LG AR-DR12-05A User manual

ROOFTOP DEDICATED
OUTDOOR AIR SYSTEM (DOAS)
VX MODELS
INSTALLATION AND OPERATION MANUAL
Base Rooftop DOAS
800 to 5750 CFM
Energy Recovery Wheel Rooftop DOAS
900 to 9550 CFM

For continual product development, LG Electronics U.S.A., Inc. reserves the right to change specifications without notice.
© LG Electronics U.S.A., Inc.
PROPRIETARY DATA NOTICE
For more technical materials such as submittals, catalogs, engineering
manuals, and forms, visit www.lghvac.com.
Do not throw away, destroy, or lose this manual.
Please read carefully and store in a safe place for future reference.
Content familiarity is required for proper installation.
The instructions included in this manual must be followed to prevent product malfunction, property damage, injury, or death to the user or
other people. Incorrect operation due to ignoring any instructions will cause harm or damage. The level of seriousness is classified by the
symbols described by the summary list of safety precautions on page 4.
This document, as well as all reports, illustrations, data, information,
and other materials are the property of LG Electronics U.S.A., Inc., and are
disclosed by LG Electronics U.S.A., Inc. only in confidence.

3
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
TABLE OF CONTENTS
SAFETY PRECAUTIONS ....................................................................... 4
Unit Nomenclature................................................................................. 8
GENERAL DATA..................................................................................... 9
Base Rooftop DOAS............................................................................ 9
Energy Recovery Wheel Rooftop DOAS............................................11
Refrigerant Safety................................................................................ 13
Receiving Guidelines .......................................................................... 14
Inspection and Maintenance .............................................................. 15
Subassemblies .................................................................................... 17
Installation............................................................................................ 19
Outdoor Air Hood Assembly .............................................................. 25
Piping Installation................................................................................ 32
Electrical Information.......................................................................... 34
Control Center Components .............................................................. 35
Component Operation......................................................................... 36
Optional Component Operation......................................................... 37
Factory-Installed Refrigeration System Components...................... 41
Start Up Unit......................................................................................... 43
Start Up Checklist................................................................................ 46
Start Up Components.......................................................................... 47
Optional Energy Wheel ....................................................................... 50
Troubleshooting - Alarms ................................................................... 53
Troubleshooting - Unit ........................................................................ 54
Troubleshooting - Refrigeration Circuit ............................................ 55
Routine Maintenance .......................................................................... 59
Reference - Venting Connection Locations ...................................... 62
AHRI Rating Conditions...................................................................... 63
Indirect Gas Fired Furnaces............................................................... 64
Typical Furnace, Electrical, and Control Components....................... 69
Gas Fired Burner Turndown .............................................................. 70
Installation of Venting for Outdoor Units ............................................ 71
Installation of Venting for Indoor Units............................................... 72
Venting Methods................................................................................ 73
Standard Indoor Venting Installation.................................................. 74
Concentric Venting Installation .......................................................... 75
Two Pipe Venting Installation - Horizontal ......................................... 78
Two Pipe Venting Installation - Vertical.............................................. 79
Sequence of Operation...................................................................... 82
Performance Data ............................................................................. 83
Furnace Start Up ............................................................................... 84
Troubleshooting - Ignition Controller.................................................. 87
Troubleshooting - 4:1 Modulating Furnace........................................ 89
Troubleshooting - 4:1 or High Turndown Modulating Furnace 94
Reference - Controls ......................................................................... 98
Maintenance...................................................................................... 99
Maintenance Log............................................................................. 100
CONTROLLER.................................................................................... 102
Overview.......................................................................................... 102
AC Smart Setup................................................................................114
Sequences of Operation...................................................................117
Set-Points Data Tables .................................................................... 129
Network Settings Data Tables.......................................................... 136
Alarm Data....................................................................................... 141
BACnet and MODBUS Points ......................................................... 145
Unit Status Modes ........................................................................... 157
LonTalk Points ................................................................................. 158

