation of a structure. To better 

quantify the impact of such air flows on the fire environment, additional experiments need to be 

conducted with structure fires in a controlled environment. 

Keywords: fire fighting, fire suppression, hose streams, nozzles, ventilation 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Section 1 

Introduction 

1.1 Background 

One of the objectives of the Fire Research Division at the National Institute of Standards and 

Technology (NIST) is to improve the safety and effectiveness of firefighters through improved 

knowledge of fire behavior and examination of how different firefighting tactics affect the fire 

environment. NIST has conducted a significant amount of research examining how ventilation 

affects the growth and spread of fire within structures and how the air flow to the fire may be 

controlled to limit or delay the growth of the fire [1, 2]. The studies have provided insight for the 

fire service regarding ventilation tactics. However, ventilation tactics alone will not extinguish the 

fire; fire suppression with hose streams is also needed. 

Fire suppression tactics using hose streams also affect the ventilation in a structure and may 

impact the movement of smoke and heat through a structure. If vents are made to advance the 

hoseline or if ventilation inducing handline tactics are in practice, hose stream impacts on ventilation may be even more significant. Additional research addressing the coordination of suppression 

tactics and the impact on ventilation is needed to complete recommendations on fire control tactics 

to appropriate standards, education, and training documents. 

There exists a multitude of different tools, methods, and techniques used to apply water for fire 

suppression using hose streams. A common type of nozzle that is used to apply water during fire 

suppression in residential structures is an adjustable-pattern spray nozzle, commonly referred to as 

a combination nozzle [3]. Most combination nozzles contain an adjustable tip that can be rotated 

to produce different stream patterns. The types of streams produced by a combination nozzle are 

often divided into three categories based on the angle of the stream with respect to the centerline 

of the nozzle: a straight stream typically produces an angle less than 15°; a narrow fog stream 

produces an angle between 15° and 45°; and a wide fog stream produces an angle between 45° and 

80° [4]. Increasing the angle of the stream allows for a larger area to be covered by the water spray 

but also decreases the distance reached by the stream and its penetration power. 

In addition to the type of stream pattern used, the method or motion of the nozzle used to apply 

the hose stream can also vary. For example, Royer suggested using a clockwise rotation instead of 

a counterclockwise nozzle movement pattern for the following reasons [5]: 

1. Clockwise rotation drives most of the heated gases, smoke, and flames away from the nozzle, 

while counterclockwise rotation does just the opposite. 

1
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
2. Steam formed by the clockwise rotation has a violent rolling action. Counterclockwise rotation 

produces steam with an inactive and lazy action. 

3. A clockwise rotation increases the efficiency of water and produces a faster knockdown time 

than counterclockwise rotation. 

1.2 Objectives 

This report focuses on examining the impact of hose stream and application pattern (or nozzle 

motion) selection on air movement inside two full-scale test structures built to represent residential sized structures. Experiments containing different flow path configurations were conducted to 

study the impact of hose stream and water application selection on ventilation in a structure. More 

specifically, the experiments were conducted to fulfill the following objectives: 

1. Determine the amount of air movement induced by different hose streams and nozzle movement patterns. 

2. Examine Royer’s nozzle movement theory on the direction of nozzle rotation. 

Four types of hose streams and four nozzle movement patterns were studied under 154 different 

configurations during the seven test series described in this report. Three of the hose stream patterns 

studied used a combination nozzle: straight stream, narrow fog stream, and wide fog stream. Water 

was flowed into the structure by having the hose in a static, or fixed, position; by moving the 

hoseline left-to-right across the room in a sweeping motion; and by rotating the hoseline in both the 

clockwise and counterclockwise directions. Additionally, experiments comparing the differences 

in impact on air flows in a structure between a straight stream from a combination nozzle and a 

solid stream from a smooth bore nozzle equipped with a 1 in. tip were conducted. Images of the 

four types of hose streams are presented in Fig. 1.1. 

2
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
(a) Narrow fog stream from combination nozzle (b) Wide fog stream from combination nozzle
 

(c) Straight stream from combination nozzle (d) Solid stream from 1 in. smooth bore nozzle
 

Figure 1.1: The four types of hose stream patterns used during water flow experiments.
 

3
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Section 2 

Experimental Overview 

To study the impact of different hose stream and nozzle movement selections on air movement 

inside a structure, water flow experiments were conducted in two experimental structures designed 

to replicate typical residential structures. The experiments focused on studying the differences in 

the amount of air movement caused by specific combinations of four different hose stream patterns 

and four different nozzle movement patterns. 

2.1 Experimental Setup 

The series of field experiments described in this report were conducted in two structures of similar design located at the Delaware County Emergency Services Training Center in Sharon Hill, 

Pennsylvania. Differential pressure and temperature sensors were installed at ventilation points 

throughout the test structures to determine air velocity during the water flow experiments. 

2.1.1 Test Structures 

Construction 

Each test structure was built on a concrete slab as shown in Fig. 2.1. The Single Story Structure was 

designed to simulate a single-story residential structure, and the Two Story Structure was designed 

to simulate a two-story residential structure. The first floor of each structure had an outer wall 

composed of interlocking concrete blocks of equal side lengths of 0.61 m (2 ft). The joints and 

gaps between the blocks were filled with high temperature insulation. 

The interior walls of the first floor of each structure were framed with steel studs set to 400 mm 

(16 in) centers and track and were lined with 13 mm (0.5 in) thick cement board. A layer of 16 mm 

(0.63 in) thick Type X gypsum board covered the cement board. Additionally, the ceiling was 

composed of two layers of 13 mm (0.5 in) thick cement board. 

4
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.1: North side of the Single Story (top) and Two Story (bottom) Structures. 

The first floor ceiling support of each structure was composed of wood truss joist I-beams (TJIs) 

with a 298 mm (11.75 in) depth. Each TJI was composed of laminated veneer lumber flanges with 

a cross section of 29 mm (1.13 in) x 44 mm (1.75 in) and an 11 mm (0.43 in) thick oriented strand 

board (OSB) web as shown in Fig. 2.2. Tongue and groove OSB of 18.3 mm (0.72 in) thickness 

was screwed to the top of the TJIs. 

5
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.2: First floor ceiling support of the Two Story Structure composed of wood truss joist 

I-beams. View is of the southeast corner of the structure. 

