238129 - VARIABLE REFRIGERANT FLOW HVAC SYSTEMS.pdf

Renovation of Historical Building 4

Project #565 20 101

VARIABLE-REFRIGERANT-FLOW HVAC SYSTEMS

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SECTION 23 81 29

PART 1 - GENERAL

1.1 DESCRIPTION

A. This section specifies variable refrigerant flow hvac system components.

B. This system shall be fully capable of simultaneous heating and cooling

(heat recovery) as requested by the individual indoor zones that can consist of single or multiple indoor units.

C. The system shall consist of an outdoor unit, distribution controller, multiple indoor units, fully insulated refrigerant lines, factory branching kits, and an integrated direct digital control system.

Refrigerant lines shall be either a 2-pipe or 3-pipe system.

1.2 RELATED WORK

A. Section 01 00 00, GENERAL REQUIREMENTS: For pre-test requirements.

B. Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, and SAMPLES.

C. Section 01 91 00 – GENERAL COMMISSIONING REQUIREMENTS

D. Section 13 05 41, SEISMIC RESTRAINT REQUIREMENTS FOR NON-STRUCTURAL

COMPONENTS: Seismic requirements for non-structural equipment.

E. Section 23 05 11, COMMON WORK RESULTS FOR HVAC: General mechanical requirements and items, which are common to more than one section of

Division 23.

F. Section 23 05 93, TESTING, ADJUSTING, AND BALANCING FOR HVAC:

Requirements for testing, adjusting and balancing of HVAC system.

G. Section 23 08 00, COMMISSIONING OF HVAC SYSTEMS: Requirements for commissioning, systems readiness checklists, and training.

H. Section 23 09 23, DIRECT-DIGITAL CONTROL SYSTEM FOR HVAC: Requirements for controls and instrumentation.

I. Section 23 23 00, REFRIGERANT PIPING: Requirements for field refrigerant piping.

1.3 QUALITY ASSURANCE

A. Refer to specification Section 23 05 11, COMMON WORK RESULTS FOR HVAC

B. Comply with ASHRAE Standard 15, Safety Code for Mechanical

Refrigeration.

C. Variable Refrigerant Flow (VRF) systems shall be fully designed by the system manufacturers representative. The design shall incorporate the indoor cassette capacities and outdoor unit sizes as indicated in the schedule on the drawing. Refrigerant piping route, sizes, fittings

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D. The units shall be listed by Electrical Testing Laboratories (ETL) and bear the ETL label.

E. All wiring shall be in accordance with the National Electrical Code

(N.E.C.).

F. The units shall be manufactured in a facility registered to ISO 9001 and ISO14001 which is a set of standards applying to environmental protection set by the International Standard Organization (ISO).

G. All units must meet or exceed the 2010 Federal minimum efficiency requirements and the ASHRAE 90.1 efficiency requirements for VRF systems. Efficiency shall be published in accordance with the Air-

Conditioning, Heating, and Refrigeration Institute (AHRI) Standard

1230.

H. System start-up supervision shall be a required service to be completed by the manufacturer or a duly authorized, competent representative that has been factory trained in system configuration and operation. The representative shall provide proof of manufacturer certification indicating successful completion within no more than two (2) years prior to system installation. This certification shall be included as part of the equipment and/or controls submittals.

I. Comply with requirements in Section 13 05 41, SEISMIC RESTRAINT

REQUIREMENTS FOR NON-STRUCTURAL COMPONENTS.

1.4 SUBMITTALS

A. Submit in accordance with specification Section 01 33 23, SHOP

DRAWINGS, PRODUCT DATA, and SAMPLES.

B. Manufacturer’s Literature and Data.

1. Air-Source Unitary Heat pump:

a. Split system

C. Certification: Submit, simultaneously with shop drawings, a proof of certification that this product has been certified by AHRI.

D. Performance Rating: Submit catalog selection data showing equipment ratings and compliance with required cooling and heating capacities EER and COP values as applicable.

