How Cold Is The Coldest Fire?
Defining Cold Fire
The phenomenon of “cold fire” refers to flames or fires that burn at relatively low temperatures compared to regular fires. The term is considered an oxymoron since “fire” evokes images of high heat. However, certain chemical reactions can produce flames at temperatures much cooler than a typical campfire or house fire.
According to Wiktionary, cold fire can be defined as: “A low-temperature flame, that is unlikely to set furnishings alight or burn flesh in incidental contact.” Wiktionary
One example of cold fire is the blue flame produced by burning alcohol. The blue color indicates that the alcohol flame burns at a lower temperature than a typical orange/red fire. Blue alcohol flames may only reach up to 1,700 degrees Fahrenheit, whereas wood fires can exceed 1,800 degrees F. Cold fires can burn handily without felt heat.
Other examples of cold fires are certain pyrotechnic flames produced through chemical reactions that do not rely on high heat. Magicians and special effects artists sometimes use cold fire illusions for entertainment purposes. Overall, while counterintuitive, fires can produce visible flames without substantial heat output.
Measuring Temperature
There are several methods for measuring the temperature of flames and fires. One of the most commonly used tools is called a thermocouple. This is an electrical probe that can be inserted directly into a fire to measure its internal temperature, as described in this paper. Thermocouples contain two metals that produce a small voltage proportional to the temperature difference between the probe tip and the connection point.
Another contact method is using a pyrometer, which contains a thermocouple or thermistor at the probing end. Pyrometers are designed for very high temperature measurements up to 3000°C. For lower temperature flame measurements, k-type thermocouples made from chromel and alumel are commonly used.
Non-contact methods like infrared thermometers can also measure flame temperatures from a distance using a technique called pyrometry. The device detects infrared energy emitted from the fire and converts it to a temperature reading. This allows taking measurements without direct contact with the flames, as explained on Science Buddies.
Properties of Cold Fires
Chemically, cold fires burn at much lower temperatures compared to conventional fires due to their unique chemical properties. According to the safety data sheet from Fire Freeze, the primary component of their Cold Fire product is water-based and contains natural surfactants and plant-based ingredients (Fire Freeze). Surfactants lower the surface tension of water, allowing it to more effectively coat and smother the fuel source. The plant-based ingredients are also naturally fire retardant. Combined, these properties allow cold fire products to suppress flames and prevent reignition.
Specifically, Cold Fire encapsulates the fuel source which cuts off oxygen supply to the fire. Without sufficient oxygen, the fire cannot sustain combustion and burns at a much lower temperature. A study by Eastern Connecticut State University found that on Class B oil fires, Cold Fire was able to prevent burning and reignition by encapsulating the oil (Eastern CT State University). So in summary, the unique chemical properties of cold fire agents allow them to effectively suppress and coat flammable sources, reducing oxygen supply which enables them to burn cold.
Examples in Nature
Natural cold fires occur in nature under certain conditions, typically involving methane gas. Methane fires can burn at relatively low temperatures compared to traditional fires, with blue flames around 1300°F versus over 1800°F for a wood fire. Cold fires naturally occur from methane releases in wetlands, landfills, coal mines, and other areas containing methane sources.[1]
One example is the eternal flame falls in Chestnut Ridge Park in New York, where natural gas seeping from shale rock ignites to create small, cool methane fires. Other cold fire examples are methane bubbles that emerge from wetlands or swamps, igniting upon reaching the air. Cold fires also occur in mines from methane buildup. While unsafe, these cool fires fascinated early miners. Coal mine methane fires can smolder for years.[2]
Natural methane fires provide examples of sustained “cold” combustion relative to hotter wood or gasoline fires. Their lower temperature blue flames showcase the phenomenon of cold fire in nature.
[1]“Cold Fire.” Natural History Magazine, May 2005, www.naturalhistorymag.com/htmlsite/0705/0705_feature.html.
[2]“Burning With Cold Fire.” Medium, Nature Story, 1 Oct. 2021, medium.com/nature-stories/burning-with-cold-fire-fd2c3c5540ab.
Everyday Uses
Cold fires have many practical applications in everyday life. One of the most common uses is in alcohol burners, which rely on the combustion of alcohol fuels like ethanol or methanol at lower temperatures than traditional fires (Cold Fire – Fire Suppressant / Extinguisher). These types of cold fires are used in applications like camping stoves, chafing dishes, and fondue sets. The lower temperature burns safer and more controllably than an open flame.
Another everyday use is in fire suppression systems, like the Cold Fire suppressant. This revolutionary water-based foam suppressant extinguishes fires through heat reduction rather than oxygen deprivation like traditional methods (Cold Fire FAQs: What is a Fire Suppression Agent?). Cold Fire is non-toxic and eco-friendly, making it suitable for commercial and industrial applications.
These types of cold fires allow us to harness the power of fire and combustion in safer, more controlled ways in our everyday lives.
Cold vs Hot Fires
There are significant differences between hot and cold fires. A hot fire burns at a very high temperature, usually above 600°C, and moves slowly as it consumes all available fuel. Hot fires are typically large blazes that give off intense heat and light. In contrast, a cold fire burns at a much lower temperature, generally below 150°C. Cold fires move quickly and do not release as much heat or light as hot fires.
