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Southern Human Services Center Smith Sinnett /2020072 <br />HVAC and Roof Renovations Orange County,North Carolina <br />Testing,Adjusting,and Balancing for HVAC <br /> 23 05 93 - 5 <br />M.Measure building static pressure and adjust supply,return,and exhaust air systems to provide <br />required relationship between each to maintain approximately 0.05 inches positive static pressure <br />near the building entries. <br />N.For variable air volume system powered units set volume controller to air flow setting indicated. <br /> Confirm connections properly made and confirm proper operation for automatic variable air <br />volume temperature control. <br />O.Single-duct,dual-duct,and fa-powered VAV boxes shall be calibrated using a multi-point <br />calibration approach.Single-point calibration will not be acceptable. <br />P.The TAB report shall indicate the critical VAV box and how the static pressure set point was <br />estalished. <br />3.07 WATER SYSTEM PROCEDURE <br />A.Adjust water systems to provide design quantities. <br />B.Use calibrated Venturi tubes,orifices,or other metered fittings and pressure gages to determine <br />flow rates for system balance. Where flow metering devices are not installed,base flow balance <br />on temperature difference across various heat transfer elements in the system. <br />C.Adjust systems to provide specified pressure drops and flows through heat transfer elements prior <br />to thermal testing. Perform balancing by measurement of temperature differential in conjunction <br />with air balancing. <br />D.Effect system balance with automatic control valves fully open to heat transfer elements. <br />E.Effect adjustment of water distribution systems by means of balancing cocks,valves,and fittings. <br /> Do not use service or shut-off valves for balancing unless indexed for balance point. <br />F.Where available pump capacity is less than total flow requirements or individual system parts,full <br />flow in one part may be simulated by temporary restriction of flow to other parts. <br />G.The TAB report shall indicate the critical circuit,which coils were closed for diversity (if applicable), <br />and how the differential pressure setpoint was established. <br />3.08 DEMONSTRATION <br />A.Training <br />1.Train the Owner's maintenance personnel on troubleshooting procedures and testing, <br />adjusting,and balancing procedures.Provide four (4)hours on site training.Review with the <br />Owner's personnel the information contained in the Operating and Maintenance Data <br />specified in Division 1 and Section 23 01 00. <br />2.Schedule training with the Owner through the Engineer with at least 7 days prior notice. <br />3.09 COMMISSIONING <br />A.Perform prerequisites prior to starting commissioning activities. <br />B.Fill out Prefunctional Checklists for: <br />1.Air side systems. <br />2.Water side systems. <br />C.Furnish to the Commissioning Authority,upon request,any data gathered but not shown in the <br />final TAB report. <br />D.Re-check minimum outdoor air intake flows and maximum and intermediate total airflow rates for <br />50 percent of the air handlers plus a random sample equivalent to 50 percent of the final TAB <br />report data as directed by Commissioning Authority. <br />1.Original TAB agency shall execute the re-checks,witnessed by the Commissioning Authority. <br /> <br />2.Use the same test instruments as used in the original TAB work. <br />3.Failure of more than 25 of the re-checked items of a given system shall result in the rejection <br />of the system TAB report;rebalance the system,provide a new system TAB report,and <br />repeat random re-checks. <br />4.For purposes of re-check,failure is defined as follows: <br />DocuSign Envelope ID: 94E7997D-4F29-42F6-A9B4-0A160438D2A6