LG MULTI F MAX Installation and operation manual

MULTI FMAX
MULTI F
HEAT PUMP SYSTEM
ENGINEERING MANUAL
Multi-Zone Heat Pump Systems
1.5 to 5 Tons
Dual and Tri-Zone
Multi F
Quad-Zone
Multi F
Eight-Zone
Multi F MAX

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. This document
is for design purposes only.
To access additional technical documentation such as submittals, indoor
unit engineering manuals, installation, service, product data performance,
general best practice, and building ventilation manuals, as well as white
papers, catalogs, LATS software programs, and more, log in to
www.lghvac.com.
For continual product development, LG Electronics U.S.A., Inc. reserves the right to change specifications without notice.
© LG Electronics U.S.A., Inc.
A summary list of safety precautions is on page 3.
PROPRIETARY DATA NOTICE

INTRODUCTION | 3
TABLE OF CONTENTS
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.
Note:
This symbol indicates situations that may result in equipment or property damage accidents only.
This symbol indicates an action that should not be performed.
Unit Nomenclature.......................................................................................................................................................................................................... 4
LG Air Conditioner Technical Solution (LATS) ......................................................................................................................................................... 5-6
Manual Equipment Selection Procedure................................................................................................................................................................ 7-12
Multi F Outdoor Unit Product Data ....................................................................................................................................................................... 13-33
0HFKDQLFDO6SHFL¿FDWLRQV .......................................................................................................................................................................................... 14
General Data ......................................................................................................................................................................................................... 15-18
Electrical Data ............................................................................................................................................................................................................ 19
Dimensions............................................................................................................................................................................................................ 20-22
Center of Gravity / Corner Weights............................................................................................................................................................................. 23
Wiring Diagram...................................................................................................................................................................................................... 24-27
Refrigerant Flow Diagrams.................................................................................................................................................................................... 28-30
Acoustic Data ........................................................................................................................................................................................................ 31-32
Operation Ranges ...................................................................................................................................................................................................... 33
Multi F MAX Outdoor Unit Product Data ............................................................................................................................................................... 34-43
0HFKDQLFDO6SHFL¿FDWLRQV .......................................................................................................................................................................................... 35
General Data ......................................................................................................................................................................................................... 36-37
Electrical Data ............................................................................................................................................................................................................ 37
Dimensions................................................................................................................................................................................................................. 38
Wiring Diagrams .................................................................................................................................................................................................... 39-40
Refrigerant Flow Diagrams......................................................................................................................................................................................... 41
Acoustic Data ............................................................................................................................................................................................................. 42
Operation Ranges ...................................................................................................................................................................................................... 43
Multi F MAX BD Unit................................................................................................................................................................................................ 44-51
0HFKDQLFDO6SHFL¿FDWLRQV .......................................................................................................................................................................................... 45
General Data .............................................................................................................................................................................................................. 46
Dimensions................................................................................................................................................................................................................. 47
Wiring Diagram........................................................................................................................................................................................................... 48
