Acknowledgements
Many thanks
to Mr. Jason Clement of the University of Canterbury, Christchurch, New
Zealand, for assistance in conducting the burn experiment. Appreciation
is also extended to Mr. Daniel Madrzykowski of NIST and Mr. Steve Austin
of the International Association of Arson Investigators (IAAI) for support
of this project
Introduction
A
public/private partnership involving multiple federal agencies and private
industrywas assembled todevelop a comprehensive fire investigation training
tool. The partnership consisted of the following federal agencies: the
Bureau of Alcohol, Tobacco and Firearms (ATF), the U.S. Fire Administration,
and the National Institute of Standards and Technology (NIST); and private
industry partners: American Re-Insurance and the National Fire Protection
Association. NIST provided technical assistance to the partnership during
development of an educational interactive CD-ROM for fire investigators,
titled "InterFIRE VR." The CD-ROM contains video of fire ignition
and development in a single family dwelling, as well as visual documentation
of the pre and post-fire scene. Prior to the fire, NIST provided input
into the choice of furnishings, fire scenarios, and ventilation conditions
necessary for the desired fire effects. Recommendations were developed
using the results of computer-based zone fire models, empirical correlations,
and engineering judgment.
During the
fire experiment, NIST conducted measurements of temperature and radiant
heat flux, and recorded video inside the structure. Data were recorded
every 3 s with a computerized acquisition system. The experiment discussed
in this report occurred on May 6, 1998, at the Massachusetts State Police
Academy, 340 Brookfield Rd., New Braintree, Massachusetts. The address
of the dwelling was 5 Circle Drive, New Braintree, Massachusetts. The
measurements conducted in the structure during the test included: ceiling
to floor temperatures within various rooms, and radiant heat flux at floor
level.
.
Structure
The building
used for the fire experiment was an unoccupied, two story, single family
dwelling. The building was of wood frame construction, with gypsum board
interior walls and ceilings. Exterior walls consisted of wood clapboard.
The floors throughout the building, except the kitchen and bathroom, were
constructed of hardwood. The floors in the kitchen and bathroom were covered
with vinyl flooring. Two of the walls in the living room were covered
with laminated wood (pine) paneling.
The
building had a full basement, but it did not extend under the attached
garage. The pitched roof of the building was covered with asphalt shingles.
The
layout of the building is shown in Figs. 1 through 3, and includes four
bedrooms, two bathrooms, living room, dining room, kitchen, and garage.
. All doors in the
building were closed fully during the experiments except the first floor
door leading to the basement, the door from the kitchen to the dining
room, and the upstairs bathroom door. Exterior doors were all fully closed
with the exception of the door from the kitchen to the outside. All windows
of the dwelling were fully closed except for the basement windows and
the upstairs bathroom window which were opened fully. The kitchen windows
over the sink were also open, but not fully.
The distance from the floor to the ceiling in the first floor of the structure
was 2.29 m (7.50 ft), while the distance from the floor to the ceiling
in the hall and bathroom on the second floor of the building was 2.32
m (7.60 ft). The dimensions of the rooms, door openings, and window openings
are given in Figs. 1 through 3. The estimated expanded uncertainties in
the ceiling height and door opening dimensions are ±0.02 m (±0.8
in).
It
should be noted that all of the uncertanties stated in this report are
expanded uncertanties1 derived from Type B evaluations with a coverage
factor, k, equal to 2. A coverage factor of 2 corresponds to a confidence
interval of approximately 95 percent, assuming a normal distribution applies.
A
diagram of approximate furniture locations is shown on Fig. 4.
.
.
Temperature
Measurement
The
temperatures were measured with 0.51 mm (0.02 in) nominal diameter bare
bead, type K thermocouples. The floor to ceiling thermocouple arrays were
in the living room and dining room as shown in Fig. 5. The elevations
of the thermocouples above the floor are given in Table 1.
The
estimated expanded uncertainties in the temperatures of the thermocouples
are ±7 oC (±13 oF) as derived from
the thermocouple wire manufacturer2,3, and voltage measurement
estimates. The estimated expanded uncertainties in the thermocouple locations
are ±0.05 m (2.0 in).
Radiant
Heat Flux Measurement
The
radiant heat flux at the floor of the living room was measured with a
water cooled, Schmidt-Boelter type heat flux transducer. The transducer
was equipped with a sapphire window to exclude convected heat flux. The
view angle of the transducer, with the sapphire window installed, was
approximately 150o. The radiant heat flux transducer was installed
through the floor of the living room in order to protect the cooling and
data lines from fire and physical damage. The face of the transducer was
parallel and flush with the upper surface of the floor. The estimated
expanded uncertainty of the radiant heat flux measurement is ±5
% from manufacturer data3,4, and voltage measurement estimates.
The estimated expanded uncertainty in the radiometer location is ±0.01
m (0.4 in).
Weather
Conditions
The
approximate weather conditions during the experiment were as follows:
temperature, 12 oC (53 oF); relative humidity, 100 %; barometric pressure,
98.3 kPa (29.1 in Hg); wind speed, 1 m/s (3 mph); wind direction, from
74o.
Results
The
sequence of events for the experiment is given in Table 2, with an estimated
expanded uncertainty of 3
s in the event times. Ignition occurred at approximately 0756 h.
The
temperatures of the thermocouples measured within the living room are
shown in Fig. 6. The data are presented for various distances from the
floor, illustrating the temperature profile as a function of height. Data
from all of the temperature measurements are presented in Appendix A of
this report.
Temperatures
of the thermocouples measured within the dining room are shown in Fig.
7.
The
radiant heat flux measured by the transducer in the living room is shown
in Fig. 8.
Table
1. Living room and dining room thermocouple elevations.
|
Thermocouple
|
Number Distance From Floor (m)
|
Distance
From Floor (ft)
|
|
|
|
0
|
2.26
|
7.42
|
1
|
1.98
|
6.50
|
2
|
1.68
|
5.50
|
3
|
1.37
|
4.50
|
4
|
1.07
|
3.50
|
5
|
0.76
|
2.50
|
6
|
0.46
|
1.50
|
7
|
0.15
|
0.50
|
Table
2. Sequence of events.
|
|
|
Event
|
Elapsed
Time (s)
|
|
|
Ignition |
0
|
Call
for suppression |
299
|
Suppression
begins |
350
|
Figure
1. Plan view of first floor.
Figure
2. Plan view of second floor.
Figure
3. Plan view of basement.
Figure
4. First floor furniture locations.
Figure
5. First floor equipment locations.
Figure
6. Living room thermocouple temperatures.
Figure
7. Dining room thermocouple temperatures.
Figure
8. Radiant heat flux at floor level in the living room.
Appendix A
Temperature Measurements
1Taylor,
B.N. and Kuyatt, C.E. "Guidelines for Evaluating and Expressing the
Uncertainty of NIST Measurement Results." NIST Technical Note 1297,
1994 Edition. National Institute of Standards and Technology, Gaithersburg,
MD.
2The Temperature Handbook. Omega Engineering, Inc., Stamford, CT.
Vol. 27.
3The mention of a particular manufacturer's products does not constitute
endorsement by NIST, nor does it indicate that the products are necessarily
those best suited for the intended purpose.
4Bulletin 118. Medtherm Corporation, Huntsville, Al. 1993.
|