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Casino Bets on Rooftop Air Handlers and Centrifugal Chillers, Wins Big

Oct. 7, 2014
CAE calculated a 13.02 percent energy savings in electricity and gas consumption above the ANSI/ASHRAE/IES Standard 90.1-2007 baseline for the entire facility.

Casinos combine a variety of space types under one roof. Hollywood Casino in Toledo, Ohio, which opened in May 2012, is no different. The 177,000-sq-ft main casino level includes 150,000 sq ft of gaming space and five restaurants, while the 167,000-sq-ft lower service level includes administrative and employee areas and a 276-space valet-parking garage.

Atlanta-based Urban Design Group (UDG) provided architectural services. It called in West Atlantic City, N.J.-based Concord Atlantic Engineers Inc. (CAE) for mechanical-engineering design. For heating and cooling the entire building and supporting owner Penn National Gaming Inc.’s pursuit of LEED (Leadership in Energy & Environmental Design) certification, CAE recommended rooftop air handlers and centrifugal chillers from Daikin Applied.

“We have a comfort level with Daikin Applied based on other projects we’ve done and their ability to meet fast-track construction schedules,” Anthony Caucci, PE, vice president/director of mechanical engineering for CAE, said.

“Daikin Applied and its representatives were a very big help because we had to get specifications for the HVAC units in line very quickly,” Matt Mitchell, LEED AP BD+C, project manager with UDG, said. “CAE spent a lot of time with Daikin Applied representatives to get the details and work through them. Getting the rooftop units manufactured and shipped was completed in one of the fastest time frames of the whole project.”

Mitchell said collaboration was essential to the successful completion of the project, for which 94 contracting firms, including more than 2,100 union tradespeople, were hired.

“There wasn’t time to make decisions without everyone’s input and buy-in,” Mitchell said. “... It wouldn’t have worked to make individual decisions and then find out later equipment had to be modified.”

Ground was broken in August 2010; construction was completed in mid-March 2012—three weeks earlier than the targeted completion date. While not officially considered design/build or design/assist delivery, construction progressed rapidly, despite record snowfalls during the winter of 2010-2011.

Dan Stark, PE, project manager with Walbridge, Ohio-based GEM Inc., which performed HVAC mechanical and electrical installation, as well as building plumbing and electrical work, said construction caught up with design during the early construction phase of pile driving.

“We had to make sure the areas we worked on next were completed from the engineering design perspective and ready to install before we worked on it,” Stark said.

The casino is located on a brownfield site.

“Architects and engineers had the complicated task of determining the location of the building on the 44-acre site while meeting all environmental requirements,” Stark said.

Digging only 10 ft into the ground was one such requirement.

HVAC Configuration

The casino features 21 Daikin Applied RoofPak variable-air-volume (VAV) air handlers with total-energy-recovery wheels and three Daikin Applied single-compressor centrifugal chillers.

Twenty-one Daikin Applied RoofPak rooftop air-handling units provide air to 344,000 sq ft of space.

“The Daikin Applied rooftop units and the variable-speed chillers heavily offset the large energy consumption of a casino,” Caucci said.

The water-cooled chillers are located in a separate steel enclosed packaged chiller plant. Cooling towers are located adjacent to the plant.

The main HVAC systems use a four-pipe system with the RoofPak units. Additionally, 276 VAV boxes located in the building ductwork control individual thermostat-controlled zones within the building.

“The VAV boxes contribute to the LEED requirement to control airflow,” Stark explained.

Two boiler rooms—one in the mechanical mezzanine level and one at the service level—contain a total of four boilers.

“We did a supply-air-temperature reset on the rooftop units to save on piping and boiler usage,” Caucci said. “The system uses gas heat in the rooftop units to an advantage on the casino floor. Of course, most rooftop air-handling units have a supply-air reset, but we programmed additional logic in the system to warm air up in lieu of reheat coils on the large gaming floor. Some of the perimeter-zone VAV boxes have reheat coils to ensure heating if the main units deliver cold air.”

HVAC Installation

The 21 RoofPak units were installed on a just-in-time, staged basis over a three-week period in June 2011.

“The delivery of the units were all coordinated to minimize costs,” Stark said. “We lifted the units off the trucks from three different pick points. Each week, the crane had to be moved and reassembled in each area.”

The enclosed chiller plant was assembled on a just-in-time basis in the fall of 2011.

“Teams put together the prefabricated building in sections, with each of the three chillers in its own packaged chiller plant,” Stark explained.

The cooling towers are situated on top of the water-cooled chiller plants in a single structure, which was assembled within two weeks.

GEM oversaw the LEED-required flush-out and commissioning of the HVAC system, which was done on a staged basis. The service-level/back-of-house flush-out occurred in November 2011; the gaming-level flush-out took place in April 2012.

The rooftop air handlers and chillers, as well as all other HVAC equipment, such as the cooling towers and pumps, were integrated with a Johnson Controls Metasys building-automation system (BAS) using the BACnet open standard protocol. The Daikin Applied equipment features Open Choices controls, which are compliant with all standard BAS communication protocols.

Significant LEED Contributor

“The energy-recovery wheels in the Daikin Applied rooftop units are big contributors to the lowered energy consumption of the HVAC equipment compared to conventional systems,” John H. Melville of West Conshohocken, Pa.-based manufacturers’ representative TriState HVAC Equipment LLP, which oversaw the specification, procurement details, and logistics of the Daikin Applied equipment, said.

The rotating energy-recovery wheels, built into each rooftop air-handling system, draw outside air across one-half of the wheel while drawing exhaust air across the other half. This process transfers sensible and latent energy between the ventilation and exhaust air, allowing heat to be recovered during winter and allowing free cooling during summer.

Energy modeling and analysis by CAE calculated a 13.02 percent energy savings in electricity and gas consumption above the ANSI/ASHRAE/IES Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings, baseline for the entire facility.

“The ASHRAE energy model uses historical weather data for Toledo and factors all aspects of the facility, such as insulation, roofing, lighting, interior loads, and mechanical equipment,” Caucci said.

CAE is overseeing rebates from the local utility company expected to total over $100,000 for equipment purchases on behalf of Penn National Gaming.

Energy analysis by CAE found the cooling equipment was responsible for 18.4 percent of the facility’s overall energy savings.

“The heat-rejection equipment, or cooling towers, contributed 5 percent, and the pumps contributed 5.3 percent,” Caucci said. “Other energy-saving elements include lighting, domestic water heaters, boilers, insulation, and construction materials.”

Between 85 and 90 percent of the cement, drywall, wood, cardboard, and steel used in construction was made from recycled material.

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