Dear Boston Green Tourism Members,  Our next meeting will be Thursday from 2:30 to 4:00 at Taj Boston. Check the reader board in the lobby for the room location.     I hope you can come!   Dan

Last summer, Mandarin Oriental Boston contracted with Siemens to install the Demand Flow Chilled Water System for their two, ten-year-old Trane chillers.

 

The Mandarin's chillers are controlled by the Siemens building management system (BMS). Siemens started the project by studying the chiller system's operating characteristics and identifying opportunities for improvement. They estimated that by installing more controls, fine-tuning the system's sequencing and adding a variable frequency drive to the condenser water pump, they could reduce energy use by 30%.

 

The project cost $115,000, including the Mass Save incentives provided by Eversource. The Mandarin expected to save $60,000 per year-a payback of roughly two years.

 

In the five months since the Demand Flow system was installed, the Mandarin's chiller system consumed 527,000 kWh--compared to 838,000 kWh had the project not been completed. The savings, based on 15.5 cents / kWh, is already over $48,000. Because energy savings have exceeded expectations and the price of energy has gone up, the project payback will be well under two years.

 

Ed Dustin, the Mandarin's Director of Engineering, called the installation process "painless." He pointed out that the system will prolong the chiller system's life and give the hotel a marketing boost.

 

Mr. Dustin said that any hotel with large tonnage chillers that still have constant speed pumps on the chilled water or condenser water side would benefit from chiller plant optimization. The biggest efficiency gains for the Mandarin have come from optimizing the condenser water pump flow in the shoulder seasons. They have also benefited from optimizing the chilled water temperature and secondary chilled water pressure; and because their first chiller is now so efficient that the second chiller runs less often.