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Orange County Health Department Improvements Smith Sinnett /2024008 <br />Hillsborough,NC Orange County Asset Management Services <br />TESTING,ADJUSTING,AND BALANCING FOR HVAC 23 05 93 - 5 <br />G Mark on drawings the locations where traverse and other critical measurements were taken and cross <br />reference the location in the final report. <br />H After adjustment,take measurements to verify balance has not been disrupted or that such disruption has <br />been rectified. <br />I Leave systems in proper working order,replacing belt guards,closing access doors,closing doors to <br />electrical switch boxes,and restoring thermostats to specified settings. <br />J Seal ducts and piping,and test for and repair leaks. <br />K Seal insulation to re-establish integrity of vapor barrier. <br />L Retest,adjust,and balance systems subsequent to significant system modifications and resubmit test results. <br />3.06 AIR SYSTEM PROCEDURE <br />A Adjust air handling and distribution systems to provide required or design supply,return,and exhaust air <br />quantities at site altitude. <br />B Test,adjust,and balance the air systems before the hydronic systems. <br />C Make air quantity measurements in ducts by Pitot tube traverse of entire cross sectional area of duct. <br />D Measure air quantities at air inlets and outlets. <br />E Adjust distribution system to obtain uniform space temperatures free from objectionable drafts and noise. <br />This includes adjusting the deflection of all diffuser and grilles. <br />F Use volume control devices to regulate air quantities only to extent that adjustments do not create <br />objectionable air motion or sound levels.Effect volume control by duct internal devices such as dampers and <br />splitters. <br />G Vary total system air quantities by adjustment of fan speeds. Provide drive changes required. Vary branch <br />air quantities by damper regulation. <br />H Measure static air pressure conditions on air supply units,including filter and coil pressure drops,and total <br />pressure across the fan.Make allowances for 50 percent loading of filters. <br />1.Artificially load filters by partially blanking to produce static pressure air drop of filter manufacturer's <br />recommeneded "dirty"pressure drop. <br />I Coordinate with Controls Contractor on adjusting static pressure setpoints of VAV systems and differential <br />pressure setpoints of VFD controlled pumps. <br />J Adjust outside air automatic dampers,outside air,return air,and exhaust dampers for design conditions. <br />K Measure temperature conditions across outside air,return air,and exhaust dampers to check leakage. <br />L Where modulating dampers are provided,take measurements and balance at extreme conditions.Balance <br />variable volume systems at maximum air flow rate,full cooling,and at minimum air flow rate,full heating. <br />M For variable air volume system powered units set volume controller to air flow setting indicated. Confirm <br />connections properly made and confirm proper operation for automatic variable air volume temperature <br />control. <br />N Single-duct,dual-duct,and fan-powered VAV boxes shall be calibrated using a multi-point calibration <br />approach.Single-point calibration will not be acceptable. <br />1.Check and readjust ATU flow rates as necessary to meet design criteria.Balance air distribution from <br />ATU on full cooling maximum scheduled cubic meters per minute (cubic feet per minute).Reset room <br />thermostats and check ATU operation from maximum to minimum cooling,to the heating mode,and <br />back to cooling.Record and report the heating coil leaving air temperature when the ATU is in the <br />maximum heating mode. <br />O The TAB report shall indicate the critical VAV box and how the static pressure set point was estalished. <br />3.07 CRITICAL FLOW PATH <br />A Provide a documented critical path for all fluid flows.There shall be at least one terminal device that can be <br />traced back to the fan or pump where there is no damper or valves that are less than 100%open. <br />3.08 DEMONSTRATION <br />A Training <br />Docusign Envelope ID: 2D852F9B-A7CF-462A-9536-444A53AA848A