<?xml version="1.0"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
	<id>https://fire-safety.academy/w/index.php?action=history&amp;feed=atom&amp;title=Fuel-controlled_fire</id>
	<title>Fuel-controlled fire - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://fire-safety.academy/w/index.php?action=history&amp;feed=atom&amp;title=Fuel-controlled_fire"/>
	<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fuel-controlled_fire&amp;action=history"/>
	<updated>2026-11-04T13:14:27Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.43.11</generator>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fuel-controlled_fire&amp;diff=2578&amp;oldid=prev</id>
		<title>Lisa: Add Intermediate SVG figures with Fire Safety Academy watermark at planned locations; preserve article text</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fuel-controlled_fire&amp;diff=2578&amp;oldid=prev"/>
		<updated>2026-11-02T17:12:49Z</updated>

		<summary type="html">&lt;p&gt;Add Intermediate SVG figures with Fire Safety Academy watermark at planned locations; preserve article text&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 18:12, 2 November 2026&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l9&quot;&gt;Line 9:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 9:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The SFPE Handbook uses the same idea. Walton and Thomas state that fires with sufficient oxygen for combustion are said to be fuel controlled, and that in such fires there is enough air to react with all the fuel within the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-171.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;WT-173&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-173.&amp;lt;/ref&amp;gt; The NIST investigation of the World Trade Center fires defines an overventilated fire in the same way. Enough air is available near the fire to react with all of the gaseous fuel being generated.&amp;lt;ref name=&amp;quot;Pitts-43&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The SFPE Handbook uses the same idea. Walton and Thomas state that fires with sufficient oxygen for combustion are said to be fuel controlled, and that in such fires there is enough air to react with all the fuel within the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-171.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;WT-173&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-173.&amp;lt;/ref&amp;gt; The NIST investigation of the World Trade Center fires defines an overventilated fire in the same way. Enough air is available near the fire to react with all of the gaseous fuel being generated.&amp;lt;ref name=&amp;quot;Pitts-43&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fuel-controlled-fire-v1.svg|thumb|upright=1.5|alt=Two room cross-sections: left, a small fire under a thin smoke layer with air flowing in; right, a large fire with a deep layer and flames out of the door.|Left: a fuel-controlled (overventilated) fire burns completely inside the room below the smoke layer. Right: a ventilation-controlled fire with unburned gases burning outside the opening. Based on Gottuk and Lattimer (2002), p. 2-55 and Walton and Thomas (2002), pp. 3-172 to 3-173.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A related term is the free-burning fire. Walton and Thomas define it as a fire whose pyrolysis rate and heat release rate depend only on the burning of the fuel itself, not on the room environment. It is comparable to a fire burning out of doors on a calm day.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt; A fuel-controlled fire in a room is not necessarily free burning. Wall linings and fuels in the hot upper layer are likely to be influenced by the room environment before flashover, and radiation feedback can enhance the burning rate.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 2.4-15.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;A related term is the free-burning fire. Walton and Thomas define it as a fire whose pyrolysis rate and heat release rate depend only on the burning of the fuel itself, not on the room environment. It is comparable to a fire burning out of doors on a calm day.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt; A fuel-controlled fire in a room is not necessarily free burning. Wall linings and fuels in the hot upper layer are likely to be influenced by the room environment before flashover, and radiation feedback can enhance the burning rate.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 2.4-15.