HomeMy WebLinkAbout238125 VARIABLE FLOW REFRIGERANT SYSTEMS.pdfa
L’Acquis Number: 12056
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Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 1
SECTION 23 81 25
Variable Flow Refrigerant (VFR) HVAC System
PART 1 � GENERAL
1.01 RELATED SECTIONS:
A. Drawings, general provisions of the Contract, including General and Supplementary
Conditions, and Division�1 Specification Sections and other Division�20 Specification
Sections, apply to work of this Section.
1.02 WORK DESCRIPTION:
A. Scope of Work:
1. Furnish and install VFR system components of configuration and capacity as
shown and/or scheduled on the Mechanical Contract Documents. Unit shall
include indoor fan coil units, exterior heat pumps, refrigerant accessories, and
controls system.
2. Controls system shall be provided and installed under Division 23.
3. Electrical service to units shall be provided as specified under Division 26
Sections.
1.03 SYSTEM DESCRIPTION:
A. The variable capacity, heat recovery air conditioning system shall be a variable
refrigerant flow heat and cool model split system as shown and specified. The system
shall consist of multiple indoor evaporators, branch selector boxes if required by
manufacturer’s product design, manufactured joints and headers, a three pipe
refrigeration distribution system, and outdoor condensing unit/s.
B. The outdoor unit shall be a direct expansion (DX), air�cooled heat recovery, multi�zone
air�conditioning system with variable speed driven compressors using R�410A
refrigerant.
C. The outdoor unit may connect an indoor evaporator capacity up to 200% of the outdoor
condensing unit capacity. All zones shall each be capable of operating separately with
individual temperature control.
D. Two�pipe systems requiring separation of the gas and liquid refrigerant are not
acceptable.
1.04 CONTRACTOR’S QUALIFICATIONS:
A. The HVAC Contractor installing the VFR (Variable Flow Refrigerant) HVAC system
shall have a minimum of two (2) years previous successful work experience installing
VFR HVAC systems of matching or larger tonnage. Contractor shall provide a list of
completed projects with references and the name of a contact person and phone number.
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L’Acquis Number: 12056
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Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 2
B. The HVAC Contractor shall furnish verification to the Engineer showing that each
worker installing VFR system components has successfully completed the
manufacturer’s VFR installation training. Training shall be completed prior to installing
any portion of a VFR system.
1.05 QUALITY ASSURANCE:
A. Energy Efficiency Ratio: Equal to or greater than prescribed by ASHRAE 90.1, “Energy
Efficient Design of New Buildings except Low�Rise Residential Buildings”.
B. Fabricate and label refrigeration system to comply with ASHRAE 15, “Safety Code for
Mechanical Refrigeration”.
C. Listing and Labeling: Provide electrically operated components specified in this Section
that are listed and labeled.
1. All wiring shall be in accordance with the National Electrical Code (N.E.C.).
2. The units shall be listed by Electrical Laboratories (ETL) and bear the ETL
label.
1.06 SUBMITTALS:
A. Submit descriptive product literature and shop drawings in accordance with Division 1
requirements.
1. Submittals and shop drawings shall include the following data:
a. Shop drawings indicating unit configurations.
b. Manufacturer’s technical data including certified unit capacity.
c. Wiring schematics including ladder type diagrams which differentiate
between factory installed and field installed portions.
d. Accessories furnished.
e. Unit dimension data and weights.
f. Manufacturer’s recommended installation methods.
B. Submit maintenance manuals in accordance with Division 1 requirements.
1. Maintenance manuals shall include the following:
a. Parts lists for each type and size of unit
b. Published installation instructions.
c. Troubleshooting maintenance guide for each type of unit.
d. Maintenance instructions for lubrication, filter replacement, etc.
1.07 DELIVERY, STORAGE, AND HANDLING:
A. Units shall be stored and handled according to the manufacturer’s recommendation.
1.08 WARRANTY:
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L’Acquis Number: 12056
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Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 3
A. General Warranty. Provide written warranty, executed by the manufacturer and signed
by the Contractor, agreeing to replace components that fail in materials or workmanship,
for a period of 1 year from the date of Substantial Completion
B. Special Warranty: Compressors shall be covered by an extended manufacturer’s limited
warranty for a period of five (5) years from date of installation.
