Fire safety strategy involves more than preventing, detecting, and suppressing fires and evacuating occupants. It also involves protecting people from smoke exposure and toxicity. Smoke inhalation, not burns, is the primary cause of death in a fire. Deaths can be caused by the toxic effluents in the smoke, such as carbon monoxide or hydrogen cyanide, and high temperatures.
Large amounts of smoke can be produced, despite a properly functioning sprinkler system, and move beyond the fire location. Smoke can reduce visibility and quickly incapacitate a person so that they can’t make it to an otherwise accessible exit. It can cause people to get disorientated during egress, increase panic and adversely impact firefighting abilities. For these reasons, high-risk buildings are required to be provided with smoke control systems.
Smoke Control Systems in Healthcare Occupancies
Smoke control systems are complex and include interaction among various systems. This often includes fire alarms, sprinklers, electrical and building management systems. Model codes, such as the International Building Code and NFPA 101, require smoke control systems in specific conditions, including large stages, atriums, high-rise buildings and underground buildings. Once required, the smoke control systems must be designed, built and maintained correctly.
Healthcare occupancies specifically have more complex building systems and protocols than other buildings. As such, the implementation of smoke control in healthcare occupancies is especially difficult. If sufficient care is not given, then the systems might not work correctly or have negative impacts.
Design of Smoke Control Systems
Smoke control systems are complex and work by either creating pressure differentials across barriers or by exhausting smoke and removing it from the area of concern. Both methods are typically accomplished by fans and input from a fire alarm system. These fans can be dedicated to smoke control uses or be non-dedicated fans that serve normal HVAC purposes and reconfigure for smoke control purposes.
The smoke control approach, equipment and sequence of operations is progressed throughout the design phases. While the approach is typically guided by a fire protection engineer who creates a rational analysis, the design should be integrated with all stakeholders. The most common types of smoke control (i.e., stair and elevator pressurization) rely on creating pressure differences across barriers. This can be in direct opposition to certain areas of hospitals that must create their own pressure differences for infectious disease control and other health-related patient safety.
Construction of Smoke Control Systems
In addition to being inspected by the authority having jurisdiction (AHJ), new smoke management systems are required to be inspected by a special inspector, who ensures that the system functions as designed. Smoke control special inspection starts in the design phase with a review of design documents and finishes once the system is commissioned and tested to work as designed. This special inspection is imperative.
Stakeholders should care as much about special inspections as the AHJ sign-off. Given the complexity of smoke control systems, many AHJs might not have the time or expertise to thoroughly review the systems. Additionally, the interaction of multiple different systems in smoke control makes it difficult to adequately capture system function within a single affidavit (such as Fire Alarm or Mechanical Engineering).
As such, the smoke control special inspector provides a detailed review and identifies areas of concern early in a construction project to minimize re-work for the design/construction team. The special inspector will also help ensure that the smoke control system works correctly once the building is complete. This sets the owner up for success throughout the lifecycle of the building. It can help minimize re-work after receiving the Certificate of Occupancy, which could be extremely difficult.
Occupancy and ITM
Similar to other life safety systems, smoke control systems must undergo inspection, testing and maintenance (ITM). In addition to maintaining smoke control systems, smoke control must be functionally tested annually or semi-annually, depending on their details. Testing is required by the International Fire Code, NFPA 1, and NFPA 101 and must be performed regardless of the system’s intent.
Smoke control system testing requires exercising of all equipment, measurements of pressure differentials and testing on secondary power. Integrated testing of smoke control systems can identify faults that are not obvious during individual system testing. Smoke control system testing post-occupancy is onerous and is frequently performed during off-hours to minimize impact to building occupants.
Deficiencies identified during periodic testing must be addressed as urgently as other life safety system deficiencies, such as fire alarm or fire sprinkler. Periodic smoke control testing is required to test the building as it was designed, with any changes made to the building post-Certificate of Occupancy considered during testing. Items missed during construction special inspection can necessitate costly re-work.
Stay Up-To-Date With Smoke Control Systems Testing
Smoke control systems are life safety systems by many base codes and standards. They involve many different systems and, as a result, can be difficult to implement. If smoke control systems are required, all stakeholders should ensure that the systems are properly designed, constructed and maintained similar to all other life safety systems. This will help ensure patient safety and minimize re-work throughout a building’s life cycle. Learn more about how Jensen Hughes can assist with fire system building inspections and testing of smoke control systems in healthcare facilities.
