Case Study 3
Building 700 of the Fleet Numerical Meteorology and Oceanography Center (FNMOC) at the Naval Postgraduate School in Monterey, California
Building 700 houses a very large computer load and as a result, has an extremely high HVAC load. The HVAC systems consist of eight air handlers, three chillers, two condensing units, two hot water boilers, and corresponding chilled water and hot water pumping and distribution systems. In addition, a steam boiler is used to provide humidification control for the computer rooms.
Implementation of the measures is expected to reduce energy consumption by approximately 1,537,622 kWh of electricity, or 26% of the adjusted baseline, and 55,528 therms of natural gas, or 42% of the adjusted baseline. Peak electric demand is estimated to be reduced by 63 kW. The aggregate energy conservation project is expected to result in the avoidance of approximately $231,245 in annual utility costs for Building 700. At an estimated cost of $506,192, the simple payback period is estimated to be 2.2 years. Should the Navy be successful in retaining $248,584 in potential rebates, the simple payback period would be reduced to 1.1 years.
Considerable non-energy benefits are also anticipated for this project. The addition of the energy management and control system (EMCS) will provide more precise temperature and humidity control than that provided by the existing controls. The EMCS will also provide for temperature alarming functions such that operating and maintenance personnel are notified of potential problems before they would otherwise. Though the EMCS will require some ongoing programming and monitoring, the additional cost to perform these functions will likely be offset by the reduced maintenance costs of the refurbished equipment it is controlling (assuming the HVAC modification ECOs are implemented). For example, as a result of implementing ECO-1, 2, 3 and 4, operating hours of some HVAC equipment, including the chillers, boilers and three of the five air handlers currently in operation, will be greatly reduced. For the purposes of this study, it was assumed the increased maintenance cost resulting from the installation of new equipment would be offset by decreased maintenance cost of existing equipment operating less hours. New system designs often improve system diagnostics, detecting and repairing problems before building occupants are aware that they exist. HVAC measures often result in improved space comfort conditions and improved indoor air quality. Spaces are more pleasant to occupants, which often results in an increase in productivity.
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