Multi F Outdoor Unit Engineering Manual

EQUIPMENT SELECTION PROCEDURE
Indoor units Outdoor units
Model Type
Indoor Unit Nominal
Capacity* (Btu/h)
LMU187HV LMU247HV LMU369HV LMU540HV
Maximum No. of Connectable Indoor Units
Btu/h 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
9,000 O O O O
12,000 O O O O
18,000 - 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
12,000 O O O O
18,000 - O O O
Vertical-Horizontal Air Handler
24,000 - - O O
36,000 - - - O
Table 156: 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.
Outdoor Units
LMU187HV LMU247HV LMU369HV LMU540HV
Nominal Capacity (Btu/h)
Cooling 15,600 19,200 34,000 52,500
Heating 17,000 26,400 41,000 58,000
Connectable Indoor
Units
Minimum No. of Connectable Indoor Units 2 2 2 2
Maximum No. of Connectable Indoor Units 2 3 4 8
Maximum Capacity Index 24,000 33,000 48,000 73,000
Table 157: Nominal Outdoor Unit Capacity.
Due to our policy of continuous product innovation, some specications may change without notication.
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