Argo SDG18MHWP User manual

Installation Manual
VRF MODULAR SYSTEMS
SLIM DUCTED TYPE
INDOOR UNITS
MODELS:
SDG18MHWP
SDG22MHWP
SDG28MHWP
SDG36MHWP
SDG45MHWP
SDG56MHWP
Thank you for choosing an Argoclima commercial air conditioner. Please read this manual carefully before using the unit and
retain it for future reference.
V 0622

To Users
Thank you for selecting Gree’s product. Please read this instruction manual carefully before
installing and using the product, so as to master and correctly use the product. In order to guide you
to correctly install and use our product and achieve expected operating effect, we hereby instruct as
below:
(1) This appliance is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge, unless they have been
given supervision or instruction concerning use of the appliance by a person responsibility
for their safety.Children should be supervised to ensure that they do not play with the
appliance.
(2) In order to ensure reliability of product, the product may consume some power under stand-
by status for maintaining normal communication of system and preheating refrigerant and
lubricant. Ifthe product isnot to be used for long, cut offthe power supply; please energize
and preheat the unit in advance before reusing it.
(3) Please properly select the model according to actual using environment, otherwise it may
impact the using convenience.
(4) This producthas gone through strict inspection and operational test before leaving the factory.
In order to avoid damage due to improper disassembly and inspection, which may impact the
normal operation of unit, please do not disassemble the unit by yourself. You can contact with
the special maintenance center of our company ifnecessary.
(5) When the product isfaulted and cannot be operated, please contact with our maintenance
center as soon as possible by providing the following information.
1) Contents of nameplate of product(model, cooling/heating capacity,productNo.,ex-
factory date).
2) Malfunction status (specify the situations before and after the error occurs).
(6) All the illustrations and information in the instruction manual are only for reference. In order
to make the product better, we will continuously conduct improvement and innovation. We
have the right to make necessary revision to the product from time to time due to the reason
of sales or production, and reserve the right to revise the contents without further notice.
(7) The final right to interpret for this instruction manual belongs to Argoclima.

Exception Clauses
Manufacturer will bear no responsibilities when personal injury or property loss is caused by the
following reasons:
(1) Damage the product due to improper use or misuse of the product.
(2) Alter, change, maintain or use the product with other equipment without abiding by the
instruction manual of manufacturer.
(3) After verification, the defect of product is directly caused by corrosive gas.
(4) After verification, defects are due to improper operation during transportation of product.
(5) Operate, repair, maintain the unit without abiding by instruction manual or related regulations.
(6) After verification, the problem or dispute is caused by the quality specification or performance
of parts and components that produced by other manufacturers.
(7) The damage is caused by natural calamities, bad using environment or force majeure.

Contents
1 Safety Notices (Please be sure to abide them) ....................................................... 1
2 Product Introduction ................................................................................................. 3
2.1 Names of Key Components.................................................................................................3
2.2 Rated Working Condition.....................................................................................................3
3 Preparations for Installation ..................................................................................... 3
3.1 Standard Fittings .................................................................................................................4
3.2 Location for Installation........................................................................................................4
3.3 Requirements for Communication Line...............................................................................5
3.4 Wiring Requirements...........................................................................................................7
4 Installation Instructions ............................................................................................ 8
4.1 Installation of Indoor Unit.....................................................................................................8
4.2 Pipe Connection................................................................................................................10
4.3 Installation and Test of Drain Pipe.....................................................................................11
4.4 Installation of Air Duct........................................................................................................15
4.5 Installation of Wired Controller ..........................................................................................17
5 Wire Connection ...................................................................................................... 17
5.1 Connection of Wire and Wiring Board Terminal.................................................................18
5.2 Power Cord Connection ....................................................................................................19
5.3 Connection of Communication Line of IDU and ODU .......................................................19
5.4 Connection of Communication Line of Wired Controller....................................................20
5.5 Instructions on Connecting Wired Controller and IDU Network.........................................21
6 General Maintenance............................................................................................... 23
6.1 Cleaning of Air Filter..........................................................................................................23
6.2 Maintenance Before Use-season......................................................................................23
6.3 Maintenance After Use-season .........................................................................................23
7 Malfunction Codes of IDU ....................................................................................... 24
8 Troubleshooting....................................................................................................... 24

