UL 864 Stairwell Pressurization Solutions for Enhanced Building Protection: Optimizing Safety and Compliance

SVL hosted an engaging Coffee Break Webinar featuring Scott Blackmon, National Sales Manager for RM Manifold. With over 18 years of experience in the HVAC industry, Scott specializes in draft control systems for boilers, commercial laundry facilities, multi-story buildings, and stairwell pressurization systems. Participants were treated to an in-depth discussion on innovative solutions for life safety in building designs.

KEY HIGHLIGHTS FROM THE PRESENTATION

Introduction to Stairwell Pressurization

Scott began the webinar by outlining the critical role of stairwell pressurization in life safety systems. The primary goal is to create a tenable environment in stairwells during fire emergencies, allowing occupants to safely evacuate by preventing smoke infiltration. Stairwell pressurization systems achieve this by maintaining positive pressure with clean air, ensuring smoke is pushed back into corridors rather than into stairwells.

Scott traced the origins of modern pressurization standards to past tragedies, such as the 1980 MGM Grand Fire and the Bronx high-rise fire in 2022. These incidents underscored the deadly effects of smoke migration, which led to overhauls in building codes and safety systems.

Challenges in Smoke Control

Two major factors influence smoke and fire movement within buildings: stack effect and fire-induced pressure. Stack effect refers to the natural movement of air due to temperature differences, which can vary significantly between seasons or building locations. Fire-induced pressure, on the other hand, can increase dramatically on the fire floor, complicating smoke control.

Scott also addressed the importance of designing systems to handle scenarios like reverse stack effect, common in hot climates, and emphasized the necessity of considering seasonal variations during system commissioning.

Design Standards and Codes

Scott reviewed the primary codes and standards influencing stairwell pressurization design, including:

• ASHRAE Handbook
• NFPA 92
• UL 864
• IBC 909

Notably, the International Building Code (IBC) now mandates compliance with UL 864 for pressurization systems, ensuring robust and reliable operation during emergencies.

LF Systems' ACSP Solution

Scott introduced LF Systems' Active Compensated Stairwell Pressurization System (ACSP), a groundbreaking UL 864-listed plug-and-play package. This system is designed to simplify pressurization projects for engineers and contractors while ensuring top-tier safety and performance.

Key features of the ACSP include:

• UL 864-Listed Components: Ensuring compliance with the latest codes and standards.
• Integrated Controls: The system includes an L864 controller, pressure transducers, VFD for fans, and actuators for relief dampers if needed.
• Rapid Modulation: The system uses fast-acting actuators with two-second response times, coupled with VFDs, to maintain precise pressure control in real time.
• Full Engineering Support: LF Systems provides custom wiring diagrams, operational plans, and design assistance tailored to specific projects.

The ACSP can be used with any smoke-rated fan on the market, offering designers flexibility and eliminating the need for complex sequences of operation.

Advanced Applications

For taller buildings, Scott discussed the Advanced System option. This setup includes additional controllers and modulating dampers to zone the stairwell into manageable sections, ensuring consistent pressure across all levels. This modular design makes it suitable for high-rise structures exceeding 100 feet.

ADDITIONAL KEY INSIGHTS

The Importance of UL864 Certification

Building owners should insist on UL864 certification to avoid any technical inaccuracies. This certification enhances the reliability of fire protection, demonstrates a commitment to safety, and can lead to compliance with local codes, lower insurance premiums, and increased property value. Prioritizing UL864 certification is an investment in both safety and peace of mind.

The UL864-listed Smoke Control System is used to maintain user-configurable pressure in a stairway or other multi-zoned area. The L864 system compares pressures across multiple zones and controls a listed stairwell pressurization fan as well as an optional relief damper to maintain the user-determined range. This is a key component of the Active Compensated Stairwell Pressurization (Advanced ACSP) System.

Common Design Considerations and Cautions

Scott shared practical tips to avoid common pitfalls:

1. Avoid Non-Compensated Systems: These systems cannot adjust for seasonal or fire-related pressure variations, compromising their effectiveness.
2. Oversize Fans Slightly: Undersized fans can exacerbate safety risks, while oversized fans can be adjusted with VFDs.
3. Adhere to UL 864 Listings: Ensure all components and designs comply with UL 864 to meet IBC 2018 and beyond requirements.

Q&A Highlights

During the Q&A, Scott addressed several key questions:

• Fan Sizing: Fan selection remains the responsibility of the mechanical engineer or manufacturer, such as Cook.
• Controller Placement: Controllers are best located near the fireman’s control station for ease of access and oversight.
• System Integration: The system ties directly into the fire alarm’s FSCS, providing seamless activation during emergencies.

Conclusion

Scott Blackmon’s presentation offered valuable insights into the complexities of stairwell pressurization and how LF Systems’ ACSP is revolutionizing safety and design efficiency. With its innovative features and engineering support, the ACSP is set to become a go-to solution for life safety systems in modern buildings.

If you'd like to stay updated on the latest HVAC technologies, be sure to join us for our upcoming SVL Coffee Break Webinars. Reach out to your SVL Sales Engineer for an invite to our future sessions.

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