- High Volume Low Speed Fan ("HVLS")
A High Volume Low Speed (HVLS) Fan is an electromechanical device designed to move large volumes of air at low rotational speeds. Typically installed in large spaces such as warehouses, factories, or commercial buildings, HVLS fans use wide-diameter blades to efficiently circulate air, enhancing ventilation and temperature control. These fans operate at lower speeds than traditional fans, providing energy-efficient airflow over a large area.
Fire Research Related to HVLS Fans
Factory Mutual (FM) Research has published a technical report titled "Impact of a High Volume Low Speed Fan on Sprinkler Performance in Rack Storage."
Here are two key takeaways from the report;
- HVLS fans can create significant downward airflow that penetrates storage tiers and disrupts the fire plume, potentially increasing the spread of fire if not managed properly.
- These fans can delay the activation of sprinklers by altering the flow of hot combustion gases, reducing the effectiveness of an automatic fire sprinkler system.
To mitigate these risks, it may be beneficial for engineers and consultants considering HVLS fans to introduce a fan shutdown system triggered by a fire alarm (GFA) signal. This may help prevent the spread of fire and combustion byproducts, giving the sprinkler system—particularly in-rack sprinklers—the opportunity to perform effectively.