The second floor of the Two Story Structure was built on the structure’s first floor wood ceiling 

support. The two floors were connected by an interior stairwell. A door made of lauan plywood 

was located at the top of the stairwell. The walls on the second floor were of wood-frame with 

51 mm (2 in) by 102 mm (4 in) studs set to 400 mm (16 in) centers. Two layers of 16 mm (0.63 in) 

Type X gypsum board lined the interior side of the wood studs, and a layer of 13 mm (0.5 in) thick 

cement board covered the gypsum board. The interior ceiling of the second story was covered by 

two layers of 13 mm (0.5 in) thick cement board. The exterior sides of the outer walls on the second 

floor were protected by 11 mm (0.44 in) thick OSB and 8 mm (0.31 in) fiber cement lap siding. 

Layout 

Simple floor plans with the total length and width of the Single Story and Two Story Structures are 

presented in Fig. 2.3 and Fig. 2.4, respectively. Fully dimensioned floor plan drawings are provided 

in Appendix A. 

The ceiling height of each structure was approximately 2.4 m (8 ft). The interior dimensions 

of the Single Story Structure were approximately 6.1 m (20 ft) by 11 m (36 ft), and the interior 

dimensions of the first and second floors of the Two Story Structure were 5.8 m (19 ft) by 10.7 m 

(35.1 ft) and 6.1 m (20 ft) by 10.9 m (35.8 ft), respectively. The stairs connecting the two floors of 

the Two Story Structure started 1.6 m (5.3 ft) off the south wall with a width of 1.2 m (4 ft) off the 

east wall and contained a 180 mm (7.25 in) rise and 190 mm (7.5 in) run. 

The exterior doorways of each structure and the stairwell doorway on the second level of the 

Two Story Structure all contained doors that were opened or closed at certain instances during tests 

to change the ventilation pathways within the structure. All other doorways in the structures did 

6
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
not contain a door. In order to close these doorways, a sheet of gypsum board was used to cover 

the opening, and the doorway remained closed for the duration of the test procedure. 

7.3 m

12.2 m

N

Figure 2.3: Simple floor plan of the Single Story Structure.
 

7
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
6.4 m

11.2 m

N

11.9 m

7.0 m

N

Figure 2.4: Simple floor plan of the second floor (top) and first floor (bottom) of the Two Story 

Structure. 

8 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
2.1.2 Instrumentation 

For every experiment, gas velocity at an interior doorway was calculated using differential pressure 

transducers connected to bi-directional velocity probes [6]. An array of six bi-directional probes 

located at the northeast interior doorway of the Single Story Structure is pictured below in Fig. 2.5. 

A single thermocouple was attached to each bi-directional probes to measure the gas temperature 

to be used in conjunction with the pressure measurement to calculate velocity. Every thermocouple attached to the bi-directional probes was an exposed-bead, Chromel-Alumel (type K) with a 

1.0 mm (0.04 in) diameter. The thermocouple wire was sheathed in a 3.2 mm (0.13 in) diameter 

Inconel shield that started at the exposed bead and was 0.76 m (2.5 ft) in length. 

The approximate locations of the bi-directional probes are annotated in the plan views of the 

experimental setups for the Single Story and Two Story Structures (Figs. 2.8–2.10) in Section 2.2. 

To minimize potential measurement errors due to external environmental conditions (i.e., wind), 

only velocity data measured by bi-directional probes located at interior doorways are considered 

in this report. The set of bi-directional probes at the northeast interior doorway of the Single Story 

Structure, denoted as “A6” and pictured in Fig. 2.5, contained six probes located at distances of 

0.30 m (1.0 ft), 0.60 m (2.0 ft), 0.90 m (3.0 ft), 1.20 m (3.9 ft), 1.50 m (4.9 ft), and 1.80 m (5.9 ft) 

below the soffit of the doorway. The set of bi-directional probes at the interior doorway in the Two 

Story Structure, denoted as “A10”, contained eight probes located at distances of 0.08 m (0.25 ft), 

0.34 m (1.1 ft), 0.61 m (2.0 ft), 0.88 m (2.9 ft), 1.15 m (3.7 ft), 1.42 m (4.7 ft), 1.68 m (5.5 ft), and 

1.95 m (6.4 ft) below the soffit of the corresponding doorway. 

A discussion of uncertainties for each type of measurement in this report can be found in 

Section 2.1.3. 

9
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.5: Array of bi-directional probes located at the northeast interior doorway in the Single 

Story Structure. View is looking at the north side of the doorway. 

2.1.3 Uncertainty 

There are different components of uncertainty in the length, differential pressure, flow rate, and 

gas velocity presented in this report. 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 [7]. 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. Then, the combined standard uncertainty 

is multiplied by a coverage factor of two, which results in the expanded uncertainty with a 95 % 

confidence interval (2σ). For some of these components, such as the zero and calibration elements, 

uncertainties are derived from referenced instrument specifications. For other components, referenced research results and past experience with the instruments provided input in the uncertainty 

determination. 

10
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Length Measurements 

Each length measurement was taken carefully. Length measurements such as the room dimensions, 

instrumentation array locations, and fire apparatus (e.g., nozzle, sprinkler, or fan) placement were 

made with a hand held laser measurement device which has an accuracy of ±6.0 mm (0.25 in) over 

a range of 0.61 m (2.0 ft) to 15.3 m (50.0 ft) [8]. However, conditions affecting the measurement, 

such as levelness of the device, yields an estimated uncertainty of ±0.5 % for measurements in 

the 2.0 m (6.6 ft) to 10.0 m (32.8 ft) range. Steel measuring tapes with a resolution of ±0.5 mm 

(0.02 in) were used to locate individual sensors within a measurement array. The steel measuring 

tapes were manufactured in compliance with NIST Manual 44, which specifies a tolerance of 

±1.6 mm (0.06 in) for 9.1 m (30 ft) tapes and ±6.4 mm (0.25 in) for 30.5 m (100 ft) tapes [9]. 

