|So What Do You Expect?|
Viewpoint: So What Do You Expect?
By Warren G. Stocker | Fire Protection Engineering
From an owner's perspective, there is a myriad of concerns relative to protecting a storage facility. The expectation is that the fire protection engineer will aggressively attack a design problem and come up with the right balance to adequately address life safety and property protection. However, adequate and least expensive should not be confused, although cost is obviously a consideration. Herein lies the biggest challenge for the design professional. How can one achieve the optimum design within the parameters dictated by the owner; that meets applicable codes and ordinances promulgated by the authorities having jurisdiction; and satisfy one's moral, professional, and ethical obligations?
Alarms to warn occupants of fire are important components of life safety. NFPA 101 calls for fire alarm systems in ordinary and high-hazard contents storage occupancies that are not protected by an automatic sprinkler system and whose total floor area exceeds 9,000 square meters (100,000 square feet). However, alarms are not required in occupancies with low-hazard contents. After reviewing the facts and making a determination that an alarm system is needed, the next question is usually, "How many devices are necessary to ensure they are audible and/or visible throughout the building?" This represents one of the areas of frustration for the owner. Codes rarely address all of the sitespecific conditions that exist in a built environment. There is a natural tendency to apply the general requirements, which in some cases may border on excess. For example, is it practical to install horn strobes in every aisle between 10-meter (35 feet)-high double-row rack storage in a 12-meter (40 foot)-high building? At issue is the balance between minimum requirements and enhanced reliability. Usually, there is an appeal for a common-sense approach that will meet the intent rather than carry out the exact letter of the code. This is where the design professional can really have an impact by carefully evaluating the options and coming up with a concept mutually acceptable to the stakeholders.
In addition to addressing life safety issues, providing systems that will mitigate losses is one of the primary objectives. Most codes require automatic sprinklers in storage occupancies, particularly those with high-piled or high-hazard contents. What is often stated is that codes provide the minimum requirements. Typically, the design is based on the most severe hazard. With the increased use of plastics in products and packaging materials, hazard classification for mixed items can be difficult. This is further complicated by the fact that the commodity mix in a storage occupancy can often change. Determining the protection requirements for other high-hazard commodities, such as aerosols and combustible/flammable liquids, can be challenging as well. There is a delicate balance between providing the right protection for the right hazard. Several years ago, a fire occurred in a warehouse that contained Class III commodities for decades. Over the years, combustible liquids in plastic containers were introduced. A total loss resulted, primarily due to the fact that the sprinkler protection had not been upgraded to handle the increased hazard. This provides one of the best opportunities for the engineer to excel by drawing on experience and utilizing resources, such as modeling and available reference data stemming from actual fire tests, in designing systems.
There is a delicate balance between providing the right protection for the right hazard.
Fire protection engineers not only have to focus on effective protection in the design process, but they also have to be cognizant of the needs of the facility owner beyond the completion of the installation. There are operational issues to be considered. The owner is looking for a trouble-free, easy-to-maintain-system. If the applications involve a refrigerated warehouse, frozen pipes are not uncommon. Although technology is available to minimize premature actuation and research is underway to develop more dependable systems, the fact remains this is a chronic and costly problem for owners. The expectation is that design professionals use their best judgment to evaluate new technology and the risks associated with concepts with not much of a track record.
It may sound like owners/operators of storage occupancies expect a lot from fire protection engineers. They do! Fortunately, the profession has yielded a number of high-quality engineers who are creative, dedicated, knowledgeable, and intuitive. Fire protection engineers as a whole have met and often exceeded expectations. Keep up the good work!
Warren Stocker is with Safeway, and is one of the SFPE's Vice Presidents.