Multi Variable Air Conditioners Duct Type Indoor Unit
1
1 Safety Notices (Please be sure to abide them)
WARNING : If not abide them strictly, it may cause severe damage to the unit or the people.
NOTICE: If not abide them strictly, it may cause slight or medium damage to the unit or the
people.
This sign indicates that the items must be prohibited. Improper operation may cause severe
damage or death to people.
This sign indicates that the items must be observed. Improper operation may cause damage
to people or property.
Follow this manual to
complete the installation
work. Please read this
manual carefully before
turning on or repairing the
unit.
Installation should be
performed by the distributor
or qualified technicians. Do
not install the product by
yourself. Improper
installation may lead to
water leakage, electric
shock or fire hazard, etc.
Before installation, please
check whether the power
supply is complied with that
specified on the nameplate
and check the safety of the
power supply.
The air conditioner must be
grounded reliably for
avoiding electric shock.
Please do not connect the
earthing wire to gas pipe,
water pipe, lightning rod or
telephone line.
Be sure to use special
accessories and parts for
installation to prevent water
leakage, electric shock and
fire hazard, etc.
If refrigerant leakage
happens, please ventilate
the room immediately.
Diameter of power cord
should be large enough. The
damaged power cord and
connection wire must be
replaced with special cables.
When the power cord is
connected, please fix the
electric box cover properly
to avoid safety accidents.
Never fail to comply with the
nitrogen-charging welding
process. Do charge nitrogen
when welding the pipes.
Never short circuit or
cancel the pressure switch
to prevent unit damage.
As for the unit controlled by
the wired controller, connect
the wired controller well
firstly and then energize the
unit; otherwise, the unit can’t
operate normally.
When installation is
finished, please check
whether the drainage
pipes, pipelines and electric
wires are connected
correctly to avoid water
leakage, refrigerant
leakage, electric shock or
fire, etc.

Multi Variable Air Conditioners Duct Type Indoor Unit
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Do not insert fingers or
objects into air outlet or air
return grille.
Open the door and window
frequently to keep good
ventilation for avoiding
oxygen deficit when gas
heater or oil heater is used
in the room.
Never plug in or unplug the
power plug directly to turn
on or turn off the air
conditioner.
Once the air conditioner is
turned on, it can be turned
off only after it has
operated for 5min at least;
otherwise, it will affect the
oil return of compressor.
Do not allow children to
operate this air conditioner. Do not operate this air conditioner with wet hands.
The air conditioner can be
cleaned only when it has
been turned off and the
power has been cut off;
otherwise, it may cause
electric shock or injury.
Never spray or flush water
towards the air conditioner;
otherwise, malfunction or
electric shock may happen.
Do not expose the air
conditioner to the moist or
corrosive environment.
Put through the power 8
hours in advance before
operation. Do not cut off the
power when the air
conditioner stops operation
for only about one night
(protect the compressor).
Volatile liquid, such as
diluent or gasoline, will
damage the appearance of
air conditioner. Only soft dry
cloth and wet cloth dipped
with neutral detergent can
be used to clean the outer
case of air conditioner.
Under cooling mode,
please don't set the room
temperature too low; keep
the temperature difference
between indoor and
outdoor within 5°C (41°F).
If there are any abnormal
circumstances (such as
burning smell, etc.), please
turn off the unit and cut off
the main power supply
immediately, and then
contact Gree appointed
service center. If those
abnormal circumstances still
exit, the unit may be
damaged and it may lead to
electric shock or fire hazard.
Do not repair the unit by
yourself. Wrong
maintenance may cause
electric shock or fire
hazard. Please contact
Gree appointed service
center for help.