4
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
The instructions below must be followed to prevent product malfunction, property damage, injury or death to the user or other people. Incor-
rect operation due to ignoring any instructions will cause harm or damage. The level of seriousness is classified by the symbols below.
WARNING
Do not install or remove the unit by yourself
(end-user). Ask the dealer or an LG trained technician to
install the unit.
Improper installation by the user may result in water leakage, re,
explosion, electric shock, physical injury or death.
Installation, startup, and service must be performed by a
qualied installer, service agency, or gas supplier.
Improper installation, adjustment, service, maintenance, or alteration
can cause personal injury or loss of life.
For replacement of an installed unit, always contact a
trained service provider.
There is risk of re, electric shock, explosion, and physical injury or
death.
Periodically check that the unit is not damaged.
There is risk of explosion, physical injury, or death.
Replace all control box and panel covers.
If cover panels are not installed securely, dust, water and animals may
enter the unit, causing re, electric shock, and physical injury or death.
Always check for system refrigerant leaks after the unit has
been installed or serviced.
Exposure to high concentration levels of refrigerant gas may lead to
illness or death.
Do not install the unit using defective hanging, attaching,
or mounting hardware.
There is risk of physical injury or death.
Wear protective gloves when handling equipment.
Sharp edges may cause personal injury.
Dispose of the packing materials safely.
• Packing materials, such as nails and other metal or wooden parts
may cause puncture wounds or other injuries.
• Tear apart and throw away plastic packaging bags so that children
may not play with them and risk suffocation and death.
Do not install the unit in any location exposed to open
ame or extreme heat. Do not touch the unit with wet
hands.
There is risk of re, electric shock, explosion, and physical injury or
death.
Install the unit considering the potential for earthquakes.
Improper installation may cause the unit to fall, resulting in physical
injury or death.
Do not change the settings of the protection devices.
If the pressure switch, thermal switch, or other protection device is
shorted and forced to operate improperly, or parts other than those spec-
ied by LG are used, there is risk of re, electric shock, explosion, and
physical injury or death.
If the unit is installed in a small space, take measures to
prevent the refrigerant concentration from exceeding safety
limits in the event of a refrigerant leak.
Consult the latest edition of ASHRAE (American Society of Heating,
Refrigerating, and Air Conditioning Engineers) Standard 15. If the re-
frigerant leaks and safety limits are exceeded, it could result in personal
injuries or death from oxygen depletion.
INSTALLATION
DANGER
Don’t use or store ammable gas or combustibles near the unit.
There is risk of re, explosion, and physical injury or death.
TABLE OF SYMBOLS
DANGER
This symbol indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING
This symbol indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION
This symbol indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
This symbol indicates situations that may result in equipment or property damage accidents only.
This symbol indicates an action that should not be performed.
SAFETY PRECAUTIONS

5
Safety Precautions
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
CAUTION
Be very careful when transporting the product.
• Do not attempt to carry the product without assistance.
• Unit must be lifted by all lifting lugs provided at top of unit.
• Spreader bars are required to prevent damage to the cabinet, failure to do so can result in damage that is the installer’s responsibility.
• Failure to follow these directions may result in minor or moderate physical injury.
INSTALLATION – CONTINUED
Installation, startup, and service must be performed by a
qualied installer, service agency, or gas supplier.
Improper installation, adjustment, service, maintenance, or alteration can
cause property damage.
Properly insulate all cold surfaces to prevent “sweating.”
Cold surfaces such as uninsulated pipe can generate condensate that
may drip and cause a slippery oor condition and/or water damage to
walls.
Do not use the product for special purposes such as pre-
serving foods, works of art, wine coolers, or other precision
air conditioning applications.
There is risk of property damage.
Do not make refrigerant substitutions. Use R410A only.
If a different refrigerant is used, or air mixes with original refrigerant, the
unit will malfunction and become damaged.
Do not install the unit in a noise sensitive area.
Take appropriate actions at the end of HVAC equipment life
to recover, recycle, reclaim or destroy R410A refrigerant ac-
cording to applicable U.S. Environmental Protection Agency
(EPA) rules.
Install the unit in a safe location where no one can step on or
fall onto it.
There is risk of unit and property damage.
Install the drain trap to ensure adequate drainage.
There is a risk of water leakage and property damage.
Don’t store or use ammable gas / combustibles near the
unit.
There is risk of product failure.
Always check for system refrigerant leaks after the unit has
been installed or serviced.
Low refrigerant levels may cause product failure.
Ductwork and other installed airow restriction devices such
as lters shall not exceed the rated maximum static pressure
limits of the DOAS fan assembly.
Doing so may cause product malfunction.
SAFETY PRECAUTIONS

