Effectiveness Of Fire Service Vertical Ventilation And Suppression Tactics

Under an award from the Federal Emergency Management Agency (FEMA) and Department of Homeland Security (DHS) Assistance to Firefighter Grant Program (EMW-2010-FP-00661), this project examines fire service ventilation practices and 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 examines the influence of these changes to the fire behavior and subsequent impact on firefighter tactics relative to horizontal and vertical ventilation.

Two houses are constructed in the large fire facility of Underwriters Laboratories in Northbrook, IL. The first house is a one-story house (1200 ft2, three bedrooms, one bathroom) with a total of 8 rooms. The second house is a two-story house (3200 ft2, four bedrooms, two and a half bathrooms) with a total of 12 rooms. The second house features a modern open floor plan, two-story great room and open foyer.

A total of seventeen experiments are conducted varying the ventilation locations and the number of ventilation openings. Ventilation scenarios include 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 study, opening the front door and ventilating over the fire and remote from the fire. Additional experiments examine controlling the front door, making different sized ventilation holes in the roof and the impact of exterior hose streams.

Context

Vertical ventilation has been used successfully. Conversely, it has also resulted in tactical firefighter failures in the past, as it is not easily coordinated with suppression and other fire ground tasks as is horizontal ventilation. It is not easy 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 fireground 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 a burning home. 

Objectives

The purpose of this study is 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 fireground.