Multi Variable Air Conditioners Duct Type Indoor Unit
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This appliance can be used by children aged from 8 years and above and persons with reduced physical, sensory or
mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning
use of the appliance in a safe way and understand the hazards involved. Children shall not play with the appliance.
Cleaning and user maintenance shall not be made by children without supervision.
Install units according to national wiring codes.
If the supply cord is damaged, it must be replaced by the manufacturer or its service agent or a similarly qualified
person in order to avoid a hazard.
An all-pole disconnection device which has at least 3mm clearances in all poles, and disconnection must be
incorporated in the fixed wiring in accordance with the wiring rules.
Gree Electric Appliances, Inc. of Zhuhai will not assume responsibility for any personal injury or property loss caused
by improper installation, improper debugging, unnecessary repair or not following the instructions of this manual.
2 Product Introduction
2.1 Names of Key Components
Fig2.1
NO. ① ② ③ ④ ⑤ ⑥
Name Electric box water pump Air Outlet Hooker Air-return
Opening
Drain Pipe
2.2 Rated Working Condition
—
Indoor Side Condition
Outdoor Side Condition
Dry Bulb Temp(°C)
Wet Bulb Temp(°C)
Dry Bulb Temp(°C)
Wet Bulb Temp(°C)
Rated Cooling 27 19 35 24
Rated Heating
20
15
7
6
3 Preparations for Installation
NOTICE: Product graphics are only for reference. Please refer to actual products. Unspecified
measure unit is mm.

Multi Variable Air Conditioners Duct Type Indoor Unit
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3.1 Standard Fittings
Please use the supplied standard fittings listed below as instructed.
No. Name Graphics Quantity Purpose
1
Wire controller package
(including wire controller,
emergency bottom case,
instruction manual, screws,
packing box)
1set Control indoor unit
2 Remote controller 0 or 1 Optional parts (including #7
batteries)
3 Sponge for drainage pipe 2 Wrap water pipe and rubber cork for
condenser
4 Insulating materials 2 Used for the joint of
gas pipe and liquid
pipe for indoor unit
5 Corrugated pipe 0 or 1 Diameter of air
pipe≥15.9mm
6 Union nut 1 or 2 One for the model
with corrugated pipe;
two for other models
7 Spring washer M8, nut M8, nut with washer M8, washer
M8 4 Used for hanging the
indoor unit
8 Tieline 6 Wrap the sponge at
the connection
position
9 Others
User Manual: 1 copy
Loosen-leaf of Instruction Manual: 1 copy (harmful substance content table)
Qualified Certificate: 1 copy
Bar Code : 1 copy
3.2 Location for Installation
(1) The top holder must be strong enough to support unit's weight.
(2) Drain pipe can drain water out easily.
(3) There is no obstacle at inlet or outlet. Please ensure good air circulation.
(4) In order to make sure the space for maintenance, please install the indoor unit according to
the dimension described below.
(5) Keep the unit away from heating source, inflammable gas or smoke.
(6) This is a concealed ceiling type unit.
(7) Indoor unit, outdoor unit, power cord and electric wire should stay at least 1m from the TV
set and radio. Otherwise, these electrical appliances may have image interference and noise
(Even if the distance is 1m, when there is strong electric wave, noise may still occur).
(8) The appliance shall not be installed in the laundry.

Multi Variable Air Conditioners Duct Type Indoor Unit
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Fig 3.1
NOTICE:
①Installation of the unit must be in accordance with National Electric Codes and local
regulations.
②Improper installation will affect unit’s performance, so do not install the unit by yourself.
Please contact local dealer to arrange professional technicians for the installation.
③Do not connect power until all installation work is finished.
3.3 Requirements for Communication Line
NOTICE:
If the unit is installed in the place with strong electromagnetic interference, shielded wire must be
applied on the communication wire between indoor unit and wired controller. Twisted pair line with
shielding function must be applied on the communication wire between indoor unit and indoor unit
(outdoor unit).
3.3.1 Select Communication Line for Indoor Unit and Wired Controller
Fig 3.2

Multi Variable Air Conditioners Duct Type Indoor Unit
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Material type
Total length of
communication line
between indoor unit
and wired controller L
(m/feet)
Wire size
(mm2/AWG)Material Standard Remarks
Light/Ordinary
polyvinyl chloride
sheathed cord.
(60227 IEC 52
/60227 IEC 53)
L≤250m
(L≤820-1/5feet)
2×0.75~2×1.25
(2×AWG18
~2×AWG16)
IEC 60227-
5:2007
(1) Total length of communication
line can't exceed 250m (820-
1/5feet).
(2) The cord shall be Circular
cord (the cores shall be
twisted together).
(3) If unit is installed in places
with intense magnetic field or
strong interference, it is
necessary to use shielded
wire.
3.3.2 Select Communication Line for Indoor Unit and Outdoor Unit
Fig 3.3
Material Type
Total Length L (m/feet)
of Communication
Cable between Indoor
Unit and Indoor
(Outdoor) Unit
Wire size
(mm2/AWG) Material Standard Remarks
Light/Ordinary
polyvinyl chloride
sheathed cord.
(60227 IEC 52
/60227 IEC 53)
L≤1000m
(L≤3280-5/6feet) ≥2×0.75 (≥2×AWG18) IEC 60227- 5:2007
(1) If the wire diameter is
enlarged to 2×1 mm2
(2×AWG16), the total
communication line length can
reach 1500 m (4921-1/4feet).
(2) The cord shall be Circular
cord (the cores shall be
twisted together).
(3) If unit is installed in places
with intense magnetic field or
strong interference, it is
necessary to use shielded
wire.

