Food Engineering
Field Reports

Freezer ceiling fans keep the stalactites away

January 7, 2013
ice forming mccain foods fan
Ice forming on freezer ceilings is a food safety regulatory issue and a sign of energy waste.
 
McCain Foods’ production plant in Carberry, MB is a distributor of McDonald’s French fries and numerous other frozen food products, and it uses the power of air movement to thaw its facility—not its food. Condensation was a big problem at the Carberry plant, especially after the Canadian Food Inspection Agency expressed concern about ceiling ice buildup, because drops of water forming the stalactites had the potential to contaminate product. 
 
“We have different air pressures in the factory,” explains Chief Engineer Geoffrey Aitchison. “In the process area, we have very moist air that is at higher pressure than the air in the freezer. What happens is that moist air comes down through the freezing tunnels and out the conveyor holes in the wall and infiltrates the freezer.”
To avoid breaking regulatory requirements, the facility had to shut down, and workers were reassigned to scrape the ceilings to keep the ice buildup at less than two inches. McCain also tried using small, high-velocity fans to circulate the air and reduce ice buildup, but they only affected a minimal area.
 
McCain Foods needed a solution sized to solve its problem and looked at the use of large-diameter, low-speed ceiling fans. The fans resemble conventional home ceiling fans—except for the diameter and rotational speed. The processor purchased a 24-ft. diameter Big Ass Fan that uses its size, not speed, to move massive amounts of air—from ceiling to floor and wall to wall.
 
Unlike small ceiling fans that struggle to send air to the floor and create insignificant pockets of air movement, large-diameter, low-speed fans gently mix air to stabilize air movement without creating a draft in winter. They use airfoils and winglets to allow the fan to operate in the forward direction without causing a draft. “After two weeks, the ceiling was completely clear, and it has been ever since,” says Aitchison. “The air is circulating, plus we’re warming the ceiling to the same temperature as the air, so the frost isn’t going to stay there.”
 
With great success in its freezer, McCain Foods added another 24-ft. fan to its processing area, where condensation was forming on the ceiling above a processing tank and constantly growing mold.
 
“After running the fan up there for two weeks, it’s the driest panel in the factory now. There’s no mold growing,” says Aitchison. Just like in the freezer, the air circulation abilities of the fan keep the ceiling and air temperature consistent, preventing the moisture buildup that allows mold to form.
 
Along with reducing condensation and creating consistent temperatures, the fans aid McCain Foods’ energy-efficiency plans. When these large fans are used to supplement heating and cooling equipment, many facilities can expect to see savings of 25 percent or more on energy bills. 
 
Since the installation of its first fans in 2007, McCain Foods Canada has installed additional fans in other processing facilities.
 
“Our Big Ass Fans are a tremendous solution to the problem we had concerning energy conservation and satisfying the Canadian Food Inspection Agency Requirements,” says Aitchison.
 
For more information:
Adam Hatton, 877-244-3267, info@bigassfans.com