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l21&quot;&gt;Line 21:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 23:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Fuel control during the course of a fire ==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;== Fuel control during the course of a fire ==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;In the [[fire development stages]], fuel control is typical of the growth stage. &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; describes the development phase of a room fire as the period from flaming ignition to flashover. The fire is still local and involves one or a few objects, so its heat release rate is limited by the pyrolysis gases produced.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt; Walton and Thomas likewise describe the growth stage as one in which the fire grows mainly as a function of the fuel itself, with little or no influence from the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;In the [[fire development stages]], fuel control is typical of the growth stage. &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; describes the development phase of a room fire as the period from flaming ignition to flashover. The fire is still local and involves one or a few objects, so its heat release rate is limited by the pyrolysis gases produced.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt; Walton and Thomas likewise describe the growth stage as one in which the fire grows mainly as a function of the fuel itself, with little or no influence from the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fuel-controlled-fire-v2.svg|thumb|upright=1.5|alt=Schematic heat release rate curve: growth, plateau after flashover and decay, with growth and decay shaded as fuel controlled.|Typical course of a compartment fire: fuel controlled during growth, usually ventilation controlled after flashover, and fuel controlled again during decay. Based on Van Rossum (2027), §4.11 and Walton and Thomas (2002), pp. 3-171 to 3-172.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Flashover usually marks the change. After flashover the whole room is involved, there is an abundance of pyrolysis gases, and the fire is usually ventilation controlled.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;VR-4.7&amp;quot;&amp;gt;Van Rossum (2027), §4.7.&amp;lt;/ref&amp;gt; More fuel is then pyrolysed than can burn with the oxygen available in the compartment, and the unburned fuel may burn outside the openings.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt; In the decay stage, as fuel is consumed, the fire may change back from ventilation control to fuel control.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Flashover usually marks the change. After flashover the whole room is involved, there is an abundance of pyrolysis gases, and the fire is usually ventilation controlled.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;VR-4.7&amp;quot;&amp;gt;Van Rossum (2027), §4.7.&amp;lt;/ref&amp;gt; More fuel is then pyrolysed than can burn with the oxygen available in the compartment, and the unburned fuel may burn outside the openings.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt; In the decay stage, as fuel is consumed, the fire may change back from ventilation control to fuel control.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l52&quot;&gt;Line 52:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 56:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;As a second example, Walton and Thomas use a room with a door opening of 1.08 m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; and 1.8 m high.&amp;lt;ref name=&amp;quot;WT-185&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-185.&amp;lt;/ref&amp;gt; Its stoichiometric heat release rate is 1,500 × 1.08 × √1.8 = 2,173 kW. A fire of 500 kW gives φ = 0.23 and is clearly fuel controlled. Babrauskas&amp;#039;s method predicts flashover in this room at about 1,087 kW, half of the stoichiometric value.&amp;lt;ref name=&amp;quot;WT-185&amp;quot; /&amp;gt; A fast t-squared fire would reach that size after about 152 s, so fuel control in a small room can end within minutes.&amp;lt;ref name=&amp;quot;NUREG-B-3&amp;quot;&amp;gt;Iqbal and Salley (2004), p. B-3.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;As a second example, Walton and Thomas use a room with a door opening of 1.08 m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; and 1.8 m high.&amp;lt;ref name=&amp;quot;WT-185&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-185.&amp;lt;/ref&amp;gt; Its stoichiometric heat release rate is 1,500 × 1.08 × √1.8 = 2,173 kW. A fire of 500 kW gives φ = 0.23 and is clearly fuel controlled. Babrauskas&amp;#039;s method predicts flashover in this room at about 1,087 kW, half of the stoichiometric value.&amp;lt;ref name=&amp;quot;WT-185&amp;quot; /&amp;gt; A fast t-squared fire would reach that size after about 152 s, so fuel control in a small room can end within minutes.