Eliminating Condensation with Large-diameter Fans

Sep 19th, 2012 | By | Category: Health and Safety

Facility managers who are struggling with condensation and other moisture issues that cause slippery floors and unsafe work conditions should take their eyes off of the floor and instead look up. Large-diameter, low speed overhead fans can help to clear condensation and the puddles that condensation leaves behind. Here’s an example of how employee safety was improved at one manufacturing facility through installation of energy-efficient large fans.


A Slippery Situation

Forklift pallet manufacturer John Rock Inc. of Coatesville, Pennsylvania, U.S.A. uses a quarter-million feet of green hardwood and 9,000 pounds of nails to create 18,000 to 20,000 wood pallets per working shift. Handling green wood on such a large scale produces an equally large problem, explained Business Development and Purchasing Manager Penn Cooper: “Green hardwood is between 30 and 45 percent moisture content. Forklift traffic and employees walking, with that kind of moisture, was a huge issue, particularly as the weather changes though the spring or the fall.”

Condensation occurs when warm, moist air contacts a cold surface. As the air becomes colder, it loses its ability to store moisture. In the summer, it’s seen as a sheen of water droplets on cans and bottles containing cold beverages. But in the spring and fall, temperature swings and the accompanying condensation can wreak havoc in workplaces of many types. The accumulation of those little droplets of water can result in a slippery work surface.

“At our old facility, the floor was so rough and beat up, it didn’t matter if it was wet, there was still lots of traction,” Cooper said. “Here, we spent a lot of money to make sure we had a very smooth floor so we could move efficiently. Well, we created a huge skating rink issue, just because it’s wet. People were getting hurt.”

Even in facilities without moisture-laden materials, simple spring and fall condensation can result in serious worker risk, operational issues, and product loss.

Dew point related issues occur when the surface of the concrete slab is at or below the saturation point of the air.  In the spring, a concrete slab will trail the air temperature by about a month. So while the April air is a balmy 72 degrees Fahrenheit, the slab might still be stuck in March at 50 degrees. Warm air sits on this cold slab, dropping moisture as it cools. In the fall, cold materials coming off of a truck into a warmed space can cause the same effect.


Techniques to Reduce Condensation

Although condensation is more probable in areas with high relative humidity, industrial air movement systems can help to reduce condensation buildup in any facility, regardless of climate. Some successful tactics to minimize condensation are:

  • A dehumidification system (air conditioning) to decrease the moisture content of the air. 
  • A heating system to increase the air temperature or surface temperature.
  • Air movement across cold surfaces to increase the surface temperature and decrease the amount of time that warm air is in contact with cold surfaces.


A Slick Solution

Because large industrial spaces are often impractical or expensive to heat and cool, air movement can be the simplest and most affordable solution. At John Rock Inc., six 24-foot diameter Big Ass Fans® were used to address the condensation problem. Unlike small ceiling fans, which struggle to send air to the floor and create insignificant pockets of air movement, large-diameter, low speed fans gently mix air to stabilize temperatures with modest air velocities. Sending warm air down from the rafters results in only slight temperature differences from floor to ceiling within the building, but an overall reduction in condensation on the floor.

“The fans dramatically improve the safety here,” Cooper said. “They’ve been a real blessing for us.”

As an added bonus, the moisture-busting air movement provided by the fans also helps to prevent mold growth on the green hardwood pallets. Controlling moisture is the key to controlling mold; thus, air movement can help to prevent the establishment of mold by more quickly drying the surfaces on which mold can form.



Utilizing a large-diameter, low speed fan to achieve air movement mitigates condensation on concrete slabs, improves workplace safety, and protects equipment, materials, and finished products. Large-diameter fans also improve worker comfort year round and save heating costs in the winter. Overall, they provide the most economical and effective solution to control moisture and reduce surface slab sweating and condensation.


About the Author

Erin Hsu is senior copywriter for Big Ass Fans, the world’s preeminent designer and manufacturer of large-diameter, low speed fans.


Photographs: Big Ass Fans at John Rock Inc.

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