Per state requirements, the casino is floating in a legal sense. "Most all of the vessels here are floating in a moat that is permanently moored," explained facilities manager Stephen Richey. "We're surrounded by five feet of water. Imagine if you would, a pond with a barge in that pond, and all the way around we built hotels, restaurants, and walkways."

Therefore, you can't actually pin the high humidity to the casinos floating nature. It's just the nature of the climate. "We're in Mississippi," said Richey. "We've got all the humidity and mosquitoes you'd want. It's a low, swampy humidity area anyway."

New Equipment, Humidity Control

Trane Mid-South, Memphis, was contracted in 2003 to handle the project at a budget of just under $1 million. Work started in November 2003 and was completed in June of 2004. Two equipment penthouses, one on each end of the two-story casino, each have six 40-hp constant-volume air-handling units.

New equipment consisted of Dynamic® Super-V air cleaners (with electronic polarized-media technology) installed on each of the 12 air-handling units. Trane heat recovery units were installed in each of the two equipment penthouses. Variable-frequency drives (VFDs) from ABB were installed on each of the air-handling units. Add-ons to the existing Tracer Summit® building automation system provided integration.

To address the high humidity, "We installed some heat recovery, basically using the exhaust air to treat the outside air and precool it," he continued. "We lowered the outside air by about 15 degrees."

To address IAQ specifically, Toxalert IAQ sensors were tied to the system. Vaisala humidistats located throughout the casino maintain a set point through Tracer Summit.

Air infiltration points on the outside of the casino were identified and sealed to prevent infiltration of untreated air. "When you come shore side onto the floating vessel, there's a 12-foot gap between the boat and the building, kind of like an enclosed gangplank area," explained Richey. The gangplank was covered, but there was a slight gap just before the entrance to the casino, similar to the gap travelers see between the walkway and "right before you step on the jet," Richey said. "These were areas that we tightened up quite a bit."

"Cleaner air and increased comfort levels were the goals," noted Joel Winstead, the Trane account manager responsible for the project. "Accomplishing it with an investment payback of less than five years was the challenge."

Filtration And Heat Recovery

The V-bank filtration systems were installed in place of 4-inch pleat filters in mixing boxes on each of the 12 air-handling units. The V-banks use nonionizing active filtration with polarized media technology to remove submicron particles and odors from the air, the manufacturer said.

The mixing boxes were modified to allow the V-bank racks to be disconnected and rolled out for service and maintenance. Each air-handling unit was fitted with 33 V-bank air cleaners, configured in three rows of 11, with a separate control panel.

"Control of tobacco smoke is something we do very well," stated Carl Mitchell, national sales manager for Dynamic Air Quality Solutions. "Most smoke particles are under 0.3 microns in size, and that's where we excel. And the activated carbon removes odors and volatile organic compounds (VOCs), in addition to providing the conductor for the polarized field."

Heat recovery installed in each of the two equipment penthouses consists of a coil loop between a new outside air unit and exhaust unit. The new unit provides approximately 27,000 cfm of outside air per penthouse, according to Trane.

There also were ductwork modifications. "We had to run a separate duct from the outside wall to the entering side of the heat recovery," said Richey. "We tied the return back to the exhaust side of the heat recovery." Exhaust air was tied into the returns of each air-handling unit. VFDs were installed on both the supply (outdoor air) and exhaust fan of each heat recovery unit.

Airflow measuring stations were also installed in each of the heat recovery sections to measure the volume of outside air and exhaust air being utilized. The heat recovery units recover and transfer leaving air temperature to the incoming fresh air.

System Control

Temperature and pressure within the building are maintained by the building automation system (BAS) for desired indoor comfort conditions on a consistent basis. According to Trane, control is achieved using the following parameters:

The outdoor air fan on each heat recovery unit modulates based on building occupancy. Occupancy data, maintained in the BAS, determines the rate at which fresh air is introduced into the casino to provide a minimum of 15 cfm per occupant.

The VFDs on each air-handling unit modulate fan speed up and down based on the temperature inside the casino that is directly dependent on the actual occupancy. IAQ sensors serve as a system safety to increase airflow at the air-handling unit and heat recovery unit if necessary, and to help ensure optimum conditions throughout the casino.

Exhaust fans on each of the two heat recovery units are controlled by pressure inside the casino. A slightly positive pressure is maintained in the building. Pressure sensors were installed on the first and second floor of the north and south side of the casino.

Outcome

"I knew there would be improvement," said Richey, "but we were truly amazed at the difference. The smoke and the haze are gone."

As for the comfort, Richey added, "We had difficulty maintaining a comfortable temperature and a comfortable humidity level in July and August. We've just finished the hottest summer in five or six years and the new system worked perfectly. If we decide to lower the humidity 10 percent, we can do so in less than an hour. In the past, it would take us all day."

The air cleaners are polarized, so they load evenly around individual fibers rather than on the face of the filter, the manufacturer explained. "We were changing four-inch pleat filters every two to three months," said Richey. "Now we are out to six months, which has a direct impact on cost."

The story doesn't end there."

Just this year, there was a fire in a service area below the casino. Smoke damage was significant enough for the gaming operation to be closed for a day, Richey said. One remediator gave the casino's owner a six-figure estimate to pump ozone into the space. As they explored their options, the smoke odor disappeared.

"It was icing on the cake for Sam's Town," said Richey.

Publication date: 10/03/2005