Westinghouse WHU09CTA21S User manual

AIR CONDITIONER
Cassette type
REFRIGERANT R410A
INVERTER
SERVICE MANUAL
INDOOR
WHU09CTA21S
WHU12CTA21S
WHU18CTA21S
WHU24CTA21S
WHU36CTA21S
OUTDOOR
WHU09SZA21S
WHU12SZA21S
WHU18SZA21S WHU24SZA21S WHU36SZA21S
, WESTINGHOUSE, and INNOVATION YOU CAN BE SURE OF are trademarks of Westing house
Electric Corporation. Used under license by FUJITSU GENERAL AMERICA, INC. All Rights Reserved.
2021.12.24

SAFETY SUMMARY
IMPORTANT NOTICE
●We pursue a policy of continuing improvement in design and performance of products. The right is
therefore reserved to vary specifications without notice.
●We cannot anticipate every possible circumstance that might involve a potential hazard.
●This air conditioner is designed for standard air conditioning only. Do not use this air conditioner for
other purposes such as drying clothes, refrigerating foods or for any other cooling or heating process.
Do not let the air-out face animals or plants, it might have an adverse effect on them.
●The installer and system specialist shall secure safety against leakage according to local regulations
or standards.
●Signal words (DANGER, WARNING and CAUTION) are used to identify levels of hazard seriousness.
Definitions for identifying hazard levels are provided below with their respective signal words.
●Installation should be performed by the dealer or other professional personnel. Improper installation
may cause water leakage, electrical shock, or fire.
●Do not perform installation work, refrigerant piping work, drain piping and electrical wiring connection
without referring to our installation manual. If the instructions are not followed, it may result in water
leakage, electric shock or fire.
●Use refrigerant R410A in the refrigerant cycle.
●Do not pour water into the indoor or outdoor unit. These products are equipped with electrical parts. If
poured, it will cause a serious electrical shock.
●Do not open the service cover or access panel for the indoor or outdoor units without turning OFF the
main power supply.
●Do not touch or adjust safety devices inside the indoor or outdoor units. If these devices are touched
or readjusted, it may cause a serious accident.
●Refrigerant leakage can cause difficulty in breathing due to insufficient air. Turn OFF the main switch,
extinguish any naked flames and contact your service contractor, if refrigerant leakage occurs.
●Do perform air-tight test. Do not charge oxygen, acetylene or other flammable and poisonous gases
into the refrigerant cycle when performing a leakage test or an air-tight test. These types of gases are
extremely dangerous and can cause an explosion. It is recommended that nitrogen be used for this
test.
●The installer and system specialist shall secure safety against refrigerant leakage according to local
regulations or standards.
●Use an ELB (Electric Leakage Breaker). In the event of a fault, there is danger of an electric shock or
a fire if it is not used.
Immediate hazards which WILL result in severe personal injury or death.
Hazards or unsafe practices which COULD result in severe personal injury or
death.
Hazards or unsafe practices which COULD result in minor personal injury or
product or property damage.
Useful information for operation and/or maintenance.
-1 -
Notices:
• Product specifications and design are subject to change without notice for future improvement.
• For further details, please check with our authorized dealer.

●Do not step or put any material on the product.
●Do not put any foreign material on the unit or inside the unit.
●It is recommended that the room be ventilated every 3 to 4 hours.
●The air conditioner may not work properly under the following circumstances.
The power transformer provides the same power with the air conditioner. The electrical equipment
is too close to the power supply of the air conditioner. With the sharp change of power
consumption and switching action, the power supply of the air conditioner will generate a large
induction surge voltage.
CHECKING PRODUCT RECEIVED
●Upon receiving this product, inspect it for any shipping damage. Claims for damage, either apparent
or concealed, should be filed immediately with the shipping company.
●Check the model number, electrical characteristics (power supply, voltage and frequency) and
accessories to determine if they are correct.
The standard utilization of the unit shall be explained in these instructions.
Therefore, the utilization of the unit other than those indicated in these instructions is not
recommended.
Please contact your local agent, as the occasion arises.
- 2 -
●Do not use any sprays such as insecticide, lacquer, hair spray or other flammable gases within
approximately one (1) meter from the system.
●If circuit breaker or fuse is often activated, stop the system and contact your service contractor.
