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DocuSign Envelope ID: B94F2D40-3B3C-47A7-86C2-6F1 B4F92C62C <br /> Orange County Emergency Services Building Construction Documents <br /> 9. Unit shall be configured as an air-source heat pump. Each refrigeration circuit shall be <br /> equipped with a factory installed liquid line filter drier with check valve, reversing valve, <br /> accumulator, and expansion valves on both the indoor and outdoor coils. Reversing valve <br /> shall energize during the heat pump cooling mode of operation. <br /> H. Condensers <br /> 1. Air-Cooled Condenser <br /> a. Condenser fans shall be a vertical discharge, axial flow, direct drive fans. <br /> b. Coils shall be designed for use with R-410A refrigerant. Coils shall be multi-pass and <br /> fabricated from aluminum microchannel tubes. <br /> c. Heat pump outdoor coil shall be constructed of copper tubes with aluminum fins <br /> mechanically bonded to the tubes and aluminum end casings. Fin design shall be sine <br /> wave rippled. <br /> d. Coils shall be designed for a minimum of 10°F of refrigerant sub-cooling. <br /> e. Coils shall be hydrogen or helium leak tested. <br /> f. Condenser fans shall be high efficiency electrically commutated motor driven with factory <br /> installed head pressure control module. Condenser airflow shall continuously modulate <br /> based on head pressure and cooling operation shall be allowed down to 35°F with <br /> adjustable compressor lockout. <br /> g. Condenser fans shall be VFD driven variable speed for condenser head pressure control. <br /> Factory provided and factory programmed VFDs shall continuously modulate the fan air <br /> flow to maintain head pressure at acceptable levels. Cooling operation shall be allowed <br /> down to 35°F with adjustable compressor lockouts. <br /> I. Filters <br /> 1. Outdoor air hood shall have a metal mesh filter section. <br /> 2. Unit shall include 2 inch thick, pleated panel filters with an ASHRAE efficiency of 30% and <br /> MERV rating of 13, upstream of the cooling coil. <br /> 3. Unit shall include 0-100% economizer consisting of a motor operated outside air damper and <br /> return air damper assembly constructed of extruded aluminum, hollow core, airfoil blades with <br /> rubber edge seals and aluminum end seals. Damper blades shall be gear driven and <br /> designed to have no more than 20 cfm of leakage per sq ft. at 4 in. w.g. air pressure <br /> differential across the damper. Low leakage dampers shall be Class 2 AMCA certified, in <br /> accordance with AMCA Standard 511. Damper assembly shall be controlled by spring return <br /> enthalpy activated fully modulating actuator. Unit shall include outside air opening bird screen, <br /> outside air hood, and barometric relief dampers. <br /> 4. Economizer shall be furnished with return air CO2 override. <br /> J. Controls <br /> 1. BAS Contractor Furnished and Factory Installed Controller <br /> a. Provide unit with terminal strip for controls. <br /> b. The Controls Contractor shall furnish a Tridium based JACE controller with an open <br /> license such that all programs are fully accessible and programmable. The unit <br /> manufacturer shall factory install the JACE. The JACE shall have the ability to integrate <br /> and control humidifiers, exhaust fans, CO2 sensors, space pressurization, etc. The <br /> controller shall have the capability of a full graphical display of all components and <br /> system operating parameters as well as remote monitoring, tuning, and programming. <br /> c. The JACE shall be a Honeywell 300E or approved equivalent. The JACE shall have the <br /> capability of full BAS integration via BACnet. <br /> d. The unit manufacturer shall program the JACE. The unit shall be programmed as a <br /> constant volume makeup air unit with supply air dewpoint temperature control. <br /> e. All sensors required for the operation of the unit shall be factory furnished. This includes <br /> outside air temperature and humidity sensors, supply air temperature and humidity <br /> sensors, coil suction pressure and temperature sensors, space temperature and humidity <br /> sensors, preheat discharge temperature sensor, and other sensors as required to <br /> implement the sequence of operations. Refer to sequence on Drawings. <br /> K. Accessories <br /> 1. Unit shall be provided with a smoke detector sensing the return air of the unit, wired to shut off <br /> the unit's control circuit. <br /> PDC Project 18102 100 PERCENT OUTSIDE AIR 23 74 00-4 <br /> 12/17/2018 PACKAGED DX UNIT <br />