HIGH VOLUME LOW SPEED FANS

High volume low speed (HVLS) fans are large mechanical fans that are 6 feet or wider and used in commercial and industrial settings. They are used for moving large amounts of air, and are commonly found in warehouses and similar environments. However, the fire protection requirements surrounding these fans are often overlooked or unknown completely. These fans affect the performance of the sprinkler system, and must be installed in such a manner that they meet NFPA 13 Standard for the Installation of Sprinkler Systems and also NFPA 72 National Fire Alarm and Signaling Code.

From the standard and code referenced above comes a set of requirements for the installation of these fans and the fire protection systems around them.

• The fan shall have a diameter that is not greater than 24 feet. • HVLS fans must be centered between four sprinklers, or approximately as close to centered as possible. By centering the fan, a sprinkler’s discharge pattern will not be obstructed by the blades. • There must be a minimum clearance of 3 feet between the deflector and the fan. • HVLS fans must be wired to shut down immediately upon a waterflow signal from the fire alarm system. This one is particularly important. It is necessary that the fans shut down as soon as the waterflow signal sounds. While the fans are still rotating and moving the air, the heat from the fire needed to activate the sprinklers may not reach the sprinklers leading to a delay in response and the fire growing too big for the sprinkler system. The sprinkler discharge pattern would also be affected, and may not put out the fire as effectively if the water is shifting from its intended pattern due to the air movement around the sprinklers.

The Fire Protection International Consortium, Inc. (FPI) is a fire protection firm that has specialized in the storage field and has assisted numerous clients as they strive to improve environmental conditions for their employees. Although it is best to bring FPI in on a project during the planning process, the firm can work with you at any stage.

Oftentimes, HVLS fans are overlooked by design teams as just another part of the warehouse. However, it is important to be aware of the fire protection impacts during any new or renovation project. FPI can recognize these possible conflicts early on and work to prevent what might be major removal and reinstallation in the future. This will ultimately save the client time and money in the long run, as well as ensure the fire protection requirements have been met and the sprinkler system will function as intended.

If you need any assistance with where to install these fans so that the sprinkler system functions as designed, contact FPI at our main number 1-630-985-3106 or email me directly at claire@the-fpi.com

Claire Brezinski