●Check that the ground wire is securely connected. If the unit is not correctly grounded, it will lead
to electric shock. Do not connect the ground wiring to gas piping, water piping, lightning conductor
or ground wiring for telephone.
●Before performing any brazing work, check to ensure that there is no flammable material around
when using refrigerant. Be sure to wear leather gloves to prevent cold injuries.
●Protect the wires, electrical parts, etc. from rats or other small animals.
If not protected, rats may gnaw at unprotected parts, which may lead to fire.
●Fix the cables securely. External forces on the terminals could lead to a fire.
●Install the air conditioner on a solid base that can support the unit weight. An inadequate base or
incomplete installation may cause injury in the event the unit falls off the base. Incomplete
connections or clamping may cause terminal overheating or fire.
●Make sure that the outdoor unit is not covered with snow or ice, before operation.

Specifications
Type
Cassette
Inverter heat pump
Model name WHU09CTA21S WHU12CTA21S WHU18CTA21S WHU24CTA21S
Power supply 208/230 V ~ 60 Hz
Power supply intake Outdoor unit
Available voltage range 198—253 V 176—253 V
Capacity
Cooling
Rated kW 2.64 3.52 5.28 7.03
Btu/h 9,000 12,000 18,000 24,000
Min.—Max. kW 1.27—3.40 1.70—3.84 1.23—6.16 2.52—7.39
Btu/h 4,850—11,600 5,800—13,100 4,200—21,000 8,600—25,200
Heating
Rated kW 2.93 3.52 5.57 7.03
Btu/h 10,000 12,000 19,000 24,000
Min.—Max. kW 1.27—3.60 1.29—4.22 1.64—7.03 2.23—8.32
Btu/h 4,340—12,280 4,400—14,400 5,600—24,000 7,600—28,400
Input power
Cooling Rated
kW
0.700 0.960 1.420 1.920
Min.—Max. 0.332—0.941 0.388—1.319 0.252—1.870 0.760—2.260
Heating Rated 0.709 0.926 1.425 1.950
Min.—Max. 0.221—1.022 0.457—1.611 0.345—2.068 0.780—2.400
Current Cooling Rated A 3.6 4.3 6.5 8.6
Heating 3.5 4.1 6.3 8.7
EER Cooling W/W 3.77 3.66 3.72 3.66
Btu/hW 12.86 12.50 12.68 12.50
COP Heating W/W 4.13 3.80 3.91 3.61
Btu/hW 14.11 12.96 13.33 12.31
SEER Cooling Btu/hW 22.0 23.0 22.0 19.0
HSPF Heating Btu/hW 10.0 11.5 11.0 10.0
Power factor Cooling %99
Heating 99
Moisture removal pints/h (L/h) 1.7 (0.8) 2.3 (1.1) 3.2 (1.5) 4.0 (1.9)
Maximum operating current*1Cooling A15.0 20.0 35.0
Heating 15.0 20.0 35.0
Fan
Airflow rate
Cooling
HIGH
CFM (m3/h)
309 (520) 324 (550) 588 (1,000) 647 (1,100)
MED 274 (460) 294 (500) 500 (850) 530 (900)
LOW 232 (390) 235 (400) 394 (670) 400 (680)
Heating
HIGH 309 (520) 324 (550) 588 (1,000) 647 (1,100)
MED 274 (460) 294 (500) 500 (850) 530 (900)
LOW 232 (390) 235 (400) 394 (670) 400 (680)
Type × Q'ty Turbo × 1
Motor output W 57 80
Sound pressure level*2
Cooling
HIGH
dB (A)
38 42 38 44
MED 34 37 36 40
LOW 31 33 34 38
Heating
HIGH 38 42 38 44
MED 34 37 36 40
LOW 31 33 34 38
Heat exchanger type
Dimensions (H × W × D) in (mm) 6-9/16 × 49-1/2 × 3/4
(166 × 1,258 × 18.8)
6-9/16 × 47-3/4 × 1-1/8
(166.7 × 1,213 × 28.2)
7-7/16 × 73-5/8 ×
1-1/16
(189 × 1,870 × 27.2)
7-7/16 × 76-3/8 × 1-5/8
(189 × 1,940 × 40.8)
Fin pitch FPI 20 17
Rows × Stages 2 × 8 3 × 8 2 × 10 3 × 10
Pipe type Copper
Fin type Aluminum
Dimensions
(H × W × D)
Net
in (mm)
8-1/2 × 22-1/2 × 22-1/2
(215 × 570 × 570)
9-3/4 × 33-1/8 × 33-1/8
(248 × 840 × 840)
Gross 4-1/2 × 26-3/4 × 27-1/8
(292 × 668 × 730)
4-3/4 × 40 × 40-3/8
(370 × 956 × 996)
Weight Net lb (kg) 32 (14.5) 34 (15.5) 56 (25) 59.5 (27)
Gross 38.5 (17.5) 40.5 (18.5) 76 (34) 79.5 (36)
Connection pipe Size Liquid in (mm) Ø1/4 (Ø6.35) Ø1/4 (Ø6.35) Ø3/8 (Ø9.52) Gas Ø3/8 (Ø9.52) Ø1/2 (Ø12.70) Ø5/8 (Ø15.88)
Method Flare
Drain hose Material PE/PVC
Tip diameter in (mm) Ø1-1/8 (Ø27.8) (I.D.), Ø1-1/4 (Ø32.3) (O.D.)