6
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
WIRING
DANGER
High voltage electricity is required to operate this system.
Adhere to the National Electrical Codes and these
instructions when wiring.
Improper connections and inadequate grounding can cause accidental
injury or death.
Always ground the unit following local, state, and National
Electrical Codes.
Turn the power o󰀨 at the nearest disconnect before servicing
the equipment.
Electric shock can cause physical injury or death.
Properly size all circuit breakers or fuses.
There is risk of re, electric shock, explosion, physical injury or death.
WARNING
The information contained in this manual is intended for use
by an experienced, trained electrician familiar with the U.S.
National Electric Code (NEC) who is equipped with the proper
tools and test instruments.
Failure to carefully read and follow all instructions in this manual can
result in injury or death.
Ensure the unit is connected to a dedicated power source
that provides adequate power.
If the power source capacity is inadequate or the electric work is not
performed properly, it may result in re, electric shock, physical injury or
death.
Refer to local, state, and federal codes, and use power wires
of su󰀩cient current capacity and rating.
Wires that are too small may generate heat and cause a re and physi-
cal injury or death.
Secure all eld wiring connections with appropriate wire
strain relief.
Improperly securing wires will create undue stress on equipment power
lugs. Inadequate connections may generate heat, cause a re and
physical injury or death.
Properly tighten all power connections.
Loose wiring may overheat at connection points, causing a re, physical
injury or death.
The information contained in this manual is intended for use by an experienced, trained electrician familiar with the U.S.
National Electric Code (NEC) who is equipped with the proper tools and test instruments.
Failure to carefully read and follow all instructions in this manual can result in equipment malfunction or property damage.
SAFETY PRECAUTIONS

7
Safety Precautions
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
OPERATION
DANGER
Do not provide power to or operate the unit if it is ooded
or submerged.
There is risk of re, electric shock, physical injury or death.
Use a dedicated power source for this product.
There is risk of re, electric shock, physical injury or death.
Do not operate the disconnect switch with wet hands.
There is risk of re, electric shock, physical injury or death.
If refrigerant gas leaks out, ventilate the area before operat-
ing the unit.
If the unit is mounted in an enclosed, low-lying, or poorly ventilated area
and the system develops a refrigerant leak, it may cause re, electric
shock, explosion, physical injury or death.
Clean up the site after installation is nished, and check
that no metal scraps, screws, or bits of wiring have been left
inside or surrounding the unit.
Do not use this equipment in mission critical or special-
purpose applications such as preserving foods, works of art,
wine coolers or refrigeration.
Provide power to the compressor crankcase heaters at least
twenty-four (24) hours before operation begins.
Starting operation with a cold compressor sump(s) may result in severe
bearing damage to the compressor(s). Keep the power switch on during
the operational season.
Do not block the inlet or outlet.
Unit may malfunction.
Securely attach the electrical cover to the indoor unit.
Non-secured covers can result in re due to dust or water in the service
panel.
Periodically verify the equipment mounting hardware has not
deteriorated.
If the base collapses, the unit could fall and cause property damage or
product failure.
Do not allow water, dirt, or animals to enter the unit.
There is risk of unit failure.
WARNING
Do not allow water, dirt, or animals to enter the unit.
There is risk of re, electric shock, physical injury or death.
Do not touch refrigerant piping during or after operation.
It can cause burns or frostbite.
Do not operate the unit with the panel(s) or protective
cover(s) removed; keep ngers and clothing away from
moving parts.
The rotating, hot, cold, and high-voltage parts of the unit can cause
physical injury or death.
Periodically check power cable and connection for damage.
Cable must be replaced by the manufacturer, its service agent, or similar
qualied persons in order to avoid physical injury and / or electric shock.
Securely attach the electrical cover to the unit.
Non-secured electrical covers can result in burns or electric shock due to
dust or water in the service panel.
Ensure no power is connected to the unit other than as
directed in this manual. Remove power from the unit before
removing or servicing the unit.
There is risk of unit failure, re, electric shock, physical injury or death.
CAUTION
To avoid physical injury, use caution when cleaning or servicing the air conditioner.
SAFETY PRECAUTIONS

8
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
UNIT NOMENCLATURE
AR D R 11 05
Cooling Capacity
Chassis Size
12 = 112
22 = 212
ERV Option
R = Base Unit
E = Energy Recovery Wheel
Type
D = Dedicated Outdoor Air System (DOAS)
Family
AR = Air-Source Packaged Rooftop Unit,
R410A Refrigerant
A
Series
A = First Series
05 = 5 Tons
07 = 7.5 Tons
10 = 10 Tons
12 = 12.5 Tons
15 = 15 Tons
17 = 17.5 Tons
20 = 20 Tons
25 = 25 Tons
30 = 30 Tons