Bi-Directional Probes 

Bi-directional probes with pressure transducers and single thermocouples were used to measure 

the gas velocity. Inconel-sheathed, exposed bead, type K thermocouples were co-located with 

each probe. A gas velocity measurement study examining the doorway flow of pre-flashover compartment fires yielded expanded uncertainty measurements ranging from ±0.14 to ±0.22 for bidirectional probes of similar design [10]. The total expanded uncertainty for gas velocity in these 

experiments is estimated to be ±18 %. 

Water Flow Rate 

Water flow rate was measured with a pressure and flow meter combination shown in Fig. 2.6. The 

meter consisted of a section of 63.5 mm (2.5 in) cast aluminum pipe with a 0 to 4.1 MPa (600 psi) 

pressure transducer and a paddlewheel type flow sensor with a range of 0 to 4800 lpm (1250 gpm). 

The pressure transducer and paddlewheel were both connected to the battery operated control box 

where the pressure transducer voltage was converted to a pressure and the paddlewheel pulse count 

was converted to a volumetric flow rate. The manufacturer reports a ±5 % calibration expanded 

uncertainty for the flow sensor and ±3 % for the pressure sensor [11]. The pressure transducer 

was calibrated with a known analog pressure gauge. The flow meter was calibrated by capturing 

water over time and measuring that mass of water to determine the flow rate. The total expanded 

uncertainty was estimated to be ±10 %. 

11
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.6: Pressure and flow meter combination used to measure water flow rate during the experiments. 

2.2 Experimental Procedure 

Every experimental test series discussed in this report involved discharging water at a set flow rate 

from a combination nozzle in a straight, narrow fog, or wide fog stream pattern or from a smooth 

bore nozzle with a 1 in. tip in a solid stream pattern. Specific doors were opened or closed before 

and/or during the tests to change the ventilation within the structure. Each time a hose stream 

pattern, nozzle movement pattern, target location, or ventilation pattern was changed during a test 

series, a new test configuration was considered to be in place. A total of 154 configurations were 

used throughout the seven experimental series. 

The seven experimental test series, summarized in Table 2.1, were conducted to study the 

impact of different hose stream and nozzle motion patterns on gas movement in a structure; three 

used a combination nozzle attached to a monitor to flow water at approximately 120 gpm, three 

used a combination nozzle attached directly to a 1.75 in. handline to flow water at approximately 

120 gpm (Fig. 2.7), and one used both a combination nozzle and a smooth bore nozzle attached 

to a monitor to flow water at approximately 180 gpm. Experiments that used a monitor to flow 

water always applied the stream in a fixed position and were focused on changing the location of 

water application in addition to the stream pattern. The experiments that used a combination nozzle 

attached directly to a 1.75 in. handline to flow water focused on impact of the motion of the nozzle. 

Three different structure flow path configurations were used for the seven experimental series. 

12
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Table 2.1: Summary of the seven experimental test series
 

Test # Appliance Structure Flow Path 

Configuration Streams Nozzle Motion 

1 Monitor Single 

Story U-shaped 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed position 

Nozzle lower 

2 Monitor Two 

Story 

level north side, 

Exhaust lower 

level south side 

and upper level 

north side 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed position 

3 Monitor Two 

Story 

Nozzle lower 

level north side, 

Exhaust upper 

level north side 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed position 

4 Monitor Two 

Story 

Nozzle lower 

level north side, 

Exhaust upper 

level north side 

Straight, 

Solid 

(180 gpm) 

Fixed position 

5 Handline Single 

Story U-shaped 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed at ceiling, 

Rotated CW, 

Rotated CCW 

Nozzle lower 

6 Handline Two 

Story 

level north side, 

exhaust lower 

level south side 

and upper level 

north side 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed at ceiling, 

Sweeping ceiling, 

Rotated CW, 

Rotated CCW 

7 Handline Two 

Story 

Nozzle lower 

level north side, 

Exhaust upper 

level north side 

Straight, 

Narrow fog, 

Wide fog 

(120 gpm) 

Fixed at ceiling, 

Sweeping ceiling, 

Rotated CW, 

Rotated CCW 

13
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.7: Monitor (left) and 1.75 in. handline (right) equipped with a combination nozzle and 

used to flow water during experiments. 

Tests 1 and 5 were conducted in the Single Story Structure and used the “U-shaped” configuration 

shown in Fig. 2.8. Test 1 used a monitor and combination nozzle to flow water, and Test 5 used 

a combination nozzle attached directly to a handline to flow water. The two additional flow path 

configurations were used for the test series conducted in the Two Story Structure. The main difference between the two configurations was the position of the south side door on the ground level. 

Tests 2 and 6 used a configuration with the door opened (Fig. 2.9), while Tests 3, 4, and 7 used a 

configuration with the door closed (Fig. 2.10). Tests 2 and 3 used a combination nozzle attached to 

a monitor to flow water; Tests 6 and 7 used a combination nozzle attached directly to a handline to 

flow water; and Test 4 used both a combination nozzle and a 1 in. tip smooth bore nozzle attached 

to a monitor to flow water in a straight and solid stream, respectively. 

14
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
N

A6

Room$A Room$B Room$C

N

Figure 2.8: Plan view of the Single Story Structure setup for Tests 1 and 5. The view is annotated 

with the approximate location of water flow (nozzle graphic), the direction of the established flow 

path (red line), and the approximate location of bi-directional probe array A6 (blue square). The 

north side double doors remained opened for the entire duration of the experiments. 

15
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
A10

N

A6

N

N

N

Figure 2.9: Plan view of the second floor (top) and first floor (bottom) setup in the Two Story 

Structure for Tests 2 and 6. The view is annotated with the approximate location of water flow 

(nozzle graphic), the direction of the established flow path (red line), and the approximate location 

of bi-directional probe array A10 (blue square). The stairwell door and the west double door on 

the north side of the second floor were opened and closed at certain instances during the tests. 

16 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
A10

N

A6

N

N

N

Figure 2.10: Plan view of the second floor (top) and first floor (bottom) setup in the Two Story 

Structure for Tests 3, 4, and 7. The view is annotated with the approximate location of water flow 

(nozzle graphic), the direction of the established flow path (red line), and the approximate location 

of bi-directional probe array A10 (blue square). The stairwell door and the west double door on 

the north side of the second floor were opened and closed at certain instances during the tests. 