Multi Variable Air Conditioners Duct Type Indoor Unit
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3.4 Wiring Requirements
(1) Power Cord Size and Air Switch Capacity.
Model Power Supply Air Switch
Capacity(A)
Minimum Sectional
Area of Ground
Wire(mm
2
)
Minimum Sectional
Area of Power
Cord(mm
2
)
GMV-ND22PLS/C-T 6 1.0 1.0
6 1.0 1.0
GMV-ND28PLS/C-T 6 1.0 1.0
6 1.0 1.0
GMV-ND36PLS/C-T 6 1.0 1.0
6 1.0 1.0
GMV-ND45PLS/C-T 6 1.0 1.0
6 1.0 1.0
GMV-ND56PLS/C-T 6 1.0 1.0
NOTICE:
①Use copper wire only as unit's power cord. Operating temperature should be within its rated
220~240V-1Ph-50Hz
208~230V-1Ph-60Hz

Multi Variable Air Conditioners Duct Type Indoor Unit
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value.
②If the power cord is more than 15m long, please increase properly the sectional area of power
cord to avoid accident due to overload.
③Above selection requirements: Power cord size is based on BV single-core wire (2~4pc) at
40°C ambient temperature when laying across plastic pipe. Air switch is D type and used at
40°C. If actual installation condition varies, please lower the capacity appropriately according
to the specifications of power cord and air switch provided by manufacturer.
(2) Install cut-off device near the unit. The minimum distance between each stage of cut-off
device should be 3mm (The same for both indoor unit and outdoor unit).
(3) If the supply cord is damaged, it must be replaced by the manufacturer or its service agent
or a similarly qualified person in order to avoid a hazard.
4 Installation Instructions
4.1 Installation of Indoor Unit
4.1.1 Outline Dimension and Installation Spots
Equip with a service port after lifting the unit. For the convenience of maintenance, the service
port should be on one side of the electric box and below unit’s lower level.
Below are the outline dimension applicable to indoor units of GMV-ND22~72PL/B-T, GMV-
ND22~71PLS/B1-T.
Fig 4.1
Below are dimensions of A, B, C, etc. for different models: Unit: mm
Item
Model
A B C D E F
SDG22M~36HWP 760 415 710 200 450 474
1060 415 1010 200 450 474
SDG45~56HWP

Multi Variable Air Conditioners Duct Type Indoor Unit
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Below are the outline dimension applicable to indoor units of GMV-ND18~71PLS/C-T.
Fig 4.2
Below are dimensions of A, B, C, etc. for different models: Unit: mm
Item
Model
A B C D E F
760
415
710
200
462
486
1060
415
1010
200
462
486
4.1.2 Punching of Bolt Spots and Bolt Installation
Punch holes on the installation area according to the 4 spots on the paper pattern; the punching
diameter may refer to the diameter of expansion bolt, about 60mm to 70mm depth, as shown in Fig
4.3 Unit: mm
Fig 4.3
Insert the expansion bolt M10 into the hole and then drive the iron nail into the bolt, as shown in
Fig 4.4.
Fig 4.4
SDG22M~36HWP
SDG45~56HWP