&amp;lt;ref name=&amp;quot;NUREG-B-3&amp;quot;&amp;gt;Iqbal and Salley (2004), p. B-3.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[File:fse-fuel-controlled-fire-v3.svg|thumb|upright=1.5|alt=Straight line of equivalence ratio against heat release rate for a room with a 1.08 m² door; markers at 500 kW, at flashover (1,087 kW) and at φ = 1 (2,173 kW).|Equivalence ratio φ against heat release rate for a room with a door of 1.08 m² and 1.8 m high: fuel controlled below φ = 1. Based on Walton and Thomas (2002), pp. 3-181, 3-184 and 3-185.]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;For design, the International Fire Engineering Guidelines recommend calculating both the ventilation-controlled and the fuel-controlled heat release rate. The lesser of the two is used as the peak heat release rate of the fully developed fire.&amp;lt;ref name=&amp;quot;IFEG-2.4-14&amp;quot; /&amp;gt; The Australian Data Sheets state the same: the maximum heat release rate is the lesser of the ventilation-controlled and fuel-controlled values.&amp;lt;ref name=&amp;quot;ABCB-B1-13&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B1, p. 13.&amp;lt;/ref&amp;gt; In New Zealand, C/VM2 (second edition, 2025) defines the ventilation limit through fire modelling. It is the heat release rate at the moment the predicted energy release first diverges from the design fire because of a lack of oxygen.&amp;lt;ref name=&amp;quot;CVM2-21&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025b), p. 21.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;For design, the International Fire Engineering Guidelines recommend calculating both the ventilation-controlled and the fuel-controlled heat release rate. The lesser of the two is used as the peak heat release rate of the fully developed fire.&amp;lt;ref name=&amp;quot;IFEG-2.4-14&amp;quot; /&amp;gt; The Australian Data Sheets state the same: the maximum heat release rate is the lesser of the ventilation-controlled and fuel-controlled values.&amp;lt;ref name=&amp;quot;ABCB-B1-13&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B1, p. 13.&amp;lt;/ref&amp;gt; In New Zealand, C/VM2 (second edition, 2025) defines the ventilation limit through fire modelling. It is the heat release rate at the moment the predicted energy release first diverges from the design fire because of a lack of oxygen.&amp;lt;ref name=&amp;quot;CVM2-21&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025b), p. 21.&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key firesb_pjbsiy42-wiki_:diff:1.41:old-457:rev-2578:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>Lisa</name></author>
	</entry>
	<entry>
		<id>https://fire-safety.academy/w/index.php?title=Fuel-controlled_fire&amp;diff=457&amp;oldid=prev</id>
		<title>Daan: New FSE wiki article: Fuel-controlled fire (written by Claude Opus 5.5)</title>
		<link rel="alternate" type="text/html" href="https://fire-safety.academy/w/index.php?title=Fuel-controlled_fire&amp;diff=457&amp;oldid=prev"/>
		<updated>2026-11-01T22:46:59Z</updated>

		<summary type="html">&lt;p&gt;New FSE wiki article: Fuel-controlled fire (written by Claude Opus 5.5)&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;A &amp;#039;&amp;#039;&amp;#039;fuel-controlled fire&amp;#039;&amp;#039;&amp;#039; is a fire whose [[heat release rate]] is limited by the fuel that is burning, not by the supply of air. There is enough oxygen to burn all the combustible gases that the fuel releases.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot;&amp;gt;Van Rossum (2027), §4.8.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;NUREG-2-4&amp;quot;&amp;gt;Iqbal and Salley (2004), p. 2-4.&amp;lt;/ref&amp;gt; Other terms in the sources are fuel-limited fire and overventilated or well-ventilated fire.&amp;lt;ref name=&amp;quot;NUREG-2-4&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Pitts-43&amp;quot;&amp;gt;Pitts et al. (2005), p. 43.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;GL-2-54&amp;quot;&amp;gt;Gottuk and Lattimer (2002), p. 2-54.&amp;lt;/ref&amp;gt; The opposite is a [[ventilation-controlled fire]], in which the air supply limits the burning.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