17 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
2.2.1 Monitor Experiments 

Three experimental test series, Tests 1–3, used a monitor equipped with a combination nozzle 

to flow water at 120 gpm in a straight stream, narrow fog stream, and wide fog stream. Test 1 

occurred in the Single Story Structure, and Tests 2 and 3 occurred in the Two Story Structure. A 

fourth test series, Test 4, was conducted in the Two Story Structure and used a combination nozzle 

and a smooth bore nozzle attached to a monitor to flow water at 180 gpm in a straight stream and 

solid stream, respectively. The monitor was always set to flow water from a fixed position. Thus, 

the monitor experiments primarily focused on the impact of different hose stream patterns on air 

movement in a structure and provided a baseline to compare the impact of the motion of the nozzle 

on the air movement through the structure. 

Test 1 

Test 1 utilized a monitor equipped with a combination nozzle to flow water from Room C of the 

Single Story Structure to the area above the doorway on the south wall of Room B (Fig. 2.11). A 

plan view of the structure’s layout during Test 1 can be found in Fig. 2.8. The figure highlights 

the general direction of the established flow path along with the approximate location of A6, the 

bi-directional probe array used to measure gas velocity through the northeast interior doorway. The 

procedure for Test 1 was the simplest of all the test procedures. First, water was flowed in a straight 

stream for 30 seconds, then the stream was changed to a narrow fog for 30 seconds, and finally the 

stream was changed to a wide fog for 30 seconds. Then, the procedure was repeated an additional 

time. 

Tests 2 & 3 

Tests 2 and 3 followed identical procedures that involved using a monitor equipped with a combination nozzle to flow water from the north side double doors to the interior ceiling on the first 

floor of the Two Story Structure. The nozzle was aimed at two regions marked on the center of the 

ceiling during the series: a “near” target located approximately 1.8 m (6 ft) from the interior side 

of the north wall and a “far” target located approximately 3.7 m (12 ft) from the interior side of 

the north wall. The procedure for each test began by flowing water in a straight stream pattern at 

the far target for 60 seconds. After 60 seconds of water flow, the stairwell door was opened. One 

minute later, the west double door on the north side of the second floor was opened, and water 

continued to flow for 60 seconds. Next, the water flow was stopped, the two doors were closed, 

and the procedure was repeated with the monitor aimed at the near target. This entire process was 

repeated using the narrow fog and wide fog streams. Fig. 2.12 contains images of each type of hose 

stream aimed at the near and far targets. 

18
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.11: Straight stream (top), narrow fog stream (middle), and wide fog stream (bottom) from 

the monitor in Room C aimed at the area above the doorway on the south wall of Room B during 

Test 1 in the Single Story Structure. 

19 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.12: Straight stream (left column), narrow fog stream (middle column), and wide fog 

stream (right column) aimed at “near” target (top row) and “far” target (bottom row) during Tests 2 

and 3 in the Two Story Structure. 

20
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Test 4 

Test 4 studied the differences in air movement caused by a solid stream from a smooth bore nozzle 

with a 1 in. tip and straight stream from a combination nozzle attached to a monitor aimed at the 

same targets used during Tests 2 and 3. The stairwell door was opened for the entire experimental 

series. The test began by flowing water in a straight stream from a combination nozzle aimed at 

the near target. Then, the west double door on the second floor was opened. After 60 more seconds 

of flow, the nozzle was closed to stop water flow for 30 seconds. The nozzle was opened for 60 

seconds and then closed for 30 seconds two additional times. Next, the monitor was aimed at the 

far target, and the procedure was repeated. This entire process was repeated for the solid stream 

from the smooth bore nozzle. Fig. 2.13 contains images of the straight stream from the combination 

nozzle and solid stream from the 1 in. tip of the smooth bore nozzle during Test 4. 

Figure 2.13: Straight stream flowing from the combination nozzle (left) and solid stream flowing 

from the 1 in. tip of the smooth bore nozzle (right) during Test 4 in the Two Story Structure. 

2.2.2 Handline Experiments 

Three experimental test series were conducted using a 1.75 in. handline with a combination nozzle 

to flow water in a straight stream, narrow fog stream, and wide fog stream. One series, Test 5, 

occurred in the Single Story Structure, and the remaining tests, Tests 6 and 7, occurred in the Two 

Story Structure. All three tests primarily focused on the impact of different hose stream and nozzle 

motion pattern selections on air movement in a structure. 

21
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Test 5 

Test 5 utilized a 1.75 in. handline equipped with a combination nozzle to flow water from Room 

C of the Single Story Structure into Room B (Fig. 2.14). The layout of the structure was identical 

to the layout for Test 1 described above in Section 2.2.1 and presented in Fig. 2.8. The procedure 

for Test 5 began by flowing water in a straight stream aimed at the ceiling of Room B for 30 

seconds in a fixed position. After 30 seconds, the nozzle was rotated in the clockwise direction for 

30 seconds. Then, the nozzle was aimed at the south doorway of Room B, and water was applied 

for 30 seconds in a fixed position followed by 30 seconds in a clockwise pattern. The procedure 

was repeated using a narrow fog stream and a wide fog stream. This entire process was repeated 

for the streams being applied in the fixed and counterclockwise patterns. The average rotation rate 

for the configurations that involved nozzle rotation was 2.1 rotations per second with a maximum 

rate of 2.3 rotations per second and minimum of 1.9 rotations per second. 

Tests 6 & 7 

Tests 6 and 7 followed identical procedures that used a 1.75 in. handline equipped with a combination nozzle to flow water from the north side double doors of the Two Story Structure into the 

first floor compartment. The water stream was aimed at the south side wall of the first floor during 

the experiments. Test 6 contained the flow path configuration presented in Fig. 2.9, and Test 7 contained the flow path configuration presented in Fig. 2.10. Each test began by using a straight stream 

to flow water in a fixed, horizontal position. After 60 seconds of water flow, the stairwell door was 

opened. One minute later, the west double door on the north side of the second floor was opened, 

and water continued to flow for 60 seconds. Next, the water flow was stopped, the two doors were 

closed, and the procedure was repeated three additional times for the sweeping (back and forth, 

left-to-right), clockwise, and counterclockwise nozzle motion patterns. This entire process was repeated using narrow fog and wide fog streams. Fig. 2.15 contains an image of a straight stream 

pattern being applied during Test 6 with the flow path fully established. The average rotation rate 

for the configurations that involved nozzle rotation with a wide fog stream or narrow fog stream 

during Tests 6 and 7 was 1.3 rotations per second with a maximum of 1.4 rotations per second 

and a minimum of 1.2 rotations per second. The average rotation rate for the configurations that 

involved nozzle rotation with a straight stream was 0.8 rotations per second during Test 6 and 0.4 

rotations per second during Test 7. 

