2018-425-E AMS - Sasser Companies Annex upfit

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DocuSign Envelope ID: 9826C043- 4C32- 49CD- A4CC- DC28ABAB7CE7 SECTION 238147 — DEDICATED OUTDOOR AIR SYSTEM B. Daikin Applied UltraSeal low leak dampers shall be provided. Damper blades shall be fully gas - keted and side sealed and arranged vertically in the hood. Damper leakage shall be less than 1.5 CFM /Sq. Ft. of damper area at 1.0 inch static pressure differential. Leakage rate to be tested in ac- cordance with AMCA Standard 500. Damper blades shall be operated from multiple sets of linkages mounted on the leaving face of the dampers. Control of the dampers shall be from a factory installed actuator. C. Control of the outdoor dampers shall be by a factory installed actuator. Damper actuator shall be of the modulating type. Damper to open when when supply fan starts, and close when supply fan stops. 2.05 ENERGY RECOVERY A. The rooftop unit shall be provided with an AHRI certified rotary wheel air -to -air heat exchanger in a cassette frame complete with seals, drive motor and drive belt. The energy recovery wheel shall be an integral part of the rooftop unit with unitary construction and does not require field assembly. Bolt -on energy recovery units that require field assembly and section to section gasketing and seal- ing are not acceptable. B. The wheel capacity, air pressure drop and effectiveness shall be AHRI certified per AHRI Stand- ard 1060. Thermal performance shall be certified by the manufacturer in accordance with ASHRAE Standard 84, Method of Testing Air -to -Air Heat Exchangers and AHRI Standard 1060, Rating Air -to- Air Heat Exchangers For Energy Recovery Ventilation Equipment. C. The rooftop unit shall be designed with a track so the entire energy recovery wheel cassette can slide out from the rooftop unit to facilitate cleaning. D. The unit shall have 2" Mery 7 filters for the outdoor air before the wheel to help keep the wheel clean and reduce maintenance. Filter access shall be by a hinged access door with '/4 turn latches. E. The matrix design shall have channels to reduce cross contamination between the outdoor air and the exhaust air. The layers shall be effectively captured in aluminum and stainless steel segment frames that provide a rigid and self- supporting matrix. All diameter and perimeter seals shall be pro- vided as part of the cassette assembly and shall be factory set. Drive belt(s) of stretch urethane shall be provided for wheel rim drive without the need for external tensioners or adjustment. F. The total energy recovery wheel shall be coated with silica gel desiccant permanently bonded without the use of binders or adhesives, which may degrade desiccant performance. The substrate shall be lightweight polymer and shall not degrade nor require additional coatings for application in marine or coastal environments. Coated segments shall be washable with detergent or alkaline coil cleaner and water. Desiccant shall not dissolve nor deliquesce in the presence of water or high hu- midity. G. Wheels shall be provided with removable energy transfer matrix. Wheel frame construction shall be a welded hub, spoke and rim assembly of stainless, plated and /or coated steel and shall be self - supporting without matrix segments in place. Segments shall be removable without the use of tools to facilitate maintenance and cleaning. H. Wheel bearings shall be selected to provide an L -10 life in excess of 400,000 hours. Rim shall be continuous rolled stainless steel. Wheels shall be connected to the shaft by means of taper lock hubs. I. The exhaust air fan shall be a direct drive SWSI plenum fan. The exhaust fan shall be sized for the airflow requirements per the construction schedule. The unit controller shall control the exhaust fan to maintain building pressure. A VFD shall be provided for the exhaust fan motor or the exhaust fan motor shall be an ECM motor.The rooftop unit shall have single point electrical power connection and shall be ETL listed. J. The control of the energy recovery wheel shall be an integral part of the rooftop unit's DDC con- troller. The DDC controller shall have visibility of the outdoor air temperature, leaving wheel temper- ature, return air temperature, and exhaust air temperature. These temperatures shall be displayed at the rooftop units DDC controller LCD display. All of these temperatures shall be made available through the BACnet interface. K. The rooftop unit with the energy recovery wheel shall incorporate the economizer operation. The energy recovery wheel shall have a bypass damper. When the unit is in the economizer mode of operation the energy recovery wheel shall stop and the bypass dampers shall be opened. The out- Reece, Noland & McElrath, Inc. 238147-3 Orange County Board of Elections Orange Co., NC 05/04/18