Like most companies, third-party warehousing provider WOW Logistics was struggling with rising energy costs. Based in Appleton, Wis., WOW Logistics serves 300 customers in nearly 60 industries with facilities in Wisconsin, Illinois and Idaho.
The company was using industrial three-foot fans to keep employees cool during the summer, but the winter months brought different challenges.
“In the winter, we were challenged with a tremendous amount of heat loss in the peaks of our buildings,” says Jamie Wally, senior vice president of sales and marketing. Energy was being wasted as heat naturally rose to the ceiling. “There was a 6°F to 8°F temperature difference between the ceiling and the floor,” he says. And, that led to high heating bills.
About a year ago, the company began researching different ways to reduce its energy costs. WOW Logistics has a company-wide green initiative, so its goal was twofold: It wanted an environmentally friendly solution that would also cut costs.
The 3PL hired Big Ass Fans (Lexington, Ky.) to conduct a facility audit, and the fan company recommended installing 20-foot to 24-foot-diameter highvolume, low-speed (HVLS) fans. WOW Logistics put the HVLS fans in all 15 of its public facilities. “We installed one fan for every 50,000 square feet,” Wally says.
By wintertime, WOW Logistics started reaping benefits. “The fans moved the warm air off the ceiling
| Envira-North Systems' Altra-Air fan with WhalePower technology |
and pushed it down, allowing us to lower our heating costs,” says Wally. The company’s heating bill was reduced by an average of 59%. Dollar savings totaled $134,000 a year.
Though each company that supplies HVLS fans offers something unique, the science behind the big fans is similar. They are “high volume” because they move massive amounts of air, and they are “low speed” because they move slowly, quietly and use little amperage.
Peter Caruso, founder and CEO of AirMotion Sciences Inc. (Holliston, Mass.), says installing HVLS fans is one of the fastest ways for a facility to go green.
AirMotion’s AltAir HVLS fans range in size from nine to 15 feet in diameter and feature “variable pitch technology” (VPT). VPT allows users to adjust the blade pitch zero to 20 degrees, up or down, allowing for “adjustable air movement.” “That angle will change the way the air moves,” Caruso explains. “This can be helpful if there are changing conditions on the floor. The air can more effectively move around materials and obstructions on the floor,” he says. “One fan can be blowing up, while one is blowing down, creating a river of air moving through the facility.” When three or more AltAir fans are arranged in an array, they result in “complete facility movement of air,” according to Caruso.
“A facility can have up to a 15°F difference in temperature from the ceiling to floor,” says Caruso. “When you mix that up and even it out, you can save at least 20% on your heating bill. In some of the northern climates, savings can be 40% or better.”
“HVLS fans and new, efficient lighting are two of the biggest steps a building can take to go green,” says Tom Helms, executive vice president of MacroAir Technologies (San Bernardino, Calif.). Helms says MacroAir’s 24- foot, 2-hp, six-blade MaxAir fan, rated by the Air Movement and Control Association (AMCA), can replace 37 high-speed industrial fans. Operating the fan costs two to three cents an hour to 16 cents an hour in the most expensive part of the country, according to Helms. “HVLS fans use little energy yet cover a large area,” he says.
In January, MacroAir introduced its Eco6 six-foot, six-blade fan for use on walls or support beams. Designed for use in long, narrow spaces or mezzanines, the Eco6 fan is less disruptive than high-speed fans yet offers a wider width of airflow. It costs between 2.5 and 3.5 cents an hour to operate in most parts of the country, Helms says.
In addition, Helms notes that the MaxAir fan can be reversed, a feature that enhances energy savings in winter months. “Most of the hot air escapes to the ceiling,” says Helms. When set in reverse, the fan compresses the warm air at the ceiling and sends it down the walls and across the floor.
“The fans equalize the temperature in a building by moving warm air trapped at the ceiling down to the floor, making the building’s temperature more uniform,” explains Dan Anderson, product manager at Rite-Hite Corp. (Milwaukee). “This process is called destratification, and it makes it easier for the heating system to keep the air warmer at the floor, saving energy costs.”
|MacroAir’s MaxAir fan|
| WOW Logistics saved an verage of 59% on its heating bill by installing HVLS fans from Big Ass Fans. |
Anderson say s Rite-Hite’s Revolution fans have the fewest blades of any fan on the market. While most HVLS fans have 10 blades, Revolution fans only have four. Fewer blades mean more airflow, according to Anderson. “Our Propell-Aire blade design is tapered and twisted as opposed to extruded,” Anderson explains. “This allows the blades to pick up the most air and distribute it evenly.”
Keith Wise, inventory manager at Stoughton Trailers (Stoughton, Wis.), a manufacturer of over-theroad drive ends, tested Revolution fans in the company’s Stoughton and Evansville, Wis., facilities. Saving money during the winter months had been on Wise’s mind. “There was a 12°F difference in temperature between the ceiling and floor,” says Wise. “With the fans installed, we’ve been able to raise the floor temperature so that there is only a 2°F difference.” This destratification allowed Stoughton Trailers to reduce burn on its air makeup unit by as much as 50%, according to Wise.
