This report provides a general overview of nozzle-aspirated class A and compressed air foam systems. It then discusses hands-on evaluations by several fire departments that are currently using class A foam systems in structural fire suppression or wildland/urban interface fire protection. Reported advantages and disadvantages in the use of class A foams and CAFS in structural firefighting, both from field experience and from recent fire protection literature, are included in this report.

It was found that the amount of water necessary to provide initial fire suppression was an average of 29.5 percent less with the use of Class "A" foam versus plain water. In total overall operations, including salvage and overhaul, the overall necessary water usage was reduced by 37.4 percent. Based upon the information obtained and the results of the experiment, several recommendations are made.

Wildland fire services have successfully integrated compressed air foam systems (CAFS) into their fire suppression arsenal over the last few decades to effectively increase the firefighting ability of water. Many urban fire departments have done the same, but far more still rely on plain water to extinguish Class A fires. Many claims have been made about the advantages and disadvantages of firefighting foams, but only limited research has been conducted on the subject to date. Fire departments need more information, beyond that provided by foam suppliers and CAFS equipment manufacturers, to make an independent decision on whether or not to adopt the technology. This thesis is part of a larger project sponsored by the United States Department of Homeland Security Assistance to Firefighter Grant Program (grant ID: EMW-2010-FP-01369) to evaluate the capabilities and limitations of compressed air foam systems (CAFS) for use in structural firefighting applications. Large-scale tests comparing water and foam suppression, which includes aspirated foam and CAFS, in a variety of scenarios were performed to measure the ability of the hose streams to reduce the temperature of a hot gas layer within a structure. These temperature reductions were recorded with thermocouples and are analyzed to determine which suppression agent has a superior gas cooling ability.

During the past few years, the Stamford Fire Department has been grappling with the idea of using Class A foam for structural firefighting. This research is based on the question of whether the Stamford Fire Department should adapt it's equipment and procedures to include the use of Class A foam for structural firefighting in Stamford, Connecticut.