9
Product Data
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
GENERAL DATA
Table 1: Base Rooftop DOAS.
Base Rooftop DOAS
• Capacity data above will change if entering air temperatures, leaving air temperatures (LAT), or airflow rates are varied.
• Take appropriate actions at the end of HVAC equipment life to recover, recycle, reclaim or destroy R410A refrigerant according to applicable
regulations (40 CFR Part 82, Subpart F) under section 608 of CAA.
Model No. AR-DR12-05A AR-DR12-07A AR-DR12-10A AR-DR12-12A AR-DR12-15A
Design Airflow (CFM) 980 1500 1800 2250 2900
ESP (in. wg) 22222
Entering Air Summer
DB / WB (°F) 95/75 95/75 95/75 95/75 95/75
Entering Air Winter
DB (°F) 00000
Cooling Performance
Coil LAT DB / WB (°F) 54.8/54.7 54.5/54.4 54.5/54 54.9/54.8 54.7/54.5
Unit LAT DB / WB (°F) 93.8 87.2 82.1 81.9 79.9
Total Cooling
Capacity (MBH) 68.2 105.4 128.3 155.6 202.9
Sensible Cooling
Capacity (MBH) 43.3 66.8 80.3 99.2 128.6
Hot Gas Reheat Coil
Capacity (MBH) 41.3 52.8 53.7 65.6 78.8
Evaporator Coil
Depth(Rows) 45466
No. of Compressors 11222
Compressor Type(s) Digital scroll Digital scroll Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Heating
Fuel Natural Gas Natural Gas Natural Gas Natural Gas Natural Gas
Capacity Input (MBH) 100 200 200 250 300
Capacity Output (MBH) 80 160 160 200 240
LAT (°F) 75.6 98.8 82.3 82.3 76.6
Turndown Type Modulating Modulating Modulating Modulating Modulating
Turndown Ratio 4:1 4:1 4:1 4:1 4:1
Supply Fan Data
Fan Quantity 11111
Wheel Diameter (in.) 14 14 14 14 18
Wheel Speed (RPM) 1809 1996 2133 2376 1716
Motor HP 1 1 1.5 1.5 3
Configuration
Outdoor Air Intake End End End End End
Supply Air Discharge Bottom Bottom Bottom Bottom Bottom
Weight (lbs.) 2253 2325 2384 2487 2646
Filtration
Hood None None None None None
Supply 2" MERV 8 2" MERV 8 2" MERV 8 2" MERV 8 2" MERV 8

10
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Table 2: Base Rooftop DOAS.
Model No. AR-DR22-15A AR-DR22-17A AR-DR22-20A AR-DR22-25A AR-DR22-30A
Design Airflow (CFM) 2900 3200 3700 4600 5100
ESP (in. wg) 33333
Entering Air Summer
DB / WB (°F) 95/75 95/75 95/75 95/75 95/75
Entering Air Winter
DB (°F) 00000
Cooling Performance
Coil LAT DB / WB (°F) 54.8/54.6 54.7/54.5 54.3/54.2 54.6/54.4 54.6/54.3
Unit LAT DB / WB (°F) 84.7 83.4 82.3 82.3 81.9
Total Cooling
Capacity (MBH) 202.2 223.8 262.2 323.1 359.6
Sensible Cooling
Capacity (MBH) 128.4 141.8 165.7 204.5 227
Hot Gas Reheat Coil
Capacity (MBH) 93.6 99.1 111.9 137.6 150.8
Evaporator Coil
Depth(Rows) 55666
No. of Compressors 22222
Compressor Type(s) Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Digital scroll /
Standard scroll
Heating
Fuel Natural Gas Natural Gas Natural Gas Natural Gas Natural Gas
Capacity Input (MBH) 300 400 400 500 500
Capacity Output (MBH) 240 320 320 400 400
LAT (°F) 76.6 92.6 80.1 80.5 72.6
Turndown Type Modulating Modulating Modulating Modulating Modulating
Turndown Ratio 4:1 4:1 4:1 4:1 4:1
Supply Fan Data
Fan Quantity 11111
Wheel Diameter (in.) 20 20 20 20 22
Wheel Speed (RPM) 1591 1622 1702 1671 1777
Motor HP 33355
Configuration
Outdoor Air Intake End End End End End
Supply Air Discharge Bottom Bottom Bottom Bottom Bottom
Weight (lbs.) 3412 3487 3633 3697 3796
Filtration
Hood None None None None None
Supply 2" MERV 8 2" MERV 8 2" MERV 8 2" MERV 8 2" MERV 8
• Capacity data above will change if entering air temperatures, leaving air temperatures (LAT), or airflow rates are varied.
• Take appropriate actions at the end of HVAC equipment life to recover, recycle, reclaim or destroy R410A refrigerant according to applicable
regulations (40 CFR Part 82, Subpart F) under section 608 of CAA.
GENERAL DATA
Base Rooftop DOAS

