Issue link: https://www.e-digitaleditions.com/i/1386104
July/August/September 2021 I 49 However, is there a connection between the systems used to seal these penetrations and a building's overall performance beyond firestopping? Could the same data cables penetrating fire-rated assemblies be causing additional concerns beyond the risk of fire or smoke migration? For example, what effect does airflow through walls and floors have on data hall pressurization for proper operation of suppression systems? What about the impact on cooling costs and energy efficiency or control of dust and whiskers that could damage server equipment? To better address airflow leakage, it is important to first understand the basics of passive fire protection. Firestopping is one of the most critical aspects of building design and construction. Model building and fire codes mandate elements of passive fire protection to help restore the integrity to the fire rating of the floor and wall barriers when openings are made to accommodate penetrations, such as data cable pathways. Many design professionals have experience on this topic, but there are still misconceptions, particularly as they relate to data centers. The process of firestop design and installation can be challenging. Consider that if a firestop system is installed 90 percent correctly, it can still be 100 percent wrong. There are many components to a firestop system and one incorrect variable could cause a code deficient installation and potentially expose a data center facility to increased risk. Optical fiber and copper data cable penetrations, a prevalent source of openings created in fire and smoke resistance barriers, present a unique challenge compared to other MEP elements. With moves, adds, and changes (MAC) throughout the life cycle of a data center, openings and pathways for data cables are continually modified, thereby amplifying potential risk. Therefore, a once compliant firestop cable penetrations installation could revert to non-compliance and leave a facility exposed. THE BALANCED APPROACH TO FIRE PROTECTION Suppression and detection systems, along with contain- ment (also referred to as compartmentation), complete the balanced approach to fire protection (Figure 1). This concept is still somewhat misunderstood. For most building occupancies, model codes require all three fire protection elements. However, it is important to understand that not only are these elements generally required by codes, but they are also necessary to function better holistically. For example, many water-based sprinkler systems are not designed to actually extinguish a fire, only to help simply control it. These type systems are designed to operate within compartments that are protected by fire-rated floor and wall barriers. In mission critical data center facilities, there may be no water-based sprinklers, but rather chemical based suppression systems. These active suppression systems rely on effective fire compartmentation in order to function properly. This could be to limit fire spread to the room of origin or to help ensure proper room pressurization by resisting airflow leakage for the suppression system activation. Relevant to data centers, Factory Mutual's (FM) July 2020 revised global document 5-32, Property Loss Prevention Data Sheet, states the following in section 2.6.2.5: "Inspect the integrity of the enclosure protected by a clean agent fire extinguishing system to determine if: A. changes have occurred that could change volume, hazard, or both. B. penetrations have occurred that could lead to extinguishing agent leakage." FIGURE 1: Illustration of the balanced approach to fire protection.