A filter is replaced on a Rupp Environmental Air Systems ENV-212 air filtration unit over a welding area. According to the company, the unit is designed to provide MERV 15-rated air.
It threatens schools, homes, buildings, and hospitals. In short, mold is a growing problem nationwide, causing numerous health conditions and billions of dollars in damage each year. Even though it is not the definitive, guaranteed-to-resolve-everything solution, portable air-conditioning units certainly have the capabilities to prevent- or at least thwart - mold and mildew damage. Their unique spot-cooling technology can effectively aid in drying out and dehumidifying mold-prone areas on an ongoing basis, or in the event of a disaster when damage occurs from leaks or flooding.

After Hurricane Katrina, for instance, relief officials used more than 300 MovinCool units, manufactured by Denso (Long Beach, Calif.), to aid in disaster relief efforts. Meanwhile, Nick Sickmen, marketing manager for Carrier Rental Systems (Houston), noted that his company had rental equipment in place at many locations two to three days before the storm. "The companies that have plans in place beforehand know that generators, air conditioners, and drying equipment go fast," said Sickmen. "There's only so much of this equipment in the rental market."

As was discovered, buildings that were submerged under water for two or more weeks not only had mold issues, but they were also potentially contaminated from all the pollutants that were in the water. (For more regarding Katrina relief, see the related story "Dealing With Katrina's Aftermath" in this issue.) Fortunately, most cases are of a much smaller magnitude, yet damage can still be significant for homeowners, building managers, and school and/or hospital administrators.

A Topaz TZ-18A provides spot cooling to an office area during permanent system service work.


According to the Insurance Information Institute (III), the insurance industry paid out $2.5 billion in water and mold claims in 2002. Mold can also lead to Sick Building Syndrome (SBS), which costs U.S. companies over $50 billion a year. Experts attribute the increase in mold infestation to modern building design. Many modern building materials, such as fake stucco, traps moisture behind walls leading to mold growth and allowing air conditioning and heating systems to recirculate contaminated air.

According to the manufacturer, MovinCool units can help prevent mold, mildew, and SBS by speeding up the drying process with flexible ducting options and various spot-drying configurations. In the fast-drying setup, the company said its units use high volume warm air to extract moisture much faster than using fans or dehumidifiers alone.

Portable cooling units can also cool and dry at the same time by simply ducting the warm air from the room. For low temperature conditions, MovinCool offers the Office Pro Series, while the Classic Plus Series is best suited for higher temperature applications, said the manufacturer.

All MovinCool® units are verified for performance by ETL, one of the leading independent testing laboratories, and are UL and CUL safety listed. They also have capabilities to pump water 100 feet to reach faraway drains, said the manufacturer. Pump is optional, but collection tank is standard.

"The MovinCool fast-drying, dehumidifying, and cooling setup speeds the drying process and spot cools at the same time," said John Doran, manager, Heat Management Department. "It can mean the difference between preventing mold and mildew issues or incurring up to hundreds of thousands of dollars in reconstruction and ventilation costs."

Because of the prevalence of mold contamination today, the U.S. Environmental Protection Agency (EPA) has developed standards on mold prevention. The company said its portable units are a resource to help maintain many of the EPA standards listed including:

  • Clean and dry wet or damp spots within 48 hours;

  • Prevent moisture due to condensation by increasing surface temperature or reducing moisture level in air;

  • Maintain low indoor humidity, ideally 30-50 percent relative humidity (RH), and

  • Don't let foundations stay wet, provide drainage, and slope the ground away from the foundation.

    "MovinCool units with their multi-purpose capabilities allow individuals to fight mold and mildew quickly and affordably," explained Doran. "Each model is completely self-contained, portable, and designed to fit a wide variety of home, work, and building space areas. They can be brought in to handle problem spots in minutes and can move quickly from place to place as needed because they simply roll in, plug in, and turn on to provide instant spot cooling and drying in any critical area."


    According to David Rupp, marketing manager for Temp-Air, a division of Rupp Industries Inc. (Burnsville, Minn.), one of the best ways of preventing or dealing with mold spores is the controlling of their access to moisture. He said Temp-Air provides its customers a full spectrum of temporary, portable heating, cooling, and dehumidifying services, "but we do not claim to be mold experts, or mold remediation experts."

    "For active, and potential mold situations, we evaluate the conditions, and provide our customers with any of a combination of five basic technologies: exhaust fans, filtration, fridge drying, desiccant, and heat," said Rupp. "To be clear, most of these technologies only deal with controlling moisture in the space. Only the exhaust fans and industrial filtration systems may have some effect in dealing with the potentially toxic mold spores."

    Once a mold problem exists - and this is usually 72 hours after flooding - only a mold remediation expert should be consulted, he advised. "You do not want to expose occupants or workers to mold without proper precautions," said Rupp. "The first thing they should do is identify and fix the moisture source, which is allowing the mold to grow. They can dry out the area and then remove all the damaged materials.

    "The big problem is that none of the technologies completely remove the toxic spores. The mold remediation contractor will have to take air samples and certify that the space is safe for occupancy. That said, the most important thing a facility manager can do once he has flood damage is dry out the space before the mold can grow."

    What technologies can be mobilized and implemented within the 72-hour window? Rupp said Temp-Air's Topaz TZ-18A units "are ideal since they can be rented, will work on 110-volt, and will get through 32-inch wide doorways." They can also be attached to condensate pumps, he added.

    "Temp-Air can provide all of the technologies as rental units," said Rupp. "We work with a network of flood remediation contractors that have contracts to respond to disasters in Houston and Miami."

    During a permament heating system replacement, a Temp-Air MIDF-1200 Mobile Heating Solutioons self-contained unit provides up to 1,200,000 Btuh of indirect-fired heat to a manufacturing facility.


    In the eyes of Mark Henry, vice president of Mobile Air Inc. (Madison Heights, Mich.), his company has taken portable a/c and portable dehumidification to "a different level." He said Mobile Air has developed a line of large portable a/c and dehumidification units designed to utilize a hot gas reheat circuit for the dehumidification mode.

    "This allows the units to provide temperature control and humidity control simultaneously," explained Henry.

    "The units begin by cooling the space and therefore dehumidifying as well. As the building air temperature approaches the temperature set point, the unit is also monitoring the relative humidity levels. If the humidity levels are still too high, the unit will activate the hot gas reheat circuit. This allows the unit to continue dehumidifying at full capacity while not lowering the temperature beyond the setpoint, providing control for temperature and humidity levels."

    According to Henry, these units are available in 12, 50, 80, and 100 tons. "The most common applications for this type of equipment is new building construction," he explained.

    "Either the permanent system is not yet completed or is not being used, due to warranty issues. The concerns for the builder are mold prevention, especially in unseen areas such as behind walls or for the preservation of moisture-sensitive building materials after installation, such as high-end ceiling tiles and expensive trim work. And then there are wood floors, especially gym floors."

    According to Henry, his units allow for faster drying times for drywall, concrete, paint, and other coatings, as well as overall comfort and productivity. He said specific applications of these units are usually higher-end facilities, such as hospitals, universities, corporate headquarters, research centers, and museums.

    One project that his company is currently involved in is the new University of Michigan Walgreen's Drama Center in Ann Arbor, Mich. The project calls for using an 80-ton unit to control humidity for all of the reasons stated above.

    For more information, visit www.temp-air.com, www.movincool.com, www.hvacportablesystems.com, and/or www.mobileair.com.

    Publication date: 07/10/2006