In a room, every fire starts as a fuel-controlled fire. At first the fire is small compared with the room, and there is plenty of oxygen.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt; A fire in the open air is always fuel controlled.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt; In the growth phase of a compartment fire, the fire is fuel controlled until flashover. After flashover the fire is usually ventilation controlled, and in the decay phase it may become fuel controlled again.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot;&amp;gt;Van Rossum (2027), §4.11.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;WT-172&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-172.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The distinction matters for fire safety engineering, because it decides whether the size of a fire follows from the fuel or from the openings. It also affects how much smoke and carbon monoxide is produced, and whether fire models and design methods can be applied.&amp;lt;ref name=&amp;quot;IFEG-1.4-6&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 1.4-6.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;GL-2-55&amp;quot;&amp;gt;Gottuk and Lattimer (2002), p. 2-55.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;VR-8.4&amp;quot;&amp;gt;Van Rossum (2027), §8.4.&amp;lt;/ref&amp;gt; Design guidance therefore calculates both the fuel-controlled and the ventilation-controlled heat release rate and uses the lesser of the two.&amp;lt;ref name=&amp;quot;IFEG-2.4-14&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 2.4-14.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Definition ==&lt;br /&gt;
&amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; distinguishes two types of fire, with the amount of oxygen as the deciding factor. In a fuel-controlled fire, the development of the fire depends mainly on the fuel, and oxygen is present in sufficient quantity.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt; The Fire Dynamics Tools of the US Nuclear Regulatory Commission describe a fuel-limited fire as a compartment fire in which the air supply is enough to maintain combustion. The amount of fuel that is burning then limits the size of the fire.&amp;lt;ref name=&amp;quot;NUREG-2-4&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The SFPE Handbook uses the same idea. Walton and Thomas state that fires with sufficient oxygen for combustion are said to be fuel controlled, and that in such fires there is enough air to react with all the fuel within the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-171.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;WT-173&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-173.&amp;lt;/ref&amp;gt; The NIST investigation of the World Trade Center fires defines an overventilated fire in the same way. Enough air is available near the fire to react with all of the gaseous fuel being generated.&amp;lt;ref name=&amp;quot;Pitts-43&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A related term is the free-burning fire. Walton and Thomas define it as a fire whose pyrolysis rate and heat release rate depend only on the burning of the fuel itself, not on the room environment. It is comparable to a fire burning out of doors on a calm day.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt; A fuel-controlled fire in a room is not necessarily free burning. Wall linings and fuels in the hot upper layer are likely to be influenced by the room environment before flashover, and radiation feedback can enhance the burning rate.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot;&amp;gt;National Research Council of Canada et al. (2005), p. 2.4-15.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== What limits the heat release rate ==&lt;br /&gt;
In practice, fuel control means that the fire is limited by the rate at which combustible pyrolysis gases are released from the fuel. &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; points out that there is often more than enough combustible material present, but not all of it is directly available as pyrolysis gases.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt; The heat release rate equals the mass burning rate of the fuel times its effective heat of combustion.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt; In a fuel-controlled fire, both depend on the fuel and on the heat it receives, not on the air flow.&lt;br /&gt;
&lt;br /&gt;
The burning rate of a fuel-controlled fire is hard to predict from theory. According to the International Fire Engineering Guidelines, it depends largely on the nature and geometric arrangement of the fuel.&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot; /&amp;gt; Burning rates of uniform fuels such as timber cribs can be estimated with published formulae. Timber cribs are, however, a rather unique arrangement, and the formulae should be used with caution for other fuels.&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot; /&amp;gt; Lie describes the same regime as a fire controlled by the surface area of the materials that can take part in the burning.&amp;lt;ref name=&amp;quot;Lie-202&amp;quot;&amp;gt;Lie (2002), p. 4-202.