PART 2 � PRODUCTS:
2.01 ACCEPTABLE MANUFACTURERS:
A. Subject to compliance with the Contract Documents provide packaged heating and
cooling units of one of the following manufacturers:
1. Sanyo
2. LG
3. Daikin AC
4. Mistubishi
2.02 GENERAL:
A. System shall be a VRF (variable refrigerant flow) multi split air conditioning system.
The system will utilize up to two exterior air cooled condensing units connected in
parallel to multiple indoor fan coil units. The systems shall utilize R�410 refrigerant.
2.03 INDOOR FAN COIL UNITS:
A. General:
1. Each fan coil unit will have a heat exchanger constructed from copper tubing
with aluminum fins. The flow of refrigerant through the heat exchanger will be
controlled by an electronic proportional expansion valve. This valve will be
controlled by two pipe thermistors (a return air and discharge air thermistor) and
shall be capable of controlling the variable capacity of the fan coil unit between
25% and 100%.
2. The indoor unit shall supply demand capacity information to the outdoor unit via
its system control algorithm.
3. It shall be possible for the total connected capacity of the indoor units to be
between 50 and 130% of the capacity of the exterior heat pump unit.
B. Heat Recovery Boxes
1. Where heat recovery boxes are required by manufacturer’s product design, they
shall be located as shown on the drawing.
2. Each heat recovery unit shall contain piping, valves, and controls to divert
refrigerant for optimum efficiency.
3. The heat recovery box shall control the operational mode of the subordinate fan
coils.
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L’Acquis Number: 12056
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Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 4
4. The use of multiple electronic expansion valves shall ensure continuous heating
during defrost, no heating impact during changeover and reduced sound levels.
C. 4 Way Ceiling Cassette Type Unit (2’ x 2’):
1. Air will be horizontally discharged by a forward curved centrifugal fan through a
4 way distribution grille in the face of the unit.
2. The 4�way supply air flow can be field modified to 3�way and 2�way airflow to
accommodate various installation configurations including corner installations.
3. Coil:
a. Coils shall be of the direct expansion type constructed from copper tubes
expanded into aluminum fins to form a mechanical bond.
b. The coil shall be of a configured louver fin and high heat exchange,
rifled bore tube design to ensure highly efficient performance.
c. A thermistor will be located on the liquid and gas line.
4. The room air will be returned to the unit through a concentric panel on the
bottom of the unit. The return air will be filtered through synthetic fiber
washable filters.
5. The unit casing will be constructed of galvanized steel plate with an ABS plastic
cover.
D. Ceiling�Mounted Type Unit:
1. Air will be horizontally discharged by a forward curved centrifugal fan through a
single outlet at the front of the unit. The outlet shall include an electronically
adjustable vane to enable variable air discharge through the horizontal to vertical
downward planes.
2. Coil:
a. Coils shall be of the direct expansion type constructed from copper tubes
expanded into aluminum fins to form a mechanical bond.
b. The coil shall be of a configured louver fin and high heat exchange,
rifled bore tube design to ensure highly efficient performance.
c. A thermistor will be located on the liquid and gas line.
3. The room air will be returned to the unit through intake grilles on the bottom of
the unit. The return air will be filtered through synthetic fiber washable filters
attached to the return air grilles.
4. The unit casing will be constructed of galvanized steel plate with an ABS plastic
cover.
E. Concealed Duct�Type High Static Pressure Unit:
1. The unit will be manufactured from galvanized steel plate and insulated with
closed cell expanded polyurethane foam.
2. Air will be discharged by a forward curved centrifugal fan horizontally out of the
front of the unit via a square discharge grill to distribute the air into the room.
Return air will brought in through the rear of the unit to allow for the return air
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L’Acquis Number: 12056
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Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 5
to be either ducted from the room or taken from the ceiling void. A EU3
compliant synthetic fiber washable filter and filter casement shall be supplied as
standard.
2.04 HEAT PUMP CONDENSING UNIT:
A. General:
1. The outdoor unit shall be factory assembled and pre�wired with all
necessary electronic and refrigerant controls. The refrigeration circuit of
the condensing unit shall consist of scroll compressors, motors, fans,
condenser coil, electronic expansion valves, solenoid valves, reversing
valve/s, distribution headers, capillaries, filters, shut off valves, oil
separators, service ports and refrigerant regulator. High/low pressure
gas line, liquid and suction lines must be individually insulated between
the outdoor and indoor units.
2. The system shall automatically restart operation after a power failure
and shall not cause any settings to be lost, thus eliminating the need for
reprogramming.
3. The outdoor unit shall be modular in design and should allow for side�
by�side installation with minimum spacing.
4. The following safety devices shall be included on the condensing unit;
high pressure switch, control circuit fuses, crankcase heaters, fusible
plug, high pressure switch, overload relay, inverter overload protector,
thermal protectors for compressor and fan motors, over current
protection for the inverter and anti�recycling timers.
5. To ensure the liquid refrigerant does not flash when supplying to the
various fan coil units, the circuit shall be provided with a sub�cooling
feature.
6. Oil recovery cycle shall be automatic.
7. The outdoor unit shall be capable of heating operation at 0° F. dry bulb
ambient temperature without additional low ambient controls.
8. The system shall continue to provide heat to the indoor units in heating
operation while in the defrost mode.
B. Unit Cabinet:
1. The outdoor unit shall be completely weatherproof and corrosion resistant. The
unit shall be constructed from rust�proofed mild steel panels coated with a baked
enamel finish.
2. The condensing unit shall consist of one or more propeller type, direct�drive fan
motors that have multiple speed operation.
3. The fan motor shall have inherent protection and permanently lubricated
bearings and shall be factory mounted. The fan motor shall be provided
with a fan guard to prevent contact with moving parts.
4. Provide hail guards for each face of the condensing unit with exposed
condensing coils.
a. For equipment manufacturers who do not offer optional hail
guards; the contractor shall obtain the guard sizes from the
manufacturer for fabrication by a sheet metal shop.
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L’Acquis Number: 12056
____________________________________________________________________________________________
Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 6
b. Prime and paint hail guards with materials suitable for the sheet
metal materials used, and match the color of the condensing unit.
5. Night setback control of the fan motor for low noise operation by way of
automatically limiting the maximum speed shall be a standard feature.
C. Condenser Coil:
1. The condenser coil shall be manufactured from copper tubes expanded into
aluminum fins to form a mechanical bond.
2. The heat exchanger coil shall be of a waffle louver fin and rifled bore tube
design to ensure high efficiency performance.
3. The fins shall be covered with an anti� corrosion acrylic resin and hydrophilic
film.
4. The pipe plates shall be treated with powdered polyester resin for corrosion
prevention.
D. Compressor:
1. The scroll compressors shall be variable speed controlled (inverter or
digital) and capable of changing the speed to follow the variations in
total cooling and heating load as determined by the suction gas pressure
as measured in the condensing unit. In addition, samplings of evaporator
and condenser temperatures shall be made so that the high/low pressures
detected are read every 20 seconds and calculated. With each reading,
the compressor capacity shall be controlled to eliminate deviation from
target value.
2. The compressor in each condensing unit shall be of highly efficient,
hermetically sealed scroll type with a maximum speed of 7,980 rpm.
3. The capacity control range shall be as low as 20% to 100%.
4. Each compressor shall be equipped with a crankcase heater, high
pressure safety switch, and internal thermal overload protector.
5. Oil separators shall be standard with the equipment together with an
intelligent oil management system.
6. The compressor shall be spring mounted to avoid the transmission of
vibration.
7. Units shall contain a minimum of 2 compressors. In the event of
compressor failure, the remaining compressor/s shall continue to operate
and provide heating or cooling as required at a proportionally reduced
capacity. The microprocessor and associated controls shall be designed
to specifically address this condition.
8. The system shall use an operating control sequence to ensure that indoor
loads are matched to compressor capacity control.
E. The condensing unit shall ship with full charge of R410A refrigerant.
2.05 INTEGRATED CONTROLS SYSTEM:
A. System shall be provided with manufacturer’s standard dedicated control system
integrating all system components.
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L’Acquis Number: 12056
____________________________________________________________________________________________
Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 7
B. General:
1. All indoor units shall maintain settings for temperature set point, start/stop
status, operating mode, fan speed, air flow direction in non�volatile memory each
time they are changed. These setting shall not be lost upon a power loss event.
2. Entire system shall automatically restart upon a power loss event.
C. Control Wiring:
1. All control wiring shall be done per control wiring drawings provided by the
manufacturer.
2. Control will be via a 2�wire shielded communication bus connected in series
from the outdoor unit(s) to each indoor fan coil unit.
D. The following unit controllers shall be provided:
1. Simplified Controller � This controller shall be wall mounted and hard wired to
the indoor fan coil units. It will be manufactured in ABS plastic with an LCD
display and will be the manufacturer’s standard color. The controller will have a
remote sensor located within it and can be covered by a colored bezel, supplied
by the installer, to suit site requirements. The controller will be capable of
switching on/off and altering the set point and mode of up to eight indoor fan
coil units. All units shall be provided with a factory installed return air
temperature sensor. This will be the controlling sensor for all units that serve a
space with a ceiling height of 10 feet or less.
2. Standard Remote Controller � This controller shall be wall mounted and hard
wired to the indoor fan coil units. It will be manufactured in ABS plastic with an
LCD display and will be the manufacturer’s standard color. The controller will
be capable of altering the following functions on up to eight indoor fan coil
units:
On/off
Operating mode
Set point
Fan speed
Louver position
7 day timer settings
Test run.
Setback control
The controller shall also be capable of displaying the following items:
On/off
Operating mode
Set point
Return air temperature
Fan speed
Louver position
Timer settings
Filter
Fault diagnosis
Test run
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L’Acquis Number: 12056
____________________________________________________________________________________________
Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 8
System diagnosis
The controller shall also be able to switch an external dry contact via a 12 volt
DC relay (field supplied).
E. Centralized System Controller:
1. System shall be supplied with a touch screen Centralized Controller. This
controller shall allow for on�site set�point changes, if EMS ever goes off line.
2. Each centralized remote controller shall be able to control up to a minimum of
128 indoor zones and 10 outdoor systems. The centralized controller shall allow
for connection to the internet for remote access to system using Microsoft
Explorer web browser.
3. The centralized controller shall provide e�mail and mobile phone malfunction
reporting.
4. Centralized remote controller shall have the following features:
a. Change Operation: Start/stop, operation mode, temperature setting, fan
speed, airflow direction.
b. Monitoring: Status, Malfunction identification, Malfunction code, filter
sign, operation mode, temperature setting, fan speed, airflow direction.
F. BACnet Interface
1. System shall be supplied with a BACnet IP interface. This interface shall allow
BMS to monitor and change certain values of system.
2. BACnet interface shall be a hardware�based device and shall mount in BMS
control panel. BACnet interface which is software�based and shall run on an
IBM�compatible computer is not acceptable.
3. BACnet interface shall be capable of interfacing to a minimum of 40 outdoor
systems and 256 indoor units.
4. Interface shall be a BACnet Application Specific Controller (B�ASC) device
profile compatible with BACnet (ANSI / ASHRAE�135)
5. Interface shall have BACnet IP Data Link Layer (Annex J)
6. Interface shall support COV � Change of Value, Property Array Index and
Segmented Requests
7. Interface shall have IPV6 and Foreign Device Registration capability
8. Interface shall have BTL Certification (Operating System Version 6.2 and
Later).
9. Interface shall provide as at a minimum the following points:
a. Monitoring points: indoor unit Start/stop status, All indoor unit Alarms,
All outdoor unit alarms, indoor unit Malfunction codes, outdoor unit
malfunction codes, indoor unit mode of operation, return air or space
temperature, indoor unit filter inspection required, Outdoor unit
compressor status, indoor unit fan status.