Operation range Cooling °F (°C) 61 to 86 (16 to 30) %RH 80 or less
Heating °F (°C) 61 to 86 (16 to 30)
Remote controller type Wireless (Wired [option])
Cassette grille
(Grid type: Option)
Model name WH-AG4CT1 WH-AG4CT2
Dimensions
(H × W × D)
Net in (mm) 1-5/8 × 24-3/8 × 24-3/8 (40 × 620 × 620) 1-3/4 × 37-3/8 × 37-3/8 (45 × 950 × 950)
Gross 4-1/2 × 26-3/4 × 27-1/8 (115 × 680 × 690) 4-3/4 × 40 × 40-3/8 (120 × 1,015 × 1,025)
Weight Net lb (kg) 5.7 (2.6) 14.3 (6.5)
Gross 9.9 (4.5) 20.9 (9.5)
NOTES:
•Specifications are based on the following conditions:
– Cooling: Indoor temperature of 80 °FDB (26.67 °CDB)/67 °FWB (19.44 °CWB), and outdoor temperature of 95 °FDB (35 °CDB)/75 °FWB (23.9 °CWB).
– Heating: Indoor temperature of 70 °FDB (21.11 °CDB)/59 °FWB (15.56 °CWB), and outdoor temperature of 47 °FDB (8.33 °CDB)/43 °FWB (6.11 °CWB).
– Pipe length: 25 ft (7.5 m), Height difference: 0 ft (0 m). (Between outdoor unit and indoor unit.)
• Protective function might work when using it outside the operation range.
• *1: Maximum current is maximum value when operated within the operation range.
• *2: Sound pressure level:
– Measured values in manufacturer’s anechoic chamber.
– Because of the surrounding sound environment, the sound levels measured in actual installation conditions might be higher than the specified values here.
-3 -

Type
Cassette
Inverter heat pump
Model name WHU36CTA21S
Power supply 208/230 V ~ 60 Hz
Power supply intake Outdoor unit
Available voltage range 176—253 V
Capacity
Cooling
Rated kW 10.55
Btu/h 36,000
Min.—Max. kW 3.69—10.79
Btu/h 12,600—36,800
Heating
Rated kW 10.55
Btu/h 36,000
Min.—Max. kW 4.40—12.49
Btu/h 15,000—42,600
Input power
Cooling Rated
kW
3.380
Min.—Max. 1.102—3.981
Heating Rated 3.190
Min.—Max. 1.200—3.760
Current Cooling Rated A 14.6
Heating 14.0
EER Cooling W/W 3.12
Btu/hW 10.65
COP Heating W/W 3.31
Btu/hW 11.29
SEER Cooling Btu/hW 19.5
HSPF Heating Btu/hW 10.5
Power factor Cooling %99
Heating 99
Moisture removal pints/h (L/h) 5.3 (2.5)
Maximum operating current*1Cooling A45.0
Heating 25.0
Fan
Airflow rate
Cooling
HIGH
CFM (m3/h)
941 (1,600)
MED 794 (1,350)
LOW 676 (1,150)
Heating
HIGH 941 (1,600)
MED 794 (1,350)
LOW 676 (1,150)
Type × Q'ty Turbo × 1
Motor output W 124
Sound pressure level*2
Cooling
HIGH
dB (A)
49
MED 43
LOW 39
Heating
HIGH 49
MED 43
LOW 39
Heat exchanger type
Dimensions (H × W × D) in (mm) 9-15/16 × 76-3/8 × 1-5/8 (252 × 1,940 × 40.8)
Fin pitch FPI 17
Rows × Stages 3 × 12
Pipe type Copper
Fin type Aluminum
Dimensions
(H × W × D)
Net in (mm) 11-3/4 × 33-1/8 × 33-1/8 (298 × 840 × 840)
Gross 16-1/2 × 37-5/8 × 39-1/4 (420 × 956 × 996)
Weight Net lb (kg) 70.5 (32)
Gross 90.5 (41)
Connection pipe Size Liquid in (mm) Ø3/8 (Ø9.52) Gas Ø3/4 (Ø19.05)
Method Flare
Drain hose Material PE/PVC
Tip diameter in (mm) Ø1-1/8 (Ø27.8) (I.D.), Ø1-1/4 (Ø32.3) (O.D.)
