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HVLS fans and Sprinkler Systems

When it comes to ensuring the safety of people and properties, the National Fire Protection Agency (NFPA) plays a vital role. In its NFPA 13 document, the NFPA provides specific guidelines for the installation and sizing of High Speed Low Volume (HVLS) fans in commercial, industrial and warehouse buildings with sprinkler systems. Understanding and adhering to these standards are crucial to ensure the effective cooling of buildings while maintaining fire safety measures. In this article, we will explore the NFPA 13 guidelines for placing HVLS fans in sprinkler-protected buildings.

What are HVLS Fans?

HVLS fans, or High Speed Low Volume fans, were developed by MacroAir in 1998 to address the issue of overheating in a dairy barn. These fans, known for their large size and low rotational speed, are designed to move massive volumes of air effectively. Since their inception, HVLS fans have become an integral part of the design of large industrial, commercial, and agricultural spaces, contributing to the comfort of both people and animals.

HVLS Fans and Sprinkler Systems:

Many larger commercial and industrial buildings equipped with HVLS fans also have automatic fire sprinkler systems in place to enhance safety. However, incorporating sprinklers into the fan installation process can pose challenges. It is essential to consider local and national regulations, including allowable sprinkler spacing and maximum fan blade size, to ensure proper fan placement and installation.

NFPA Guidelines for HVLS Fans:

The NFPA, as a government organization dedicated to preventing fires, provides guidelines in its NFPA 13 document for the installation of HVLS fans in buildings with sprinkler systems. Here are the key guidelines outlined in Chapter 11 of the NFPA 13:

  1. Maximum Fan Diameter: The maximum diameter of an HVLS fan should not exceed 24 feet (7.3 meters).

  2. Fan Placement: The HVLS fan should be centered approximately between four adjacent sprinklers.

  3. Vertical Clearance: A minimum vertical clearance of 3 feet (0.9 meters) between the HVLS fan and the sprinkler deflector is required.

  4. Interlock System: All HVLS fans should be interlocked to shut down immediately upon receiving a water-flow signal from the alarm system, following the requirements of NFPA 72.

Importance of NFPA 13 Compliance:

  1. Building Layout and Design: Adhering to NFPA 13 guidelines ensures that your building layout and design comply with fire safety regulations. Consider the size of the fan, placing it within the prescribed diameter limits if you have a suppressive sprinkler system installed. Centering the fan between sprinkler heads and maintaining the required vertical clearance also contributes to proper placement.

  2. Safety: Sprinklers are crucial for fire safety, and their presence does not exclude the use of HVLS fans. Compliance with NFPA 13 ensures the safety of occupants, employees, and customers. NFPA reports indicate that facilities with alarm systems and sprinklers installed have significantly lower fatality rates in fire incidents compared to those without such systems.

HVLS Fans and Sprinkler Interaction:

The NFPA guidelines regarding HVLS fans and sprinklers address two primary concerns:

  1. Obstruction: The guidelines ensure that HVLS fans do not obstruct the operation of sprinklers located nearby.

  2. Fire Spread: Studies have shown that properly installed HVLS fans do not negatively impact the operation of sprinkler systems or contribute to the spread of fires.

Studies Confirming Safety: In 2009 and 2011, separate studies were conducted to evaluate the interaction between HVLS fans and sprinkler systems during fires. Both studies concluded that when HVLS fans are installed according to NFPA guidelines, they pose no threat to sprinkler operation. The reports also found no evidence that the placement of an HVLS fan directly above the ignition point of a fire would increase fire spread.

Adhering to the NFPA 13 guidelines is essential when installing HVLS fans in buildings protected by sprinkler systems. These guidelines ensure proper fan placement, size, and interlock systems, promoting both effective cooling and fire safety. With compliance, HVLS fans can be safely integrated into buildings, providing optimal airflow while maintaining the protection provided by sprinkler systems.

JSO'Will is an Authorized HVLS Dealer serving the greater Seattle, Tacoma, Everett, Yakima, Spokane and Portland area. Visit us at for your commercial industrial warehouse ceiling fan needs.

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