This page contains information about Fire Prevention and Safety Research and Development Grant number EMW-2010-FP-00661. The content is useful for those in the fire service seeking information about to how to improve the safety and health of firefighters.
|Project Title:||Study of the Effectiveness of Fire Service Vertical Ventilation and Suppression|
|Organization:||Underwriters Laboratories, Inc.|
|Principle Investigator:||Thomas Fabian, Ph.D|
|Period of Performance:||06/12/2011 – 06/11/2013|
Ventilation is believed to be one factor that is contributing to firefighter injuries and deaths inside structures. There is a lack of understanding of the rapid changes in fire conditions in residential structures that can result from changes in natural ventilation and use of enhanced ventilation as common firefighting practice. The potential for rapid increase in fire spread and intensity in residential fires as a result of changes in construction materials, building contents and building size and geometry over the past 30 years compounds the lack of understanding of the contributions of changing ventilation on firefighter safety.
This project will increase firefighter safety by providing credible scientific information developed from full-scale testing in realistic single-family homes. The project will develop the empirical data on vertical ventilation techniques that is needed to quantify the fire behavior associated with various residential ventilation scenarios and develop the necessary fire fighting ventilation practices that will reduce the risk of firefighter death and injury. Suppression techniques used to fight these modern fire conditions will also be examined. Additionally, this fire research project will address questions of smoke alarm response associated with different smoke alarm technologies and alarm location to support fire department smoke alarm distribution programs including those funded by the AFG Fire Prevention and Safety Grant program.
The project will develop empirical data from full-scale house fire experiments conducted in a large laboratory facility. Vertical ventilation, suppression techniques and the resulting fire behavior will be measured and documented. Additionally, during the same full-scale house fire experiments, but prior to the ventilation and suppression activities, measurements of smoke alarm response associated with different smoke alarm technologies and alarm location will be measured.
Two houses were constructed in the large fire facility of Underwriters Laboratories in Northbrook, Illinois. The first house was a one-story house (1200 sq. ft., three bedrooms, one bathroom) with a total of eight rooms. The second house was a two-story house (3200 sq. 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 17 experiments were conducted varying the ventilation locations and the number of ventilation openings. Based on the research, tactical fire ground considerations for vertical ventilation and suppression were developed including the following presented in the online training:
- Limiting the air supply to the fire was found to be an important consideration for the ventilation-limited fires.
- There was not a ventilation hole size used (4 ft. by 4 ft. or 4 ft. by 8 ft.) in the experiments that slowed the growth of the fire. Once water was applied to the fire, however, the larger the hole was, and the closer it was to the fire, allowed more products of combustion to exhaust out of structures, causing temperatures to decrease and visibility to improve.
- Ventilation over the fire is the best choice if the fire attack is coordinated.
- Ventilating remote from the fire can be effective under some circumstances. Vertical ventilation remote from the fire can provide a visibility benefit, but the fire and temperatures in the area of the fire increase.
- Flow paths and timing are very important to understanding fire dynamics and the impact of firefighter tactics on the fire ground. The closer the air is provided to the seat of the fire, the faster it can intensify.
- As home furnishings have evolved over decades to be made of synthetic materials, the heat release rates generated by home furnishings have increased significantly. This change speeds up the stages of fire development, creating and increased potential for ventilation-limited fire conditions prior to fire department arrival.
- Water application considerations include: softening the target prior to making entry into the structure; the inability to push fire, as fire was never close to being forced from one room to another with a hose stream, and the benefits of applied water to the seat of the fire in a large open volume.
- The fire dynamics of home fires are complex and challenging for the fire service. Ventilation is paramount to understand for safe and effective execution of the mission of the fire service to protect life and property. Vertical ventilation is especially important because it requires being positioned above the fire and can have a fast impact on interior fire conditions.
The UL Firefighter Safety Research Institute reported that the research results have been used to modify tactics for departments including the Fire Department of New York, the Chicago Fire Department, the Los Angeles Fire Department, and the Central Whidbey Island Fire and Rescue.
Reports and Resources
Online Interactive Training:
Based on the results of this study, UL developed online training modules for the benefits of all firefighters. This training is offered by the UL Firefighter Safety Research Institute without cost. The training material titled “Effectiveness of Fire Service Vertical Ventilation and Suppression Tactics in Single Family Homes” may be accessed via the UL website using the link:
A full report of this research, Effectiveness of Fire Service Vertical Ventilation and Suppression Tactics, is available for download from the UL Firefighter Safety Research Institute website via the link above.