The 3 Most Overlooked Items in an Atrium Smoke Control System

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An atrium smoke control system controls the flow of smoke and air in an atrium to maintain tenability. But not all systems are designed and implemented the same way. In this blog, we look at three of the most overlooked items in an atrium smoke control system.

Performance Based Fire is a fire protection engineering firm that specializes in providing computer fire and egress modeling. One of the most common applications of fire and egress modeling is in the design of atrium smoke control systems. In the event that our firm does not perform the design rationale of these systems on a specific project, we usually still find ourselves on the project team as a third-party reviewer or special inspector.

A third-party special inspector plays a critical role in commissioning an atrium smoke control system. They are responsible for ensuring that the system is installed and designed per code and contract documents. Through our experience with hundreds of smoke control projects, we have started to notice a trend in when and where issues arise in an atrium smoke control system.

Here are the top three items that we see commonly overlooked in designing and implementing an atrium smoke control system and ways to identify and prevent these issues from causing project delays and budget overruns.

Atrium Smoke Control Systems: 3 Most-Missed Items

Item #1: Verification of Controls

The most common deficiency we find in review and inspections of atrium smoke control systems is with improper verification of control systems. When this occurs, system commissioning comes to a complete halt until the deficiencies are resolved. In the best case, we can work with the contractor on-site to resolve these issues within a few hours, but sometimes this can cause weeks of delay.

In accordance with Section 909.12.1 of the International Building Code, verification needs to be provided for the following:

  • Positive confirmation of actuation
  • Confirmation of weekly testing
  • Confirmation of manual overrides
  • Confirmation of the presence of power downstream of all disconnects

Of these verification items for the atrium smoke control system, monitoring the power downstream of all disconnects is the most commonly missed item. Not only does this monitoring point need to be provided for the feed to exhaust or supply fans, but also all dampers, motored door or window openers, and any other powered mechanical system serving the atrium smoke control system. If not identified and addressed during design or early installation, this requirement will delay the commissioning and issuance of certificates of occupancy (CO) until proper verification is provided.

Item #2: Fire Fighter’s Smoke Control Panel

Design teams and contractors not familiar with atrium smoke control systems consistently overlook one of the most important and prominent features of these systems – the Fire Fighter’s Smoke Control Panel (FSCP).

The Fire Fighter’s Smoke Control Panel is a key element of an atrium smoke control system which provides a visual representation of all components of the smoke control system, with indicator lights as well as manual controls and override functions to the automatic controls of the mechanical system.

In high-rise buildings, the panel would be located in the fire command center (FCC), while in low- and mid-rises it is generally located adjacent to the main fire alarm control panel or other readily identifiable and accessible location. Additional requirements of the Fire Fighter’s Smoke Control Panel can be found in Section 909.16.1 through 909.16.3 of the International Building Code.

When not identified early in an atrium smoke control system project, the provision of the Fire Fighter’s Smoke Control Panel often becomes a finger-pointing game amongst the project team. We find that no one really understands who is responsible to provide, pay for or install the panel. This results in project delays until the contracting disputes are settled and usually change orders are issued. To avoid this commonly overlooked item, make sure the Fire Fighter’s Smoke Control Panel is coordinated and understood early in the project.

Item #3: The Rational Analysis

The most common item missing from an atrium smoke control system design is a formal written Rational Analysis. This analysis is responsible for documenting the most important elements of the system, such as the rationale for design and commissioning requirements. Failure to provide this written analysis could result in inadequate system design and significant construction changes after the system has been installed.

Section 909.4 of the International Building Code requires that a rational analysis be provided supporting the types of smoke control systems being utilized, and general methods of operation. 

At a minimum, the following items must be addressed:

  • Stack effect on the system
  • Temperature effect of fire
  • Wind effects on the system
  • HVAC effects on the system
  • Climate on the system
  • Duration of operation of the system
  • System interactions between multiple smoke control systems

Computational fire modeling is the most comprehensive and robust approach in determining exhaust capacities and other design elements of an atrium smoke control system. This is one of the only methods which allows for direct consideration of all the design conditions as required by the building code. In addition, the rational analysis would discuss design fire scenarios and performance metrics such as the pass/fail criteria for tenability conditions.

Conclusion

Atrium smoke control systems only work when they are designed and implemented with the right items. Avoid project delays and budget overruns by considering the verification of controls, the Fire Fighter’s Smoke Control Panel and the rationale analysis.

Performance Based Fire has the experience required to properly design and implement state-of-the-art atrium smoke control systems. Contact us to learn more about this service offering.

Atrium Smoke Control and Rational Analysis Projects

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Learn more about atrium smoke control systems and testing as provided by the SFPE.

Reference code sections based on the 2018 International Building Code: