The YORK YVFA Free Cooling Air-Cooled Screw Chiller delivers the lowest possible operating cost by combining our legacy of innovation in a packaged design that’s simple to own and operate.

Advanced technologies including a variable speed drive compressor, energy optimized hybrid cooling mode and air to liquid free cooling coils designed by our heat transfer experts are intelligently controlled to maximize efficiency year-round, automatically.

Johnson Controls is the first manufacturer to utilize free-cooling coils that are integrated within the chiller to conserve space and be AHRI certified. 

• Annual Energy Cost (AEC) tool verifies payback in as little as three years - To confirm that your chiller selection delivers the smallest possible energy footprint, we use an AEC tool to produce a customized report factoring in all key variables — geographic location, building type, operating hours, utility costs and local weather data
• Simple to operate with packaged controls include single-point convenience -YVFA controls simplify operation with single-point control that easily accommodates process or building changes
• Reliability from the start - Variable-frequency inverter technology enables a zero-inrush soft start and a high displacement power factor across the entire operating range. Quick Start option achieves full load after a power-loss restart in four minutes or less.

The YORK YVFA Free Cooling Air-Cooled Screw Chiller delivers the lowest possible operating
cost by combining superior engineering and technology in a packaged design that’s
simple to own and operate. Advanced technologies including a variable speed drive compressor,
energy optimized hybrid cooling mode and air to liquid free cooling coils designed
by our heat transfer experts are intelligently controlled to maximize efficiency year-round,
automatically. YORK, the leader in air cooled chillers with Variable Speed Drive compressors,
continues a legacy of innovation with the first integrated Variable Speed Drive screw
chiller with free cooling.
EFFICIENCY
Industry-Leading Variable-Speed Drive (VSD) Technology - Allows YVFA compressors
to operate efficiently across all cooling load and ambient temperature conditions.
High-Efficiency, Air-To-Liquid “Free Cooling” Coils - Reduce or eliminate the need for
mechanical cooling when ambient conditions allow. Plus, the free-cooling coils are integrated
within a traditional chiller footprint to conserve space.
Intelligent Controls - optimize operation year-round, constantly evaluating conditions
and controlling bypass valves to reduce pump energy when free cooling is not beneficial.
Performance is assured by AHRI Certification - the first time certification has been
given to an air-cooled screw chiller with free cooling.*
Annual Energy Cost (AEC) Report verifies payback in as little as three years - To
confirm that your chiller selection delivers the smallest possible energy footprint, we use
AEC modeling to produce a customized report factoring in all key variables — geographic
location, building type, operating hours, utility costs and local weather data. In most locations,
a facility operating 24/7 with a constant cooling load can achieve an operating cost
payback within three or four years. Our AHRI-certified testing laboratory can demonstrate
performance under your application’s conditions.
Hybrid mode uses advanced technologies - For unsurpassed efficiency at part-load
conditions. The VSD screw compressor can turn down capacity to reduce power draw
below the power required by fan motors to move air. At part-load conditions, the chiller
uses optimized “Hybrid Mode” with free-cooling coils to provide pre-cooling, with the compressor
efficiently delivering the final cooling to meet the setpoint.
Optimized liquid circuit prevents wasted pump energy - Designed with low liquid
pressure drop in mind, the YVFA chiller employs oversized pipe and fittings, a highly optimized
free cooling coil, and an automatic bypass to prevent pumping through the coils
when not beneficial.

SIMPLICITY
Packaged controls include single-point convenience
YVFA controls simplify operation with single-point control that easily accommodates process
or building changes. When a new setpoint is required, adjustment can be made at
the chiller control panel or through a Building Automation System (BAS). The free-cooling
function automatically adjusts to deliver the best performance at the required conditions.
Open-loop unit design maximizes free cooling
The YVFA open-loop unit design permits building glycol to flow through the free-cooling
coils directly, providing the best performance at the lowest first cost.
Reliability
Three generations of Johnson Controls expertise in variable-speed driven, air-cooled
chillers ensure superior efficiency and reliability in the YVFA design. Variable-frequency
inverter technology enables a zero-inrush soft start and a high displacement power factor
across the entire operating range. For critical process and data center applications, the
Quick Start option achieves full load after a power-loss restart in four minutes or less. On
the jobsite, all YVFA models fit within a standard 40-foot shipping container for lowest possible
rigging and shipping costs.

SEMI-HERMETIC YORK TWIN SCREW COMPRESSORS
The direct-drive, semi-hermetic rotary twin-screw compressors incorporate advanced
technology in a rugged design. The continuous function, microprocessor controlled VSD
provides smooth capacity control from 100% down to 10% of chiller capacity. State-ofthe-
art technology, obtained from decades of screw compressor design, ensures optimal
efficiencies at all chiller load points. With no unloading steps or slide valves in the compressors,
the YVFA variable speed driven compressors have 50% fewer moving parts
than fixed speed compressors with slide valves. The YVFA compressor is one of the most
efficient and reliable screw compressors in the industry.
FREE COOLING ECONOMIZER
YVFA is the first Variable Speed Drive Screw chiller to include integrated free cooling
economizer coils. The free cooling coils reject heat directly to the atmosphere when
ambient temperature permits, reducing mechanical cooling requirement and saving energy.
The free cooling economizer coils are round tube, plate fin design, delivering a low
liquid-side pressure drop to reduce pump energy and providing a robust design that can
accommodate small particle debris from the building liquid loop without clogging. Coils
are two-row depth and circuited to make draining for service easy. The coils are factory
piped to the evaporator, providing simple single-point inlet and outlet connections to the
unit. A pair of factory mounted, unit powered and controlled butterfly valves divert liquid to
the economizer when ambient is suitable for free cooling. The coils are bypassed during
high ambient to avoid unnecessary pressure drop and reduce pump energy.
EVAPORATOR
The evaporator is a shell and tube, hybrid falling film type heat exchanger. It contains a
balance of flooded and falling film technology to optimize efficiency, minimize refrigerant
charge, and maintain reliable control. A specially designed distribution system provides
uniform refrigerant flow for optimum performance.
CONDENSER
YVFA uses microchannel condenser heat exchangers, which provide excellent heat transfer
and airflow for the best efficiency while operating mechanical cooling. Charge quantity
is reduced up to 30% compared to traditional round tube condenser coils and the heat
exchangers are single-row depth for simple rinse cleaning. Microchannel coils are made
of a single material to avoid galvanic corrosion due to dissimilar metals. Tubes, fins and
headers are brazed as one piece, minimizing leaks. The inherently rugged construction,
which includes non-overhanging fins, eliminates the possibility of fin damage.
The condenser fans are composed of corrosion resistant aluminum hub and glass-fiber
reinforced polypropylene composite blades molded into a low-noise airfoil section. All
blades are statically and dynamically balanced for vibration-free operation. Fan motors
are Totally Enclosed Air-Over (TEAO), inverter duty, IP54 rated, and current protected.
Variable speed drives, standard, reduce energy use and sound at part load while maximizing
condenser and economizer heat transfer performance. The motors feature double-
sealed and permanently lubricated ball bearings, reducing maintenance costs over
the life of the unit.

REFRIGERANT CIRCUIT
The YVFA has one independent refrigerant circuit per compressor. Each circuit uses
copper refrigerant pipe formed on computer-controlled bending machines. By using computer-
aided technology, over 60% of system piping brazed joints have been eliminated
(as compared to designs that use fittings), resulting in a highly reliable and leak-resistant
system.
COMPLETE FACTORY PACKAGE
Each unit is shipped as a complete factory package, completely assembled with all interconnecting
refrigerant piping and internal wiring and ready for field installation. Prior
to shipment, each individual chiller undergoes an extensive testing procedure, ensuring
workmanship is the highest quality and that the initial start-up is trouble-free.
Before leaving the factory, each refrigerant circuit is factory pressure tested, evacuated,
and then fully charged with R134a refrigerant and oil. An operational test is performed
with water flowing through the evaporator to ensure each circuit functions correctly.
ELECTRICAL
All controls and motor starting equipment necessary for unit operation are factory wired
and function tested. There are no surprises when you go to start-up; you can have confidence
that the unit will start up right the first time and every time.
The chillers are available with a single point power connection and are supplied with a
factory mounted and wired control transformer that powers all unit controls from the main
unit power supply. The transformer utilizes scheduled line voltage on the primary side and
provides 115 V/1Ø on secondary. The standard unit is equipped with terminal block electrical
connections. All exposed power wiring is routed through liquid-tight, UV-stabilized,
non-metallic conduit. Selection of frame 36 and larger are standard dual point, with single
point option.
VSD Power/Control Panel includes main power connection(s), VSD and fan motor contactors,
current overloads, and factory wiring. All display and control features can be accessed
through the keypad and control display access door, eliminating the need to open
the main cabinet doors.
BUILDING AUTOMATION SYSTEM CAPABILITIES
The YVFA chiller comes standard with native communication capability for BACnet (MS/
TP), Modbus and N2, with optional capabilities available for LON. The standard unit capabilities
include built-in-scheduling, remote start-stop, remote water temperature reset
and up to two steps of demand (load) limiting depending on model. The standard control
panel can be directly connected to a Johnson Controls Building Automated System via the
standard factory-installed RS232 communication port.
For connection with Johnson Controls Connected Services, an optional interface card
(SC-EQUIP) is required and may be factory installed for easier field commissioning. Additional
hardware (SC-AP access point), field provided, must be installed remotely from the
chiller to interface with the Connected Services remote operations center. Contact your
local Johnson Controls office to learn more about Connected Services and to schedule
installation during chiller commissioning.

AHRI CERTIFICATION PROGRAM
YORK YVFA chillers have been tested and certified by Air-Conditioning, Heating and Refrigeration
Institute (AHRI) in accordance with the latest edition of AHRI Standard 550/590
(I-P). Under this Certification Program, chillers are regularly tested in strict compliance
with this Standard. This provides an independent, third-party verification of chiller performance.
Refer to the AHRI site at www.ahrinet.org/ for complete Program Scope, Inclusions,
and Exclusions as some options listed herein fall outside the scope of the AHRI
certification program. For verification of certification, go to the AHRI Directory at www.
ahridirectory.org.
Rated in accordance with the latest issuance of AHRI Standard 550/590 and 551/591.
YVFA units conform with the following European Directives:
• Machinery Directive (2006/42/EC)
• EMC Directive (2004/108/EC)
• Pressure Equipment Directive (97/23/CEE)
• Safety Code for Mechanical Refrigeration EN 378- 2 (2008)/A2(2012) [Safety accessories
according to essential requirements in PED paragraph 2.11.1 have been calculated
according to EN13136:2001/A1:2005 and are not following the requirements
in EN378-2:2008 paragraph 6.2.6.2, unless dual relief valves are fitted]
• Safety of machinery - Electrical Equipment of Machine (EN 60204-1)
• Generic emissions and immunity standards for industrial environment EN61000-6-
4:2007 & 61000- 6-2:2005
• ISO 9614 – Determination of sound power levels of noise sources using sound intensity
• ECO Design Directive (2009/125/EC) Fan/motor Efficiency EN ISO 5801
• Manufactured in an EN ISO 9001 accredited organization
• Conform to CE Testing Services for construction of chillers and provide CE Listed
Mark

OFF-DESIGN PERFORMANCE
Since the vast majority of operating hours are spent at off-design conditions, a chiller
should be chosen not only to meet the full load design, but also for its ability to perform
efficiently at lower loads. It is not uncommon for chillers with the same full load efficiency
to have an operating cost difference of over 10% due to differences in off-design (part
load) efficiencies.
Annual Energy Cost can be calculated quickly and accurately by computer using simple
inputs of geographic location, building load profile and operating hours. For a facility with
higher operating hours and load profile than comfort cooling, Annual Energy Cost must be
considered when comparing overall performance of mechanical and economizer operation.
In addition to Annual Energy Cost, YVFA ratings also include Integrated Part Load Value
(IPLV) and Non-Standard Part Load Value (NPLV), standardized within the AHRI Certification
Program. These values do not include economizer operation, as this is outside the
scope of the AHRI program.

UNIT CONTROL CENTER
The unit control center provides automatic control of chiller operation including compressor
start/stop and load/unload anti-recycle timers, condenser fans, chilled liquid pump,
evaporator heater, unit alarm contacts and run signal contacts. The microcomputer control
center comes online as soon as the main power switch on the unit is switched on;
immediately, the microcomputer control center will begin to continuously monitor all variables.
Figure 1 - YVFA CONTROL CENTER KEYPAD AND DISPLAY
LD19911
The microprocessor controls the unit’s capacity by matching the actual leaving chilled
liquid temperature (LCHLT) to the user-defined setpoint. Factors that may cause the
system’s actual LCHLT to fluctuate are changes in ambient temperature, load, and chilled
liquid loop flow rate and volume. The controls system reacts to such changes by adjusting
the number of compressors that are on and the loading of each compressor in order
to keep the LCHLT at the setpoint.
The controls system logic monitors the rate at which the LCWT is approaching the setpoint
to ramp up or down compressor capacity as required. The variable frequency drive
allows the compressor capacity to match the load.
During extreme or unusual conditions (i.e. blocked condenser coils, ambient above scheduled
maximum, etc.) the chiller control system will avoid shutdown by varying capacity. By
monitoring motor current and suction and discharge pressures, the chiller can maintain
maximum available cooling output without shutting down.
Unit Safeties are provided for the chiller to perform auto-reset shut down for the following
conditions:
• Ambient temperature above or below allowable range
• Out of range leaving chilled liquid temperature
• Under voltage
• Flow switch operation

