Section 15500 HEATING, VENTILATING, AND AIR CONDITIONING

Section 15500

HEATING, VENTILATING, AND AIR CONDITIONING

PART 1 – GENERAL

1.1 THE REQUIREMENT

A. The work of this Section includes providing heating, ventilation, and air conditioning equipment in the locations as shown on the drawings and as specified herein.

1.2 REFERENCE SPECIFICATIONS, CODES AND STANDARDS

A. The work of the following sections applies to the work of this Section. Other sections of the Specifications, not referenced below, shall also apply to the extent required for proper performance of this work:

1. General Conditions

2. Section 01660, Installation, Testing, Commissioning and Training

3. Section 09800, Protective Coating

4. Section 11000, Equipment General Provisions

5. Section 16220, Electric Motors

B. All equipment, products, and their installation shall be in accordance with the following standards, as applicable, and as specified:

ANSI/NFPA 90A Installation of Air Conditioning and Ventilation Equipment

ARI 210 Unitary Air-Conditioning Equipment

ARI 240 Air Source Unitary Heat Pump Equipment ARI 270 Sound Rating of Outdoor Unitary Equipment ANSI/ASME Boilers and Pressure Vessels Code ANSI/NEMA 250 Enclosures for Electrical Equipment

ASHRAE 52 Air-Cleaning Devices Used in General Ventilation for Removing

Particulate Matter SMACNA Duct Construction Manual UL Underwriters Laboratories

1.3 SUBMITTALS

A. Shop drawings showing dimensions, electrical service, duct dimensions, water, drain and rough in connections.

B. Manufacturer’s product data including catalog cuts.

C. Calculations of equipment anchorage forces and anchorage details. D. Shipping weights.

E. Operation Manual including the following:

1. Manufacturer’s installation instructions.

2. Manufacturer’s maintenance and repair procedures.

3. Manufacturer’s certification that products comply with the indicated requirements.

4. Certification that the products have been factory tested.

5. Certification that work has been field tested, and the work complies with the requirements of this specification.

6. Control and wiring diagrams.

PART 2 – PRODUCTS

2.1 PERFORMANCE AND DESIGN REQUIREMENTS A. Primary Equipment Gallery

1. Centrifugal Supply Fan (F331)

a. Capacity: 2,400 CFM

b. Horsepower: 1/2 HP

c. Specific Pressure: 0.375 inches

2. Centrifugal Exhaust Ventilator (F332)

a. Capacity: 2,700 CFM

b. Horsepower: 3/4 HP

c. Specific Pressure: 0.250 inches

2.2 SPLIT SYSTEM AIR CONDITIONERS AIR HANDLING UNITS

A. Furnish and install two outdoor air conditioners (heat pumps) and two air handling units as shown and specified for the two electrical buildings.

B. Outdoor Heat Pumps

1. Each heat pump shall consist of outdoor coil, fan, motor, compressor, refrigerant specialties, and controls, all contained in a weatherproof casing, installed on weather-resistant 1-inch thick sandwich isolation pad of neoprene waffle bottom and flat top pads with cork center core, and bearing the UL-label.

2. Casing shall be 18-gauge zinc-coated steel phosphatized and finished in manufacturer's standard enamel paint, supported on steel full-length mounting rails, with removable access panels to all internal components. Provide protective guards on each fan discharge and each coil inlet.

3. Cooling components shall include spring mounted hermetic compressor, crankcase heater, condenser coil with seamless copper tubes bonded to aluminum fins, upflow propeller condenser fans with direct-drive motor with integral thermal overload protection, connections for refrigerant piping and specialties. Compressor shall carry a 5-year warranty.

4. Control section shall include starters for compressor and all fans with overload protection in each leg, HIGH and LOW pressure refrigerant controls, refrigerant- side condenser fan controls, compressor winding and overheat protection, anti- short cycle device, control voltage transformer, and terminal strip for connection of remote controls.

5. Units with multiple compressors shall have completely independent refrigeration circuits and controls.

6. Each of the two heat pumps shall meet the following requirements:

a. Cooling capacity of 91.1 mbh total (7.5 tons), 80/67 degrees F entering air temperature, 95 degrees F ambient temperature, 460-volt, 3-phase power supply. Unit shall be matched with Air Handling Unit.

b. Heat Pump Units shall use R-410A refrigerant.

7. Manufacturers or Equal

a. Trane Model TWA-090A

b. Carrier

c. Or Approved Equal

C. Indoor Air Handling Units

1. Packaged indoor blower-coil unit shall consist of direct-expansion evaporator coil, fans, motor, supplementary electric heating coil, filters, and insulated drain pan, all contained in a common casing installed on open spring isolators with neoprene waffle base pad, selected for 1-inch total deflection.

2. Casing shall be 20-gauge furniture steel sheets phosphatized and finished in manufacturer's standard enamel paint, supported on a structural steel frame, with sufficient removable panels for access to all internal components. Insulated drain pan shall have drain connections. Interior of the casing shall be insulated with 1-inch, 1.0-pound density coated glass fiber insulation attached with adhesive material, duct flanges for connection of supply and return ductwork, and filter racks.