11
Product Data
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Table 3: Energy Recovery Wheel Rooftop DOAS.
• Capacity data above will change if entering air temperatures, leaving air temperatures (LAT), or airflow rates are varied.
• Take appropriate actions at the end of HVAC equipment life to recover, recycle, reclaim or destroy R410A refrigerant according to applicable
regulations (40 CFR Part 82, Subpart F) under section 608 of CAA.
GENERAL DATA
Energy Recovery Wheel Rooftop DOAS
Model No. AR-DE12-05A AR-DE12-07A AR-DE12-10A AR-DE12-12A AR-DE12-15A
Design Airflow (CFM) 1700 2600 2950 3700 4150
ESP (in. wg) 22222
Entering Air Summer DB / WB
(°F) 95/75 95/75 95/75 95/75 95/75
Entering Air Winter DB (°F) 00000
Cooling Performance
Coil EAT DB / WB (°F) 81.4/67.1 81.6/67.3 82.2/67.6 82.3/67.7 83/68.1
Coil LAT DB / WB (°F) 54.8/54.4 54.7/54.3 54.6/53.8 54.7/54.4 53.1/52.7
Unit LAT DB / WB (°F) 79.9 78.3 74.7 74.5 73.3
Total Cooling Capacity (MBH) 67 104 126.6 153.1 196.5
Sensible Cooling Capacity
(MBH) 49.6 76.7 89.6 112.1 136.3
Hot Gas Reheat Coil Capacity
(MBH) 46.1 66.1 64.1 79.2 90.7
Evaporator Coil Depth (Rows) 45466
Number of Compressors 11222
Compressor Type(s) Digital scroll Digital scroll Digital scroll /
standard scroll
Digital scroll /
standard scroll
Digital scroll /
standard scroll
Heating
Fuel Natural Gas Natural Gas Natural Gas Natural Gas Natural Gas
Capacity Input (MBH) 100 100 150 200 200
Capacity Output (MBH) 80 80 120 160 160
LAT (°F) 92.9 76.9 83.7 85.7 78.9
Turndown Type Modulating Modulating Modulating Modulating Modulating
Turndown Ratio 4:1 4:1 4:1 4:1 4:1
Fan Data
Supply Fan Quantity 11111
Supply Fan Wheel Diameter (in.) 14 18 14 18 18
Supply Fan Wheel Speed (RPM) 2316 1951 3089 2299 2462
Supply Fan Motor HP 1 3 5 5 7.5
Exhaust Fan Quantity 11111
Exhaust Fan Wheel Diameter
(in.) 14 18 18 18 18
Exhaust Fan Wheel Speed
(RPM) 2302 1725 1725 1750 1750
Exhaust Fan Motor HP 1 3 3 5 7.5
Configuration
Outdoor Air Intake End End End End End
Supply Air Discharge Bottom Bottom Bottom Bottom Bottom
Return Air Opening Bottom Bottom Bottom Bottom Bottom
Weight (lbs.) 2997 3213 3239 3414 3557
Filtration
Hood none none none none none
Supply 2" MERV8 2" MERV8 2" MERV8 2" MERV8 2" MERV8

