AG 2012 11 19 - Laserfiche WebLink

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I � 5 Energy Conservation Measures The following Energy Conservation Measures (ECMs) should be evaluated further. 5.1 ECM 1: Chiller Plant Upgrades The chiller plant can readily be modified for more efficient operation. We would recommend the following improvements: Controls Upgrade: Provide new controls as part of the larger controls retrofit of Building 1000 from pneumatic to DDC. Automating plant operation will enable better sequencing and efficient operations of the chiller plant. In current operations the oldest chiller is being base loaded, due to problems with the newer machine. While at light load this is probably a good strategy, in warmer weather the larger, newer chiller should be operated. Automating this sequence will allow for the most efficient machine to be automatically selected as part of the sequence. Add VFDs to the Tower Fans: The cooling towers presently have two fans. The use of variable frequency drives on the cooling tower fans will provide improved efficiency and control as well the ability to "soft start" these fans. Condenser Water Optimization: Currently the cooling towers operate at a constant set point. We would recommend resetting the condenser water set point based on the outdoor wet bulb temperature and limits of the chiller. Resetting condenser water allows for the tower to do more work, and the chiller to do less. Since the tower is much more efficient then the chiller this results in improved energy efficiency. Convert Secondary Chilled Water Pumps to Variable Flow: The secondary pumps, which circulate chilled water to the three buildings, currently operate at constant speed and utilize three way control valves to keep flow from varying. Generally one pump should be able to provide enough capacity to cool the campus, although currently two pumps are operating. Converting the plant to variable secondary flow requires retrofitting the pumps with variable frequency drives and changing control valves at the three primary air handlers from three -way to two -way operation. The benefit of this strategy is that the pumps can run at part capacity for much of the year providing for significantly improved efficiency. 5.2 ECM2: Air Handler and Terminal Unit Control Upgrades 5.2.1 Control Upgrades The most important change to improve comfort and efficiency for the air handlers is proper control. This includes correctly managing outdoor air, sequencing, and scheduling. Convert Buildings 1000 and 2000 to DDC: Currently these buildings are a mix of DDC and pneumatic controls. New DDC controls will allow for better occupant comfort and will also allow for strategies including static pressure reset and improved zoning. Occupancy Control: Air handling units, VAV boxes and the chiller plant shall be scheduled to follow building occupancy hours. An optimal start routine Rev A 2012 -05 -15 Page 22 Final Draft G -2 Page 346