E. Completed System Readiness Checklists provided by the Commissioning

Agent and completed by the contractor, signed by a qualified technician and dated on the date of completion, in accordance with the requirements of Section 23 08 00 COMMISSIONING OF HVAC SYSTEMS.

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1.5 APPLICABLE PUBLICATIONS:

A. The publications listed below form a part of this specification to the extent referenced. The publications are referenced in the text by the basic designation only.

B. Federal Specification (Fed. Spec.):

A-A-50502-1990..........Air-conditioner (UNITARY HEAT PUMP), AIR TO

AIR(3000 TO 300,000 BTUH)

C. Air-Conditioning Heating and Refrigeration Institute (AHRI) Standards:

DCPP-2008...............Directory of Certified Product Performance -

Applied Directory of Certified Products

270-2015................Sound Rating of Outdoor Unitary Equipment

340/360-2015............Commercial and Industrial Unitary Air-

Conditioning and Heat Pump Equipment

D. Air Movement and Control Association (AMCA):

210-2016................Laboratory Methods of Testing Fans for

Aerodynamic Performance Rating (ANSI)

410-1996................Recommended Safety Practices for Users and

Installers of Industrial and Commercial Fans

E. American National Standards Institute (ANSI):

S12.51-2017.............Acoustics - Determination of Sound Power Levels of Noise Sources Using Sound Pressure - Precision Method for

Reverberation Rooms (same as ISO 3741:1999)

F. American Society of Heating, Refrigerating and Air-Conditioning

Engineers Inc (ASHRAE):

15-2019.................Safety Standard for Refrigeration Systems

(ANSI)

90.1-2016...............Energy Standard for Buildings except Low-Rise

Residential Buildings

2016 Handbook...........HVAC Systems and Equipment

G. American Society of Testing and Materials (ASTM):

B117-2018...............Standard Practice for Operating Salt Spray

(Fog) Apparatus

D4587-2019..............Standard Practice for Fluorescent UV-

Condensation Exposures of Paint and Related Coatings

H. National Electrical Manufacturer’s Association (NEMA):

ICS 1-2005..............Industrial Controls and Systems: General

Requirements

MG 1-2019...............Motors and Generators (ANSI)

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I. National Fire Protection Association (NFPA):

90A-2018................Standard for the Installation of Air-

Conditioning and Ventilating Systems

J. Underwriters Laboratory (UL):

1995-2005...............Heating and Cooling Equipment

PART 2 - PRODUCTS

2.1 OUTDOOR UNIT HEAT RECOVERY

A. Factory-assembled, single-piece, air-cooled outdoor unit. Contained within the unit enclosure shall be all factory wiring, piping, controls, and the multiple inverter-driven twin rotary compressors.

1. The maximum sound pressure rating for a single outdoor unit shall not exceed 66.2 dBA in cooling or heating. Sound pressure ratings are measured at a distance of 3.3 ft out and 4.3 ft up from the side of the outdoor unit.

2. The outdoor unit shall include an oversized accumulator to prevent liquid slugging.

3. The outdoor unit shall be protected by a high-pressure switch, high-pressure sensor, low-pressure switch, low-pressure sensor, fusible plug, PC board, and an inverter overload protector.

4. The outdoor unit shall be capable of operating in cooling mode down to 5 °F dry bulb ambient air temperature and down to -13 °F wet bulb ambient air temperature in heating mode. For simultaneous heating and cooling, in heating main mode, the unit shall be capable of operating between 21 °F and 64 °F wet bulb ambient air temperature.

For simultaneous heating and cooling, in cooling main mode, the unit shall be capable of operating between 23 °F and 75 °F dry bulb ambient air temperature.

5. The outdoor unit shall include a total oil management system that balances oil between compressors within a module and replenishes compressor oil to the compressors in a module from the oil separator if required.