G. Writable points: indoor unit start/stop operation, indoor unit mode of operation, room
temperature setting, indoor unit filter inspection reset, remote controller enable/disable,
indoor unit fan speed setting, indoor unit air direction setting, forced system stop, forced
thermostat disable
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L’Acquis Number: 12056
____________________________________________________________________________________________
Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 9
PART 3 � EXECUTION
3.01 INSTALLATION:
A. Install units according to manufacturer's written instructions.
B. Install units level and plumb, maintaining manufacturer's recommended clearances.
C. Evaporator�fan components shall be installed using manufacturer's standard mounting
devices securely fastened to building structure.
3.02 CONNECTIONS:
A. Piping installation requirements are specified in other Division 15 Sections. Drawings
indicate the general arrangement of piping, fittings, and specialties. The following are
specific connection requirements:
1. Install and connect refrigerant tubing piping, fittings, and insulation to meet
manufacturer’s requirements.
2. Install piping to allow service and maintenance.
3. Installer shall supply isolation ball valves for zoned refrigerant isolation.
4. Installer shall supply Schrader valves for isolated refrigerant charge and
evacuation.
3.03 CONDENSATE PIPING
A. Piping shall be schedule 40 PVC or type M copper; be 3/4” diameter minimum size, and
have a cleanout w/ plug at all changes in direction.
B. Supports for piping shall be placed 4 foot�on�centers for PVC, and 6 foot�on�centers for
copper.
C. Insulate piping w/ 1/2” Armaflex type insulation. All joints and seams in insulation
shall be glued together w/ the manufacturers recommended glue. Duct tape and
insulation tape will not be allowed.
3.04 START UP AND COMMISSIONING:
A. Verify that installation is as indicated and specified.
B. Complete manufacturer's installation and startup checks and perform the following:
1. Level exterior unit on housekeeping base.
2. Inspect for visible damage to unit casing and condenser coils.
3. Inspect for visible damage to fans.
4. Verify that clearances have been provided for servicing.
5. Check that labels are clearly visible.
6. Verify that controls are connected and operable.
7. Verify that filters are installed on indoor fan coils.
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L’Acquis Number: 12056
____________________________________________________________________________________________
Matt the Miller's Tavern
Carmel, Indiana
Project No. 12056 VARIABLE FLOW REFRIGERANT (VFR) HVAC SYSTEM 23 81 25 � 10
C. Manufacturer's Field Service: Engage a factory�authorized service representative to
inspect field assembled components and equipment installation, including connections,
and to assist in field testing.
D. Engage manufacturer or factory�authorized service representative to perform startup
service. Manufacturer shall provide on�site startup and commissioning assistance
through job completion. Complete installation and startup checks according to
manufacturer's written instructions.
E. Start�up date, time and personnel performing / attending the equipment start�up shall be
documented. A copy of the start�up documentation shall be placed in the O&M manuals.
3.05 TESTING AND START�UP:
A. Testing of the refrigerant piping and connections to the condensing units shall be done in
strict compliance with the VFR manufacturer’s testing instructions.
B. The VFR system shall be tested for a full 24 hours at minimum of 450 to a maximum of
600 PSI, or as recommended by the manufacturer, whichever is greater.
C. Pressure test shall be witnessed / monitored by a representative of the Using Agency
and/or a Commissioning agency, as applicable.
D. After vacuum evacuation has been completed the proven leak free the system shall be
filled with refrigerant. The amount of refrigerant shall be calculated based on the
manufacturer’s method specific to the equipment, line sizes, and lengths, and then
‘weighed’ and installed in each system. The exact amount of refrigerant shall be
documented for each system and be documented in the O&M Manuals.
E. Operational Test: After electrical circuitry has been energized, start units to confirm
proper motor rotation and unit operation.
F. Test and adjust controls and safeties. Replace damaged and malfunctioning controls and
equipment.
G. Remove and replace malfunctioning units and retest as specified above.
3.06 DEMONSTRATION:
A. Demonstration Services: Engage factory authorized service representative to train
Owner's maintenance personnel on the following:
1. Procedures and schedules related to adjusting, operating and maintaining units,
start�up and shut down, troubleshooting, servicing, preventative maintenance,
and how to obtain replacement parts.
2. Schedule training with at least 7 days advanced notice.
END OF SECTION