This issue of  Emerging Trends is brought to you by DuPont.

Letter from the Editor: Welcome to the May 2007 issue of Fire Protection Engineering Emerging Trends, Fire Protection Engineering magazine's 8-time a year e-newsletter that deploys on the off-months of the magazine. Each issue will highlight a new trend and/or innovation in the fire protection engineering industry. This issue will focus on security film.

Please enjoy the May issue and thank you for your continued support!

Sincerely,

Morgan J. Hurley, P.E.

ADVERTISEMENT:

DuPont Fire Extinguishants

The DuPont FE line of clean agent fire extinguishants offers an alternative to Halon-based products. The products cease the combustion process through heat absorption and chemical interaction; are safe for people assets; and the environment. DuPont clean agents can be used in new applications or replace other agents in existing systems with minimal modifications.

www.cleanagents.dupont.com

SECURITY WINDOW FILM

Conventional window glass was not designed to resist windblown debris, earthquakes, explosions or terrorist attacks.

Subjected to such stresses, existing glass can break into shards that can endanger building occupants and passers-by. Broken glass can also cause property damage that would not have occurred had the glass remained in its frame.

Security window film can improve the ability of existing glass to mitigate the impact of explosive force and windblown debris. The primary function of security film is to hold glass intact in the event of it being broken, preventing glass from becoming flying projectiles. In some cases, the glass may shatter but remain intact.

Hurricanes and tornadoes produce intense winds, which create damage and injury from flying glass. Earthquakes twist or flex the glass. The intensity of the earthquake will determine whether the glass breaks.

Most injuries from glass are caused by walking into panes of glass. A hurricane can project an object through a window causing shards to strike occupants. The explosion of a bomb creates a shock wave that causes glass to break into lethal projectiles.

How to make window glass safer
Windows transmit light and enable building occupants to see outside. In storefronts, windows facilitate objects being seen from the outside. Windows can also generate passive solar energy.

Typical window performance problems include unacceptable air infiltration, poor insulating capability, inability to block solar heat, the transmission of ultraviolet radiation and noise and vulnerability to electronic eavesdropping. Security enhancements to glass become more economically feasible if they do not impede, but actually improve energy and other window performance capabilities.

Existing glass can be replaced with laminated glass, two or more pieces of glass bonded by an interlayer. Compared to conventional glass, laminated glass can provide increased resistance to windblown debris, and seismic and explosive forces.

Security window film
Security window film is the alternative to replacing existing glass with laminated glass. Security window film can be optically clear, tinted, or reflective layers of polyester film applied to the interior surface of existing glass. Typical film installations cover the visible portion of the surface of the glass all the way to the edge of the frame, but do not extend to the glass edge within the frame.

Film can be applied to both single-pane and many types of insulating glass. Proper application of appropriate film to insulating glass does not impact the integrity of an insulating glass sealant or generate thermal stress to glass from uneven heat absorption. Applied security window film is available with and without solar control capabilities.

Because security window film has the ability to stretch without tearing, it can absorb a significant degree of the shock wave of an explosion. As this explosive force moves toward the glass and pushes it inwards, the glass eventually cracks and breaks. However, the security film applied to the glass can absorb the shock wave, stretching until it can no longer bear the pressure, at which time it bursts.

The shock wave, when great enough to break the glass, may not be enough to shear the film. This results in the glass being broken, but held intact by the film. In these cases, not only are there no injuries, but there is no damage in the building. In other cases, the shock wave breaks the glass and shears the film. The glass collapses, attached to the security film, causing minimal damage and injuries. In multistory buildings, security film may also prevent glass from falling to the street below.

Security window film vs. laminated glass
Both laminated glass and security window film may mitigate the impact of explosions, windblown debris and earthquakes. The performance of both depends on the relationship of each to the existing window frames.

In the case of laminated glass, the window frame must support the weight and thickness of the glass for the total glass and window system to resist stress. Installing laminated glass in existing window frames that are not designed to support the weight of laminated glass may not prevent the glass separating from the frames when the glass is stressed.

Similarly, the ability of security window film to resist force may increase if the film is not only applied to the glass but attached to the frame. Many window film manufacturers market film-attachment mechanisms to secure film to the window frame.

Also, laminated glass is not as energy-efficient as other glass options, resulting in a trade-off between energy and safety/security performance. Its composition and resistance to force impede the ability to break laminated glass for emergency entrance or egress.

Cost of laminated glass vs. security window film
The optimum security window film not only provides increased protection from stress; it may reduce a building's energy consumption by blocking solar heat. The cost of disruptions to building occupants in removing and replacing existing glass compared to applying security window film to existing glass also needs to be taken into account when comparing laminated glass and security film.

What to look for when evaluating a security film
• Price – The true value of the film is determined by its independently verified performance in terms of mitigating explosive and other forces, life expectancy and energy efficiency. More expensive films should perform better than less expensive films.

• Energy benefits – The film's ability to block solar heat and its ability to transmit desirable daylight should be reviewed. Most security films that block heat also block significant amounts of light.

• Aesthetic considerations – The ideal security film provides optimum security and energy performance without changing the appearance of the building. Clear, colorless security film is applicable on all or selective windows of a building.

Marty Watts is with V-Kool, Inc.

ADVERTISEMENT: SFPE Job Board

http://jobs.sfpe.org/

The Society of Fire Protection Engineers and Fire Protection Engineering magazine are excited to introduce a new Internet Job Board site featuring career opportunities in
fire protection engineering.

http://jobs.sfpe.org/ is designed for communicating the availability of employment opportunities in the fire protection engineering market. This special job board is ideal both for those seeking to fill positions and those looking for employment opportunities in
fire protection engineering.

Job categories include:
• Consulting
• Research & Testing
• Government
• Fire Equipment Manufacturing & Installation
• Insurance
• Education

Whether you're looking to make a career move, or you need to fill a fire protection engineer opening, http://jobs.sfpe.org/ is just a click away!

FPE Spring 2003 - Study of Building Performance in the WTC Disaster
The impacts of aircraft into the twin towers of the World Trade Center set off a chain of events seen via television coverage by many of the world's population on September 11, 2001. These aircraft damaged portions of the structure of the twin towers and also initiated fires on several floors. By the end of the day, four buildings collapsed, three buildings were severely damaged by fire, and seven buildings sustained significant damage, while numerous others suffered minor damage.
READ MORE

FPE Fall 2003 - How the GSA Ensures Safety and Security
This article highlights how fire protection engineers with the U.S. General Services Administration (GSA) work with security specialists from the Federal Protective Service (FPS) to ensure that fire safety and security features are integrated into the design of new buildings and major renovation projects.
READ MORE

Copyright 2007, Penton Media, Inc. All rights reserved. This e-newsletter is protected by United States copyright and other intellectual property laws and may not be reproduced, rewritten, distributed, re-disseminated, transmitted, displayed, published or broadcast, directly or indirectly, in any medium without the prior written permission of SFPE and Penton Media, Inc.