6. The outdoor unit shall be non-modular and not require twinning to create larger systems.

7. Unit shall be provided with a corner panel quick check board for simplified system setup and diagnostics.

B. Unit Cabinet:

1. Unit cabinet shall be constructed of pre-coated steel, finished on both inside and outside.

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2. Unit access panels shall be removable with minimal screws and shall provide full access to the compressors, fan, and control components.

3. Compressors shall be isolated in a compartment and have an acoustic wrap to assure quiet operation.

4. The outdoor unit control panel shall include a hinged cover for access to adjustable controls and an LED display for setup and diagnostics.

5. Unit cabinet shall be capable of withstanding 500-hour salt spray test.

C. Fans:

1. Outdoor fan shall discharge air vertically and be driven by a DC inverter variable-speed motor with 25 steps.

2. Outdoor fan motor shall be totally-enclosed with permanently-lubricated bearings.

3. Motor shall be protected by internal thermal overload protection.

4. Fan blade shall be non-metallic and shall be statically and dynamically balanced.

5. Outdoor fan shall be protected by a raised metallic protective grille.

D. Compressors:

1. Each outdoor unit module shall be equipped with inverter-driven asymmetric scroll compressor(s). 6, 8, and 10-ton outdoor units shall utilize a single compressor; 12, 14, 16, 18, and 20-ton outdoor units shall utilize 2 compressors, 20L, 22, 24, 26 and 28 ton outdoor units shall utilize 3 compressors.

2. Compressor shall be totally enclosed in the machine compartment.

3. Compressors shall be equipped with factory-mounted crankcase heaters.

4. Internal safety logic shall protect the compressor from over-temperature operation.

5. Motor shall be suitable for operation in an R-410A refrigerant atmosphere.

6. Compressor assembly shall be installed on rubber vibration isolators.

7. To maximize compressor reliability, multiple compressors within a module shall be started and operated in variable patterns to ensure equal run time on all compressors.

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8. To ensure maximum efficiency throughout the system operation range, no compressor is required to run at maximum speed under any condition.

E. Outdoor Coil:

1. Coil shall be constructed of aluminum fins mechanically bonded to seamless copper tubes, which are cleaned, dehydrated, and sealed.

2. The coil configuration shall be 3-sided, with fourth side providing access panels for service and maintenance.

3. The coil fins shall have a factory-applied corrosion resistant blue-fin finish.

F. Controls and Safeties:

Operating controls and safeties shall be factory selected, assembled, and tested. The minimum control functions shall include the following:

1. Controls:

a. Compressor speed to match the refrigerant flow and capacity with the system requirements.

b. Outdoor fan motor speed for higher efficiency and lower sound.

c. Oil control for improved system reliability and comfort.

d. Electronic expansion valve control for precise control of the refrigerant distribution and accurate capacity management to avoid starving any units.

e. Control of compressor staging to maximize reliability and equalize run time on all compressors.

f. Module control of compressor operation, compressor speed, and fan speed to maximize efficiency and reliability across the entire operating range of the system.

g. Control of the outdoor heat exchanger surface areas for maximum efficiency and comfort.

h. System shall be capable a programmable refrigerant temperature reset to match building heating load and provide additional energy savings.

i. System shall be capable of adjusting target evaporation and condensation temperature based on indoor PMV position and outdoor temperature.

2. Safeties:

The following safety devices shall be part of the condensing unit:

a. High-pressure switch

b. Fuses

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c. Crankcase heater

d. Fusible plug

e. Over current relay for the compressor

f. Thermal protectors for compressor and fan motor

g. Compressor time delay

h. Oil recovery system

i. Over-current sensor

j. Compressor suction and discharge temperature sensor

k. Compressor suction and discharge pressure sensor

G. Electrical Requirements:

1. All sizes shall utilize 208/230-3-60 or 460-3-60 (V-Ph-Hz) field power supply.

2. Systems shall have separate field power supply to each module.

3. Two-core, stranded, shielded, twisted pair cable shall be required for communication among outdoor and indoor units.

4. All power and control wiring must be installed per NEC and all local electrical codes.

5. Outdoor unit shall be single-point power connection up to 28 tons.

6. Unit shall be provided with hinged electrical panel for serviceability.

H. Refrigerant Piping and Line Lengths:

1. Piping connections shall be from the front or the bottom of the unit.

2. The unit shall be capable of operating with maximum connected refrigerant line lengths of 2642 ft (actual).

3. The outdoor unit shall have the ability to operate with a maximum height of 164 ft. between the outdoor and the lowest indoor unit.