22
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.14: Straight stream (top), narrow fog stream (middle), and wide fog stream (bottom) from 

the handline in Room C aimed at the south doorway of Room B during Test 5 in the Single Story 

Structure. 

23 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Figure 2.15: North side of Two Story Structure containing a fully established flow path while water 

is flowed in a straight stream pattern during Test 6. 

24
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Section 3 

Results and Discussion 

In the following sections, the measurements are presented in graphic and tabular form. In the 

graphs, an error bar represents the estimated uncertainty of the measurement. In the tables, the 

uncertainty is included in the caption of each table as a percentage enclosed in brackets. 

3.1 Monitor Experiments 

Fig. 3.1 contains a plot of the average gas velocity measured by the bi-directional probes in the 

array at the interior stairwell door (A10) for the straight stream, narrow fog stream, and wide fog 

stream during Test 2. Similar plots of the average measured velocity through the interior doorway 

for Tests 1, 3, and 4 are presented in Appendix B. Additionally, Table 3.1 lists the average velocity 

measured by the bi-directional probes in A10 when the flow path was fully established for each 

hose stream and target location combination studied during Tests 1–4. 

Looking at the table and figures, a number of trends can be observed. For example, there was air 

movement—an average gas velocity greater than 0.5 m/s (1.1 mph)—through the interior doorway 

while the flow path was fully established for every hose stream and target location combination except the straight stream in Test 1. Looking at Table 3.1, the narrow fog and wide fog streams caused 

higher velocities through the interior doorway when the flow path was fully established compared 

to the straight stream. This trend can also be seen graphically in Fig. 3.1 and Figs. B.1 and B.2 

in Appendix B. Furthermore, the wide fog stream generally produced equal or higher air velocities compared to the narrow fog stream. Finally, the Test 4 results listed in Table 3.1 and plotted 

in Fig. B.3 suggest that the straight stream from a combination nozzle and the solid stream from 

a smooth bore nozzle equipped with a 1 in. tip produced approximately the same amount of air 

movement through the interior doorway. 

25
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Table 3.1: Average gas velocity and airflow rate [±18 %] through interior doorway when flow path 

was fully established for each monitor experiment 

Stream Value Units 

———————————– 120 gpm ———————————– 

Test 1 Test 2 Test 3 

Room B 

South 

Doorway 

Near 

Target 

Far 

Target 

Near 

Target 

Far 

Target 

Straight (SS)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

-0.3 ±0.1 

(-0.7 ±0.1) 

-0.6 ±0.1 

(-1250 ±200) 

0.9 ±0.2 

(2.0 ±0.4) 

1.5 ±0.3 

(3100 ±550) 

0.9 ±0.2 

(2.1 ±0.4) 

1.5 ±0.3 

(3250 ±600) 

0.7 ±0.1 

(1.5 ±0.3) 

1.1 ±0.2 

(2400 ±450) 

0.7 ±0.1 

(1.5 ±0.3) 

1.1 ±0.2 

(2400 ±450) 

Narrow

Fog (NF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.1 ±0.2 

(2.5 ±0.5) 

2.1 ±0.4 

(4500 ±800) 

1.0 ±0.2 

(2.1 ±0.4) 

1.6 ±0.3 

(3350 ±600) 

1.4 ±0.3 

(3.2 ±0.6) 

2.4 ±0.4 

(5000 ±900) 

0.8 ±0.1 

(1.7 ±0.3) 

1.3 ±0.2 

(2750 ±500) 

0.8 ±0.1 

(1.7 ±0.3) 

1.2 ±0.2 

(2650 ±450) 

Wide

Fog (WF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

2.5 ±0.4 

(5.6 ±1.0) 

4.6 ±0.8 

(9800 ±1750) 

1.3 ±0.2 

(2.8 ±0.5) 

2.1 ±0.4 

(4400 ±800) 

1.4 ±0.2 

(3.1 ±0.6) 

2.3 ±0.4 

(4800 ±850) 

1.2 ±0.2 

(2.7 ±0.5) 

2.0 ±0.4 

(4200 ±750) 

0.8 ±0.1 

(1.7 ±0.3) 

1.3 ±0.2 

(2750 ±500) 

Stream Value Units 

——– 180 gpm ——– 

Test 4 

Near 

Target 

Far 

Target 

Straight (SS)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.8 ±0.3 

(3.9 ±0.7) 

2.9 ±0.5 

(6150 ±1100) 

2.0 ±0.4 

(4.4 ±0.8) 

3.2 ±0.6 

(6900 ±1250) 

Smooth

Bore (SB)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.8 ±0.3 

(4.0 ±0.7) 

3.0 ±0.5 

(6250 ±1150) 

2.1 ±0.4 

(4.8 ±0.9) 

3.5 ±0.6 

(7450 ±1350) 

26
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
0 60 120 180 240 300 360 420

Time (s)

0.0

0.5

1.0

1.5

Velocity (m/s)

0.0

1.1

2.2

3.4

Velocity (mph)

Water on, near targetStairwell door opened2nd floor, W door openedWater off, doors closedWater on, far targetStairwell door opened2nd floor, W door openedWater off, doors closed

SS A10 Avg

NF A10 Avg

WF A10 Avg

Figure 3.1: Average gas velocity measured by the bi-directional probes at the interior stairwell door 

(A10) during Test 2 for the three hose stream patterns. 

3.2 Handline Experiments 

Fig. 3.2 contains a plot of the average gas velocity measured by the bi-directional probes in the 

array at the interior stairwell door (A10) for the straight stream, narrow fog stream, and wide 

fog stream being applied in a fixed position, a sweeping pattern (back and forth, left-to-right), a 

clockwise rotation, and a counterclockwise rotation during Test 6. Similar plots of the average 

measured velocity through the interior doorway for Tests 5 and 7 are presented in Appendix C. 

