Understanding the Benefits of HVLS Fans
How a slower fan can increase efficiency, comfort, and savings
Nothing is as critical as the air we breathe, but managing IAQ can be challenging. High-volume, low-speed (HVLS) fans can mobilize and destratify large volumes of air in any facility. This enables HVAC systems to operate more efficiently while optimizing comfort and health in unconditioned environments.
What Are HVLS Fans?
In simple terms, these fans are the solution to many of the issues large facilities run into while trying to keep employees cool and comfortable.
For example, HVLS fans are designed to hang from the ceiling without any cords, which allows for a safe environment by eliminating trip hazards –– an important factor, considering many plant and facility managers identify cords as one of the top workplace hazards. In fact, the overall direct interaction between an employee and a fan is virtually eliminated with many HVLS models. This feature is compounded by the maintenance-free aspect of direct-drive motors, which also eliminates the risk of oil leaks.
This brings us to another differentiator between fans: Some HVLS fans have gearbox motors, while others have direct drive motors. With a direct drive motor, there are significant reductions in the amount of noise generated, the maintenance that goes into workability, and their weight. Direct-drive motors have fewer parts and hardware but still maximize performance. They move more air for less money.
How Do HVLS Fans Work?
In the past, engineers have mistakenly focused efforts on the speed of fans, overlooking productivity and efficiency. While most would agree that cool air feels good in the heat of the day, there is such a thing as too much air circulation. This is why engineers now design HVLS fans to slowly circulate large amounts of air.
HVLS fan blade wingspans range from 7 to 24 feet and move large volumes of air with minimal energy consumption per square foot, which lowers costs and increases comfort. Additionally, in buildings with HVLS fans installed, companies experienced less absenteeism, reduced employee complaints, and boosted overall productivity.
Aaron Bowersock, project manager for mechanical contracting firm The Comfort Group, lives and works in Nashville, Tennessee. The high temperatures of a summer in Nashville can often feel unbearable, especially when working in a sheet metal fabrication shop like Bowersock does. Determined to make his workplace more comfortable for everyone, Bowersock recently invested in an HVLS fan for the shop.
“Some of the benefits I’ve noticed are in the comfort level: It pushes air throughout the whole shop,” Bowersock said. “We saw a reduced cost with the performance of the fan because we’re able to turn off our main HVAC unit system and rely solely on the fan.”
After installing an HVLS fan, summers won’t be so harsh for Bowersock or his team, and neither will the winters.
Buildings with high ceilings often experience significant heat stratification in the winter months, where warmer air rises to the ceiling and cooler air remains at floor level. This phenomenon forces a facility’s heaters to work two to three times harder to keep employees and building occupants adequately warm while most of the heat continues to be trapped above their heads. It has been estimated that air temperature can increase 0.5 to 1.5°F per foot in ceiling height ––meaning that if it’s 65° on the floor, it could be 85° to 90° at the roofline. HVLS fans, however, circulate air so that warm air trapped at ceiling level is cycled down to the floor.
A building’s indoor air quality and temperature are critical factors that influence everything, from the heating bill to employees’ health. HVLS fans provide comprehensive solutions to improve indoor air conditions and ultimately optimize a facility’s efficiency, comfort, and savings.
Publication date: 5/27/2019