Engineering Manual
Table Of Contents
- Convergence of Technology, Innovation, Flexibility, & Style
- Unit Nomenclature
- Outdoor Unit Overview
- Indoor Unit Overview
- Controls and Options Overview
- Art Cool Mirror Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Art Cool Gallery Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Standard Wall-Mounted Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Duct (Low Static) Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure
- Acoustic Data
- Refrigerant Flow Diagrams
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Duct (High Static) Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure / Acoustic Data
- Refrigerant Flow Diagrams
- Wiring Diagrams
- Factory Supplied Parts and Materials / Installation
- Installation and Best Layout Practices
- Four-Way Ceiling Cassette Indoor Units
- General Data / Specifications
- Dimensions
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- Acoustic Data
- Air Velocity and Temperature Distribution
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Vertical-Horizontal Indoor Units
- General Data / Specifications
- Dimensions
- Cooling Capacity Table
- Heating Capacity Table
- External Static Pressure
- Acoustic Data
- Refrigerant Flow Diagram
- Wiring Diagram
- Factory Supplied Parts and Materials
- Installation and Best Layout Practices
- Equipment Selection Procedure
- Building Ventilation Design Guide
- Placement Considerations
- Refrigerant Piping Design
- Design Guideline Summary
- Creating a Balanced System / Manual Layout Procedure
- LG Engineered Multi F MAX Y-Branch Kit
- Refrigerant Charge
- Installation & Layout Best Practices
- Refrigerant Piping System Layout
- Piping Insulation
- Condensate Drain Piping
- Y-Branch Kit
- Wiring Connections
- Power Wiring (208-230V) and Communications Cable Details
- Indoor Unit Group Control
- Acronyms
EQUIPMENT SELECTION PROCEDURE
Indoor units Outdoor units
Model Type
Indoor Unit Nominal
Capacity (Btu/h)
LMU18CHV LMU24CHV LMU36CHV LMU540HV
Maximum No. of Connectable Indoor Units
2 3 4 8
ART COOL Mirror
9,000 O O O O
12,000 O O O O
18,000 - O O O
ART COOL Gallery
9,000 O O O O
12,000 O O O O
Wall Mounted
7,000 O O O O
9,000 O O O O
12,000 O O O O
15,000 O O O O
18,000 - O O O
24,000 - O O O
Ceiling Concealed Duct-Low Static
9,000 O O O O
12,000 O O O O
18,000 - O O O
Ceiling Concealed Duct-High Static
24,000 - - O O
36,000 - - - O
Four-Way Ceiling Cassette
7,000 O O O O
9,000 O O O O
12,000 O O O O
18,000 - O O O
Vertical-Horizontal Air Handler
24,000 - - O O
36,000 - - - O
Table 97: Allowable Indoor Unit to Outdoor Unit Connections.
Choosing the Appropriate Outdoor Unit
After all indoor units are properly sized to offset the applicable loads in each zone, select the outdoor unit by choosing a size that meets
both the load-cooling requirement, and offsets the sum of the heating load. Then, the system’s combination ratio should be evaluated and
confirmed it is within the allowable range (the combination ratio compares the nominal capacity of all connected indoor units to the nominal
capacity of the outdoor unit serving them). The total nominal capacity of all indoor units should be smaller than the total nominal capacity of
the outdoor unit. If the combination ratio is more than 100%, the designer is undersizing the outdoor unit relative to the combined nominal ca-
pacity of the connected indoor units. In some designs, oversized indoor units may be unavoidable in the case where the smallest size indoor
unit available from LG is larger than what is necessary to satisfy the zone load. This scenario may also occur when an indoor unit selection
one size down from the selected unit is slightly short of fulfilling the design load requirements, and the designer must choose the next larg-
est size unit. Sometimes it is recommended to choose a larger capacity outdoor unit if the installation space is big enough. Also, it may be
prudent to oversize the outdoor unit to address those times when the weather conditions may exceed the design conditions, to minimize the
possibility of ventilation systems that causes the space temperature to drift outside design parameters, or when the indoor unit’s entering air
temperature falls outside the approved design temperature range.
Branch Distribution Unit (PMBD3620)
+
24 x 1.2 24 x 1.2 + Total Capacity Index = = 57.6 < 73
Branch Distribution Unit (PMBD3641)
First Indoor Unit:
LMCN125HV
+ + Outdoor Unit: LMU540HV
12 9 36 x 1.3 + + Total Capacity Index = = 67.8 < 73
Acceptable
Combination
Second Indoor Unit:
LSN090HSV4
Third Indoor Unit:
LMVN360HV
Outdoor Unit: LMU540HV
First Indoor Unit:
LMVN240HV
Second Indoor Unit:
LMVN240HV
Acceptable
Combination
Example 1
Example 2
Multiplier Examples
Due to our policy of continuous product innovation, some specications may change without notication.
©LG Electronics U.S.A., Inc., Englewood Cliffs, NJ. All rights reserved. “LG” is a registered trademark of LG Corp.
APPLICATION GUIDELINES | 175
Application Guidelines
MULTI
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MAX
MULTI
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