12
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Table 4: Energy Recovery Wheel Rooftop DOAS.
• Capacity data above will change if entering air temperatures, leaving air temperatures (LAT), or airflow rates are varied.
• Take appropriate actions at the end of HVAC equipment life to recover, recycle, reclaim or destroy R410A refrigerant according to applicable
regulations (40 CFR Part 82, Subpart F) under section 608 of CAA.
GENERAL DATA
Energy Recovery Wheel Rooftop DOAS
Model No. AR-DE22-15A AR-DE22-17A AR-DE22-20A AR-DE22-25A AR-DE22-30A
Design Airflow (CFM) 5000 5510 6300 6750 7450
ESP (in. wg) 22222
Entering Air Summer DB / WB
(°F) 95/75 95/75 95/75 95/75 95/75
Entering Air Winter DB (°F) 00000
Cooling Performance
Coil EAT DB / WB (°F) 81.1/67 81.5/67.2 82.8/67.6 81.6/67.3 82.2/67.6
Coil LAT DB / WB (°F) 54.5/54.1 54.8/54.3 54.7/54.4 52.5/52.2 52.8/52.4
Unit LAT DB / WB (°F) 77.4 75.5 74.9 74.8 74.9
Total Cooling Capacity (MBH) 198.6 220.4 259.7 310.2 346.4
Sensible Cooling Capacity
(MBH) 146.1 161.8 190.2 216 240.4
Hot Gas Reheat Coil Capacity
(MBH) 123.8 123 137.5 162.8 178.3
Evaporator Coil Depth (Rows) 55666
Number of Compressors 22222
Compressor Type(s) Digital scroll /
standard scroll
Digital scroll /
standard scroll
Digital scroll /
standard scroll
Digital scroll /
standard scroll
Digital scroll /
standard scroll
Heating
Fuel Natural Gas Natural Gas Natural Gas Natural Gas Natural Gas
Capacity Input (MBH) 300 300 300 300 300
Capacity Output (MBH) 240 240 240 240 240
LAT (°F) 94.6 88.9 81.3 81.1 76.1
Turndown Type Modulating Modulating Modulating Modulating Modulating
Turndown Ratio 4:1 4:1 4:1 4:1 4:1
Fan Data
Supply Fan Quantity 11111
Supply Fan Wheel Diameter (in.) 20 20 20 20 22
Supply Fan Wheel Speed (RPM) 1986 2106 2305 2364 2049
Supply Fan Motor HP 7.5 7.5 10 10 10
Exhaust Fan Quantity 11111
Exhaust Fan Wheel Diameter
(in.) 20 20 20 20 22
Exhaust Fan Wheel Speed
(RPM) 1750 1750 1750 1765 1765
Exhaust Fan Motor HP 5 7.5 7.5 10 10
Configuration
Outdoor Air Intake End End End End End
Supply Air Discharge Bottom Bottom Bottom Bottom Bottom
Return Air Opening Bottom Bottom Bottom Bottom Bottom
Weight (lbs.) 4624 4731 4901 5028 5084
Filtration
Hood none none none none none
Supply 2" MERV8 2" MERV8 2" MERV8 2" MERV8 2" MERV8

13
Product Data
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
REFRIGERANT SAFETY
WARNING
Installation, startup, and service must be performed by a qualied installer, service agency, or gas supplier.
Improper installation, adjustment, service, maintenance, or alteration can cause personal injury or loss of life.
The customer must provide proper equipment and fully trained installers to follow local safety requirements when receiving, installing, or
servicing equipment. Consult all local building, electrical, occupational safety, and gas codes.
Lock out all power supplies before servicing the unit to prevent accidental startup. All fan blades should be secured to prevent wind rotation.
Remove any restrictive device before restoring power.
The Clean Air Act of 1990 bans the intentional venting of refrigerant (CFC and HCFC) as of July 1, 1992. Approved methods of recovery,
recycling, or reclaiming refrigerant must be followed. Fines and / or incarceration may be levied for non-compliance.
ASHRAE Standards 15-2101 and 34-2010 offer guidelines that address refrigerant safety and the maximum allowable concentration of
refrigerant in an occupied space. Refrigerant will dissipate into the atmosphere, but a certain volume of air is required for this to occur safely.
For R410A refrigerant, the maximum allowable concentration of refrigerant is twenty-six (26) lbs. per 1,000 cubic feet of an occupied space.
Institutional buildings allow half of that concentration.
ASHRAE Standards 15 and 34 assume that if a system develops a leak, its entire refrigerant charge will dump into the area where the leak
occurs. To meet ASHRAE Standards 15 and 34, calculate the refrigerant concentration that may occur in the smallest room volume on the
system, and compare the results to the maximum allowable concentration number. Also, consult state and local codes in regards to refriger-
ant safety.
Installation, startup, and service must be performed by a qualied installer, service agency, or gas supplier.
Improper installation, adjustment, service, maintenance, or alteration can cause property damage.
WARNING
Verify the maximum refrigerant concentration level for spaces served by DOAS meets the concentration limit for the application.

