Reliability and Consistency Make Danfoss Variable Frequency Drives a Sure Bet in Las Vegas
Las Vegas may be the capital of variety and excess, with seemingly unlimited choices of entertainment and food. But for the mechanical systems that manage the indoor environment in this desert city, consistency and simplicity are more desirable traits. Owners of casino hotels and restaurants that operate around-the-clock require HVAC equipment that is reliable and easy to operate and maintain.
Those criteria became vitally important to the developer of CityCenter, an $8.5-billion resort destination on the Las Vegas Strip that was the largest and most elaborate commercial construction project in U.S. history.
MGM Resorts International opened the 18-million-square-foot development in December of 2009. It contains a smorgasbord of facilities, including 6,000 hotel rooms, 2,400 condominiums, 38 restaurants and bars, a convention center, a shopping mall, a Cirque du Soleil theater, and a 150,000-square-foot casino. In addition, an 8.5-megawatt, natural-gas-fired cogeneration plant provides a portion of CityCenter’s electricity, hot water, and heat.
MGM Resorts project managers and consulting engineers WSP Flack and Kurtz knew that the project’s scope and the Las Vegas environment would place extraordinary demands on its HVAC system. They needed to make the system operation as simple and efficient as possible. As part of their solution, they chose during the planning stages in 2006 to integrate variable frequency drives on every HVAC system motor 5 hp and larger. MGM Resorts eventually selected the line of VLT® HVAC Drives from Danfoss because of the product’s performance history and consistent interface.
“MGM Resorts had nearly 20 years of experience using Danfoss products in other facilities,” commented the leading engineer on the project. “Their products had a solid track record.”
That familiarity was an important concern because of the scope of the CityCenter project, which took more than four years to complete. MGM Resorts’ vision for CityCenter included creating a sustainable urban core that was significantly different than the isolated, sprawling casinos typically found in Las Vegas. Several architects and more than 250 consultants worked to create that vision by managing development of multiple structures on 67 acres.
“There were several buildings under construction at one time, so there was pressure to stay on track and deliver a product the day it was needed,” said the project’s leading engineer. “And because of that aggressive construction schedule, we had to be confident that the products we were installing were going to perform.”
Mechanical contractors installed 744 VLT® Drives during the four-year construction process, ranging in size from 1 hp to 600 hp. The drives, which are designed to work at maximum output in ambient temperatures up to 122°F, were installed in nearly every area of the HVAC system, including:
- Primary-loop chilled water pumps (600 hp), which provide chilled water for comfort cooling to the entire CityCenter complex.
- Condenser water pumps (450 hp), which return water to the chillers, maintaining the proper temperature and flow necessary for optimum chiller operation.
- Hot water pumps (300 hp), which circulate hydronic heating water for applications such as comfort heat during the winter months and domestic water heating throughout the year.
- Air handler system of supply fans and return fans containing more than 250 VFDs.
- Cooling tower fans (250 hp), which control the temperature of the condenser water for the facility’s six 5,500-ton chillers.