Display Data
• Leaving Chilled Liquid Temperature
• Returning Liquid Temperature
• Ambient Temperature
• Lead System
• Compressor Capacity (% of Full Load Amps)
• VSD Output Frequency/Compressor Speed
• Compressor Run Hours
• Compressor Number of Starts
• Oil Pressure and Temperature (per Compressor)
• Chilled Liquid Pump Status
• Evaporator Heater Status
• History Data for Last 20 Normal Shutdowns
• History Data for Last Ten Shutdown Faults
Programmable Setpoints
• Chiller On/Off
• Chilled Liquid (Water or Glycol)
• Local or Remote Control
• Units of Measure (Imperial or SI)
• System Lead/Lag
• Remote Temperature Reset
• Remote Current Limit
• Leaving Chilled Liquid Temperature Setpoint and Range

All options factory mounted unless otherwise noted.
FREE COOLING CIRCUIT TYPE
The standard YVFA design permits the building liquid loop to circulate through the free
cooling coils when ambient temperature is low enough to provide energy savings. Glycol
is required in the building loop to prevent freeze damage from occurring in the free cooling
coils at low ambient temperatures.
Closed Loop Option – The closed loop option isolates the free cooling coils from the
building liquid loop by use of a brazed plate heat exchanger and circulating pump that
moves glycol through the free cooling coils. This permits water to be used on the building
loop. The brazed plate heat exchanger is protected by a factory installed removable core
wye-strainer and unit powered heaters. The free cooling glycol pump is controlled and
powered by the chiller to operate when ambient temperature is low enough to provide
energy savings. This option also includes evaporator water box heaters, powered by the
chiller. Factory installed, unit powered heat trace on the internal water pipework completes
freeze protection for the entire chiller to -20F / -28.9C. The glycol loop can be selected to
have either 30% or 50% propylene or ethylene glycol.
SOUND ATTENUATION
Low Noise Kits – The standard chiller configuration is equipped with variable speed,
high airflow fans. There are several sound attenuation options available to further reduce
sound at its source thereby meeting local sound level regulations.
CONDENSER COIL PROTECTION
The alloys used in the YVFA microchannel condenser and economizer coils have been
carefully selected and tested for high corrosion resistance. However, all metals can corrode
in harsh conditions. Consider protecting coils from corrosive environments such as
coastal, marine, urban, and industrial.
Environment Guard Premium – Microchannel condenser coils coated with an electro-
deposited and baked flexible epoxy coating that is finished with a polyurethane
UV resistant top-coat.
Environment Guard Basic – Microchannel condenser coils treated with immersion
bath-applied chemical treatment.
Microchannel condenser shall be provided with a 5-year warranty against corrosion
damage.

EVAPORATOR OPTIONS
Flange Kit – Provides contractor with the couplings best suited to connect the chiller to
the chilled liquid piping. All flanges are ANSI 150 psig (10.3 barg). Field mounted. Options
include:
• ANSI/AWWA C-606 Flanges – Two flanges, for applications where field piping has
existing flanges
• Weld Flanges – Four flanges, two ANSI/AWWA C-606 connections to chiller and two
weld flanges for field piping
Water Box Heater – The standard unit comes with freeze protection on the evaporator
down to 0°F (-17.8°C) Unless the appropriate concentration of glycol is used, optional
water box heaters are required for storage below 0°F (-17.8°C). See "Application Data" on
page 19 for additional information on freeze protection. Separate 120 V/60 Hz or 230
V/50 Hz single phase power supply required.
CONTROLS OPTIONS
Building Automation System Interface (Temperature) – Factory installed option to accept
a 4 to 20 mA or a 0 to 10 VDC input to allow remote reset of the Leaving Chilled
Liquid Temperature Setpoint. The setpoint can be positively offset upwards up to 40°F
(22.2°C). This option is useful for process applications or for periods where higher chilled
liquid temperatures are adequate for low loads. Available alone or in combination with
BAS Load Limit.
Building Automation System Interface (Load Limit) – Factory installed option to accept
a 4 to 20 mA or a 0 to 10 VDC input to allow remote reset of the Load Limit Setpoint.
The setpoint can limit system demand from 30-100%. Available alone or in combination
with BAS Temperature Reset.
E-Link – The E-Link gateway provides full communication to Building Automation Systems,
including BACnet (MS/TP), Modbus, LON and N2.
GENERAL OPTIONS
Thermal Dispersion Flow Switch – Solid state thermal dispersion flow switch with no
moving parts for high reliability and long service life. Stainless steel probe and IP 67
housing with LED status indicator of flow and output condition. Includes 10m IP67 cable
required for field installation near chiller and bronzed steel welding adapter to ensure correct
insertion depth. Field Mounted.
Differential Pressure Switch – This 3-45 PSIG (0.2-3 BarG) range switch, with 1/4
inch NPTE pressure connections, is an alternative to the paddle-type flow switch. Field
mounted.
Service Isolation Valve – Service suction isolation valve added to the unit for each refrigerant
circuit. Valve is available in both manual and chiller actuated configurations. Actuated
valve is recommended for operation below freezing ambients with water in evaporator
(refer to "Operation in Sub-freezing Conditions" on page 21).
Chicago Code Relief Valve – Special relief valves per Chicago code.
Dual Pressure Relief Valve – Two safety relief valves are mounted in parallel; one is
always operational to assist in valve replacement during maintenance.