4. The maximum distance between the outdoor unit and the furthest fan coil shall not exceed 541 ft actual or 623 ft equivalent. No oil traps shall be required.

5. The system shall be capable of operating when the height difference between the upper and the lower fan coil is 98 ft.

I. Auxiliary Refrigerant Components:

1. All field supplied copper tubing connecting the outdoor unit to the indoor unit shall use factory-supplied branching kits consisting of

Y joints to ensure even refrigerant flow.

2. To ensure piping flexibility the system shall allow having Y joints downstream of a multiport distribution controller (MDC).

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3. A multiport distribution controller (MDC) will be required to regulate the flow of high-pressure hot gas or high-pressure liquid to the fan coil requiring heating or cooling.

4. Up to 16 fan coils may be connected to a single MDC.

5. The main MDC can be installed up to 360 ft from the outdoor unit.

6. MDCs can be installed up to 196 ft from the indoor unit.

7. MDCs shall be powered by a dedicated 208/230-1-60 field power supply.

8. MDCs shall require a drain connection.

9. MDCs shall include a painted galvanized steel enclosure, and shall be tested prior to shipment.

2.2 DISTRIBUTION CONTROLLERS

A. General:

1. Indoor multiport distribution controller (MDC) shall include brazed-plate heat exchanger(s), electronic expansion valves (EXVs), solenoid valves, check valves, strainers at each IDU and main piping port, temperature sensors, pressure sensors, and microprocessor control system. Main MDCs shall also include a gas-liquid separator.

B. Unit Cabinet:

1. Cabinet shall be constructed of pre-painted, zinc-coated, galvanized steel.

C. Piping:

1. MDCs shall be available in four sizes--with 6, 8, 10, or 16 ports.

Each indoor unit port shall be capable of serving indoor units of capacities up to 54,000 Btu/hr. For indoor units with capacities greater than 54,000 Btu/hr, two ports may be “twinned” together using Y-joints to provide the necessary refrigerant flow. MDC ports shall also be capable of being “split” with downstream Y-joints to serve up to 3 indoor units requiring the same mode.

2. Unit shall have condensate drain connections on either end for installation ease.

3. MDCs shall be capable of utilizing field-provided accessory full-port ball valves for system service, isolation, and future expansion.

4. MDCs can be installed up to 196 ft from the indoor unit.

a. Main MDCs:

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1) A 2-pipe connection with ODU shall be implemented. In Cooling

Main mode, MDCs receive high-pressure, mixed-phase refrigerant from ODU through high-pressure pipe; and return low-pressure gas through the low-pressure pipe. In Heating Main mode, MDCs receive high-pressure gas from the ODU through high-pressure pipe; and return low-pressure mixed-phase through the low-pressure pipe.

2) Main MDCs can be installed up to 360 ft from the outdoor unit.

b. Sub MDCs:

1) Sub MDCs shall be supplied refrigerant by Main MDC. A 3-pipe connection with Main MDC shall be implemented, with dedicated pipes for high-pressure gas, low-pressure gas, and liquid.

D. MDC Combinations:

1. Heat recovery VRF system can support a maximum of one Main MDC and two Sub MDCs.

E. Controls:

1. The system shall be microprocessor-controlled to maintain precise refrigerant conditions for indoor units, whether they require heating or cooling. Controls shall modulate solenoid valves and

EXVs to manage flow of refrigerant to IDUs, as well as sub-cooling of liquid via brazed-plate heat exchangers. MDC shall communicate with IDUs over 2 core shielded twisted pair wire, with individual

“home run” plugs for each IDU. MDCs shall communicate with each other and ODU using a “daisy chain” configuration, also using 2-core shielded twisted pair wire.

