The chilled water plant upgrade consisted of the installation of two 32-ton centrifugal chillers and chilled water pumps. Equipment was selected based on a life cycle cost analysis that considered first cost, refrigeration energy, pump energy, and maintenance costs. Features of the system include:
- Variable speed chillers with an NPLV rating of 0.393kW/ton
- Conversion to variable primary chilled water pumping
- Chilled and condenser water temperature reset
- Continuous calculation of plant operating efficiency (plant kW/ton tracked hourly, daily, weekly, and monthly)
The heating boiler plant upgrade consisted of the installation of two high-efficiency condensing boilers with stainless steel heat exchangers, modulating burners, and an efficiency as high as 95%. The domestic hot water plant upgrade included the installation of three high-efficiency condensing boilers with stainless steel heat exchangers and modulating burners and an efficiency as high as 98%, along with four insulated hot water storage tanks.
The cost savings realized from these projects include:
- The hotel’s existing building automation system was outdated and could not support the new central plant equipment. A new vendor installed a building automation system to control the central plant equipment. Cost savings of over $100,000 were realized compared with upgrading the existing building automation system.
- Gas savings of approximately 20% of the hotel’s total usage have been realized through the first 4 months of operation of the new high-efficiency heating boilers and water heaters.
- Electric savings of approximately 12% of the hotel’s total usage have been realized through the first 3 months of operation of the new chilled water plant.
- The hotel was awarded approximately $55,000 in incentives from the local utility due to the energy efficiency measures incorporated in the design of the new systems.