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Measured burning rates of furniture and other fuel packages are therefore the main data source. They come from free-burn tests and reflect fuel-controlled burning. The guidelines warn that in a building the burning may be inhibited by ventilation or enhanced by radiation feedback, so engineering judgement is needed.&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot; /&amp;gt; Babrauskas notes the same for liquid pools. Burning rates from the literature hold only in a very large, well-ventilated room, and radiation from a hot layer increases the burning rate.&amp;lt;ref name=&amp;quot;Bab-3-26&amp;quot;&amp;gt;Babrauskas (2002b), p. 3-26.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Fuel control during the course of a fire ==&lt;br /&gt;
In the [[fire development stages]], fuel control is typical of the growth stage. &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; describes the development phase of a room fire as the period from flaming ignition to flashover. The fire is still local and involves one or a few objects, so its heat release rate is limited by the pyrolysis gases produced.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt; Walton and Thomas likewise describe the growth stage as one in which the fire grows mainly as a function of the fuel itself, with little or no influence from the compartment.&amp;lt;ref name=&amp;quot;WT-171&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Flashover usually marks the change. After flashover the whole room is involved, there is an abundance of pyrolysis gases, and the fire is usually ventilation controlled.&amp;lt;ref name=&amp;quot;VR-4.11&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;VR-4.7&amp;quot;&amp;gt;Van Rossum (2027), §4.7.&amp;lt;/ref&amp;gt; More fuel is then pyrolysed than can burn with the oxygen available in the compartment, and the unburned fuel may burn outside the openings.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt; In the decay stage, as fuel is consumed, the fire may change back from ventilation control to fuel control.&amp;lt;ref name=&amp;quot;WT-172&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
The Australian Fire Safety Verification Method Data Sheets describe how this can unfold in a fully developed fire. Just after flashover, small items and easily pyrolysed materials produce a very high pyrolysis rate. The fire is then strongly ventilation controlled, with long flames from the openings. Later the pyrolysis rate falls, the flames outside shrink, and at some stage the fire becomes fuel controlled with limited flame extension from the openings.&amp;lt;ref name=&amp;quot;ABCB-B1-14&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B1, p. 14.&amp;lt;/ref&amp;gt; Changes in ventilation, such as breaking windows, can shift the balance during the fire.&amp;lt;ref name=&amp;quot;ABCB-B1-14&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-1.4-6&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
A fully developed fire can also remain fuel controlled throughout. Whether a fire is controlled by the fuel surface or by the ventilation depends on the amount of combustible contents and on the size of the windows.&amp;lt;ref name=&amp;quot;Lie-202&amp;quot; /&amp;gt; In experiments with wood cribs in a 29 m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; compartment, both window areas gave enough air for the lower fire load to burn at its free-burning rate. With the doubled fire load, the burning rate did not double, because the window restricted the ventilation.&amp;lt;ref name=&amp;quot;WT-175&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-175.&amp;lt;/ref&amp;gt; In the World Trade Center, NIST characterised the fires in WTC 2 as fuel controlled and those in WTC 1 as oxygen controlled. In the WTC 2 simulations, a higher burning rate of the furnishings therefore raised the total heat release rate noticeably.&amp;lt;ref name=&amp;quot;McG-111&amp;quot;&amp;gt;McGrattan et al. (2005), p. 111.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;Prasad-230&amp;quot;&amp;gt;Prasad and Baum (2005), p. 230.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Distinguishing fuel and ventilation control ==&lt;br /&gt;
A simple check compares the heat release rate of the fire with the largest heat release rate that the air flowing through the openings can support. For most fuels, about 3,000 kJ of heat is released for each kilogram of air consumed.&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt; The air flow through an opening is roughly proportional to its area times the square root of its height, the [[ventilation factor]] of the opening. This leads to a stoichiometric heat release rate of 1,500 kW per unit of ventilation factor.&amp;lt;ref name=&amp;quot;WT-184&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-184.&amp;lt;/ref&amp;gt; The ratio of the actual heat release rate to this value is the equivalence ratio φ:&amp;lt;ref name=&amp;quot;WT-181&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-181.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;\phi = \frac{\dot{Q}}{1500\,A_0\sqrt{H_0}}&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