2. MDCs shall not require any port assignments and shall come with controls quick connects.

3. All control wiring from the MDC shall follow the piping to each indoor unit.

F. Accessories:

1. Piping adapters shall be provided with MDCs as standard accessories to accommodate various pipe sizes among ODUs, MDCs, and IDUs.

G. Electrical Requirements:

1. MDCs shall be powered by a dedicated 208/230-1-60 (V-Ph-Hz) field power supply.

2.3 4-WAY CEILING CASSETTE

A. General:

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1. Indoor, direct-expansion, ceiling-mounted fan coil. Unit shall be complete with coil, fan driven by DC motor, EXV (electronic expansion valve), piping connectors, electrical controls, microprocessor control system, and integral temperature sensing.

B. Unit Cabinet:

1. Cabinet shall be constructed of zinc-coated steel. Fully insulated discharge and inlet grilles shall be attractively styled, high-impact non- metallic material. The inlet grille shall have hinges and can be opened to obtain access to the cleanable filters, indoor fan motor and control box.

C. Fans:

1. Fan shall be centrifugal direct-drive blower type with air intake in the center of the unit and discharge at the perimeter. Automatic, motor-driven vertical air sweep shall be provided standard.

D. Coil:

1. Coil shall be copper tube with aluminum fins and galvanized steel tube sheets. Fins shall be bonded to the tubes by mechanical expansion, and fins shall be coated with blue-fin finish for enhanced wettability and corrosion resistance. A drip pan under the coil shall have a factory-installed drain connection for hose attachment to remove condensate. Unit shall be furnished with condensate lift mechanism with 29-1/2 in of lift capacity.

E. Motors:

1. Motors shall be totally enclosed, permanently lubricated ball bearing with inherent overload protection. Fan motors shall be inverter controlled variable speed.

F. Controls:

1. The units shall be connected into a controls network with the other indoor units and outdoor units via a two wire 18GA stranded shielded control wire and shall have controls quick connections as standard.

2. The system shall be microprocessor-controlled to maintain precise room temperature and maximize efficiency.

3. The units shall be capable of performing all initial settings from the remote controller without the need for adjusting physical dip switches.

4. Unit shall come with IR receiver as standard.

5. The system shall include ACB (auxiliary control board) interface adjacent to the indoor unit control board. This ACB interface shall

23 81 29 - 11 provide three dry contact outputs to indicate operation (on/off) status of fan, cooling mode, and heating mode. This interface shall also provide a fourth dry contact output to trigger auxiliary heat.

Auxiliary heat output shall be configurable via wired controller with settings for temperature differentials and time delay.

6. Any of the following user interface accessories shall be compatible with the unit.

a. Wireless Remote Controller

1) All indoor units shall come with factory-installed IR

(infrared) receivers to allow the use of wireless controller.

Wireless controller may be used to set indoor unit address.

b. Wired Remote Controller (Non-Programmable)

1) Wired controller (non-programmable) shall communicate over 2 core shielded twisted pair wire up to 820 ft. It may be used as one per unit; or, it may be used in a daisy chain arrangement for group control of up to 16 units. The wired controller (non-programmable) shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. The controller shall include a back-lit display, and shall be capable of displaying system error codes.

c. Wired Remote Controller (Programmable)

1) Wired controller (programmable) shall communicate over 2 core shielded twisted pair wire up to 820 ft. It may be used as one per unit; or, it may be used in a daisy chain arrangement for group control of up to 16 units. The wired controller

(programmable) shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. The controller shall include a back-lit display, and shall be capable of displaying system error codes.

2) The wired controller (programmable) shall be configurable with weekly schedule settings, and shall be available in two interfaces:

3) Standard LCD display with touch buttons, or

4) Color, touch screen display with resolution of 800 x 480.

