Located in the historic Warehouse District of downtown Minneapolis, the 40,000-seat open-air ballpark contains a natural limestone exterior, baseball-themed restaurants, state-of-the-art locker rooms, 54 private suites, and 3,400 club seats. Target Field also features one of the closest seating bowls to the playing field in all of professional baseball, and a 360-degree open main concourse, giving fans an uninterrupted view of the action.
The indoor portions of the new facility - the ornate millwork, cabinetry, and high-end finishes in the lounges, clubs, bars, locker rooms, executive suites, and restaurants - required special care during construction in 2009.
THE GAME PLANWith summer approaching, Eric Keleny, mechanical, electrical, and plumbing coordinator (MEP) with Minneapolis-based M.A. Mortenson, the construction firm, needed a game plan for protecting the sensitive indoor materials from high humidity and warm weather.
“The manufacturer had specifications for temperature and humidity for the wide variety of wood and laminate being installed,” said Keleny. “Extremes in the indoor environment could potentially expand or shrink the wood, causing warping.”
Having worked together on several previous projects, Keleny added to his team’s lineup Munters Moisture Control Services (MCS), a temporary humidity control company, to provide a controlled environment during construction.
Keleny requested that relative humidity levels indoors remain below 50 percent and that temperatures remain below 80°F. John Pfeffer, industrial accounts manager for Munters, called up three 6,000-cfm Humidity Control Units (HCU), in combination with several blowers, for shipment to the site.
“The HCU is capable of delivering dew points as low as 40°F in even the highest humidity load conditions,” said Pfeffer. “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 different parts of the main concourse and flexible duct was utilized to move the air inside of the building. Twelve 48-inch turbofans moved the air around the club level spaces requiring humidity control.
The quick timeline of the construction project required that Munters have all systems up and running in spaces that were 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,” said Pfeffer.
M.A. Mortenson realized additional benefits from the use of the temporary dehumidification. Lower temperatures made the environment more comfortable for workers, especially during the warm summer months. In addition, the dry air decreased the drying times of building materials. These extra benefits helped keep the construction timeline on target during these construction phases.
WRAP-UPIn total, Munters conditioned 150,000 square feet of the 500,000-square-foot 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,” said Keleny. “We are very pleased with the performance of the units, their easy installation, and the monitoring by Munters technicians.”
The dehumidification units used on site also will help the contractor obtain a LEED point. The units were used in conjunction with the permanently installed HVAC systems to flush out the building prior to occupancy per LEED guidelines. The ballpark is scheduled to open in April.