Refrigerant Flow Diagram........................................................................................................................................................................................... 49
Y-Branch Accessory.................................................................................................................................................................................................... 50
Branch Distribution Unit Orientation ........................................................................................................................................................................... 51
Electrical Connections............................................................................................................................................................................................ 52-62
General Information............................................................................................................................................................................................... 53-55
Systems for Multi F................................................................................................................................................................................................ 56-58
Systems for Multi F MAX....................................................................................................................................................................................... 59-60
Indoor Units / Controllers....................................................................................................................................................................................... 61-62
Piping Limitations and Placement Considerations.............................................................................................................................................. 63-75
Piping Limitations .................................................................................................................................................................................................. 64-65
Selecting the Best Location for the Outdoor Unit .................................................................................................................................................. 66-67
Outdoor Unit Clearance Requirements ................................................................................................................................................................. 68-70
Installing Outdoor Units Indoors ............................................................................................................................................................................ 71-73
Selecting the Best Location for the Indoor Units ........................................................................................................................................................ 74
Selecting the Best Location for Branch Distribution Units ..................................................................................................................................... 74-75

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4|INTRODUCTION
Multi F and Multi F MAX Heat Pump System Engineering Manual
MULTI FMAX
MULTI F
UNIT NOMENCLATURE
Multi-Zone Systems —Indoor Units and Outdoor Units
MDN 12 7HV
Generation
Features:
H = Heat Pump
V = Inverter
T = High Wall-Mounted Indoor Unit
P = Art Cool Gallery Indoor Unit
Nominal Capacity
(Nominal cooling capacity in Btu/h):
Component:
AN: Art Cool™ Wall-Mounted Indoor Unit
N: Standard Wall-Mounted Indoor Unit
CN: Four-Way Ceiling-Cassette Indoor Unit
DN: Ceiling-Concealed Duct (Low Static) Indoor Unit
HN: Ceiling-Concealed Duct (High Static) Indoor Unit
QN: Low-Wall Console Indoor Unit
VN: Vertical-Horizontal Air Handling Indoor Unit
U: Outdoor Unit
L = LG
07 = 7,000
09 = 9,000
12 = 12,000
15 = 15,000
18 = 18,000
24 = 24,000
30 = 30,000
36 = 36,000
42 = 42,000
48 = 48,000
54 = 54,000
60 = 60,000
L
Type: M = Multi-Zone
• Voltage for all equipment is 208-230V, 60 Hz, 1-phase.
• All indoor units are compatible with wired controllers.
• All outdoor units are LGAP control network compatible with PI-485 V-net Control Integration Board (PMNFP14A1, sold separately).
• Compatible single zone IDU nomenclature is listed in the Single Zone Engineering Manuals.
Branch Distribution Units
MBD 36
BD: Branch Distribution Unit
P = Part (Accessory)
P
Type: M = Multi-Zone
Family
Number of Port Connections
(Maximum Number of Connectable Indoor Units): 2, 3, 4
Generation: 0, 1
02

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Introduction
MULTI FMAX
MULTI F
LG Air Conditioner Technical Solution (LATS) Software
A properly designed and installed refrigerant piping system is critical to the optimal performance of LG air-conditioning systems. To assist
engineers, LG offers, free of charge, LG Air Conditioner Technical Solution (LATS) software—a total design solution for LG air conditioning
systems.
To reduce the risk of designing an improper applied system or one that will not operate correctly, LG prefers that LATS software be used all projects.
Formats
LATS is available to LG customers in three user interfaces: LATS HVAC, LATS CAD2, and LATS Revit. All three LATS formats are available
through www.myLGHVAC.com, or contact an LG Sales Representative.
LATS HVAC is a Windows®-based application that aids engineers in designing LG Variable Refrigerant Flow (VRF), Multi F / Multi F MAX,
Multi F / Multi F MAX with LGRED, Single-Zone, and Energy Recovery Ventilator (ERV) systems.
*Windows®is a registered mark of Microsoft®Corporation.
LATS CAD2 combines the LG LATS program with AutoCAD® soft-
ware**. It permits engineers to layout and validate LG Multi V Vari-
able Refrigerant Flow (VRF), Multi F / Multi F MAX, Multi F / Multi
F MAX with LGRED, Single-Zone, and Energy Recovery Ventilator
(ERV) systems directly into CAD drawings.
LATS Revit integrates the LG LATS program with Revit®software**.
It permits engineers to layout and validate Multi V VRF systems
directly into Revit drawings.
**AutoCAD®and Revit®are both registered marks of Autodesk, Inc.
Features
All LG product design criteria have been loaded into the program,
making LATS simple to use: double click or drag and drop the
component choices. Build systems in Tree Mode where the refriger-
ant system can be viewed. Switch to a Schematic diagram to see the
electrical and communications wiring.
LATS software permits the user to input region data, indoor and outdoor design temperatures, modify humidity default values, zoning, specify
type and size of outdoor units and indoor units, and input air flow and external static pressure (ESP) for ducted indoor units.
