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Engineering Laboratory / Fire Research Division

National Fire Research Laboratory

Tree04

Table 1. Test Information
Name
Tree04
Date
Description

3.95 m Douglas fir tree ignited with gas ring buner at base. Moisture Content 8.4 %
Specimen
14 ft Douglas Fir Tree
Ignition
Natural Gas Ring Burner with spark
Project ID (s)
Design Fires - Tall Trees
Test Director
Hamins

Timelapse Video with Heat Release Rate Plot

Table 2. Summary of Test Results
Measurement Value Uc Unit
Peak Heat Release Rate, PHRR
13,668
813
kW
Time to Peak Heat Release Rate
0.12
0.07
min
Total Heat Released, THR
218
15
MJ
Gas Burner Total Heat Released, NGTHR
2.183
0.032
MJ
Heat Release Quality Confirmation, HRQC
 Not measured -
MJ/MJ
Net Specimen Mass (gravimetric), NM = Mi-Mf
11.30
0.14
kg
Net Effective Heat of Combustion = THR / NM
19.3
1.3
MJ/kg
O2 Yield = O2 Consumed / NM
1.496
0.051
kg/kg
CO2 Yield = CO2 Generated / NM
1.825
0.070
kg/kg
CO Yield = CO Generated / NM
0.0863
0.0033
kg/kg
Soot Yield = Soot Generated / NM
0.00344
0.00044
kg/kg
Baseline Hood Exhaust Flow
90.8
2.7
kg/s
Test Duration = Time(Fire Out) - Time(Ignition)
5.75
0.03
min

Uc = Combined Expanded Uncertainty with 95% confidence level

Table 3. Summary of Test Input Parameters
Parameter Value Uc Unit
Fuel Type
Cellulose
 - -
Hood Size
15
 -
m
Effective Duct Diameter
2.424
0.009
m
Exhaust Flow Correction Factor
1.042
0.032
 -
Net Heat of Combustion (per unit mass O2), Ef
13.23
0.66
MJ/kg
Net Heat of Combustion(per unit mass fuel), HOCf
21.00
1.30
MJ/kg
Initial Specimen Mass, Mi (gravimetric)
24.46
0.10
kg
Final Specimen Mass, Mf (gravimetric)
13.16
0.10
kg
Plot of Fire Heat Release Rate with event markers. Uncertainty bar shown at peak value.
Figure 1. Plot of Heat Release Rate data with event markers and error bars shown at peak.
Table 4. Summary of Observed Test Events
Event Time (min) Description Video Snapshot Image
1
0.00
Ignition
Ignition
peak
0.12
Peak HRR
Peak HRR
2
5.42
water suppression
water suppression
3
5.75
Fire Out
Fire Out

Table 5. Supplemental Data Plots

Plot of Oxygen Dry Volume Fraction in hood exhaust stream.
Plot of Oxygen Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Dioxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Dioxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Monoxide Dry Volume Fraction in hood exhaust stream.
Plot of Carbon Monoxide Dry Volume Fraction in hood exhaust stream.
Plot of Radiant Heat Flux data with event markers. r= radial distance from center of hood, h=height above floor.
Plot of Radiant Heat Flux data with event markers. r= radial distance from center of hood, h=height above floor.
Plot of Smoke Laser Extinction Coefficient in hood exhaust stream.
Plot of Smoke Laser Extinction Coefficient in hood exhaust stream.
Plot of Exhaust Duct Mass Flow Rate.
Plot of Exhaust Duct Mass Flow Rate.

Bryant, R. and Bundy, M. The NIST 20 MW Calorimetry Measurement System for Large-Fire Research, Technical Note (NIST TN) 2077, 2019
https://doi.org/10.6028/NIST.TN.2077

NIST Fire Calorimetry Database (FCD)
https://doi.org/10.18434/mds2-2314

Report Process Script Version
NFRL_Report_8.6.0
Last Updated April 30, 2025
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