Some key differences between hot and cold fires include:
- Temperature – Hot fires burn at >600°C while cold fires burn at <150°C
- Speed – Cold fires move rapidly while hot fires move slowly
- Fuel consumption – Hot fires consume all available fuel, cold fires only burn the most volatile fuels
- Light and heat – Hot fires give off intense light and heat, cold fires release less
- Flame height – Hot fires have tall flames reaching high into the air, cold fire flames stay low and close to the ground
Both types of fires involve combustion and can be dangerous. However, hot fires pose more risk in terms of the intense heat generated and damage caused. Cold fires may not be as visually dramatic but can still lead to rapid fire spread. Understanding the differences between hot and cold fires helps explain their behavior and guides appropriate suppression tactics.
Sources:
https://envirowildfire.co.za/fire-intensity/
https://www.quora.com/What-is-the-closest-thing-to-fire-or-burning-on-the-cold-side-of-the-temperature-spectrum
World’s Coldest Fire
Cool flames, also known as cold fires or invisible flames, burn at much lower temperatures compared to a typical fire. While most fires burn at temperatures above 600°C, cool flames burn at around 400°C or lower (1). This allows some cool flames to be cold enough to even touch. These unique fires result from specialized chemical reactions under certain conditions.
One of the coldest types of natural fire is will-o’-the-wisp, also known as ignis fatuus. These are ghostly lights that can form over marshy areas at night due to the spontaneous ignition of gases emitted by rotting organic matter (2). The process involves a cool flame combustion reaction estimated to burn around 400–700°C.
In terms of man-made cool flames, researchers have achieved extremely cold fires in laboratory settings. In 2017, scientists from MIT generated a flame sustaining at just 240°C using diluted methane and oxygen mixtures (3). This broke the previous record for the world’s coldest flame of 310°C set in 2015.
Thus, some of the coldest fires recorded so far burn at around 240-400°C. By manipulating specialized fuel sources and conditions, fires can be made much colder than typical open flames, opening up unique applications.
(1) https://en.wikipedia.org/wiki/Cool_flame
(2) https://www.reddit.com/r/askscience/comments/10glbj/what_is_the_coldest_temperature_a_flame_can_be/
Impacts and Applications
Studying cold fires and their properties can have many practical impacts and applications. One key area is in agriculture and land management. As discussed in research from Discovery Farms, understanding cold fires allows farmers to use techniques like no-till farming that conserve nutrients and require less fertilizer (https://talkbusiness.net/2018/11/cold-fire-advanced-human-agriculture-practices-350-years-ago). This can improve sustainability and reduce environmental impacts of modern agriculture.
Additionally, the “Cold Fire Project” utilizes knowledge of cold fires to create healthier forests and soils by lowering wildfire risk and producing edible mushrooms (https://coldfireproject.com/index.php/who-we-are). This demonstrates how cold fire principles can be applied to improve forestry and land use.
Cold fires are also being studied as an alternative to toxic fire fighting foams that contain harmful PFAS chemicals. As discussed by RDR Technologies, cold fire fluids may provide a safer and more sustainable way to fight certain fires without releasing carcinogenic PFAS into the environment (https://rdrtechnologies.com/blog/cold-fire-the-proven-alternative-to-afff). This shows how cold fire research can lead to innovations in fire safety.
Overall, by better understanding the science of cold fires, researchers can find new ways to support agriculture, ecosystem management, fire fighting, and other fields in more sustainable and beneficial ways.
Latest Research
Recent studies have provided new insights into the properties and behavior of cold fires. In 2020, researchers at the University of Arizona published a paper examining the chemical reactions behind cold combustion (https://www.sciencedaily.com/releases/2023/10/231003104756.htm). They found that cold fires rely on oxidization reactions that occur at much lower temperatures compared to conventional fires. This discovery could lead to advances in fire safety and prevention.
Another team at the Desert Research Institute confirmed that climate change will increase wildfire risk and lengthen fire seasons (https://www.dri.edu/climate-change-will-increase-wildfire-risk-and-lengthen-fire-seasons-study-confirms/). Their models predict more days with ideal conditions for cold and hot fires alike. This underscores the need for adaptive fire management strategies.
Ongoing research on cold fires focuses on topics like early detection methods, fuel management tactics, and impacts on ecosystems (https://www.sciencedaily.com/news/earth_climate/wildfires/). As climate change worsens, controlling both hot and cold fires will become an even greater challenge.
Future Directions
Cold fire is an emerging technology with much potential and room for innovation. According to a 2014 report, future research may focus on refining cold fire agents to achieve even lower temperatures and reduced toxicity while maintaining effectiveness. Scientists aim to create cold fires that are safe for humans while still suppressing flames during firefighting. Additionally, there is interest in scaling up production of cold fire chemicals to enable large-scale deployment.
On the application side, researchers envision uses for cold fire beyond firefighting and suppression. For example, cold fire could potentially enable low-temperature controlled burning for agricultural purposes. The Coldfire Project is exploring the use of cold fire in prescribed burns to mitigate wildfire risks. Cold fire may also find industrial applications such as low-temperature welding and more efficient fuel combustion. As the technology matures, cold fire could emerge as a versatile, eco-friendly fire management solution.
Overall, cold fire represents an exciting new frontier in fire science. With continued research, there is tremendous potential to create even colder fires and find novel uses that benefit society. The next decade will likely see rapid advances as scientists refine their understanding of cold fire physics and chemistry. If these efforts succeed, humanity may gain an invaluable tool for managing fire in the 21st century.
