The complexities of industrial, manufacturing, and warehouse facilities: fire/life safety
Russell Ashcroft, PE, Principal Engineer, Southland Engineering, Tempe, Ariz.
Mike Barbes, PE, LC, Senior Electrical Engineer, AECOM, Atlanta
Reinhard Hanselka, PhD, Director of Code Compliance, CRB, Kansas City, Mo.
Marcin Jakubowski, Senior Mechanical Engineer, RTM Engineering Consultants, Orlando, Fla.
Eric M. Roeder, PE, Project Manager, Security & Fire Protection, JENSEN HUGHES, Arlington, Va.
Sunondo Roy, PE, LEED AP BD+C, Vice President, CCJM Engineers Ltd., Chicago
CSE: Describe unique security and access-control systems you have specified in such facilities.
Ashcroft: There have been projects where the desire has been not so much to keep people out of a certain area, but to oversee what they are doing while in a certain area and to keep them in. This was a different perspective from the usual design requirements.
Roeder: In an assessment of an existing high-value storage and restoration facility, we found that 125-kHz proximity (prox) cards were still in use for access control. This type of card has recently been shown to be easily duplicated at a distance by adversarial actors without alerting the target. The simplicity of cloning a 125-kHz card is such that hard keys should be considered more difficult to duplicate. We recommended implementing combination devices that could read the existing 125-kHz cards while also supporting the more secure 13.56-MHz frequency as part of a mitigation strategy. The client can roll out the newer cards and readers on their own timeline.
CSE: Describe the cost and complexity of fire protection systems involved with such structures. How have they changed over the years, and what changes should be watched going forward?
Roeder: Due to the scale and elevated hazards presented in industrial, manufacturing, and warehouse facilities, hydraulic demands on fire suppression systems are generally extreme. These large facilities may be located away from public water sources, so fire pumps and onsite water supplies are important components to consider when budgeting a system. Even existing systems need attention, as commodity changes, system degradation, facility expansions, and other changing demands on an existing water supply may outpace the original design safety factors over time, leading to a system that no longer provides an adequate level of protection.
CSE: What unique egress or emergency communication systems have you specified in industrial, manufacturing, and warehouse facilities?
Roeder: In a large bus and train repair shop, our team identified multiple travel-distance issues. The bays weren’t originally designed with egress in mind, so occupants had to travel a large distance to reach compliant egress points. Because of the scope of an ongoing renovation, the building’s egress had to be brought up to contemporary code requirements. We had to design a fire-rated egress corridor in the bays that provided an exit within the required travel distance while minimizing loss of usable floor area. On similar projects with extensive (800-ft) travel distances, we have employed combination fire and egress modeling to demonstrate that occupants have more than sufficient time to escape the building during emergency scenarios.
CSE: What unique smoke-control or fire suppression systems have you specified? Please describe.
Ashcroft: The most challenging type of smoke-control system has been a very early smoke detection apparatus (VESDA) system in semiconductor facilities. Due to the exacting nature of the design, it has now become necessary to use a performance-based system and then have the installing vendor and contractor complete the design to make sure the piping systems are not too long to pick up the correct amount of airflow, thus the smoke intake.
CSE: What types of special enclosures or dust- or explosion-control systems have you incorporated into a design?
Roeder: We have consulted for numerous facilities that handle combustible dusts. The two-pronged approach specified in NFPA standards requires good dust collection at the point of generation and a robust housekeeping protocol to mitigate fuel hazards remote from the point of origin. We have specified many acceptable solutions including deflagration venting to a safe outdoor location, deflagration venting through flame arrestors, explosion control through inerting and suppression. These solutions can be applied to both rooms and equipment. Determining which is the proper approach depends on the equipment involved, a thorough understanding of the dust hazard characteristics, the site plan, and the facility’s tolerance for maintaining complex protection systems—among many other factors. Painting enclosures (spray booths) produce a common hazard that is more involved from a fire suppression standpoint than most people would think. The high flammability of the atomized paint means that the area must be separate from the rest of the facility and protected by an alternative suppression system. These environments are common enough that solutions are well-specified, but building owners and operators should keep in mind the hazard they pose when considering adding or relocating paint operations.
Ashcroft: We’ve designed chemical-resistant NEMA 4X stainless steel control enclosures and variable frequency drive cabinets in chemical-reactive rooms. Also, the typical explosion-proof enclosures in areas where there is the possibility of reactive gases building up.