The program can also:
LG AIR CONDITIONER
TECHNICAL SOLUTION (LATS)
• Import building loads from a separate Excel file.
• Present options for outdoor unit auto selection.
• Automatically calculate component capacity based on design
conditions for the chosen region.
• Verify if the height differences between the various system
components are within system limits.
• Provide the correct size of each refrigerant piping segment and LG
Y-Branches and Headers.
• Adjust overall piping system length when elbows are added.
• Check for component piping limitations and flag if any parameters
are broken.
• Factor operation and capacity for defrost operation.
• Calculate refrigerant charge, noting any additional trim charge.
• Suggest accessories for indoor units and outdoor units.
• Run system simulation.
Features depend on which LATS program is being used, and the type of system being designed.
Figure 1: Example of LATS CAD2.

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6|INTRODUCTION
Multi F and Multi F MAX Heat Pump System Engineering Manual
MULTI FMAX
MULTI F
LATS Generates a Complete Project Report
LATS software also generates a report containing project design parameters, cooling and heating design data, system component perfor-
mance, and capacity data. The report includes system combination ratio and refrigerant charge calculations; and provides detailed bill of
material, including outdoor units, indoor units, control devices, accessories, refrigerant pipe sizes segregated by building, by system, by pipe
size, and by pipe segments. LATS can generate an Excel GERP report that can imported into the LG SOPS pricing and ordering system.
Proper Design to Install Procedure
LG encourages a two report design-to-install-proce-
dure. After the design engineer determines building /
zone loads and other details, the engineer opens the
LATS program and inputs the project’s information.
When the design is complete, the “Auto Piping” and
“System Check” functions must be used to verify
piping sizes, limitations, and if any design errors are
present. If errors are found, engineers must adjust
the design, and run Auto Piping and System Check
again. When the design passes the checks, then
the engineer prints out a project “Shop Drawing”
(LATS Tree Diagram) and provides it to the install-
ing contractor. The contractor must follow the LATS
Tree Diagram when building the piping system, but
oftentimes the design changes on the building site:
• Architect has changed location and/or purpose of room(s).
• Outdoor unit cannot be placed where originally intended.
• Structural elements prevent routing the piping as planned.
• Air conditioning system conflicts with other building systems (plumbing, gas lines, etc.).
The contractor must mark any deviation from the design on the Shop Drawing, including as-built straight lines and elbows. This “Mark Up”
drawing must be returned to the design engineer or Rep, who must input contractor changes into the LATS file. (Copy the original LATS soft-
ware file, save and rename as a separate file, and modify all piping lengths by double-clicking on each length and editing information.) Like
the shop drawing, the Auto Piping and System Check must also be run on this new “As Built” drawing. The design engineer or Rep must then
provide the final As Built file to the contractor. The Mark Up version must be compared to the As Built version for:
• Differences in pipe diameter(s). If incorrect diameters have been installed, the piping must be changed out. If pipe diameters have changed,
check to see if Y-Branches will also need to be changed.
• Changes to outdoor unit and indoor unit capacities. Capacities changes may impact line length changes.
• Additional refrigerant charge quantity (“Trim Charge”). Trim charge will change if piping lengths and diameters change. The As Built version
must reflect installed piping lengths to ensure correct trim charge.
All documents submitted by the contractor, as well as the Shop Drawing and the As Built Drawing files must be provided for commissioning
purposes. Model and serial numbers for all system components must also be submitted. If the steps previously detailed are not followed, and
all documents are not provided to the commissioning agent, the project runs the risk of not being commissioned and voiding any limited war-
ranty LG offers on the equipment.
LG AIR CONDITIONER
TECHNICAL SOLUTION (LATS)
Contact your LG representative for the best software program for your application.
Figure 2: Example of a LATS Tree Diagram.