3. Filters shall be 1-inch thick strainer type with pleated nonwoven fabric media, rated at 30 percent efficiency and 90 percent average arrestance per ASHRAE Test Standard 52-76, accessible for replacement through a removable panel in the unit casing. Provide four sets per unit, Farr 30/30, or equal.

4. Fan section shall include double-inlet, double-width, forward-curved fans, direct- drive or belt-drive motor as standard with the unit furnished with integral overload protection.

5. Both Electrical Building Air Handling Units shall have seamless copper tubes cooling coils with factory bonded aluminum fins, or copper fins. Refrigerant distributors and expansion valves shall be suitable for use on R-410A refrigerant.

6. Each air handling units shall be rated at 3,000 cfm at 0.6-inch w.c. static pressure and equipped with 1-1/2 HP fan motor with 91.1 mbh total (7.5 tons), 65.9 mbh sensible, 80/67 degrees F DB/WB entering air temperature, 95 degrees F ambient temperature, 460-volt, 3-phase power supply.

7. Manufacturers or Equal

1. Trane Model TWE-090A

2. Carrier

3. Or Approved Equal

2.3 GENERAL

A. Quality: All mechanisms and parts shall be amply proportioned for the stresses, which may occur during operation and during fabrication and installation. Individual parts which are alike in all units shall be alike materials workmanship, and design and shall be of the manufacturer’s top of the line, industrial-commercial grade.

B. Supports: Equipment and appurtenances shall be firmly anchored or connected to supporting members. Supports required for the proper installation of the equipment, but not forming an integral part of the building structure, shall be provided by the heating and ventilating subcontractor. Equipment shall be supported on restrained spring-type vibration isolators.

C. Nose/Vibration Control: The systems shall be free of any objectionable vibrations and noise. Flexible connections shall be provided in all ducts and piping connections to fans, compressors, and any other vibrating equipment.

D. Electric Motors: Electric motors shall be provided in accordance with Section 16220.

2.4 DUCTWORK AND MISCELLANEOUS ACCESSORIES

A. Construction: Sheet metal ducts and plenums shall be constructed with airtight joints and seams in accordance with ASHRAE standards and SMACNA Duct Construction Manual. Joints on concealed ducts shall be taped with pressureless tape and adhesive, except for welded or soldered joints. Ductwork materials shall be stainless steel Type 316 unless otherwise indicated.

B. Supports

1. Supports for horizontal ducts and plenums shall be galvanized steel angles with hanger rods. Band iron straps shall be allowed for ductwork sizes recommended by SMACNA. Supports for vertical ducts shall be band iron strap or angle bracket type. Inlet ducts shall be amply braced to withstand maximum negative pressure.

2. Seismic Supports: Duct supports and restraints shall be designed for static, dynamic, and seismic load in zone 4 per the Uniform Building Code. Seismic restraints shall not induce stresses in the ductwork caused by thermal expansion and contraction.

C. Duct Dimensions: Sheet metal duct dimensions shall be increased by 2-inches for internally lined ducts.

D. Insulation: The ductwork located outside of buildings shall be insulated with flexible glass fiber material with a UL-labeled vapor barrier. Insulation thickness shall be 2-inches or as necessary to provide the R-value required by the Energy Conservation Standard, whichever is greater. Joints shall be taped to provide a continuous vapor seal. The insulation shall be attached to the ducts with adhesive applied to provide at least 50 percent coverage. Insulation shall also be secured to the bottom of the rectangular ducts over 24 inches wide with mechanical fasteners spaced 12 inches on center.

E. Fire Dampers: Fire dampers shall be 1-1/2 hour rated. Blades shall be stored out of the air stream. Dampers shall be approved for horizontal or vertical installation as indicated. Fire dampers for connection to ceiling grilles, registers, and diffusers shall be UL-labeled and shall have minimum 1-hour rating and be approved for horizontal installation. Fire Dampers shall be as manufactured by the following or equal:

1. Pacific Air Products Company

2. Or equal

F. Bird Screens: Removable bird screens shall be provided on all outside air intakes and exhaust air discharged to outside air. Screens shall be secured in frames made from the same metal as the screens. Bird screens shall be ½-inch mesh by 14-guage and shall be of the same material and finish as duct, hood, louver, or equipment to which the screens are attached.

G. Flexible Connectors: Flexible duct connections shall be made with banded or flanged

8-oz canvas, reinforced plastic, or equal at each point where a blower unit is connected to a duct. A minimum clearance of 3 inches between the duct and source of vibration shall be maintained.

H. Diffusers, Grilles, and Registers: Supply air registers and diffusers shall be of stainless steel construction with smooth corners, flanges, and sponge rubber gaskets. The air registers and diffusers shall have individually adjustable blades and volume control dampers. Wall-mounted outlets shall be factory prime-coated. Terminals shall be as manufactured by the following or equal:

1. Titus

2. Agitair

3. Krueger

4. Or equal

I. Door Louvers: Unless otherwise indicated for architectural work, door louvers shall be of type which integrally frames the opening and can be securely attached. Louvers shall be inverted “Y” blade type for exterior use and “V” blade for interior use. Exterior louvered opening shall be provided with removable type inset screen. Door louvers shall be uniformly located in doors or sizes indicated. Blades shall be minimum 18-gauge galvanized steel. Coat louvers in accordance with Section 09800.

