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<br /> <br /> <br />“Page content is subject to Confidentiality Restrictions” <br /> <br />City of Arvada, Colorado | Project #37213 | M&V Report – Year 2 | Page 13 <br /> <br /> <br />City of Arvada, Colorado <br />ECM 4: Cooling Upgrades <br />Savings Unit Guaranteed Verified <br />kWh 51,803 56,168 <br />kW 126 147 <br />Dollars $4,536 $5,147 <br /> <br />Overview of ECM <br />This measure included replacing the direct expansion (DX) split cooling systems serving roof top unit (RTU) 1, RTU 2, <br />and air handling units (AHUs) 4, 5, and 6 at the Arvada Center with an air-cooled chiller plant that has a combined <br />nameplate capacity of 340 tons. (The nominal capacity of the chillers is 180 tons each, or 360 tons total, at AHRI <br />conditions. The design capacity is 170 tons each, or 340 tons total. These values are shown in the Technical Data Sheet <br />in Appendix C.) New roof mounted air-cooled chillers, each with a separate variable frequency drive (VFD) pumping <br />system, were installed to provide chilled water to new chilled water coils that were installed to replace the DX coils <br />serving the five existing units. New chilled water control valves were also installed for each of the existing units. A new <br />insulated chilled water piping system was installed with each chiller/pump combination. <br /> <br />During project development, a bin weather data spreadsheet calculation was utilized to determine the baseline and <br />proposed energy consumption associated with cooling the spaces. The existing kW/ton cooling efficiency and proposed <br />kW/ton cooling efficiency were applied to the cooling load that was calculated by the bin weather data calculation to <br />determine the energy savings. <br /> <br />Commissioning <br />After the installation of the ECM, commissioning activities were performed in accordance with Schedule Q of the EPC. <br /> <br />In order to verify proper installation during construction, Ameresco completed a submittal review, installation checkout, <br />operational verification, and a point-to-point check. <br /> <br />The commissioning process for this ECM included performance testing of the air-cooled chillers, chilled water coils, <br />chilled water control valves, chilled water pumps, VFDs, and safety and freeze stat operation. Als o verified were <br />schedules, setpoints, sequences, lockouts, alarms, interlocks, and control strategies. <br /> <br />Installation of the new chillers, their platforms, chilled water piping, AHU cooling coils, and chilled water control valves <br />were inspected and found to be acceptable by Ameresco. <br /> <br />Correct phase rotation of the chillers was verified, and the chilled water piping and coils were pressure tested by the <br />electrical subcontractor. Point-to-point checks were performed on the chilled water control valves, temperature sensors, <br />and differential pressure sensors. Integration of the BACnet enabled chillers to the building automation system (BAS) <br />was completed. <br /> <br />Functional testing of the new chilled water cooling system was completed after the delivery of the Post Install Report. A <br />Functional Performance Test was generated that showed equipment performing as expected. A copy of the test can be <br />provided for the cooling system, or any other systems that required functional performance testing, upon request. <br />