Additionally, Tables 3.2 and 3.3 list the average velocity measured by the bi-directional probes in 

27
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
A10 when the flow path was fully established for each hose stream and nozzle movement pattern 

combination studied during Test 5 and Tests 6–7, respectively. 

0 150 300 450 600 750 900

Time (s)

-1.0

-0.5

0.0

0.5

1.0

1.5

Velocity (m/s)

-2.2

-1.1

0.0

1.1

2.2

3.4

Velocity (mph)

Water on, fixedStairwell door opened2nd floor, W door openedWater off, doors closedWater on, sweepingStairwell door opened2nd floor, W door openedWater off, doors closedWater on, rotate CWStairwell door opened2nd floor, W door openedWater off, doors closedWater on, rotate CCWStairwell door opened2nd floor, W door openedWater off, doors closed

SS A10 Avg

NF A10 Avg

WF A10 Avg

Figure 3.2: Average gas velocity measured by the bi-directional probes at the interior stairwell door 

(A10) during Test 6 for the three hose stream patterns. 

28
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Table 3.2: Average gas velocity and airflow rate [±18 %] through interior doorway when flow path 

was fully established for Test 5 

Room A 

Counter Stream Value Units Fixed Clockwise Clockwise 

Straight (SS)

Narrow

Fog (NF)

Wide

Fog (WF)

Velocity
 

Airflow
 

Rate
 

Velocity
 

Airflow
 

Rate
 

Velocity
 

Airflow
 

Rate
 

m/s 

(mph) 

m3/s 

(cfm) 

m/s 

(mph) 

m3/s 

(cfm) 

m/s 

(mph) 

m3/s 

(cfm) 

0.2 ±0.03 

(0.4 ±0.1) 

0.3 ±0.1 

(650 ±100) 

1.7 ±0.3 

(3.9 ±0.7) 

3.2 ±0.6 

(6800 ±1200) 

1.8 ±0.3 

(4.1 ±0.7) 

3.4 ±0.6 

(7300 ±1300) 

0.7 ±0.1 

(1.5 ±0.3) 

1.2 ±0.2 

(2600 ±450) 

1.8 ±0.3 

(4.0 ±0.7) 

3.3 ±0.6 

(7000 ±1250) 

2.1 ±0.4 

(4.8 ±0.9) 

4.0 ±0.7 

(8450 ±1500) 

0.8 ±0.2 

(1.9 ±0.3) 

1.6 ±0.3 

(3300 ±600) 

1.6 ±0.3 

(3.5 ±0.6) 

2.9 ±0.5 

(6250 ±1100) 

2.2 ±0.4 

(4.9 ±0.9) 

4.1 ±0.7 

(8650 ±1550) 

Room B Ceiling 

Counter Stream Value Units Fixed Clockwise Clockwise 

Straight (SS)
 

Narrow
 

Fog (NF)
 

Wide
 

Fog (WF)
 

Velocity
 

Airflow
 

Rate
 

Velocity
 

Airflow
 

Rate
 

Velocity
 

Airflow
 

Rate
 

m/s -0.1 ±0.02 0.6 ±0.1 0.5 ±0.1 

(mph) (-0.2 ±0.04) (1.4 ±0.3) (1.2 ±0.2) 

m3/s -0.2 ±0.03 1.2 ±0.2 1.0 ±0.2 

(cfm) (-400 ±50) (2450 ±450) (2150 ±400) 

m/s 0.9 ±0.2 1.5 ±0.3 1.6 ±0.3 

(mph) (2.1 ±0.4) (3.4 ±0.6) (3.7 ±0.7) 

m3/s 1.8 ±0.3 2.9 ±0.5 3.1 ±0.6 

(cfm) (3750 ±650) (6050 ±1100) (6500 ±1150) 

m/s 2.1 ±0.4 2.3 ±0.4 2.6 ±0.5 

(mph) (4.7 ±0.8) (5.2 ±0.9) (5.8 ±1.1) 

m3/s 3.9 ±0.7 4.3 ±0.8 4.8 ±0.9 

(cfm) (8250 ±1500) (9150 ±1650) (10250 ±1850) 

29
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Table 3.3: Average gas velocity and airflow rate [±18 %] through interior doorway when flow path 

was fully established for Tests 6 and 7 

Stream Value Units Fixed 

Test 6 

Sweeping Clockwise Counter 

Clockwise 

Straight (SS)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

-0.2 ±0.03 

(-0.4 ±0.1) 

-0.3 ±0.1 

(-650 ±100) 

0.5 ±0.1 

(1.2 ±0.2) 

0.9 ±0.2 

(1850 ±350) 

0.7 ±0.1 

(1.6 ±0.3) 

1.2 ±0.2 

(2550 ±450) 

0.7 ±0.1 

(1.7 ±0.3) 

1.2 ±0.2 

(2600 ±450) 

Narrow

Fog (NF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

0.4 ±0.1 

(0.9 ±0.2) 

0.7 ±0.1 

(1450 ±250) 

1.1 ±0.2 

(2.4 ±0.4) 

1.7 ±0.3 

(3700 ±650) 

0.9 ±0.2 

(1.9 ±0.3) 

1.4 ±0.3 

(3050 ±550) 

1.1 ±0.2 

(2.4 ±0.4) 

1.8 ±0.3 

(3800 ±700) 

Wide

Fog (WF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.0 ±0.2 

(2.2 ±0.4) 

1.6 ±0.3 

(3350 ±600) 

1.0 ±0.2 

(2.1 ±0.4) 

1.6 ±0.3 

(3350 ±600) 

1.0 ±0.2 

(2.2 ±0.4) 

1.6 ±0.3 

(3450 ±600) 

0.9 ±0.2 

(2.0 ±0.4) 

1.4 ±0.3 

(3050 ±550) 

Stream Value Units Fixed 

Test 7 

Sweeping Clockwise Counter 

Clockwise 

Straight (SS)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

0.0 ±0.01 

(-0.1 ±0.02) 

-0.1 ±0.01 

(-150 ±50) 

0.5 ±0.1 

(1.2 ±0.2) 

0.9 ±0.2 

(1800 ±300) 

0.7 ±0.1 

(1.6 ±0.3) 