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Introduction
MULTI FMAX
MULTI F
To use the manual equipment selection procedure in choosing the multi-zone system that is the most appropriate for the space, as with
traditional air-conditioning systems, follow similar protocols outlined in Manual J from the Air Conditioning Contractors of America (ACCA; see
www.acca.org).
1. Obtain the design conditions, and calculate the maximum cool and heat loads for the structure.
2. Select the equipment (choosing the appropriate indoor units and outdoor unit):
• Determine number of zones.
• Determine total number of indoor units (refer to zone load calculations when choosing indoor units).
• Determine number of indoor units allocated to each outdoor unit, considering allowable indoor unit connections, both indoor unit and
outdoor unit capacities, and system piping capabilities.
3. Determine the corrected capacity for the indoor units and outdoor unit using LATS Multi F software (preferred method) or:
• System Combination Tables.
• Capacity Tables (it may be necessary to interpolate).
• Capacity Coefficient Factors (such as refrigerant line length derates, design condition derates, defrost operation derate [heating mode],
altitude derate [if applicable]).
4. Compare corrected capacities to load calculations.
5. Reselect equipment if necessary.
Obtain Design Conditions, Calculate Maximum Cool / Heat Loads
Obtain the winter outdoor / indoor temperature and summer and winter outdoor / indoor temperature design parameters for the location in
which the system is installed. Determine if summer or winter design gains, relative humidity, and building features like skylights, orientation,
number of occupants, etc., would change the total heat loss / gain and sensible / latent heat gain, and then calculate the maximum cool and
heat loads for the space (using Manual J or energy modeling programs).
Select the Equipment
Determine the Number of Zones
Multi F heat pump systems can cool or heat, but not simultaneously. When designing larger-capacity Multi F heat pump systems or a Multi
F MAX system, the designer may be able to combine spaces with similar load profiles located near or adjacent to each other into “thermal
zones.” After combining like spaces into zones that will be served by a single (or grouped) indoor unit(s), calculate the peak cooling and
heating loads for each zone.
Choosing the Appropriate Indoor Units
Determine the appropriate indoor unit capacity that satisfies the given zone load calculations, and choose how many (and which styles of)
indoor units will be required. See the table on the next page for allowable indoor unit to outdoor unit connections, and the maximum number
of connectable indoor units on each Multi F and Multi F MAX outdoor unit. When choosing indoor units, also consider the cooling and heating
CFM, featured airflow specifications, and static pressure (if applicable) for each indoor unit.
Avoid oversizing indoor units in an attempt to increase the air exchange rate in the space. Multi F and Multi F MAX systems are designed for
minimum airflow over the coil to maximize latent capacity while cooling, maintain a comfortable, consistent discharge air temperature while
heating, and minimize fan motor power consumption. In extreme cases, oversizing the indoor units may affect outdoor unit size selection and
compromise the outdoor unit’s ability to effectively match the space load(s).
For proper system operation:
1. At least two indoor units must be connected to the outdoor unit.
2. Total connected indoor unit nominal capacity should be a minimum 40% and a maximum of 133% of outdoor unit nominal capacity.
3. To calculate the connected total indoor unit nominal capacity, simply sum up the nominal capacities of all indoor units.
• For high static duct and vertical-horizontal air handling indoor units, a 1.3 multiplier must first be applied before adding to the sum of
other indoor units (when connected to an outdoor unit other than the LMU600HV).
• When high static duct and / or vertical-horizontal air handling indoor units are the only connected indoor units, the multiplier is 1.2.
For allocated capacity information, see the combination tables in the "Multi F / Multi F MAX Combination Data Manual" on www.lghvac.com. For
performance data, see "Multi F / Multi F MAX Performance Data Manual" on www.lghvac.com.