Multi Variable Air Conditioners Duct Type Indoor Unit
10
NOTICE:
The length of bolt depends on the installation height of the unit, bolts are field supplied.
4.1.3 Lift the Unit
Lift up the unit to the ceiling and secure it on the bolt. Use specialized nut to secure the unit.
Fig 4.5
NOTICE:
①Before installation, please finish the preparation work of all pipes (connection pipe, drain pipe)
and wires (wired controller wire, connection wire of IDU and ODU) that need to be connected
with the indoor unit.
②Punch holes on the ceiling (air return opening or air inlet). Ceiling may have to be
strengthened to make it level and to prevent it from vibration. You may consult user or
constructor for details.
③If the ceiling is not strong enough, you can install a beam bracket in a corner and secure the
unit on the beam.
4.1.4 Horizontal Alignment
After the indoor unit is installed, remember to check the horizontal status of the whole unit. It
should be horizontal from front to back and slant 1% from left to right, following the drainage direction,
as shown in Fig 4.6.
Fig 4.6
4.2 Pipe Connection
(1) Direct the flaring of copper pipe to the center of screwed connection and then screw the
flaring nut tight as shown in Fig 4.7
(2) Use a torque wrench to tighten up the flaring nut until the wrench gives out a click sound.

Multi Variable Air Conditioners Duct Type Indoor Unit
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Fig 4.7
Torque for tightening nut
Pipe diameter (mm)
Torque (N·m)
Φ6.35
15~30
Φ9.52
35~40
Φ12.7
45~50
Φ15.9
60~65
(3) The pipe should not be bent too much or it may crack. Use a pipe bender when bending the
pipe.
(4) Use a sponge to wrap the uninsulated connection pipe and the joint. Then tie it tight with a
plastic tape.
4.3 Installation and Test of Drain Pipe
4.3.1 Notices for Installation of Drain Pipe
(1) The drain pipe should be as short as possible and slope downward for at least 1%~2% so
that condensate can drain out easily.
(2) Size of the drainage hose must not be smaller than that of the drain pipe.
(3) Install the drain pipe according to the following diagram and make it insulated. Improper
installation will lead to water leakage and furniture and other objects may get wet.
(4) You can buy local hard PVC pipe as drain pipe. When connecting the pipe, insert the end of
PVC pipe into the drain hole and then tighten it up with a drain hose and cable tie. Do not
use adhesives to connect drain hole and drain hose.
(5) When the drain pipe is used for several equipments, the shared pipe should be about 100mm
lower than the drain hole of each equipment. In this case, use thicker pipe.
(6) It is not allowed to connect the condensate drain pipe into waste pipe or other pipelines which
are likely to produce corrosive or peculiar smell to prevent the smell from entering indoors or
corrupt the unit.
(7) It is not allowed to connect the condensate drain pipe into rain pipe to prevent rain water from
pouring in and cause property loss or personal injury.
(8) Condensate drain pipe should be connected into special drain system for air conditioner.

Multi Variable Air Conditioners Duct Type Indoor Unit
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Fig 4.8
4.3.2 Installation of Drain Pipe
(1) Insert the drain hose into the drain hole and tighten it with tapes, as shown in Fig 4.9
(2) Tighten the pipe clamp, with the distance between screw nut and hose smaller than 4mm.
①metal clamp(accessory) ②drain hose(accessory) ③Grey tape(accessory)
(3) Use sealing plate to make the pipe clamp and hose insulated, as shown in Fig 4.10
①metal clamp(accessory) ②thermal sponge(accessory)
Fig 4.9
Unit: mm
Fig 4.10
(4) When connecting several drain pipes, follow the instruction as indicated in Fig4.11. Choose
the drain collecting pipe that matches with unit capacity.
Unit: mm
Fig 4.11
(5) For indoor units that have high pressure at the outlet of drain pipe, use water-sealed joint.
(6) For indoor units that have high pressure at the outlet of drain pipe, use water-sealed joint.
(7) Install the water-sealed joint according to Fig 4.12.

Multi Variable Air Conditioners Duct Type Indoor Unit
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(8) Each unit should be installed with one water-sealed joint.
Unit: mm
Fig 4.12
(9) The horizontal pipe can be connected to vertical pipe in the same level; please select the
connection way as shown in Fig4.13~ Fig4.15
Fig 4.13 Fig 4.14 Fig 4.15
①: Connection of drainage pipe joints (Fig 4.13)
②: Connection of downspout elbow (Fig 4.14)
③: Inserting pipe connection (Fig 4.15)
(10) The installation height of raising pipe for drainage should be lower than 850mm. The gradient
from raising pipe towards drainage direction should be at least 1%~2%. If the raising pipe is
vertical with the unit, the raising height should be less than 800mm.
Fig 4.16
(11) Drain pipes should have a downward slope of at least 1%~2%, in order to prevent pipes from
sagging, install hanger bracket at intervals of 1000~1500mm.
Fig 4.17

