There is a continued tragic loss of firefighter and civilian lives, as shown by fire statistics. One significant contributing factor is the lack of understanding of fire behavior in residential structures resulting from the use of ventilation as a firefighter practice on the fire ground. The changing dynamics of residential fires as a result of the changes in home construction materials, contents, size and geometry over the past 30 years compounds our lack of understanding of the effects of ventilation on fire behavior. Positive Pressure Ventilation (PPV) fans were introduced as a technology to increase firefighter safety by controlling the ventilation. However, adequate scientific data is not available for PPV to be used without increasing the risk to firefighters.
This fire research project acquired experimental data from full-scale house fire experiments and examined positive pressure ventilation used during fire attack, suppression techniques and the resulting fire dynamics. The experimental results were used to develop tactical considerations outlining firefighting ventilation and suppression practices to help reduce firefighter death and injury. This fire research project drew from and enhanced previous DHS AFG sponsored research (EMW-2008-FP-01774) which studied the impact of horizontal ventilation through doors and windows and (EMW-2010-FP-00661) which studied the impact of vertical ventilation through the roof. This project addressed the concerns the firefighter community has expressed and provided a baseline for choosing the most appropriate type or types of ventilation on the fire ground. The fire service now has scientific based comparisons between the three types of ventilation used on the fire ground everyday across the country. A comprehensive fire service outreach program was created to ensure the science met the street.
The residential structures utilized mirrored those used from the horizontal ventilation (EMW-2008-FP-01774) and vertical ventilation (EMW-2010-FP-00661) to allow for direct comparisons. The full scale testing was broken into two phases. The first phase incorporated testing both the electric and gas powered 18” fan from six major manufactures to compare their performance capabilities. The fans were ranked according to their total flow and pressure capabilities. The fan which most closely matched the average flow of all fans was selected for phase two, the full scale fire experiments. Twenty five full scale fire experiments were conducted, fifteen in the single story and ten in the two story structure.
The results of the experiments were then examined with the fire service technical panel and utilized to develop 16 fire service tactical considerations for use when conducting positive pressure attack or positive pressure ventilation. For more information on these tactical considerations download the full project report in the resources section above. These tactical considerations include: