The east entrance of Thunder Valley Casino. Not only are casinos uninterruptible, the gaming floor must be able to change at a moment’s notice. To that end, each zone is serviced by genererously sized coils or VAV boxes. (Photo courtesy of JMA Architecture Studios.)
In a world where the customer walks through the door 24 hours a day, the indoor environment must feel completely comfortable and inviting - day or night. HVAC systems are crucial to success in the hospitality industry, whether in a hotel, a casino, or a restaurant. A partnership between Harris Consulting Engineers (HCE), Perini Building Company, and JMA Architecture Studios tackled the design and engineering for the expansive 240,000 sq-ft Thunder Valley Casino project in a remarkable 10 months. The casino (located near Sacramento, CA on Auburn Rancheria Indian Community land) includes a wastewater treatment plant and a fire station in addition to the nearly 2,000 slot machines, 100 gaming tables, four 8,000 sq-ft restaurants, 500-seat buffet, and a separate food court.

Mission Critical Operations

The complexities of the HVAC system in the ever-changing layout of the gaming facility create many unique challenges for architects and engineers, not the least of which is that once a casino is operational, gaming cannot be interrupted. Specifically, there is no downtime in which to make alterations to the HVAC ducting or to the overall capacity of the system. Potential changes to the HVAC system load and configuration must be anticipated and engineered into the system when initially constructed.

In addition to an uninterruptible casino environment, when a gaming floor is reconfigured, the ceiling typically remains the same. In the fast-paced casino world, today's slot machine and gaming tables may become next month's buffet seating, necessitating an easily accessible and adaptable ducting system. The HVAC systems designed by HCE are flexible in layout and in function to keep pace with this ever-changing 24-hour environment.

HCE designs casino HVAC systems with some spare capacity, so that if the air conditioning load increases or decreases, it can be accommodated in each zone by generously sized coils or VAV boxes. Other considerations in designing HVAC ductwork for casinos center around the necessity of accommodating all ducting in the ceiling. Often, gaming room ceilings have sections with T-bar lay-in panels, so all serviceable equipment can be placed behind the lay-in panels for easy access.

In this case, the ceilings in the gaming areas are designed around a 30-ft by 30-ft grid, with the lowest elements at 15 ft and the highest at 22 ft. The lowest faces and vertical sides of the ceiling elements utilize hard decorative surfaces, while the upper vertical portions act as light coves. The top of the 18-ft by 18-ft grids are decorative T-Bar lay-in panels.

Where possible, the supply plenums from the rooftop air handlers are located above lay-in ceiling sections, allowing easy access to the main supply plenums for future taps. All taps from the supply plenum to the area served are also routed over the lay-in ceiling sections. This is primarily due to the amount of framing required to support the ceiling structure, but it also allows for easy access to the branch ducts for future taps. All VAV boxes, CAV (constant-air volume) boxes, and reheat coils are installed above the 18-ft by 18-ft lay-in ceiling sections for easy access and service.

In addition to designing the air system for flexibility, the chilled water and hot water mains that serve the rooftop equipment are routed above the gaming floor in a similar manner. Hot taps can be made at any number of locations on the mains through the lay-in sections of the ceilings.

In a standard office building utilizing a VAV system, the main supply trunks are continually renovated during tenant changes and improvements. In an office space, the interiors are usually demolished, exposing the mechanical systems, and allowing for modifications prior to the reinstallation of the ceiling. In a casino renovation, the ceiling stays in place while the gaming floor and its associated loads change. The HVAC system has to accommodate any changes or shifts in space load without affecting the 24/7 gaming operations.

The chilled and hot water mains that serve Thunder Valley Casino are routed above the gaming floor in the lay-in sections of the ceiling for easy access. (Photo courtesy of JMA Architecture Studios.)

A Breath Of Fresh Air

Other casino-specific needs revolve around keeping the air clean and oxygen rich. In the often smoke-filled rooms it is important to minimize the mixing of the smoke-laden air with the supply air. Typical gaming floor areas have multi-elevation ceilings, and by locating the supply air at the lowest point in the ceiling and the return air at the highest point, the HVAC ducting design minimizes the mixing of air, keeping customers breathing fresh air.

While future solutions may ideally employ an underfloor supply air distribution system to keep the fresh air moving up and pushing the smoky air toward the intakes in the ceilings, gaming floors currently lack this flexibility. This is due in part to in-floor power distribution systems that allow for nearly unlimited slot machine configurations yet make underfloor air distribution systems difficult to execute.

Additionally, with the ever-shifting slot machine groupings, there are no permanent locations for air distribution systems. Finally, underfloor plenums create security issues in a gaming environment not typically faced in an office building. HCE continues to investigate viable options to the challenges faced in designing in-floor air systems.

During the design of the Thunder Valley Casino, the central plant was modeled in 3-D using AutoDesk's "Building Systems" software to coordinate all the spaces, utilities, and system components including wetside, dryside, and electrical gear. This proved beneficial to contractors for estimating costs and illustrating the design intent. JMA Architecture Studios also utilized these 3-D models in the design of the facility. ES

Harris Consulting Engineers (HCE) has been engaged in the private practice of professional mechanical and electrical engineering in the greater Las Vegas area since 1983, specializing in HVAC, plumbing, and electrical systems designed for physical comfort, convenience, function, and value. HCE's success comes from providing top quality services to clients through strong individual and team efforts and adherence to the highest professional standards.