Multi Variable Air Conditioners Duct Type Indoor Unit
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4.3.3 Test of Drainage System
Models without water pump
(1) Fill some water to the water tray of indoor unit as following.
1) Connect the drain hose to the other drain connection pipe of water tray and fill about 1L
water (as shown in Fig 4.18). (Remove the drain hose after finishing testing and then put
on the plug of water tray.)
2) Spray 1L water on evaporator with sprayer, as shown in Fig 4.19
Fig 4.18 Fig 4.19
(2) Check if the water drains smoothly from the drain pipe and check if there is water leakage on
the connection pipe.
(3) Arrange insulation of drain hose and pipe clamp after checking the drain system.
Models with water pump
(1) Fill some water to the water tray of indoor unit as following.
1) Connect the drain hose to the other drain connection pipe of water tray and fill about 1L
water (as shown in Fig 4.18). (Remove the drain hose after finishing testing and then put
on the plug of water tray.)
2) Spray 1L water on evaporator with sprayer, as shown in Fig 4.19
(2) Start the water to check if water drain smoothly. The starting method of water pump is as
below.
1) If project debugging of unit has been done, please set the indoor unit in cooling or dry
mode. In this case, the water pump will operate automatically.
2) If electrical wiring of unit hasn’t been done, please open the electric box cover. Connect
one phase power cord at L1, N or L, N of wiring board; about 60s after connecting power
supply, indoor unit will report “C0” communication malfunction. In this case, the water
pump will automatically operate for 10min and then stop; after checking the drain system,
please cut off power supply, disconnect power cord and then put on the electric box cover.
(3) Check if the water drains smoothly from the drain pipe and check if there is water leakage on
the connection pipe.
(4) Arrange insulation of drain hose and pipe clamp after checking the drain system.

Multi Variable Air Conditioners Duct Type Indoor Unit
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4.4 Installation of Air Duct
NOTICE:
①There should be insulation layer on air-out duct, air-return duct and fresh air duct to avoid
heat loss and moisture. Adhere a nail on the air duct and then add thermal sponge with a
layer of tin. Fasten it with a nail cover and then seal the junction with tin tapes; you can also
use other materials that have good insulation quality.
②Each air-out duct and air-return duct should be fixed on a pre-made board with iron frame.
The junction of air duct should be well-sealed in order to prevent air leakage.
③The design and construction of air duct should comply with national requirements.
④The edge of air-return duct is suggested to be more than 150mm away from the wall. Add a
filter to the air-return opening.
⑤Please consider noise-damping and vibration damping for the design and construction of air
duct. Besides, noise source must be away from people. For instance, do not have the air-
return opening installed on top of the user (offices, rest area, etc.).
4.4.1 Installation of Air-out Duct
(1) Installation of Rectangular Duct
Fig 4.20
(2) Installation of Circular Duct
Fig 4.21
No. Name No. Name
1
Return Air Duct
6
Transition Pipe
2
Canvas Duct
7
Supply Air Duct
3
Return Air Blinds
8
Diffuser
4
Hanger Rod
9
Diffuser Connector
5
Supply Air Outlet
— —

Multi Variable Air Conditioners Duct Type Indoor Unit
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4.4.2 Shape and Size of Air Outlet and Air-return Opening
As shown in Fig 4.22 is applicable for the models below:
Fig 4.22
Unit: mm
Item
Model
Dimension of air outlet flange
Dimension of air return
A B C D
122 585 200 710
122 885 200 1010
4.4.3 Installation of Air-return Duct
(1) Square flange is defaulted to be fitted on the back before ex-factory. Air-return cover is on
the bottom, as shown in Fig 4.23.
Fig 4.23
(2) If air return from the bottom is needed, switch the positions of square flange and air-return
cover.
(3) Use a clincher to connect air-return duct to the air-return opening of indoor unit. The other
end of air-return duct connects with the air-return louver. In order to adjust the height
conveniently, you can make a folded canvas duct and have it strengthened by 8# iron wire.
(4) Air return from the bottom will produce more noise than air return from the back. So we
suggest you to add a noise damper and static pressure case to lower noise if you choose air
return from the bottom.
SDG22M~36HWP
SDG45~56HWP