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Duke <br />(Energy. <br />4.2.2 Building 2000 <br />Building 2000 was constructed in 1998 and <br />also has a mix of pneumatic and DDC controls. <br />Facility staff indicated they have trouble <br />controlling two zones in the same room with <br />the existing pneumatic controls. AHU2 is a VAV <br />unit that serves this building and has chilled <br />water and hot water coils. Upon observation, <br />this unit should have been in economizer <br />mode, but it was not even bringing in minimum <br />OA. This unit had recently been retrofitted with <br />a VFD which is attempting to control both the <br />supply and return air fans. The BAS also <br />indicated that the VFD was running at full <br />speed and only making 1.7" static. <br />• Return Fan = 30 HP <br />• Supply Fan = 50 HP with IGV's <br />Building 2000 has a natural gas boiler for guide vanes on AMU supply fan <br />heating which is original to the building. We <br />would estimate that this boiler is operating at between 60% - 80% efficiency. Like <br />building 1000 this boiler is not resetting hot water temperature and may not be <br />properly locked out through the BAS. <br />4.2.3 Building 3000 <br />Building 3000 has DDC controls and one large air handling unit equipped with VFDs <br />on the supply and return fans. Upon observation, this unit was supplying 50% <br />outside air. Building 3000 has many laboratories; therefore, in addition to the one <br />main AHU3, it has a small packaged unit. <br />AHU3 supply fan was at 75 %; return fan was A�� <br />at 63 %. The return fan is controlled by return <br />air static pressure. <br />Building 3000 is equipped with a secondary <br />chilled water pump, P1 that boosts pressure <br />from the primary loop to serve the two air <br />handlers. The pump does have a variable L �, - 7_ <br />frequency drive but was operation at 100 %. It <br />is not clear if this pump is required or if the <br />current piping configuration will work with <br />OFF <br />variable flow pumping. i <br />Pump P2 supplies hot water to AHU3 and upon Figure 15: Building 3000 CHW <br />observation was running at 30 %, even though pump P1 at 100% speed <br />there was very little (if any) heating load in the <br />building. <br />Rev A 2012 -05 -15 Page 19 <br />Final Draft <br />G -2 Page 343 <br />Figure 14: Building 2000 - inlet <br />