MANUAL EQUIPMENT
SELECTION PROCEDURE

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8|INTRODUCTION
Multi F and Multi F MAX Heat Pump System Engineering Manual
MULTI FMAX
MULTI F
Indoor Units Outdoor Units
Model Type
Indoor Unit
Nominal Capacity
(Btu/h)
LMU180HV LMU18CHV LMU240HV LMU24CHV LMU30CHV LMU36CHV LMU480HV LMU540HV LMU600HV
Maximum No. of Connectable Indoor Units
223344888
ART COOL Mirror
9,000 OOOOOOOOO
12,000 OOOOOOOOO
18,000 - - O O O O O O O
ART COOL
Gallery
9,000 OOOOOOOOO
12,000 OOOOOOOOO
Standard Wall
Mounted
7,000 OOOOOOOOO
9,000 OOOOOOOOO
12,000 OOOOOOOOO
15,000 O O O O O O O O O
18,000 - - O O O O O O O
24,000 - - O O O O O O O
Ceiling Concealed
Duct-Low Static
9,000 OOOOOOOOO
12,000 OOOOOOOOO
18,000 - - O O O O O O O
Ceiling Concealed
Duct-High Static
24,000 - - - - O O O O O
36,000 - - - - - - O O O
Four-Way Ceiling
Cassette
7,000 OOOOOOOOO
9,000 OOOOOOOOO
12,000 OOOOOOOOO
18,000 - - O O O O O O O
Low-Wall Console
9,000 OOOOOOOOO
12,000 OOOOOOOOO
15,000 OOOOOOOOO
Vertical-Horizontal
Air Handler
24,000 - - - - O O O O O
36,000 - - - - - - O O O
Table 1: 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
capacity 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 largest 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
MANUAL EQUIPMENT
SELECTION PROCEDURE

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Introduction
MULTI FMAX
MULTI F
Determine the Corrected Capacity
The corrected cooling / heating capacity is different from the rated cooling / heating capacity. The corrected capacity includes changes in
unit performance after considering design temperatures, available capacity that can be allocated from the outdoor unit, pressure drop due
to refrigerant line length, defrost operation in heating mode, and (if applicable) altitude. Depending on the location of the building, additional
capacity correction factors may need to be applied.
Using the Outdoor Unit Cooling and Heating Capacity Tables
Rated cooling capacity ratings are obtained with air entering the indoor unit at 80ºF dry bulb (DB) and 67ºF wet bulb (WB), and outdoor ambi-
ent conditions of 95ºF dry bulb (DB) and 75ºF wet bulb (WB). Rated heating capacity ratings are obtained with air entering the indoor unit at
70ºF dry bulb (DB) and 60ºF wet bulb (WB) and outdoor ambient conditions of 47ºF dry bulb (DB) and 43ºF wet bulb (WB).
To evaluate the total outdoor unit capacity at design conditions, using LATS software (preferred method) or reference the Performance
Data Capacity Tables found in the Multi F outdoor unit section in this manual. All design temperatures are not explicitly shown in the charts,
therefore, interpolation may be necessary to calculate the capacity for specific design conditions. Based on the premise that capacity follows
a linear curve, the following formula can be applied:
(y - y1) / (y2 - y1) = (x - x1) / (x2 - x1)
Where
y = Missing Capacity (Capacity at the Design Temperature).1
y1 = Capacity at Lower Temperature (Smaller value of the two nearest published TC datapoints).
y2 = Capacity at Higher Temperature (Higher value of the two nearest published TC datapoints).
x = Design Temperature (Temperature not shown in published capacity tables).2
x1 = (Smaller value of the two nearest published temperature datapoints).
x2 = (Larger value of the two nearest published temperature datapoints).
1Median between two published Total Capacity [TC] Btu/h datapoints in the capacity table.
2Median between two nearest published temperature datapoints.
Using the Indoor Unit Cooling and Heating Capacity Tables
The datapoints shown in the indoor unit cooling and heating capacity charts are based on (and convey) an indoor unit operating with maxi-
mum possible refrigerant flow from the outdoor unit and before any derates are applied. In other words, the capacities displayed reflect what
the indoor unit would produce if it was the only indoor unit that required capacity, and the outdoor unit did not have to allocate any capacity to
another indoor unit.