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d. Centralized Controller (Touch Screen)

1) Centralized controller shall communicate over 2 core shielded twisted pair wire up to 3937 ft. The controller shall be wired directly to the header outdoor unit’s “XY” centralized control communication bus. Centralized controller shall be able to manage up to 384 indoor units, for up to 20 users, with 3 levels of account management. The controller shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. Controller shall be capable of displaying system error codes and configuring weekly schedules. The controller shall have a 10.1 inch color touch screen, with resolution of 1200x800.

G. Filters:

1. Unit shall have factory-supplied resin net (cleanable) type filters.

2. Units shall be capable of accepting a 2” MERV 13 filter as standard.

H. Electrical Requirements:

1. Indoor units are 208/230-1-60 (V-Ph-Hz).

2.4 HIGH WALL CASSETTES

A. General:

1. Indoor, direct-expansion, wall-mounted fan coil. Unit shall be complete with coil, fan driven by DC motor, EXV (electronic expansion valve), piping connectors, electrical controls, microprocessor control system, and integral temperature sensing.

Unit shall be furnished with integral wall mounting bracket and mounting hardware.

B. Unit Cabinet:

1. Cabinet discharge and inlet grilles shall be attractively styled, high-impact nonmetallic material.

C. Fans:

1. Fan shall be tangential direct-drive blower type with air intake at the top of the unit and discharge at the bottom front. Automatic, motor-driven vertical air sweep shall be standard.

2. Vertical air sweep operation shall be user selectable using the remote control, and the horizontal air direction may be set manually.

D. Coil:

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1. Coil shall be copper tube with aluminum fins and galvanized steel tube sheets. Fins shall be bonded to the tubes by mechanical expansion, and fins shall be coated with blue-fin finish for enhanced wettability and corrosion resistance. A drip pan under the coil shall have a factory-installed drain connection for hose attachment to remove condensate.

E. Motors:

1. Motors shall be totally enclosed, permanently lubricated ball bearing with inherent overload protection. Fan motors shall be inverter controlled variable speed.

F. Controls:

1. The units shall be connected into a controls network with the other indoor units and outdoor units via a two wire 18GA stranded shielded control wire and shall have controls quick connections as standard.

2. The system shall be microprocessor-controlled to maintain precise room temperature and maximize efficiency.

3. The units shall be capable of performing all initial settings from the remote controller without the need for adjusting physical dip switches.

4. Unit shall come with IR receiver as standard

5. The unit shall be provided with an integral display.

6. The system shall include ACB (auxiliary control board) interface adjacent to the indoor unit control board. This ACB interface shall provide three dry contact outputs to indicate operation (on/off) status of fan, cooling mode, and heating mode. This interface shall also provide a fourth dry contact output to trigger auxiliary heat.

Auxiliary heat output shall be configurable via wired controller with settings for temperature differentials and time delay.

7. Any of the following user interface accessories shall be compatible with the unit.

a. Wireless Remote Controller

1) All indoor units shall come with factory-installed IR

(infrared) receivers to allow the use of wireless controller.

Wireless controller may be used to set indoor unit address.

b. Wired Remote Controller (Non-Programmable)

1) Wired controller (non-programmable) shall communicate over 2 core shielded twisted pair wire up to 820 ft. It may be used as one per unit; or, it may be used in a daisy chain

23 81 29 - 14 arrangement for group control of up to 16 units. The wired controller (non-programmable) shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. The controller shall include a back-lit display, and shall be capable of displaying system error codes.

c. Wired Remote Controller (Programmable)

1) Wired controller (programmable) shall communicate over 2 core shielded twisted pair wire up to 820 ft. It may be used as one per unit; or, it may be used in a daisy chain arrangement for group control of up to 16 units. The wired controller

(programmable) shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. The controller shall include a back-lit display, and shall be capable of displaying system error codes.