! Symbol !! Description !! Unit&lt;br /&gt;
|-&lt;br /&gt;
| &amp;lt;math&amp;gt;\phi&amp;lt;/math&amp;gt; || equivalence ratio, actual heat release rate relative to the stoichiometric one || dimensionless&lt;br /&gt;
|-&lt;br /&gt;
| &amp;lt;math&amp;gt;\dot{Q}&amp;lt;/math&amp;gt; || heat release rate of the fire || kW&lt;br /&gt;
|-&lt;br /&gt;
| &amp;lt;math&amp;gt;A_0&amp;lt;/math&amp;gt; || area of the opening || m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
| &amp;lt;math&amp;gt;H_0&amp;lt;/math&amp;gt; || height of the opening || m&lt;br /&gt;
|-&lt;br /&gt;
| 1500 || stoichiometric heat release rate per unit ventilation factor || kW/m&amp;lt;sup&amp;gt;5/2&amp;lt;/sup&amp;gt;&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
At stoichiometry φ equals 1. A value below 1 means fuel-lean burning, which corresponds to a fuel-controlled fire, and a value above 1 means fuel-rich burning.&amp;lt;ref name=&amp;quot;WT-181&amp;quot; /&amp;gt; The relation is an approximation for fires near flashover and after flashover, when the hot layer reaches close to the floor and the air inflow depends mainly on the opening. It assumes a fuel that releases about 3,000 kJ per kilogram of air.&amp;lt;ref name=&amp;quot;WT-174&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-174.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;WT-173&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
As a first worked example, the 2013 commentary on C/VM2 shows a space of 15 m by 10 m with a vent 8.0 m wide and 3.5 m high. A fast t-squared fire grows to 20 MW, nearly unaffected by the space, and the upper layer never reaches the flashover temperature of 500 °C.&amp;lt;ref name=&amp;quot;MBIE13-61&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2013), p. 61.&amp;lt;/ref&amp;gt; The ventilation factor is 28 × √3.5 = 52.4 m&amp;lt;sup&amp;gt;5/2&amp;lt;/sup&amp;gt;, so the stoichiometric heat release rate is about 78.6 MW. The equivalence ratio is 20 / 78.6 = 0.25, well below 1, so the fire is fuel controlled.&lt;br /&gt;
&lt;br /&gt;
As a second example, Walton and Thomas use a room with a door opening of 1.08 m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; and 1.8 m high.&amp;lt;ref name=&amp;quot;WT-185&amp;quot;&amp;gt;Walton and Thomas (2002), p. 3-185.&amp;lt;/ref&amp;gt; Its stoichiometric heat release rate is 1,500 × 1.08 × √1.8 = 2,173 kW. A fire of 500 kW gives φ = 0.23 and is clearly fuel controlled. Babrauskas&amp;#039;s method predicts flashover in this room at about 1,087 kW, half of the stoichiometric value.&amp;lt;ref name=&amp;quot;WT-185&amp;quot; /&amp;gt; A fast t-squared fire would reach that size after about 152 s, so fuel control in a small room can end within minutes.&amp;lt;ref name=&amp;quot;NUREG-B-3&amp;quot;&amp;gt;Iqbal and Salley (2004), p. B-3.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
For design, the International Fire Engineering Guidelines recommend calculating both the ventilation-controlled and the fuel-controlled heat release rate. The lesser of the two is used as the peak heat release rate of the fully developed fire.&amp;lt;ref name=&amp;quot;IFEG-2.4-14&amp;quot; /&amp;gt; The Australian Data Sheets state the same: the maximum heat release rate is the lesser of the ventilation-controlled and fuel-controlled values.&amp;lt;ref name=&amp;quot;ABCB-B1-13&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B1, p. 13.&amp;lt;/ref&amp;gt; In New Zealand, C/VM2 (second edition, 2025) defines the ventilation limit through fire modelling. It is the heat release rate at the moment the predicted energy release first diverges from the design fire because of a lack of oxygen.&amp;lt;ref name=&amp;quot;CVM2-21&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025b), p. 21.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Use in design and modelling ==&lt;br /&gt;