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Rooftop Dedicated Outdoor Air System Installation Manual
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RECEIVING GUIDELINES
Receiving Guidelines
This product may have been subject to road salt during transit. If so, immediately wash off all visible white residue from all exterior surfaces.
Upon receiving the product, check to ensure all line items are accounted for by referencing the delivery receipt or packing list.
Inspect each crate or carton for shipping damage before accepting delivery.
Alert the carrier if any damage is detected, do not refuse shipment.
The customer shall make notation of damage (or shortage of items) on the delivery receipt and all copies of the bill of lading which should be
countersigned by the delivering carrier. If damaged, immediately contact your manufacturer’s representative. Any physical damage to the unit
after acceptance is not the responsibility of the manufacturer.
Handling Guidelines
Units are to be rigged and moved by the lifting brackets provided or by the skid when a forklift is used. Location of brackets varies by model
and size.
Handle in such a manner as to keep from scratching or chipping the coating. Damaged finish may reduce ability of unit to resist corrosion.
Unpacking Guidelines
Verify that all required parts and the correct quantity of each item have been received. If any items are missing, report shortages to your
local representative to arrange for obtaining missing parts. Sometimes it is not possible that all items for the unit be shipped together due to
availability of transportation and truck space.
Confirmation of shipment(s) must be limited to only items on the bill of lading.
Check control cabinet for eld mounted sensors shipped loose.
Storage Guidelines
Units are protected against damage during shipment. If the unit cannot be installed and operated immediately, precautions need to be taken
to prevent deterioration of the unit during storage. The user assumes responsibility of the unit and accessories while in storage. The manu-
facturer will not be responsible for damage during storage. These suggestions are provided solely as a convenience to the user.
The ideal environment for the storage of units and accessories is indoors, above grade, in a low humidity atmosphere which is sealed to pre-
vent the entry of blowing dust, rain, or snow. Units designed for outdoor applications may be stored outdoors. All accessories must be stored
indoors in a clean, dry atmosphere.
Indoor Maintenance Guidelines
Maintain temperatures evenly to prevent condensation. Remove any accumulations of dirt, water, ice, or snow and wipe dry before moving
to indoor storage. To avoid condensation, allow cold parts to reach room temperature. Leave coverings loose to permit air circulation and to
allow for periodic inspection.
The unit should be stored at least 3½ in. (89 mm) off the floor. Clearance should be provided to permit air circulation and space for inspec-
tion.
Outdoor Placement Guidelines
The unit should be placed on a level surface to prevent water from leaking into the unit. The unit should be elevated so that it is above water
and snow levels.
Ensure sufficient support to prevent unit from settling into soft ground. Locate parts far enough apart to permit air circulation, sunlight, and
space for periodic inspection. To minimize water accumulation, place all unit parts on blocking supports so that rain water will run off.
Do not cover parts with plastic film or tarps as these cause condensation of moisture from the air passing through heating and cooling
cycles.

15
Installation
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Inspection and Maintenance
While in storage, inspect units once per month. Keep a record of inspection and maintenance performed.
If moisture or dirt accumulations are found on parts, the source should be located and eliminated. At each inspection, rotate the fan wheel
by hand ten to fifteen revolutions to distribute lubricant on motor. If paint deterioration begins, consideration should be given to touch-up or
repainting. Units with special coatings may require special techniques for touch-up or repair.
Machined parts coated with rust preventive should be restored to good condition promptly if signs of rust occur. Immediately remove the
original rust preventive coating with petroleum solvent and clean with lint-free cloths. Polish any remaining rust from surface with crocus cloth
or fine emery paper and oil.
Do not destroy the continuity of the surfaces. Wipe thoroughly clean with Tectyl® 506 (Ashland Inc.) or the equivalent. For hard to reach
internal surfaces or for occasional use, consider using Tectyl® 511M Rust Preventive, WD-40® or the equivalent.
Removing from Storage
As units are removed from storage to be installed in their final location, they should be protected and maintained in a similar fashion until the
equipment goes into operation.
Prior to installing the unit and system components, inspect the unit assembly to make sure it is in working order.
1. Check all fasteners, set screws on the fan, wheel, bearings, drive, motor base, and accessories for tightness.
2. Rotate the fan wheel(s) by hand and assure no parts are rubbing.
• Failure to follow proper instructions could result in serious injury or death.
• Use the appropriate crane equipment to transport each unit; ensure the crane is capable of supporting the weights listed in the specification
tables. If the crane is not properly secured, it may result in an accident that causes physical injury or death.
• Never lift the units in windy conditions.
• Wear protective gloves when handling equipment. Sharp edges may cause personal injury.
• Tear apart and throw away plastic packaging so that children may not play with them and risk suffocation and death.
WARNING
Failure to follow proper instructions could result in property damage.
INSPECTION AND MAINTENANCE