1.2 ±0.2 

(2450 ±450) 

0.7 ±0.1 

(1.5 ±0.3) 

1.1 ±0.2 

(2350 ±400) 

Narrow

Fog (NF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.3 ±0.2 

(2.9 ±0.5) 

2.1 ±0.4 

(4500 ±800) 

1.2 ±0.2 

(2.8 ±0.5) 

2.0 ±0.4 

(4350 ±800) 

1.2 ±0.2 

(2.7 ±0.5) 

2.0 ±0.4 

(4200 ±750) 

1.3 ±0.2 

(2.9 ±0.5) 

2.1 ±0.4 

(4500 ±800) 

Wide

Fog (WF)

Velocity 

Airflow 

Rate 

m/s 

(mph) 

m3/s 

(cfm) 

1.0 ±0.2 

(2.2 ±0.4) 

1.7 ±0.3 

(3500 ±650) 

0.7 ±0.1 

(1.6 ±0.3) 

1.2 ±0.2 

(2500 ±450) 

0.9 ±0.2 

(2.1 ±0.4) 

1.6 ±0.3 

(3300 ±600) 

1.0 ±0.2 

(2.2 ±0.4) 

1.6 ±0.3 

(3450 ±600) 

30
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
With the exception of the narrow fog stream in the fixed position during Test 6, every hose 

stream and nozzle movement pattern combination using a narrow fog or wide fog stream during 

the handline experiments produced air movement—an average gas velocity greater than 0.5 m/s 

(1.1 mph)—through the interior doorway while the flow path was fully established. For the straight 

stream, however, air movement through the interior doorway only occurred when the stream was 

applied in a pattern that involved moving the nozzle. Similar to the monitor experiments, the average air velocity through the interior doorway was always greater in magnitude for the nozzle 

movement patterns using the narrow and wide fog streams than the same patterns using the straight 

stream. Another important result seen in Tables 3.2 and 3.3 is that there are no statistically significant differences (greater than the uncertainty associated with the bi-directional probes) in the 

amount of air flow through the interior doorway when rotating the hoseline in the clockwise direction compared to rotating it in the counterclockwise direction for any of three hose streams tested. 

The similarities in air flow produced by the clockwise and counterclockwise nozzle movement 

patterns can also be seen graphically in Fig. 3.2 and Figs. C.1 and C.2 in Appendix C. 

31
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Section 4 

Summary 

Seven experimental test series containing a total of 154 configurations were conducted to study 

the impact of different hose stream and nozzle movement pattern combinations on air flows within 

residential scale structures. 

Three of the experimental series studied the differences between a straight stream, narrow fog 

stream, and wide fog stream emitted from a combination nozzle attached to a monitor aimed at specific locations in a structure containing different ventilation configurations. For each of the three 

test series, the average air velocity through the interior doorway while the flow path was fully established was greatest for the wide fog stream no matter the location and ventilation pattern within 

the structure. The magnitude of the average air velocity through the interior doorway while the 

flow path was fully established for the narrow fog stream was always equal to or greater than the 

magnitude of the average air velocity for the straight stream. Additionally, a fourth experimental 

series using a monitor was conducted to compare the impact of a straight stream from a combination nozzle to a solid stream from a smooth bore nozzle with a 1 in. tip on air flows within a 

structure. The streams were compared across six different 60 second periods with a fully established flow path: three times each for the monitor aimed at two locations. The results from the four 

monitor test series suggest a wide fog stream impacts air movement within a structure the most out 

of any of the tested streams, followed by the narrow fog stream, and then the straight stream and 

solid stream from a smooth bore nozzle, which both caused approximately the same amount of air 

movement through the structure. 

In addition to the monitor test series, three different experimental series were conducted using 

a combination nozzle attached to a handline to study the impact of different stream and nozzle 

movement pattern combinations on air movement within a structure. Similar to the monitor experiments, the average air velocity through the interior doorway of a structure with a fully established 

flow path was greater for the wide fog and narrow fog streams than the straight stream. It was 

discovered that a straight stream increased air movement through the interior doorway only when 

it was applied in a moving pattern. With regard to Royer’s theory, throughout all the handline 

test series, there were no statistically significant differences in the average air velocity measured 

through the interior doorway between the clockwise and counterclockwise nozzle movement patterns. However, these experiments only addressed cold flow. 

The results from the limited series of water flow experiments demonstrate that hose streams 

can affect air movement within a structure for the described flows and configurations. The type of 

hose stream used and manner in which it is applied dictates the extent to which a stream impacts 

32
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
the ventilation of a structure. These experiments have shown there is a potential for hose streams 

to affect air flows within a structure during fire scenarios. To better quantify the impact of air 

flows from hose streams on the fire environment, additional experiments need to be conducted 

with structure fires in a controlled environment. 

33
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Section 5 

Acknowledgments 

The authors would like to thank Roy McLane (currently with Thermal Fabrication), Kristopher 

Overholt (currently with Continuum Analytics), Keith Stakes (currently with UL FSRI), Nicholas 

Dow (SURF student), and Jay MCElroy (retired) from NIST for their contributions in preparing and conducting these experiments. These experiments could not have been conducted without 

them. 

The Delaware County Emergency Services Training Center provided the location and logistical 

support for these experiments. The Delaware county team was under the direction of Kerby Kerber. 

For construction and test support the team included: Joe Bingham, Dave Wright, Dave Nercesian 

(small engine repair), Mike Gura, Scott Wiercinski, Bill Fields (Fields Fire Protection). We also 

thank the dedicated team of fire instructors and firefighters that supported these experiments; Brian 

Righter (Rudy), John McGowan, Matthew Poissant, John Frey, Brian Embert, Raymond Keller III, 

Mike Bramble, Edward McBride, Mark Morrissey, Bill Norris, and Matt LeTourneau. 

Thank you for assisting NIST in generating data that will assist the fire service in making 

tactical choices. 

34
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
References 

[1] D. Madrzykowski and S. Kerber. Fire Fighting Tactics Under Wind Driven Conditions: Laboratory Experiments. NIST Technical Note 1618, National Institute of Standards and Technology, Fire Research Division Engineering Laboratory, 2009. 

