Dealing in comfort
"We've been in the casino business for over 10 years, and in that time we've formed some opinions on how to maintain a good indoor environment," he said.
Ruecker and others who work for the Barona Band of Mission Indians had a chance to test those opinions when they designed the HVAC system for the tribe's 16-month-old, $260 million hotel and casino.
The resort is located about 30 minutes northeast of downtown San Diego. The resort includes a large casino, a luxury hotel and an award-winning new golf course created by Gary Roger Baird Design International.
The eight-story, 397-room hotel and resort was designed by the Las Vegas architecture firm of Bergman, Walls & Associates - the same group responsible for such Vegas landmarks as the Bellagio, Paris and the Mirage - with a 1930s ranch theme, representing the decade the Barona tribe's reservation was established.
Working with the architect was general contractor Hensel Phelps Construction Co., which managed the project from their district office in Irvine, Calif. The mechanical engineer for the project was FEA Consulting Engineers of Las Vegas, and the mechanical contractor for the piping, plumbing and sheet metal work was San Diego-based A.O. Reed & Co.
The resortThe heart of the resort is the 310,000-square-foot casino, which features 2,000 slot machines, 59 table games, a poker room, bingo and an off-track betting parlor. It also contains three full-service restaurants and a food court.
While most building owners want to ensure a comfortable indoor environment for occupants, this poses a special challenge for casinos, Ruecker said. Wide variations in occupancy and the need to handle a large amount of tobacco smoke are among the special considerations.
"A significant percentage of our customers are smokers," Ruecker said.
Since it's on American Indian property and the tribe is considered a sovereign nation, the Barona Valley Ranch Resort and Casino is exempt from California's strict indoor smoking law. Since 1998, smoking has been banned in most buildings, including restaurants, bars and poker rooms.
While casino officials want to accommodate smokers, they want to keep nonsmoking patrons happy as well.
"And we believe that the best air quality solution is a high rate of ventilation, but in a way that doesn't in itself become a comfort problem," Ruecker said.
That conclusion was based on their experiences during the last decade at a smaller Barona-run casino on the same site, he said.
"We learned that large-volume ventilation with appropriately conditioned air is the best solution. So when we began planning our new facility, we insisted on a mechanical system that could meet that challenge."
Construction scheduleConstruction of the casino began in the summer of 2001 and was completed Dec. 11, 2002. The casino had a "soft" opening on that date, with slot machines and other equipment being brought in and started up over a two-week period.
"We wanted to be able to adjust to the new environment gradually, rather than having massive crowds on an ‘opening night,' " Ruecker said.
Planning the mechanical plant for the new casino was based extensively on the experience of the owners with the earlier facility.
Part of its design challenge came from the location itself. The Barona Valley area has much higher summer temperatures than nearby San Diego, with annual temperatures ranging from 40°F to 115°F. So, it was necessary to have a major chilled-water resource to supply the air handlers. Two centrifugal chillers, with a third identical machine standing by, furnish the casino complex. The units are 800-ton Trane CenTraVac Model CVHF electric chillers.
The three machines are located in a separate building that serves as the mechanical plant. The chillers are rotated to keep the hours balanced. The plant produces chilled water at 42°F, with a 54°F return. The building-automation-control cooling towers are adjacent to the mechanical building and are supplied with softened well water from the facility water plant.
The cooling plant is also equipped with a plate-and-frame heat exchanger, which permits "free cooling operation" during the cooler months. In this mode, the cooling towers alone can economically supply much of the cooling needed. This method is especially effective, building managers say, since the humidity is low during the cooler months.
To supply heat, the mechanical plant is equipped with three 700,000-Btu hot water boilers, which are used for heating as well as for reheating the ventilation air.
Rooftop air handlersSince smoking would be permitted in much of the casino, the comfort plan called for large volumes of conditioned air, provided by rooftop air handlers and indoor, central-station air handlers in a mezzanine space above the casino floor. The rooftop air handlers are Trane T-Series Climate Changer units. The modular T-Series units are designed for outdoor use. They were specified with the exact combination of elements for each application.
The rooftop air handlers provide conditioned outdoor air that discharges through overhead diffusers into the casino's gambling areas. The large number of units allow an enormous volume of air to be discharged into the spaces without patrons feeling drafts.
Some areas of the casinos are designated as nonsmoking. For these areas especially, a high ventilation rate is essential, officials said.
The indoor units chosen are Trane Modular Climate Changer air handlers. The indoor modular air handlers in the mezzanine provide cooling for offices and other administrative spaces, as well as the large restaurant areas. These were selected with the specific combination of heating, cooling and filtration modules to serve the 140-Plus VariTrane variable-air-volume terminal units serving these areas.
Trane account manager Mike McCabe said that the installation was notable because of the generous space for service technicians allowed around all of the units.
"Very often, air handlers are installed in very confined spaces," McCabe said. "This makes regular inspection and needed service difficult. In this case, they allowed plenty of room around the units. The technicians really appreciate that."
Fan coilsThere are also 36 Trane fan coils providing cooling in key equipment rooms, corridors, lobbies and special-use areas. All communicate electronically with the Tracer Summit System to provide monitoring and control to support areas.
The Tracer building-control system plays a critical role in assuring continuous good air quality. According to Cesar Madlangbayan, the facilities mechanical manager responsible for the day-to-day operation of the mechanical plant, the control system helps ensure everyone's comfort.
"We can precisely set conditions in different zones, and can closely monitor conditions in all of the areas," Madlangbayan said.
The Summit system normally adjusts ventilation rates based on carbon dioxide levels as an indicator of area occupancy and also by measuring volatile organic compounds as an indicator of secondhand tobacco smoke levels.
Although this is the standard control approach, Madlangbayan said that during periods of peak casino occupancy, usually in the late afternoon and evening, the control program overrides these control parameters and operates at maximum ventilation rates. This period typically extends for several hours. The Tracer Summit system also manages the chiller plant, determining when to use free cooling with the cooling towers, and the system works with other building systems, including fire and safety systems.
Remote monitoringMcCabe points out that a key feature of the Summit system is its remote monitoring capabilities. The system is connected to a Web server, which allows operations to be monitored and adjustments made from any location with an Internet connection.
"If Cesar gets a call at home on evenings or weekends, he can make any adjustments necessary without coming in here," McCabe said.
"That's really a great feature and the Web server solution is working great," he said.
In addition to the demanding casino system, the mechanical plant also includes the hotel and other facilities. The hotel rooms and suites are equipped with horizontal, concealed fan-coil units.
"We wanted a quality room comfort system. These fan coils give us this very reliable and quiet system with capabilities for individual room control," Ruecker said.
The fan coils are served by the same central plant as the rest of the facility.
The resort's wedding chapel uses Trane Voyager rooftop air conditioners. The golf center has split-system direct-exchange units.
"We learned a lot from our earlier operations on this site," Ruecker said. "We now have a system that gives us pretty much everything we wanted in comfort, control and operating efficiency. And we have a system that will take us a long way into the future. It's built to last."
(This article was supplied by Trane.)