North to South, employee discomfort runs hot and cold

Fans’ air movement improves productivity, reduces energy bills

December 19, 2011

Extreme temperatures in winter in Ontario and in summer in Texas have challenged facility managers to find new methods to provide comfort to employees as well as to reduce energy consumption.

Increasing employee comfort translated to increasing productivity by 60 percent at the Samuel Jackson manufacturing plant in Lubbock, Texas. This was done with the installation of three large-diameter, low-speed fans from the Big Ass Fan Company®.

Ventilation systems do a good job of supplying air to a facility, but often the air in a large building is not well-circulated. Traditional HVAC systems consume a lot of energy, regardless of their efficiency ratings. In addition, many facility managers measure energy use, but not all measure comfort. Part of the problem is that energy costs are visible and easy to measure, while comfort can be difficult to quantify. Equally troublesome, with high ceilings and metal construction, most warehouses are not designed for traditional HVAC systems. In larger, open spaces where a person moves around, it's hard to maintain comfort without proper airflow.

In facilities without HVAC systems, the lack of air circulation can throw off the delicate balance between facility temperature and worker productivity. In large buildings, it is often difficult to achieve a uniform temperature and distribute ventilation with a traditional air handling system because of the size of the space.

In both Ontario, Canada, and Texas, large manufacturing plants and warehouses face similar heating, venting, and air-conditioning challenges. Many of them have poor insulation and inadequate ventilation. Extreme temperatures in Ontario winters and in Texas summers have challenged facility managers to find new methods to make employees comfortable as well as to reduce energy consumption.

Two plants in these locations found they could benefit from infusing air movement created by large-diameter, low-speed fans that circulate the air to increase comfort and lessen the load on ventilation and HVAC systems.

Canadian Winter

Figure 1 Much of the air being heated to warm The Beer Store’s employees was rising to the warehouse ceiling where it was heating no one. The company installed high-efficiency, low-speed fans from the Big Ass Fan Company to circulate the trapped heat down to the occupant level.

Canada is renowned for its cold winters. Trying to heat plants and warehouses in Canada in the winter can be akin to trying to warm a cave with a candle.

The Beer Store, Mississauga, Ont., has established a global reputation for establishing a green working environment. It was Canada's first business recipient of the Environmental Choice Leadership Award. The company touts that it recycles more glass than any other recycling program in Ontario, and takes back all of the bottles, cans, cartons, caps, kegs, plastic bags, and can rings that it sells. More than 1 billion liquor containers have been returned to The Beer Store.

The green company sought a way to provide thermal comfort to its employees as well as to reduce natural gas usage in an energy-efficient way (see Figure 1).

In the company's warehouse, the air from a forced-air heater and from the processing equipment itself was rising to the ceiling. This resulted in a significant temperature difference between the floor and ceiling, called stratification, which occurs because cold air is denser than hot air.

With 34-ft.-high ceilings in the warehouse, floor-to-ceiling temperature variances were 11 to 15 degrees. When the company tried to maintain 65 degrees F at the occupant level, the ceiling temperature rose to 80 degrees. "We realized we were predominantly heating the ceiling," said Mark Lynch, facility manager of The Beer Store warehouse.

Fans Circulate Trapped Heat. Lynch installed two 24-ft.-diameter, low-speed Powerfoil®X fans from the Big Ass Fan Company to destratify the air in the space (see lead image). The fans slowly circulate this trapped heat down to the occupant and thermostat level before it is able to escape from the building.

Similar to aircraft wings, the blades—or airfoils—allow for a much smaller, energy-efficient motor. Winglets at the tips further enhance the efficiency of the airfoils by helping eliminate wing-tip vortices that can induce drag and lower overall efficiency (see Figure 2).

The type of airfoils and the angle at which they are placed play an important role. An airfoil angled at 30 degrees or more will lower aerodynamic efficiency. Conversely, a flat airfoil that is almost horizontal typically will not move much air at all. Moderately pitched, narrow, aerodynamic airfoils help move air efficiently without incurring excessive drag.

Thoroughly mixing the air within the space using the fans reduced the heat buildup at the ceiling. Less thermal conduction occurred through the walls and roof, and uniform space temperature was established. Even though the thermostat setpoint remains the same, the heating system does not have to work as hard to maintain it.

The lower ceiling and average space air temperature decreased gas usage. The energy savings achieved from reducing the amount of heat escaping through the roof was similar to turning the thermostat down 3 to 5 degrees. One full year after installing the fans, The Beer Store had tracked a 19 percent reduction in natural gas usage while equalizing the temperature in the space.

Summer, Texas-style

The Samuel Jackson Co., located in the western Texas town of Lubbock, manufactures fiber-drying machinery and fiber-dehumidifying equipment for cotton gins, polyester mills, and nylon mills. The company's employees are subject to intense heat, especially this past summer, when they endured 50 straight days of record-breaking temperatures.

Exhaust fans drew air from open overhead doors inside, which was effective for much of the year, according to Chris Jackson, company owner. However, for two to three months in the summer, more was needed, he said. "We had exhaust fans and some portable evaporative coolers that we would just roll around and try to aim at different work areas."

The severe heat was severely affecting worker productivity. "With a 24-ft. roof, the air can stay very stagnant in between the machines where people are assembling them, putting the nuts and bolts on," Jackson said. "I've been out there to do some troubleshooting on products on these lines, and it's impossible to concentrate there without air movement."

Fans' Evaporative Cooling. Three separate buildings of varying sizes were fitted with large-diameter, low-speed fans from the Big Ass Fan Company to enhance the existing exhaust system.

Although the fans do not lower the air temperature in a space, as they circulate the air, they have an evaporative cooling effect. This made the employees feel 8 to 12 degrees F cooler, improving their comfort.

"The difference was night and day. It's remarkable," Jackson commented.

Worker Productivity Rose. The air movement the fans produced increased production by 60 percent, according to a shop supervisor. "Once the fans were installed, our guys increased production from 10 units to 16 units per week," Jackson said. "That was simply because without it [air movement], you're spending all of your time wiping the sweat off your eyebrows and focusing on anything but the job at hand. With it on, it's like this giant breeze ... not a blast of air, just a constantly moving giant breeze, which is just wonderful.

"Our best return on investment is the fan we installed in our assembly area," he added. "When I saw what the impact was on productivity … my motivation is not altruistic. It's all about bottom line, and the more comfortable I can make our folks, the more they deliver. They're smiling the whole time, they're taking care of the tooling, looking out for each other ... it's just amazing how smoothly things go! The courtesy quotient goes up dramatically with the comfort quotient."

Jackson relayed that his teenaged daughter voiced the workers' opinions about the fan. "When she worked in the assembly area last summer, the fans had to be turned off for about 15 minutes. She came in a little later that morning and said, 'Dad, I've got news for you. That big fan is not optional.'"

Samuel Jackson Inc., 3900 Upland Ave., Lubbock, TX 79407, 806-795-5218, www.samjackson.com

The Beer Store, 5900 Explorer Drive, Mississauga, ON, L4W 5L2, Canada, 905-361-1005, www.thebeerstore.ca