Most [[design fire]] curves describe a fuel-controlled fire. In C/VM2 (second edition, 2025), the design fires are intended to represent free-burning fires. They must be modified during the analysis to account for building ventilation and for automatic suppression.&amp;lt;ref name=&amp;quot;CVM2-57&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025b), p. 57.&amp;lt;/ref&amp;gt; In the OZone software, the heat release rate, mass loss and fire area curves entered by the user likewise correspond to a fuel-controlled fire, the fire that would occur without any influence of the compartment.&amp;lt;ref name=&amp;quot;CF-402&amp;quot;&amp;gt;Cadorin and Franssen (2003), p. 402.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Fire models must then decide what happens when oxygen runs short. OZone offers several combustion models. As long as oxygen is present in the compartment, the fire is fuel controlled and all the fuel lost releases its energy inside the room.&amp;lt;ref name=&amp;quot;CF-420&amp;quot;&amp;gt;Cadorin and Franssen (2003), p. 420.&amp;lt;/ref&amp;gt; In the decay phase the fire returns to the fuel-controlled regime.&amp;lt;ref name=&amp;quot;CF-421&amp;quot;&amp;gt;Cadorin and Franssen (2003), p. 421.&amp;lt;/ref&amp;gt; &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039; notes that most models handle ventilation-controlled fires poorly or not at all. Users must therefore specify whether unburned gases burn inside, burn outside the room or stop burning.&amp;lt;ref name=&amp;quot;VR-8.4&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Fuel control also affects the products of combustion. In an overventilated compartment fire, the plume stays in the lower layer, combustion is nearly complete and little carbon monoxide is formed.&amp;lt;ref name=&amp;quot;GL-2-55&amp;quot; /&amp;gt; Free-burning, well-ventilated fires are generally of little concern for toxic species.&amp;lt;ref name=&amp;quot;GL-2-54&amp;quot; /&amp;gt; C/VM2 (second edition, 2025) reflects this with separate yields. Before flashover it uses a soot yield of 0.07 kg/kg and a carbon monoxide yield of 0.04 kg/kg. After flashover or once the fire is ventilation limited, these rise to 0.14 and 0.40 kg/kg.&amp;lt;ref name=&amp;quot;CVM2-20&amp;quot;&amp;gt;Ministry of Business, Innovation and Employment (2025b), p. 20.&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;CVM2-21&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
For structural fire design, the distinction appears in the Eurocode parametric fire curve. As described by the Australian Data Sheets, the choice depends on a time calculated from the fire load density and the opening factor. This time is compared with a limiting time of 25 minutes for slow, 20 minutes for medium and 15 minutes for fast fire growth. If the calculated time is at least the limiting time, the fire is ventilation controlled. Otherwise it is fuel controlled, and a modified heating curve is used.&amp;lt;ref name=&amp;quot;ABCB-B3-40&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B3, p. 40.&amp;lt;/ref&amp;gt; Models for a travelling fire in large open floors are also commonly built from a series of localised fuel-controlled fires.&amp;lt;ref name=&amp;quot;ABCB-B1-16&amp;quot;&amp;gt;Australian Building Codes Board (2020a), Data Sheet B1, p. 16.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Limits and common misconceptions ==&lt;br /&gt;
A common misconception is that a fuel-controlled fire is small or harmless. The commentary example above reaches 20 MW while remaining fuel controlled.&amp;lt;ref name=&amp;quot;MBIE13-61&amp;quot; /&amp;gt; In small rooms, flashover often occurs while the fire is still fuel controlled. Babrauskas found that test fires reached flashover at between 0.3 and 0.7 times the stoichiometric heat release rate.&amp;lt;ref name=&amp;quot;WT-185&amp;quot; /&amp;gt; Fuel control describes what limits the fire, not how large or dangerous it is.&lt;br /&gt;
&lt;br /&gt;
A second misconception is that fuel control depends on the total amount of fuel present. It depends on how fast the fuel releases combustible gases, which is governed by its nature, arrangement and exposed surface.&amp;lt;ref name=&amp;quot;VR-4.8&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot; /&amp;gt; In the [[compartment fire]] experiments described by Walton and Thomas, doubling the fire load did not double the burning rate once the window limited the air supply.&amp;lt;ref name=&amp;quot;WT-175&amp;quot; /&amp;gt; For ventilation-controlled fires, a higher fuel load mainly extends the duration of the fire.&amp;lt;ref name=&amp;quot;NUREG-8-1&amp;quot;&amp;gt;Iqbal and Salley (2004), p. 8-1.&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Assuming ventilation control where a fire is actually fuel controlled can also mislead. Drysdale notes that calculating a fire&amp;#039;s temperature history with the ventilation-controlled burning rate overestimates the severity of fuel-controlled fires with large openings.&amp;lt;ref name=&amp;quot;Drys-1-95&amp;quot;&amp;gt;Drysdale (2002), p. 1-95.&amp;lt;/ref&amp;gt; Lie adds that in shallow rooms of limited size, more combustible gas burns outside as ventilation increases, so that the temperature may fall.&amp;lt;ref name=&amp;quot;Lie-203&amp;quot;&amp;gt;Lie (2002), p. 4-203.&amp;lt;/ref&amp;gt; Conversely, burning rates measured under free-burning conditions may underestimate the burning in a hot room, where radiation feedback increases it.&amp;lt;ref name=&amp;quot;IFEG-2.4-15&amp;quot; /&amp;gt;&amp;lt;ref name=&amp;quot;Bab-3-26&amp;quot; /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== See also ==&lt;br /&gt;
