Study of the Effectiveness of Fire Service Vertical Ventilation and Suppression Tactics in Single Family Homes

Abstract

Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Program, Underwriters Laboratories examined fire service ventilation and suppression practices as well as the impact of changes in modern house geometries. There has been a steady change in the residential fire environment over the past several decades. These changes include larger homes, more open floor plans and volumes, and increased synthetic fuel loads. This investigation examined the influence of these changes to the fire behavior and subsequent impact on firefighter tactics relative to horizontal and vertical ventilation and suppression. It is anticipated that the results of this investigation will be incorporated into improved firefighting tactics and decision making to reduce firefighter injuries and fatalities. Vertical ventilation has been used successfully but also resulted in firefighter fatalities in the past, as it is not easily coordinated with suppression and other fire ground tasks such as horizontal ventilation. It is not straightforward for firefighters to train on the effects of vertical ventilation since fire service training structures and props do not allow for ventilation-limited fire conditions with representative fuel loads and floor plans that will be encountered on the fire ground. Thus, guidance on the effectiveness of vertical ventilation comes from experience gained during real incidents, but under many different fire ground conditions. This has made it difficult to develop comprehensive guidance on the coordination of vertical ventilation with other firefighter tactics, and how these tactics may influence the fire dynamics in the burning home. The purpose of this study was to improve the understanding of the fire dynamics associated with the use of vertical ventilation so that it may be more effectively deployed on the fire ground. Two houses were constructed in the large fire facility of Underwriters Laboratories in Northbrook, IL. The first house was a one-story house (1200 ft, three bedrooms, one bathroom) with a total of 8 rooms. The second house was a two-story house (3200 ft, four bedrooms, two and a half bathrooms) with a total of 12 rooms. The second house featured a modern open floor plan, two-story great room and open foyer. A total of seventeen experiments were conducted varying the ventilation locations and the number of ventilation openings. Ventilation scenarios included ventilating the front door and a window near the seat of the fire (with modern and legacy furnishings) to link to the previous research on horizontal ventilation, opening the front door and ventilating over the fire and remote from the fire. Additional experiments examined controlling the front door, making different sized ventilation holes in the roof and the impact of exterior hose streams. The results from the experiments led to identification of tactical considerations for the fire service to integrate into their education and fire ground strategies and tactics where applicable.