Specifications include, but are not limited to: replace existing Heating, Ventilation, and Air-Conditioning (HVAC) system. Construction work to be done in phases. Limit planned utility outages, limit disrupt of air conditioning service and normal Tunnel 407 work operations. Work also covers the demolition and replacement of the acoustical tile and gypsum board ceilings, and ceiling grid systems.; AIR CONDITIONING AND VENTILATION: AIR HANDLING AND FAN COIL UNITS: A. Air handling and fan coil units shall be factory-fabricated units. Units shall be low pressure single-zone draw-through type as indicated. Units shall include fan, coil, airtight insulated casing, filter sections, access sections, vibration-isolators, starter and appurtenances required for specified operation. Air handling and fan coils unit shall have published ratings based on tests performed in accordance with AHRI 430. Units shall meet NFPA 90A requirements.; B. Unit Casing (AHU-1 and AHU-2): 1. Units shall be constructed with a complete frame and panels. Removable access panels shall be gasketed.; 2. Units shall have an insulated, double wall, stainless steel drain pan under the cooling coil section for drainage of condensate. Drain pan shall be sloped towards the drain pan outlet. Plastic drain pans will not be accepted.; 3. Units shall be supplied with a perimeter, high tensile steel base rail.; C. Unit Casing (FCU-1, FCU-2 and FCU-3): 1. Unit panels shall be constructed of prepainted galvanized steel. Casing panels shall be removable for easy access to the unit. All panels shall be gasketed.; 2. Removable access door shall be double wall with 1.5 pound dual density fiberglass between galvanized steel panels.; 3. Condensate drain panels shall be constructed of stainless steel, shall have double wall construction, and shall be sloped towards the drain connections.; DEHUMIDIFYING UNITS (DU): A. Dehumidifying units shall be packaged water cooled and specifically designed for dehumidification and cooling purposes. Units shall have hermetic compressors, evaporator, air reheat coils, blower, motor, motor contactors, microprocessor controls, and a holding charge of R-410A. Blower motors shall be UL listed and dehumidifying units shall be ETL or UL listed. Units shall be factory assembled and factory-tested.; B. Cabinet: 1. Unit panels shall be of single-wall construction using minimum 20 gauge pre-painted steel with 1-inch of fiberglass insulation protected by an antimicrobial top coat.; 2. Access doors shall be removable.; 3. Units shall have a stainless steel or aluminum, insulated, sloped drain pan positioned under the evaporator coil.; C. Evaporator Coil: 1. Coil shall be copper tubes mechanically bonded to aluminum fins.; 2. Fins shall be coated.; ULTRAVIOLET LIGHTS: A. Ultraviolet Emitters: Ultraviolet light (C-band) emitters and fixtures shall be factory fabricated, assembled wired and tested. The UVC assembly shall consist of a housing, power source, reflector, emitter sockets and emitter. Housing shall be of NEMA 4X stainless steel construction. Emitter shall be designed for cold moving airstreams of 55 degrees F, 100 percent relative humidity at a velocity up to 1,000 fpm. Emitter tube shall be T5 diameter that provides broadband UVC of 250-260 nm. Tubes shall produce no ozone or other secondary contamination. Operating voltage shall be 120-volt single phase. UVC assemblies shall be installed downstream of cooling coils as indicated. Steril-Aire X-Mount Plus or approved equal.; B. UVC sign: Provide a corrosion resistant metal sign on the AC Unit access door. Sign shall have in red lettering with black shadowing, “Danger! UVC Light Emitter in Use - Turn Off Before Servicing”.; FANS: A. General: Fans, AMCA 99, statically and dynamically balanced, with air capacities, fan types, fan arrangement and pressure ratings as indicated. Fans shall be sound rated in accordance with AMCA 300. Provide Type 316 stainless steel bird screens for outdoor inlets/outlets. Provide thermal overload protection and disconnect switches. Housing and fan wheels shall be aluminum, except as specified otherwise. Fans shall be tested and rated in accordance with AMCA 211/311.; B. Propeller Fan: Propeller fan shall be belt driven sidewall mounted cast aluminum propeller type with performances as indicated on the drawing. Frame shall be bolted structural steel channel construction. Wheel shall be constructed of cast aluminum blades and hubs securely attached to fan shaft with a standard square key and set screw or tapered bushing. Wheels shall be statically and dynamically balanced. Motors shall have totally enclosed fan cooled enclosures. Fan bearings shall be cast iron pillow block type with grease fittings. Bearings shall be selected for a basic rating fatigue life (L-50) of 500,000 hours at maximum catalogued operating speed. Drive assembly including belts, pulleys and keys shall be oversized for a minimum of 150 percent of driven horsepower. Furnish fan with closure angles, flush exterior wall housing, weather hood and motor side guard. Fan shall be factory coated with industrial epoxy (high performing epoxy powder).; C. Utility Fan: Utility fan shall be belt driven, forward curved centrifugal type with performances as indicated on the drawing. Housing shall be constructed of heavy gage galvanized steel with tight lock formed seams. Housing and bearing support shall be constructed of welded structural steel members. An OSHA compliant belt guard shall be included to completely cover the motor pulley and belts. Fan wheel shall be of the non-overloading forward curved centrifugal type. Wheel shall be statically and dynamically in accordance to AMCA 204. Motor shall have a TEFC enclosure. Drive belts and sheaves shall be sized for 150% of the fan operating brake horsepower and shall be readily and easily accessible for service. Fan shaft shall be turned and polished steel that is sized so the first critical speed is at least 25% over the maximum operating speed for each pressure class. Fan bearings shall be permanently sealed. Bearings shall be selected for a basic rating fatigue life (L-50) of 500,000 hours at maximum operating speed for each pressure class. Furnish fan with access door, and heat slinger and shaft seal. Fan shall be factory coated with industrial epoxy (high performing epoxy powder).
