Located in the historic Warehouse District of downtown Minneapolis, Target Field, the new 40,000-seat, open-air ballpark Major League Baseball's Minnesota Twins call home, includes themed restaurants, state-of-the-art locker rooms, and 54 private suites. The ornate millwork, cabinetry, and high-end finishes in these and other indoor areas required special care during the facility's construction in 2009.
"The manufacturer had specifications for temperature and humidity for the wide variety of wood and laminate being installed," Eric Keleny, mechanical, electrical, and plumbing coordinator with Minneapolis-based M.A. Mortenson, the construction firm, said. "Extremes in the indoor environment could potentially expand or shrink the wood, causing warping."
Keleny turned to Munters Moisture Control Services for temporary dehumidification.
Keleny wanted indoor relative-humidity levels kept below 50 percent and indoor temperatures kept below 80°F. John Pfeffer, industrial-accounts manager for Munters, selected three 6,000-cfm Humidity Control Units (HCUs) and several blowers for shipment to the site.
Combining cooling and desiccant-dehumidification technologies, the HCU controls dew-point temperatures in hot, humid climates. It is well-suited for structural drying, temporary humidity control in building construction, and condensation and corrosion control in surface-preparation and coating applications.
"The HCU is capable of delivering dew points as low as 40°F in even the highest humidity-load conditions,” Pfeffer said. “Because the unit utilizes reactivation energy, it uses less energy while providing comfortable outlet temperatures."
When the equipment arrived, accessibility was an issue. Using the ballpark's inner field to reach the indoor spaces was not an option, so the units were placed in small areas on the main concourse, with flexible duct utilized to move air inside of the building. Twelve 48-in. turbofans moved air around the club-level spaces requiring humidity control.
The short timeline of the construction project required that Munters have all systems up and running in spaces ready for temperature control.
"We moved quickly to make sure indoor spaces were conditioned as millwork was installed in bar areas, administration offices, board rooms, executive and corporate suites, and throughout locker-room areas," Pfeffer said.
M.A. Mortenson realized additional benefits from the use of temporary dehumidification. Lower temperatures made the environment more comfortable for workers, especially during the warm summer months. Additionally, the dry air decreased the drying times of building materials. These extra benefits helped keep the project on schedule.
Munters conditioned a total of 150,000 sq ft of the 500,000-sq-ft structure. Throughout the project, Munters technicians periodically monitored conditions and handled maintenance work, such as filter replacement.
"Munters stepped up to the plate to keep the high-end millwork safe from high humidity levels during the hot and humid summer and fall months, while keeping our workers comfortable," Keleny said. "We are very pleased with the performance of the units, their easy installation, and the monitoring by Munters technicians."
The Munters HCUs will help the contractor obtain a point under the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) Green Building Rating System, as the units were used in conjunction with permanently installed HVAC systems to flush out the building prior to occupancy per LEED guidelines.
Information and photograph courtesy of Munters Corp.