* [[Post-flashover fire]]&lt;br /&gt;
* [[Flashover]]&lt;br /&gt;
* [[Hot gas layer]]&lt;br /&gt;
&lt;br /&gt;
== Notes ==&lt;br /&gt;
&amp;lt;references /&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
* Australian Building Codes Board. (2020a). &amp;#039;&amp;#039;Data sheets: Fire Safety Verification Method&amp;#039;&amp;#039; (Handbook annex, Print version 1.1).&lt;br /&gt;
* Babrauskas, V. (2002b). Heat release rates. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., &amp;amp; J. M. Watts Jr. (Eds.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed., pp. 3-1–3-37). National Fire Protection Association; Society of Fire Protection Engineers.&lt;br /&gt;
* Cadorin, J.-F., &amp;amp; Franssen, J.-M. (2003). A tool to design steel elements submitted to compartment fires – OZone V2. Part 1: Pre- and post-flashover compartment fire model. &amp;#039;&amp;#039;Fire Safety Journal&amp;#039;&amp;#039;, &amp;#039;&amp;#039;38&amp;#039;&amp;#039;, 395–427. https://doi.org/10.1016/S0379-7112(03)00014-6&lt;br /&gt;
* Drysdale, D. D. (2002). Thermochemistry. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., &amp;amp; J. M. Watts Jr. (Eds.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed., pp. 1-90–1-98). National Fire Protection Association; Society of Fire Protection Engineers.&lt;br /&gt;
* Gottuk, D. T., &amp;amp; Lattimer, B. Y. (2002). Effect of combustion conditions on species production. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., &amp;amp; J. M. Watts Jr. (Eds.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed., pp. 2-54–2-82). National Fire Protection Association; Society of Fire Protection Engineers.&lt;br /&gt;
* Iqbal, N., &amp;amp; Salley, M. H. (2004). &amp;#039;&amp;#039;Fire Dynamics Tools (FDTs): Quantitative fire hazard analysis methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program&amp;#039;&amp;#039; (NUREG-1805). U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation.&lt;br /&gt;
* Lie, T. T. (2002). Fire temperature-time relations. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., &amp;amp; J. M. Watts Jr. (Eds.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed., pp. 4-201–4-208). National Fire Protection Association; Society of Fire Protection Engineers.&lt;br /&gt;
* McGrattan, K. B., Bouldin, C., &amp;amp; Forney, G. P. (2005). &amp;#039;&amp;#039;Computer simulation of the fires in the World Trade Center towers&amp;#039;&amp;#039; (NIST NCSTAR 1-5F). National Institute of Standards and Technology.&lt;br /&gt;
* Ministry of Business, Innovation and Employment. (2013). &amp;#039;&amp;#039;Commentary for Building Code clauses C1–C6 and Verification Method C/VM2&amp;#039;&amp;#039;.&lt;br /&gt;
* Ministry of Business, Innovation and Employment. (2025b). &amp;#039;&amp;#039;Verification Method C/VM2: Framework for fire safety design&amp;#039;&amp;#039; (2nd ed.).&lt;br /&gt;
* National Research Council of Canada, International Code Council, Department of Building and Housing, &amp;amp; Australian Building Codes Board. (2005). &amp;#039;&amp;#039;International fire engineering guidelines&amp;#039;&amp;#039; (2005 ed.). Australian Building Codes Board.&lt;br /&gt;
* Pitts, W. M., Butler, K. M., &amp;amp; Junker, V. (2005). &amp;#039;&amp;#039;Visual evidence, damage estimates, and timeline analysis&amp;#039;&amp;#039; (NIST NCSTAR 1-5A). National Institute of Standards and Technology.&lt;br /&gt;
* Prasad, K., &amp;amp; Baum, H. (2005). &amp;#039;&amp;#039;Fire Structure Interface and thermal response of the World Trade Center towers&amp;#039;&amp;#039; (NIST NCSTAR 1-5G). National Institute of Standards and Technology.&lt;br /&gt;
* Van Rossum, E. (2027). &amp;#039;&amp;#039;Introduction to Fire Safety Engineering&amp;#039;&amp;#039;. Fire Safety Academy.&lt;br /&gt;
* Walton, W. D., &amp;amp; Thomas, P. H. (2002). Estimating temperatures in compartment fires. In P. J. DiNenno, D. Drysdale, C. L. Beyler, W. D. Walton, R. L. P. Custer, J. R. Hall Jr., &amp;amp; J. M. Watts Jr. (Eds.), &amp;#039;&amp;#039;SFPE handbook of fire protection engineering&amp;#039;&amp;#039; (3rd ed., pp. 3-171–3-188). National Fire Protection Association; Society of Fire Protection Engineers.&lt;br /&gt;
&lt;br /&gt;
[[Category:Enclosure Fires]]&lt;/div&gt;</summary>
		<author><name>Daan</name></author>
	</entry>
</feed>