For years, the McCain Foods production plant in Carberry, Manitoba, Canada, had experienced two problem areas, both of which involved condensation. The plant, which started as an aircraft hangar during World War II, was later turned into a plant producing frozen French fries, mainly for the McDonald’s chain. It contains both cold and hot environments.
Within the factory is an approximately 12,000 ft2 freezer area with 12' ceilings that acts as a bag-off area where the product is packaged. Due to the difference in air temperatures inside and outside the freezer, the chief engineer at the facility, Geoffrey Aitchison, had a big ice-accumulation problem on his hands.
“We have different air pressures in the factory. In the process area, we have very moist air that is at a higher pressure than the air in the freezer. That moist air comes down through the freezing tunnels and out the conveyor holes in the wall, and infiltrates the freezer,” explains Aitchison.
The problem with having ice on the ceiling was one the Canadian Food Inspection Agency was more than willing to point out to the plant through the years. It is unsafe to have particulate matter that could possibly drop into the open containers of fries in the freezer and contaminate the food. Every few days, during shutdowns, workers would have to scrape the ceilings to keep the ice below 1 to 2" thick. They tried using small high-velocity fans to keep the air circulating and reduce the ice, but the fans only affected a minimal area.
Then Aitchison saw an advertisement for Big Ass Fans, based in Lexington, Ky., and he decided to give them a try. After installing a 24' Powerfoil fan, the plant had no further problems with ice buildup.
“After two weeks the ceiling was completely clear, and it has been ever since,” Aitchison says. “We reversed the fan so it’s pulling air up. 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.”
Volume, Not VelocityThe fans work so well because they operate on the principle of moving large amounts of air at slow speeds. Due to the foil shape of each blade and their winglets, one 24' fan is efficient enough to move 337,000 ft3 of air per minute over areas as large as 20,000 ft2. That’s enough air movement to replace 16 box or column fans. Because each fan is equipped with a variable frequency drive, the fan’s speed is adjustable depending on the environment in which the fan is needed. In Aitchison’s case, he was able to order a reversed fan to pull air from below to target his problem area and create consistent air and ceiling temperatures.
The second large-diameter ceiling fan was installed in the process area in the McCain Foods plant. Above a tank where a substantial amount of steam was released, condensation was forming on the ceiling and constantly growing mold, an unhealthy condition for any environment.
“After the fans had run up there for two weeks, [the condensation problems were gone]. It’s the driest panel in the factory now. There’s no mold growing,” says Aitchison.
In this area, Aitchison chose another 24' Powerfoil fan, but this time he didn’t reverse it. Just like in the freezer, the air circulation created by the fan keeps the ceiling and air temperature consistent and prevents condensation and mold from collecting on the ceiling.
Besides using the fans to solve the condensation problems in the plant, Aitchison also has used their energy efficiency to reduce the plant’s energy costs.
“We put the second fan in the process area for energy conservation. We wanted to keep the warm air at the top circulating so we wouldn’t have to run the air makeup units as hard,” Aitchison explains.
When large-diameter ceiling fans are used to supplement heating and cooling equipment, facilities can expect to see savings of 25 percent or more on energy bills. The fans are a cost-effective solution to air circulation problems in large spaces.
“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.
Big Ass Fans, Lexington, Ky., is a manufacturer of large-diameter ceiling fans. For more information, call (877) 244-3267 or (859) 233-1271, or visit www.bigassfans.com.