16
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
This is a horizontally configured High Percentage Outdoor Air unit designed for installation either indoors or outdoors. Each unit has multiple
options for cooling and/or heating. The unit is designed to replace air that is exhausted from the building and also heat and cool, as needed.
The air volume produced by the unit is constant, but can be optionally modulated to provide a variable air volume (VAV) and recirculation is
also offered as an option.
Cooling Options
Units have the following cooling options available:
• Packaged DX
• Split DX (thermal expansion valve is field-provided)
• Chilled water coil
Units with packaged DX are shipped fully charged with refrigerant and are ready for operation upon arrival.
Heating Options
There are three different optional heat sources that can be ordered for this unit:
• Indirect gas-fired furnace with one or two sets of heat exchangers
• Electric heat with infinitely variable SCR control
• Hot water coil
Airow Arrangement
The unit is capable of Constant Air Volume (CAV), Variable Air Volume (VAV), 100% Outdoor Air and have recirculating air options.
Safety Listing
Models are listed per ANSI/UL 1995, Heating and Cooling Equipment and are ETL Certified.
Models and Capacities
Model Cooling Capacity
AR-DR12-XX 5 to 15 tons
AR-DR22-XX 15 to 30 tons
AR-DE12-XX 5 to 15 tons
AR-DE22-XX 15 to 30 tons
Table 5: Energy Recovery Wheel Rooftop DOAS.
INSPECTION AND MAINTENANCE

17
Installation
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
SUBASSEMBLIES
Blower
Either one or two plenum-type fans. All units are equipped with a plenum fan for Supply Air and a second may be selected for Exhaust (Re-
lief) Air.
Coils
• Evaporator coil (optional)
• Condenser coil (optional, packaged DX only)
• Water coil (optional)
• Reheat coil (optional)
Compressors
Each unit having packaged DX will have one or two refrigerant compressors. One of the compressors will be a digital scroll type compressor.
Dampers
Motorized intake air damper, motorized recirculating damper. Optional return air damper. Optional gravity-type exhaust damper.
Optional Barometric Relief Damper
Used during economizer mode of the unit when building pressure increases, relief damper will open due to over pressurization.
Electric Heater
An SCR controlled electric heater is available on the units. It requires a separate power supply and has its own control panel. See unit-
specific wiring diagram.
Filters
2-inch thick metal mesh filters in the outdoor weatherhood intake, 2-inch thick pleated paper MERV 8 (standard) or MERV 13 filters in the
air stream. Optional 4-inch thick filter bank with a 2-inch thick MERV 8 and 2-inch thick MERV 13 or a 4-inch thick MERV 14 pleated paper
supply filters.
Indirect Gas-Fired Furnace
Furnace model PVG is available on AR-DR12, AR-DE12, AR-DR22, and AR-DE22.
Packaged DX System
Any unit may be ordered with a packaged DX system. Housing size 112 will include either one or two compressors; housing size
212 will include two compressors; a condenser coil(s) and evaporator coil(s) and all required components. Units that have packaged DX are
charged with R410A refrigerant. Do not use tools or parts designed for other refrigerants on these units.
Vestibule
Some units may be ordered with a factory- assembled vestibule that is to be field-attached to the side of the unit. See lifting instructions.

18
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
Open view of Model AR-DE showing optional condenser coil, fans and
energy recovery wheel.
SUBASSEMBLIES
Figure 1: DOAS AR-DE Model Open View

19
Installation
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
INSTALLATION
Typical Unit Weights and Dimensions
Figure 2: DOAS AR-DE Model
All dimensions are shown in inches. Weight is shown in pounds and includes largest supply and exhaust fans, PDX with reheat, largest indi-
rect-gas fired furnace, and all dampers. Actual weights will vary based on the unit configuration.
* Only available with powered exhaust. **Only available without barometric relief.
+Only available with barometric relief. ‡ Length with side return.

20
Rooftop Dedicated Outdoor Air System Installation Manual
Due to our policy of continuous product innovation, some specifications may change without notification.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
INSTALLATION
Service Clearnces
Figure 3: DOAS AR-DE Model
All dimensions are shown in inches. *No condensing section or piping vestibule, or unit has top condensing section.