System operation with a combination of indoor units is not conveyed in these charts, however, the information can be used to calculate
indoor unit allocated capacity (without using the system combination tables). Simply calculate by using the formula:
Where
Qidu(combi) = Qodu(rated) x Qidu(rated)
   ȉ4LGXUDWHG
• The formula can be used to find individual indoor unit capacity for Multi F MAX systems.
• A more accurate method to determine expected capacity would be to apply the outdoor unit’s corrected capacity instead of rated capacity.
Qidu(combi) = Individual Indoor Unit Combination Capacity.
Qodu(rated) = Outdoor Unit Rated Capacity.
Qidu(rated) = Individual Indoor Unit Rated Capacity.
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Outdoor Units
LMU180HV LMU18CHV LMU240HV LMU24CHV LMU30CHV LMU36CHV LMU480HV LMU540HV LMU600HV
Rated
Capacity
(Btu/h)*
Cooling 18,000 17,000 23,600 20,000 30,000 32,000 48,000 52,500 60,000
Heating 22,000 22,000 24,600 24,000 32,000 36,000 54,000 58,000 64,000
Connectable
Indoor
Units
Minimum No. of
Connectable IDUs 222222222
Maximum No. of
Connectable IDUs 223344888
Maximum Capacity
Index 24,000 24,000 33,000 33,000 40,000 48,000 65,000 73,000 81,000
Table 2: Rated Outdoor Unit Capacity.
*Rated capacity shown is based on a non-ducted indoor unit combination. Refer to combination tables for rated capacity of other combinations.
MANUAL EQUIPMENT
SELECTION PROCEDURE

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10 | INTRODUCTION
Multi F and Multi F MAX Heat Pump System Engineering Manual
MULTI FMAX
MULTI F
Qidu(combi) = Qodu(rated) x Qidu(rated)
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Using the System Combination Tables
Multi F system combination tables illustrate how each indoor unit receives a percentage of total outdoor unit rated capacity. Allocation is
based on:
• Combinations of Non-Ducted Indoor Units
• Combinations of Ducted Indoor Units
• Combinations of Mixed Non-Ducted and Ducted Indoor Units
Multi F MAX system combination tables only show the total connected indoor unit capacity, but individual indoor unit capacity can be
calculated using the formula:
• A more accurate method to determine expected capacity would be to apply the outdoor unit’s corrected capacity instead of rated capacity.
• For allocated capacity information, see the combination tables in the “Multi F / Multi F MAX Combination Data Manual” on www.lghvac.com.
For performance data, see “Multi F / Multi F MAX Performance Data Manual” on www.lghvac.com.
Table 3: Multi F Outdoor Unit (Multiple Piping) to Indoor Unit Refrigerant Line Length Derates.
Piping Length (feet) Cooling Capacity (%) Heating Capacity (%)
7,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 98.4 99.2
49.2 95.8 97.8
65.6 93.2 96.4
82.0 90.6 95.0
9,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 98.0 99.0
49.2 94.8 97.4
65.6 91.6 95.8
82.0 88.4 94.2
12,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 97.6 98.6
49.2 93.8 96.4
65.6 89.9 94.1
82.0 86.1 91.9
15,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 97.2 98.2
49.2 93.0 95.4
65.6 88.8 92.6
82.0 84.6 89.8
18,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 98.6 99.6
49.2 96.4 99.0
65.6 94.1 98.3
82.0 91.9 97.7
24,000 Btu/h Indoor Unit Models
25.0 100.0 100.0
32.8 98.2 99.2
49.2 95.4 98.0
65.6 92.4 96.6
82.0 89.6 95.4
Capacity Coefficient Factors
Refrigerant Line Length Derates
For air-cooled systems, a capacity correction factor may have to be applied to account for the length of the system’s refrigerant pipe. Rate of
change in capacity due to increased piping lengths is shown in the table below, and in the tables on the next page.
MANUAL EQUIPMENT
SELECTION PROCEDURE