2.5 FIRE ALARM AND DETECTION SYSTEM

A. The Contractor shall furnish and install a complete, electrically supervised, non-coded,

24-volt DC, 2-wire automatic, fire alarm system as described herein. Operation shall be such that actuation of any automatic smoke detector shall cause building alarm devices to sound. The smoke detector shall be of the type that is either automatic resetting or is

reset from a remote control panel. The unit shall include two sets (minimum) of dry

contacts, rated at 120 volts, 2 amp (minimum).

2.6 PIPING

A. Piping in air conditioning systems shall be of Type “K” copper tube or Schedule 40 galvanized steel pipe.

2.7 CONTROLS

A. General: Heating, cooling, ventilating, and air conditioning equipment shall be provided with manual or automatic control systems as indicated. Where various items of equipment are operating in conjunction with one another, they shall be controlled by an integrated control system located in a control panel as indicated. Such systems shall have 12-hour timers and 7-day setback programming for automatic setback comfort time periods to meet the requirement of the Energy Conservation Standards. Unless otherwise indicated, individual cooling fans shall be controlled from HAND-OFF- AUTOMATIC line voltage cooling thermostats, wall-mounted. Individual exhaust fans shall have manual switches for single or 2-speed motors as indicated. Exhaust fans operating in conjunction with central ventilating or air conditioning systems shall be interlocked with these systems.

B. Thermostats: Room thermostats shall be digital type with heating and cooling setp points.

Adjustments shall be by pressing the thermostat up or down arrows. Comfort set points shall be adjustable from 68 to 80 degrees. Setback setpoints shall be adjustable from 55 to 70 degrees for heating seatback and 70 to 100 degrees for cooling setback. Automatic setback time period shall be 7-day setback programming, with up 2 automatic setback comfort time periods per day, a built-in setback override, adjustable from 10 minutes to

40 hours, a 7-day electric time clock, and a heat/cool/fan annunciators to indicate equipment operation and automatic heating/cooling changeover. Thermostats shall meet the Energy Conservation Standard approval where required by the State. An insulating

back shall be provided where exterior wall mounting is indicated. Guards shall be

provided for room thermostats installed in areas other than administrative offices or control rooms.

C. Thermostats shall be as manufactured by the following or equal:

1. Honeywell

2. Johnson Controls Company

3. Or equal

2.8 CONTROL PANELS

A. General: Control panels shall contain all relays, control switches, transformers, pilot lights, timers, time clocks, step controllers, gauges, thermostats (unless otherwise indicated), and other accessories necessary for the particular system. Panels shall be aluminum with baked enamel finish, with hinged front door and locking handle. Manual

switches and direct-reading gauges shall be flush-mounted on the front face, identified by engraved and riveted Bakelite or laminated plastic nameplates with white letters on black background. Manual switches shall be of heavy-duty, oil-tight construction.

B. Wiring: Control devices shall be pre-wired internally. Wires leaving the panel shall be terminated at separate number terminal strips. Individual connectors shall be provided for every item of mechanical equipment, all integral and remote pilot lights, and other devices described for each panel. Power and control circuit requirements shall be as on Electrical Drawings. Wire shall be identified by color coding or numerical tags at both ends. Each control device shall be wired without splices to the terminal strip. Integral circuit protection shall be provided for all panel-mounted control devices. Each panel shall be wired with a single 20-amp, 120-volt feeder in accordance with Section 16120.

C. Diagrams: Black and white graphic schematic diagrams shall be provided on the front face of each panel, showing all equipment within the respective systems. Pilot lights and temperature-indicating dials shall appear on the schematic in a location corresponding to the actual system location. Manual selector switches shall be directly below the equipment symbol being controlled. One spare light build shall be furnished for each four (4) pilot lights, stored inside the panel in dummy light sockets secure to the back panel surface. Schematics shall be smooth laminated plastic or engraved Formica. Panel electrical wiring diagrams shall be secured to the inside of the panel door.

PART 3 – EXECUTION

3.1 GENERAL

A. The Contractor shall ascertain that all inserts, chassis, shafts and openings are correctly located: if not, cut new opening as part of the work.

B. The Contractor shall test and tighten all work, furnish all equipment necessary to carry out the tests, and thoroughly clean the system before startup.

3.2 STARTUP AND TRAINING

A. An authorized representative of the manufacturer shall visit the site and witness the following:

1. Installation of the equipment.

2. Inspection, checking, and adjusting of the equipment.

3. Startup and field-testing for proper operation.

4. Performing field adjustments to ensure that the equipment installation and operation comply with this Specification.

B. The authorized service representative shall instruct the City’s personnel in the operation and maintenance of the equipment, including step-by-step troubleshooting procedures with necessary test equipment for not less than 1 day.

C. The manufacturer shall a local service agency within 50 miles of the site which maintains properly trained personnel and adequate spare parts and is able to respond and complete repairs within 24-hours.

END OF SECTION