[2] S. Kerber and D. Madrzykowski. Fire fighting tactics under wind driven fire conditions: 7­

story building experiments. NIST Technical Note 1629, National Institute of Standards and 

Technology, Fire Research Division Engineering Laboratory, 2009. 

[3] National Fire Protection Association, Quincy, Massachusetts.	 NFPA 1964: Standard for

Spray Nozzles, 2013. 

[4] IFSTA.	 Essentials of Fire Fighting and Fire Department Operations. Prentice Hall, 5th 

edition, 2008. 

[5] K. Royer and F.W. Nelson. Water for Fire Fighting. Iowa State University Bulletin. Iowa 

State University, Ames, Iowa. 

[6] B.J. McCaffrey and G. Heskestad. A Robust Bidirectional Low Velocity Probe for Flame and 

Fire Application. Combustion and Flame. Technical Report 1, February 1976. 

[7] B.N. Taylor and C.E. Kuyatt. Guidelines for Evaluating and Expressing the Uncertainty of 

NIST Measurement Results. NIST Technical Note 1297, National Institute of Standards and 

Technology, Gaithersburg, Maryland, 1994. 

[8] Stanley Hand Tools, New Britain, Connecticut. User Manual TLM 100, 2013. 

[9] T. Butcher, S. Cook, L. Crown, and R. Harshman. NIST Handbook 44: Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices. National

Institute of Standards, Gaithersburg, MD, 2012. 

[10] R.A. Bryant. A comparison of gas velocity measurements in a full-scale enclosure fire. Fire

Safety Journal, 44:793–800, 2009. 

[11] Akron Brass Company, Wooster, Ohio.	 Style 9300 Flow/Pressure Meter Installation and

Operating Instructions, 2009. 

35
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Appendix A 

Dimensioned Floor Plans 

3.7 m

11.0 m

1.0 m

1.7 m

2.0 m

2.1 m

7.3 m 6.1 m

2.4 m

12.2 m

2.6 m

5.0 m

0.1 m

(all interior walls)

N

Figure A.1: Dimensioned floor plan of the Single Story Structure. Interior dimensions are symmetric across horizontal and vertical centerlines. 

36
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
6.4 m

11.2 m

10.9 m

0.9 m

1.9 m

2.8 m

4.2 m

4.7 m

5.9 m

0.5 m

1.7 m

2.1 m

3.0 m

3.7 m

4.0 m

4.9 m

5.2 m

6.0 m

6.1 m

(all interior walls)

0.1 m

N

11.9 m

10.7 m

0.9 m

1.6 m

7.0 m

5.8 m

4.9 m

2.0 m

3.8 m

0.1 m

2.3 m

2.4 m

3.4 m

3.5 m

N

Figure A.2: Dimensioned floor plan of the second floor (top) and first floor (bottom) of the Two 

Story Structure. 

37 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Appendix B 

Monitor Test Plots 

38 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
0 60

Time (s)

0.0

1.0

2.0

3.0

Velocity (m/s)

0.0

2.2

4.5

6.7

Velocity (mph)

 Water on, S doorway in Room B Water flow stopped

SS A6 Avg

NF A6 Avg

WF A6 Avg

 Each plot is of data from

two separate 30 sec periods ¤

¤ The drop in the shaded region for each plot is a result of the fact that data from two

 nonconsecutive 30 second periods during Test 1 are plotted here as a single data set

 for simplicity. See Section 2.2.1 for more details about the procedure.

Figure B.1: Average gas velocity measured by the bi-directional probes at the interior doorway 

(A6) during Test 1 for the three hose stream patterns. 

39
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
0 60 120 180 240 300 360 420

Time (s)

0.0

0.5

1.0

1.5

Velocity (m/s)

0.0

1.1

2.2

3.4

Velocity (mph)

Water on, near targetStairwell door opened2nd floor, W door openedWater off, doors closedWater on, far targetStairwell door opened2nd floor, W door openedWater off, doors closed

SS A10 Avg

NF A10 Avg

WF A10 Avg

Figure B.2: Average gas velocity measured by the bi-directional probes at the interior stairwell 

door (A10) during Test 3 for the three hose stream patterns. 

40
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
0 80 160 240 320 400 480 560

Time (s)

-1.0

0.0

1.0

2.0

3.0

Velocity (m/s)

 Door

opened ¤

-2.2

0.0

2.2

4.5

6.7

Velocity (mph)

Water on, near target2nd floor, W door openedWater offWater on, near targetWater offWater on, near targetWater off, doors closedWater on, far target2nd floor, W door openedWater offWater on, far targetWater offWater on, far targetWater off, doors closed

SS A10 Avg

SB A10 Avg

¤

Increase is result of opening then closing the second story, west double door

Figure B.3: Average gas velocity measured by the bi-directional probes at the interior stairwell 

door (A10) during Test 4 for the straight stream and smooth bore stream patterns. 

41
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
Appendix C 

Handline Test Plots 

0 30 60 90 120 150 180 210 240

Time (s)

0.0

1.0

2.0

3.0

Velocity (m/s)

0.0

2.2

4.5

6.7

Velocity (mph)

Fixed at Room B ceilingCW at Room B ceilingFixed at S doorway in Room BCW at S doorway in Room BFixed at Room B ceilingCCW at Room B ceilingFixed at S doorway in Room BCCW at S doorway in Room B Water off

SS A6 Avg

NF A6 Avg

WF A6 Avg

Figure C.1: Average velocity through stairwell door during Test 5 for the three hose stream patterns.
 

42
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938
0 150 300 450 600 750 900

Time (s)

0.0

0.5

1.0

1.5

Velocity (m/s)

0.0

1.1

2.2

3.4

Velocity (mph)

Water on, fixedStairwell door opened2nd floor, W door openedWater off, doors closedWater on, sweepingStairwell door opened2nd floor, W door openedWater off, doors closedWater on, rotate CWStairwell door opened2nd floor, W door openedWater off, doors closedWater on, rotate CCWStairwell door opened2nd floor, W door openedWater off, doors closed

SS A10 Avg

NF A10 Avg

WF A10 Avg

Figure C.2: Average velocity through stairwell door during Test 7 for the three hose stream patterns.
 

43
 

______________________________________________________________________________________________________ 

This publication is available free of charge from: http://dx.doi.org/10.6028/NIST.TN.1938