HVLS Fans Save Money, Improve Comfort

If you’ve ever looked overhead in a factory, warehouse or other large open space, you’ve probably seen those enormous fans spinning slowly overhead.  Known as High Velocity Low Speed (HVLS) fans, they can save you substantial amounts of money, help make building occupants more comfortable and even help you achieve LEED certification. 

In an HVLS fan installation, the extremely long (up to 24′ diameter) blades spin much more slowly than a traditional ceiling or ventilating fan.  The blades are specially designed to capture the maximum amount of air possible and send it gently down to the floor.

In the summer, the gentle breezes created by an HVLS fan keep people cool by speeding up the evaporation of sweat.  In the winter the fans take the warm air created by your HVAC system and pull it down from the ceiling to the floor where the people are, allowing them to be more comfortable with a lower thermostat setting.

They are much cheaper to operate and more efficient than smaller, high-speed ceiling fans.   In the summer, you can run an HVLS fan at a relatively slow 30-60 rpm.  In the winter, to pull warm air down without the cooling effects of higher-speed air, slow it to positively glacial 15 rpm.

A massive 24-foot diameter fan, capable of moving as much as 350,000 cfm can be powered with a 2-hp motor and will sip a mere 440 watts and cost  just a few pennies per hour to operate.

A properly sized HVLS fan can lower the perceived temperature in a room from 8 to 15 degrees F, allowing you to turn down the air-conditioning.  With conventional wisdom figuring a 2-3 percent energy savings for every 1 degree change in a thermostat, an HVLS fan can pay for itself quickly.

Finally, an HVLS fan can help you meet LEED requirements in several areas, including energy and atmosphere (pre-requisite 3 and credit 4) and indoor air quality (credits 2 and 7.1).

Rich Silverman

Goodway Blogging Team