Engineering Manual
Table 111: Multi F/ Multi F Max Rated Outdoor Unit Capacity.
Outdoor Units
LMU18CHV LMU24CHV LMU30CHV LMU36CHV LMU480HV LMU540HV LMU600HV
Rated Capacity
(Btu/h)*
Cooling 17,000 20,000 30,000 32,000 48,000 52,500 60,000
Heating 22,000 24,000 32,000 36,000 54,000 58,000 64,000
Connectable
Indoor
Units
Minimum No. of Connectable IDUs 2 2 2 2 2 2 2
Maximum No. of Connectable IDUs 2 3 4 4 8 8 8
Maximum Capacity Index 24,000 33,000 40,000 48,000 65,000 73,000 81,000
EQUIPMENT SELECTION PROCEDURE
Table 112: Allowable Indoor Unit to Multi F/ Multi F MAX with LGRED 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.
Indoor units Outdoor units
Model Type
Indoor Unit Nominal
Capacity (Btu/h)
LMU180HHV LMU240HHV LMU300HHV LMU360HHV LMU420HHV
Maximum No. of Connectable Indoor Units
2 3 4 5 6
ART COOL Mirror
9,000 O O O O O
12,000 O O O O O
18,000 - O O O O
ART COOL Gallery
9,000 O O O O O
12,000 O O O O O
Standard Wall Mounted
7,000 O O O O O
9,000 O O O O O
12,000 O O O O O
15,000 O O O O O
18,000 - O O O O
24,000 - O O O O
Ceiling Concealed Duct-
Low Static
9,000 O O O O O
12,000 O O O O O
18,000 - O O O O
Ceiling Concealed Duct-
High Static
24,000 - - O O O
36,000 - - - - O
Four-Way Ceiling Cassette
7,000 O O O O O
9,000 O O O O O
12,000 O O O O O
18,000 - O O O O
Vertical-Horizontal Air Handler
18,000 - O O O O
24,000 - - O O O
36,000 - - - - O
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.
186 | APPLICATION GUIDELINES
Multi F and Multi F MAX Indoor Unit Engineering Manual
MULTI
F
MAX
MULTI
F