2) The wired controller (programmable) shall be configurable with weekly schedule settings, and shall be available in two interfaces:

a) Standard LCD display with touch buttons, or color, touch screen display with resolution of 800 x 480.

d. Centralized Controller (Touch Screen)

1) Centralized controller shall communicate over 2 core shielded twisted pair wire up to 3937 ft. The controller shall be wired directly to the header outdoor unit’s “XY” centralized control communication bus. Centralized controller shall be able to manage up to 384 indoor units, for up to 20 users, with 3 levels of account management. The controller shall be able to control settings for on-off, dual set point, mode, fan speed, louvered swing functions (for applicable indoor units), address, and set point temperature range limiting. Controller shall be capable of displaying system error codes and configuring weekly schedules. The controller shall have a 10.1 inch color touch screen, with resolution of 1200x800.

G. Filters:

1. Unit shall have factory-supplied resin net (cleanable) type filters.

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H. Electrical Requirements:

1. Indoor units are 208/230-1-60 (V-Ph-Hz).

I. Special Features (Accessories):

1. Condensate pump

2.5 LOW PROFILE CONCEALED DUCTED CASSETTE

A. General:

1. Indoor, slim ducted fan coils direct-expansion, low profile (8.3 in.). Unit shall be complete with a coil, fan driven by DC inverter motor, PMV (pulse modulating valve), piping connectors, electrical controls, microprocessor control system, integral temperature sensing, and hanging brackets.

B. Unit Cabinet:

1. Cabinet shall be constructed of zinc-coated steel. The unit shall be capable of being configured for either bottom or rear return. The cabinet shall have a knockout for fresh air intake.

C. Fans:

1. The fan shall be of the multi-blade type with its performance designed to match the coil performance. The fan shall be statically and dynamically balanced to ensure low noise and vibration and capable of up to 0.2 in. wg external static pressure.

D. Coil:

1. Coil shall be copper tube with aluminum fins and galvanized steel tube sheets. Fins shall be bonded to the tubes by mechanical expansion and specially coated for enhanced wettability. A drip pan under the coil shall have a factory-installed drain connection for hose attachment to remove condensate.

E. Motors:

1. Motors shall be totally enclosed, permanently lubricated ball bearing with inherent overload protection. Fan motors shall be inverter controlled variable speed.

F. Controls:

1. The system shall be microprocessor-controlled to maintain precise room temperature and minimum power consumption. The controls system shall employ a genetic algorithm for temperature control.

2. Any of the following user interface accessories shall be compatible with the unit.

a. Wireless Remote Controller

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1) Wireless remote controller kit shall include a hand held device and a receiver not integral to the unit. The receiver shall be field installed on the wall.

b. Wired Remote Controller (Lite Vision Plus)

1) Wired remote controller shall communicate over two-core shielded wire up to 1640 ft. It shall be capable of controlling groups of up to 8 indoor units. It shall be able to operate as a primary or secondary controller when two remote controllers are connected to a single indoor unit or group. The system shall be able to be configured so that the return air (TA) can be sensed at the unit, at the remote controller or through a remote sensor. The local controller shall minimally be able to control On-OFF, set point, mode, and be able to display system generated error codes.

c. Central Controller (Smart Manager)

1) Central controller shall communicate over two-core shielded wire up to 6500 ft and use existing indoor – outdoor communication protocol to communicate. A single central controller shall be capable of controlling up to 128 indoor units individually with capability to program maximum of 10 setups for each day. It shall be able to create 2 indoor unit line-ups with 64 units on each line. It shall provide master, weekly, four special day and monthly scheduling feature.