Destratification allows a facility manager to set the thermostat to a lower number in the winter months, and each degree set back translates into a 4% to 6% savings on the fuel bill, according to Bob Green, vice president of operations and strategic planning at Humongous Fan, a division of Acorn Technology (Cleveland).
Green says Humongous Fan HVLS fans use tapered blades that are twisted like those of a propeller. This allows each section of the blade to have the optimum “angle of attack” to push more air, he says. Compared to other HVLS fans, “we can move the same or more air with less horsepower,” says Green. Humongous Fan’s 16-foot fan uses a 0.5-hp motor, while its 20-foot fan uses a 1-hp motor. A 16-foot fan covers 5,000 square feet.
Dave Smith, product manager at Patterson Fan (Blythewood, S.C.), says payback from the use of HVLS fans is less than two years in most applications. Patterson Fan sells eight- to 24-foot-diameter sizes of MacroAir Airvolution fans with 1-hp motors as well as MacroAir MaxAir fans. The company recommends using one fan per 20,000 square feet of facility space.
“The blade design on the fans is like the airfoils on a plane,” says Smith. “They cool in the summer. In the winter, you can reverse them and get heat to come down the walls, creating a thermal blanket and keeping warm air on the floor.”
Patterson Fan offers a remote control so that controllers can be kept away from the workspace. Smith also says the HVLS fans are silent. “The speed of the fans is low, so you don’t get the noise
|Rite-Hite’s Revolution fan|
| HVLS fan from Humongous Fan |
you get from small, industrial fans,” he says.
Keep Employees Productive
Winter isn’t the only prime time for HVLS fans. In the summertime, the gentle breeze from an HVLS fan—moving at about 3 mph— maximizes cooling from evaporating perspiration yet doesn’t blow paperwork around, disturb the workspace or use a lot of energy, Green says. “However, it lowers the apparent temperature by 7°F to 8°F,” he points out.
Josh Eddy, engineering sales manager at Big Ass Fans, calls this phenomenon “operative temperature.” “The fans don’t change the temperature in the facility,” says Eddy. “They change what the people in the space feel.”
Big Ass Fans offers 10-blade HVLS fans in six- to 24-foot diameters, with ¾- to 2-hp motors. The company’s Powerfoil and PowerfoilPlus HVLS fans have been popular among customers, Eddy says. Powerfoil features a new airfoil that generates 33% more air than previous airfoil designs, according to the company, and the PowerfoilPlus has “hybrid airfoils” that create “deeper jets of air” without using more energy. In addition, Big Ass Fans’ new sixfoot- diameter Pivot fan is specially designed for air movement within confined spaces, such as between narrow aisles, mezzanines or racking. The Pivot fan has 73 different hanging positions.
Paul Lauritzen, director of sales at Big Ass Fans, says HVLS fans can improve employee productivity and reduce turnover. “Heat stress is a real problem in a lot of facilities,” he says. “Comfortable employees make far fewer mistakes, and injuries are less common.”
Eddy notes that air movement is one of the components of American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) standard 55: Thermal Environmental Conditions for Human Occupancy. The ASHRAE standard describes the effect of air speed on thermal comfort. In addition, “thermal comfort is an aspect of LEED [Leadership in Energy and Environmental Design],” says Eddy. “Energy efficiency is a huge part of the sustainability movement,” he concludes.
“Fossil fuels and energy prices are not going to get any cheaper,” adds Lauritzen. “In some cases, air conditioning is either not an option or very expensive,” he says. “These fans give businesses options where they didn’t have options before.”
A Whale of a Fan
Fascinated by the underwater agility of humpback whales, marine biologist Dr. Frank Fish, president of WhalePower, discovered that these whales had “tubercles,” or bumps, on the leading edges of their flippers that allow water to be pushed downward more effectively. The technology has been applied to wind turbines, and now, HVLS fans.
Thanks to precisely formed bumps, air is pushed downward more effectively, so less power is needed to operate the fans. “The WhalePower technology allows the air on top of the blades to flow faster with less disturbance,” says Stephan Gingras, R&D manager at Envira- North. “A fan that pushes air too fast will disturb paper and spread dust. And, circular fans at floor level produce a lot of noise.”
Envira-North’s existing line of HVLS fans, Altra-Air, is available in eight- to 24-foot diameters, and can result in a 30% reduction in energy costs, according to the company. Gingras says facility managers can save on air-conditioning costs during the summer by setting the temperature higher. “The fans don’t reduce the temperature,” Gingras notes. “Instead, the air movement provides a cooling effect from evaporation from the skin.” Productivity goes up when employees are comfortable, says Gingras.
A Different Approach
“The Coenco Air Mover creates an effective bullet of air that bounces off corners and walls, creating thermal uniformity of the air mass,” according to the company. “This causes a total circulation and destratification of an open space.” Coenco says the Air Mover can result in up to 75% less energy use in a facility.