Pressure Vessel Options – The evaporator can be provided with ASME, PED or GB
pressure vessel codes certification.
Circuit Breaker – Unit-mounted circuit breaker(s) with external lockable handle(s) will be
supplied to isolate the power voltage for servicing. The circuit breaker(s) is (are) sized to
provide motor branch circuit protection, short circuit protection and ground fault protection
for the motor branch-circuit conductors, the motor control apparatus, and the motors.
Quick Start – Special software allows the chiller to achieve full capacity within four minutes
of power being restored. Designed for process and data center applications where
recovering liquid temperature control rapidly after power loss is especially critical. Not
recommended for comfort cooling applications as chiller may temporarily reach liquid temperature
below set point while ramping quickly to achieve full load.
Non-Fused Disconnect Switch – Unit-mounted disconnect switch(es) with external lockable
handle can be supplied to isolate the unit power voltage for servicing. Separate external
fusing must be supplied by the power wiring, which must comply with local codes.
Special Requirement Documents – There are two options to select from:
• Special Requirement Document Package (SRDP) includes Pressure Vessel Report,
Unit Run Test Report, Production System Check Sheet, and Final Unit Inspection
Check Sheet.
• Materials Package includes steel mill material reports for vessels in addition to the
SRDP.
VIBRATION ISOLATION
Elastomeric Isolation – This option is recommended for normal installations. It provides
very good performance in most applications for the least cost. Field mounted.
1 Inch Spring Isolators – Spring and cage type isolators for mounting under the unit
base rails are available to support unit. They are level adjustable. 1” nominal deflection
may vary slightly by application. Field mounted.

Low pressure refrigerant (liquid and gas) enters the evaporator and is sprayed across the
top of the tube bundle from spray nozzles. The liquid refrigerant from the nozzles gravity
drains down across the tube bundle and is evaporated and superheated by the heat
energy absorbed from the chilled liquid passing through the tubes.
The low pressure refrigerant vapor leaves the top of the evaporator and enters the compressor
where the refrigerant vapor is compressed and the pressure and superheat are
increased. The high pressure superheated gas enters the air cooled condenser where
heat is rejected via the condenser coils and fans.
The fully condensed and sub-cooled liquid leaves the air cooled condenser, flows through
the filter drier and enters the economizer tank. The flow of refrigerant into the economizer
is controlled by the electronic expansion valve.
Additional cooling of the refrigerant liquid may take place in the economizer tank when
the economizer valve is opened. After leaving the economizer tank, liquid refrigerant
flows through an orifice where pressure reduction and further cooling take place. The low
pressure refrigerant (liquid and gas) then enters the evaporator.

UNIT SIZING
Avoid over-sizing a chiller. Properly sized chillers operate stably and provide the best
life cycle cost. When designing phased projects, select multiple small chillers to match
demand for each phase. Use multiple small chillers when the minimum cooling demand
is less than 10% of the maximum cooling demand.
UNIT LOCATION
The YVFA chillers are designed for outdoor installation. To achieve optimum performance
and trouble-free service provide adequate space around chillers (see Figure 7).
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Figure 6 - ACCEPTABLE MINIMUM CLEARANCES AROUND/BETWEEN UNIT(S)
FOR PROPER AIRFLOW
When selecting chiller installation sites, follow these requirements:
A. Installation sites may be either on a roof or on ground level. (See FOUNDATION on
Page 20)
B. Provide space for air to flow into condensers per dimensions shown on the dimension
drawing on "Dimensions" on page 18. Restricted airflow or hot air recirculation
will diminish performance. Johnson Controls’ unit controls will optimize the operation
without nuisance high pressure safety cutouts; however, the system designer MUST
consider potential performance degradation. Recommended clearances for all units
are as follows:
1. Access to the unit control center stipulates the unit is no higher than on spring isolators.