During schedule operation, user can set the power status

(ON/OFF), operation mode, temperature setup, and remote control operation, restricted / allowed, return back and ventilation operation. It shall provide a web interface for remote monitoring, control, and scheduling. It shall be capable of monitoring energy consumption for each tenant and generate monthly billing reports.

d. Central Controller (Touch Screen)

1) Central controller shall communicate over two-core shielded wire up to 1600 ft and use existing indoor – outdoor communication protocol to communicate. A single central controller shall be capable of controlling up to 512 indoor units individually with capability to program maximum of 20 setups for each day. It shall provide master, weekly, five special day and monthly scheduling feature. In addition, an

23 81 29 - 17 optional digital I/O interface shall provide alarm, fire and locking signals. It shall provide a web interface for remote monitoring, control, and scheduling. It shall be capable of monitoring energy consumption for each tenant and generate monthly billing reports.

e. Building Management Systems

1) The system shall be able to be controlled by BACnet protocols either directly or through an external gateway.

2) BACnet shall be able to control:

a) ON / OFF

b) operation mode

c) fan speed

d) louver

e) set temperature

f) permit / prohibit local operation

3) BACnet shall be able to monitor:

a) ON / OFF

b) operation mode

c) fan speed

d) louver

e) set temperature

f) permit / prohibit local operation

g) room temperature

h) error status

i) error code

4) The unit shall have the following functions as a minimum:

a) Selectable automatic restart. After power failure the system will restart at the same operating conditions as before the failure.

b) Temperature-sensing controls shall sense return air temperature at the unit or at the remote control

c) Indoor coil freeze protection in both cooling and heating

(reversing valve failure) modes.

d) Dehumidification mode shall provide increased latent removal through total system modulation.

e) Fan-only operation to provide room air circulation when no cooling is required.

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f) Fan speed control shall be user-selectable: high, medium, low, or microprocessor determined (Auto) based on the differential between the room temperature and the set point during all modes of operations.

g) Indoor coil high temperature protection shall be provided to detect excessive indoor discharge temperature in heating.

h) Cold blow prevention in heating.

i) Adjustable compensation for air stratification in heating.

G. Filters:

1. Filters shall be field supplied.

H. Electrical Requirements:

1. Indoor units are 208/230-1-60 (V-Ph-Hz).

I. Special Features (Accessories):

1. Auxiliary fresh air flange

PART 3- EXECUTION

3.1 INSTALLATION

A. Install outdoor and indoor units according to manufacturers printed instructions.

B. Install electrical and control devices furnished by the manufacturer but not specified to be factory mounted. All electrical work shall comply with Division 26 Sections.

C. Ductwork: Comply with requirements in Section 23 31 00, HVAC DUCTS AND

CASINGS.

D. Piping: Comply with requirements in Section 23 23 00, REFRIGERANT

PIPING.

3.2 STARTUP AND TESTING:

A. Perform startup checks according to manufacturer’s written instructions.

B. The Commissioning Agent will observe startup and contractor testing of selected equipment. Coordinate the startup and contractor testing schedules with the COR and Commissioning Agent. Provide a minimum of 7 days prior notice

C. Test controls and demonstrate its compliance with project requirements.

Replace damaged or malfunctioning controls and equipment and retest the equipment to the satisfaction of the COR.

D. Furnish test reports to the COR in accordance with specification

Section 01 00 00, GENERAL REQUIREMENTS.

23 81 29 - 19

3.3 INSTRUCTIONS

A. Provide services of manufacturer’s technical representative for four hours to instruct VA personnel in operation and maintenance of heat pumps.

3.4 COMMISSIONING

A. Provide commissioning documentation in accordance with the requirements of Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS for all inspection, start up, and contractor testing required above and required by the

System Readiness Checklist provided by the Commissioning Agent.

B. Components provided under this section of the specification will be tested as part of a larger system. Refer to Section 23 08 00 –

COMMISSIONING OF HVAC SYSTEMS and related sections for contractor responsibilities for system commissioning.

3.5 DEMONSTRATION AND TRAINING

A. Provide services of manufacturer’s technical representative for four hours to instruct VA personnel in operation and maintenance of units.

B. Submit training plans and instructor qualifications in accordance with the requirements of Section 23 08 00 – COMMISSIONING OF HVAC SYSTEMS.

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