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While the spring and fall seasons bring great weather, they also bring a problem all too familiar to warehouse facility managers: condensation. More than simply an annoyance, condensation has the potential to create dangerous working conditions for warehouse employees, and it can ruin expensive products and inventory.
There are several ways in which airflow can help to prevent or reduce condensation. To understand how airflow mitigates condensation, it’s important to learn how and why condensation forms.
How condensation occurs
Condensation forms when warm, moisture-laden air contacts a colder surface. For example, consider a cold can of soda that “sweats” on a hot summer day. This happens because air cools next to the can, and cooler air holds less moisture. Water is deposited onto the cold surface when the air cools to the point where it can no longer hold moisture. This is commonly known as the dew point.
This same “sweating” scenario can happen with a concrete floor, a giant coil of sheet metal or cardboard boxes. But unlike a soda can, wet floors and products can be costly.
Spring is the most problematic time for condensation because large, dense objects are slow to react to air temperature changes. A roll of sheet metal might hold its winter temperature for days or weeks after the weather warms. And it can take a month or more of warm weather for the core temperature of a concrete slab to rise above the dew point.
During the fall months, it’s common for the dew point to surpass the surface temperature of floors, products and equipment. When warmer air moves in during the day, it brings a rise in dew point and humidity which causes a slick layer of condensation to form over colder objects. During the fall and winter months, it’s common for condensation to form on products that have been moved from a cold truck into a heated warehouse.
Condensation can be dangerous
Wet warehouse floors can lead to employee slips and falls, and they can prevent forklifts from slowing down. According to EHS Today, slip and fall accidents cost approximately $70 billion in workers’ compensation claims and associated medical costs every year, with an average of $20,000 in claims per accident. Condensation also causes rust, mold and mildew, which can cost businesses billions. Rust alone costs the production and manufacturing sectors roughly $17.6 billion each year, and can be damaging to both products, facilities and equipment.
How proper airflow can help
While there are numerous factors that cause condensation—weather patterns, heat, humidity and dew point—there are many ways to combat it, too, such as through the use of dehumidifiers and air conditioners. However, one of the most cost-effective ways to combat condensation involves the use of energy-efficient equipment many facilities already own: fans.
Airflow from overhead fans reduces condensation by:
Reducing stagnant, cool air: Air molecules don’t have to touch a cold surface to fall below the dew point and deposit moisture. Cold surfaces have a boundary layer of cool air around them. It’s in this boundary layer of air that temperatures fall below the dew point and condensation forms. Air movement generated by overhead fans can disperse this layer of stagnant air and reduce the real estate in which condensation forms.
Raising surface temperature: Cold surfaces in warm rooms eventually warm due to natural convection (the transfer of heat energy from the air into the cold surface). Fans speed up this process by exposing the cold surface to warm air quickly and in greater volumes. To prevent condensation, the air being blown over the surface must be warmer than the dew point prior to the arrival of a warm, moist weather front. Heaters may be used to achieve this, but even the heat from equipment, lights and people, which naturally rises to the ceiling in a tall building, can be “recycled” and used to prevent condensation.
Reducing and stabilizing humidity: Many factors affect indoor humidity levels, including perspiring occupants, evaporation from sinks and mop buckets, and steam-generating processes. Throughout the course of the day, the air in a warehouse can become more humid than the air outside. In this case, fans—in conjunction with natural or mechanical ventilation—can replace humid air with drier air from outside.
Drying moisture: When a condensation event can’t be prevented, elevated airflow can quickly dry the water that forms on surfaces, raising surface temperature faster than would naturally occur.
Aside from fans, another way to keep condensation in check involves the installation of monitoring systems that maintain the right amount of airflow in warehouse facilities. This type of technology helps to predict weather occurrences and adjusts fans and heating systems so that warehouse managers can mitigate condensation events.
Problem prevention
Proper airflow can help to prevent or reduce costly and dangerous condensation conditions inside of warehouses. By utilizing fans and/or automatic monitoring systems within a facility, condensation levels can be controlled to preserve the longevity of investments.
Alex Risen handles public relations for Big Ass Fans, an American company that manufactures fans, comfort solutions and controls for industrial, agricultural, commercial and residential use.
SIDEBAR: Condensation woes
Warm, humid days and cool nights are a recipe for condensation. If left unchecked, condensation inside a warehouse can lead to:
- Slippery concrete floors
- Hazardous working conditions
- Rust
- Mold and mildew
- Damaged products, equipment and inventory