Kitchen Fire Prevention
CoolGuard ™ is a Disruptive Kitchen Fire Prevention Technology
There is great impetus for residential fire prevention solutions from government agencies, non-profit organizations and the insurance industry. There is an international awareness of the need for residential fire protection. Historically, there have been no mandatory fire protection systems such as sprinkler or automated suppression systems in residential kitchens.
CoolGuard initially cools then inerts the overhead space of hot oil on stove-top items by blocking fresh air from entering the surface, thus preventing auto ignition of the fuel-food item. This process breaks one edge (oxygen) of the well-known "Fire Triangle" so that the hot oil or food does not reach the ignition temperature. CoolGuard fire prevention device can be retrofitted for existing homes and pre-installed in new homes for any type of stoves - either gas or electric. With CoolGuard installed in the kitchens of manufactured homes, residential homes, apartment complexes, hotels and motels, the chance of kitchen related fire developing will be significantly reduced.
The CoolGuard setup contains a smoke alarm or any preignition detector that when activated by dense smoke created by overheated food (above 300 C) or cooking oil on the stove-top sends a signal to an ultrafine water mist device to discharge a gas-like ultrafine mist which slowly moves and covers the cooktop and the cooking vessel. At the same time, the system cuts off the heat source (whether electric or gas) then powers on an exhaust fan to clear the smoke from the area. The ultrafine mist is produced by a specially designed and patented ultrasonic misting device, NanoMist® (US 6,883,724). Because the mist droplet size is extremely small (< 10 micron), it looks and behaves like a gas. It initially vaporizes quickly taking away the heat from the overheated item and then blankets the food item from fresh air entering the surface with no splattering or danger of re-ignition, so the overheated item does not reach the point of ignition. Below are some images of NanoMist in action, courtesy of FS World Magazine publication.
The high density (mist concentration or mass loading) mist shown above blankets the overheated oil surface and prevents air entrainment into the hot surface thus preventing the ignition process. The overhead space saturates quickly, and the rest of the un-vaporized mist serves as a thick blanket. In the event of a false alarm, the ultrafine dry water mist causes no collateral damage. The cooking range looks dry and clean, no electronic equipment is damaged, and the system can be reset in seconds. The influence of extremely fine water mist (< 10 micron) on ignition, flammability, and the fire processes are presented in Articles and in Publications.
A schematic here shows the core concept of CoolGuard technology. The high density mist discharged initially cools the surface and then blocks oxygen entrainment into the hot surface and disrupts one arm of the Fire Triangle, as shown below. The combined cooling and inerting process prevents the ignition process and the development of fire above the hot oil.
However, in the absence of pre-emptive mist discharge on the hot oil surface, unlike in CoolGuard, three arms of Fire Triangle are not disrupted. This will result in auto ignition of oil leading to kitchen stovetop fire, causing damage to the kitchen and threatening lives. The current methods use chemicals or water sprays to put out such fires bringing additional damage and safety concerns.
Preventing Auto Ignition Leading to Residential Kitchen Fires
Put out the fire after it starts?
Prevent fire from ever starting?
Preventing Auto Ignition Leading to Restaurant Deep Fat Fryer Fires
CoolGuard is the Sentinel Standing Watch
• CoolGuard principle is a paradigm shift from fire suppression to fire prevention
• Detects the potential for fire by preignition detectors
• Prevents fire from developing by cooling and inerting with NanoMist®, an ultrafine water mist
• No need to modify cooking ranges or burners
• A platform technology for "micro-volume" cooling and inerting fire prevention scenarios
• Protected by patents and trademarks for cooling and flammability inerting technologies
Fire Suppression and industrial applications are presented in NanoMist Fire Safety section.
The CoolGuard fire prevention product-prototype system has been installed and tested extensively for preventing auto ignition of overheated oils on stovetops in a laboratory kitchen. The CoolGuard fire prevention system consists of a NanoMist generator under the sink, a connection to the water line, a mist discharge port, a preignition detector, and an electronic signal activation unit (CoolGuard Control Unit, CCU). The wiring from CCU to the cooking range and the ultrafine water mist generator, NanoMist® is internal. If the preignition detectors are wireless, there is no hard wire connection to CCU.
CoolGuard Product-Prototype Outlay
CoolGuard Product Description
Ultrafine mist discharge on stovetop
Cooking Oil Temperature - time Plot
CoolGuard Product Package and Projected Cost
The following are essential parts of CoolGuard Package and a best estimate of cost based on volume production:
Ultrafine water mist generator (NanoMist®).
CoolGuard Control Unit (CCU).
Connecting ducts, connectors, mist port, and electrical cables.
The installation-ready CoolGuard Package should cost around $295.
CoolGuard™ Not Activated
NanoMist® Ultrafine Mist for CoolGuard™
NanoMist® Inerting Process for CoolGuard™
Ultrafine Mist Port
CoolGuard Control Unit (CCU)
NanoMist® Ultrafine Mist Generators for CoolGuard™ video shows the high density mist production by NanoMist® ultrafine mist generator.
CoolGuard™ Activated video shows prevention of auto ignition and fire upon activating CoolGuard.
CoolGuard™ Not Activated video shows the development of fire when CoolGuard was not activated,
NanoMist® Inerting Process for CoolGuard video shows the flooding and inerting of a small volume (micro-volume). Although not shown in the video, a heptane pool fire does not ignite in this inerted micro volume.
NanoMist Publication, Spring 2007
CoolGuard Fire Prevention Brochure
Ultrafine Water Mist Work With NRL and Geo-Centers
AHAM Cooking Fire Research Report, 2014
International Association of Fire Chiefs Residential Range Top Safety Report, 2013
Electronic Space Fire Protection Study with Ultrafine Mist with NRL and Hughes Associates
CFD Modeling Study of Ultrafine Water Mist with NRL
Technology Assessment : Home Cooking Fire Mitigation Workshop Report, 2011
CFD Modeling and Testing of Ultrafine Water Mist
Droplet Break up and Formation of Ultrafine Droplets in Blast Mitigation
UL Research Report on Detection of Kitchen Fires
IWMA Conference Paper on NanoMist Fire Safety
Aircraft Hidden Fire Safety by NanoMist Ultrafine Mist
Selected CoolGuard Related Articles
CoolGuard fire prevention technology has a wide array of industrial applications
Preignition detector activated, CoolGuard's cooling/inerting technology consists of low momentum, high density ultrafine mist. Most of the applications are based on micro volumes, localized fire sources, small enclosures or in-cabinet inerting and ignition prevention. These are not total flooding scenarios. For example, each server or heat source is protected by an automatic activation of mist and power down of the fire source upon receiving the preignition or pre-set maximum temperature detection signals.
Some examples include:
Residential kitchen fire prevention
Restaurant kitchen fire prevention
Lithium ion battery over-heating and fire containment
Thermal management and in-cabinet fire protection for individual server racks
Elevator gear control rooms
In general, any enclosed areas or heat source that can be localized can be protected by NanoMist® cooling and inerting behaviors.