Carrier’s Turnkey Chiller Delivers Efficiency
The Cherokee Nation W.W. Hastings Hospital is a 150,000 square foot facility. Over the years, patient visits have grown from 60,000 to 400,000 per year, with an attendant increase in staffing numbers. Heat generated from advanced healthcare equipment has added to the cooling demand. Carrier provided a solution to the increasing chiller requirements.
Located in Talequah, Oklahoma, the Cherokee Nation W.W. Hastings Hospital is a 150,000 square foot facility. The original chillers, dating back to the hospital’s 1984 construction, were two 250-ton Carrier 19D units, which served the facility for more than three decades. Over the years, however, patient visits have grown from 60,000 to 400,000 per year, with an attendant increase in staffing numbers. Heat generated from advanced healthcare equipment has also added to the cooling demand. These conditions prompted Dale Dreadfulwater, Supervisor of Facility Management and Jason Helsley, HVAC Technician for the Cherokee Nation W.W. Hastings Hospital, to propose to the Cherokee Nation Health Team of Directors and Chief Bill John Baker that the hospital should implement a turnkey chiller plant upgrade.
The team immediately discovered, however, that due to the existing infrastructure and cost considerations, the original chilled water piping system could not be expanded. Therefore, the final chiller plant solution would have to utilize the existing piping configuration to deliver more tons of comfort cooling. The hospital’s facilities staff then turned to the Carrier team in Tulsa for a successful solution.
Carrier delivered a turnkey equipment replacement solution by custom-engineering two new 400-ton AquaEdge® 19XRV chillers to provide more cooling from the existing piping system by accommodating a larger than normal ΔT – the variation in temperature between water entering the chiller versus water exiting the chiller. In addition, a plate frame heat exchanger will provide free cooling in the winter. By integrating a plate frame heat exchanger into the piping system, the hospital can take advantage of cold condenser water in the winter months and satisfy their cooling load with less energy consumption.
The new system integrates into the existing building footprint and infrastructure delivering 60% more cooling capacity with an expected annual energy savings of approximately 17%. Through variable speed chiller technology, plate frame heat exchanger utilization and new Carrier i-Vu® controls, major improvements in building comfort and energy efficiency are being achieved.
Cooling is critical in healthcare facilities and the hospital could not afford any downtime during the project installation. As part of Carrier’s overall turnkey solution, rental chillers and related equipment were provided for temporary cooling during the modernization. The transition from the old system to the new system occurred seamlessly without any interruption to the facility’s indoor environment.
The project, which is now producing substantial improvements in all aspects of comfort level, reliability, redundancy and energy savings, is a big win for the Cherokee Nation. Key to the project’s success was the entire hospital engineering staff’s technical expertise, facility knowledge and thorough understanding of the requirements to achieve all the project’s goals. Dale Dreadfulwater said, “The Carrier team engineered and delivered the complete solution we wanted. After 20 years of running both original chillers year-round, it’s great to have a better way to serve our patients and staff.”