Operation range Cooling °F (°C) 61 to 86 (16 to 30) %RH 80 or less
Heating °F (°C) 61 to 86 (16 to 30)
Remote controller type Wireless (Wired [option])
Cassette grille
(Grid type: Option)
Model name WH-AG4CT2
Dimensions
(H × W × D)
Net in (mm) 1-3/4 × 37-3/8 × 37-3/8 (45 × 950 × 950)
Gross 4-3/4 × 40 × 40-3/8 (120 × 1,015 × 1,025)
Weight Net lb (kg) 14.3 (6.5)
Gross 20.9 (9.5)
NOTES:
•Specifications are based on the following conditions:
– Cooling: Indoor temperature of 80 °FDB (26.67 °CDB)/67 °FWB (19.44 °CWB), and outdoor temperature of 95 °FDB (35 °CDB)/75 °FWB (23.9 °CWB).
– Heating: Indoor temperature of 70 °FDB (21.11 °CDB)/59 °FWB (15.56 °CWB), and outdoor temperature of 47 °FDB (8.33 °CDB)/43 °FWB (6.11 °CWB).
– Pipe length: 25 ft (7.5 m), Height difference: 0 ft (0 m). (Between outdoor unit and indoor unit.)
• Protective function might work when using it outside the operation range.
• *1: Maximum current is maximum value when operated within the operation range.
• *2: Sound pressure level:
– Measured values in manufacturer’s anechoic chamber.
– Because of the surrounding sound environment, the sound levels measured in actual installation conditions might be higher than the specified values here.
- 4 -

Type Inverter heat pump
Model name WHU09SZA21S WHU12SZA21S WHU18SZA21S WHU24SZA21S
Power supply 208/230 V ~ 60 Hz
Available voltage range 198—253 V 176—253 V
Fan
Airflow rate CFM (m3/h) 1,355 (2,300) 1,853 (3,150) 2,235 (3,800)
Type × Q'ty Propeller fan × 1
Motor output W 30 60 121
Sound pressure level *1dB (A) 52 55
Heat exchanger type
Dimensions
(H × W × D) in (mm)
21-1/2 × 33-1/16 ×
1-7/16
(546 × 840 × 36.4)
21-1/2 × 33-1/16 ×
1-11/16
(546 × 840 × 43.3)
24-13/16 × 35-7/16 ×
1-11/16
(630 × 900 × 43.3)
31-7/16 × 38-3/16 ×
1-11/16
(798 × 970 × 43.3)
Fin pitch FPI 17 18 20
Rows × Stages 2 × 26 2 × 30 2 × 38
Pipe type Copper
Fin type Type (Material) Aluminum
Surface treatment Blue fin
Compressor Type Rotary
Refrigerant
Type R410A
Charge lb oz 2 lb 2 oz 2 lb 14 oz 3 lb 8 oz 5 lb 12 oz
g 950 1,300 1,600 2,600
Refrigerant oil Type VG74 VG74 (POE)
Enclosure Material Steel sheet
Color White
Dimensions
(H × W × D)
Net
in (mm)
22-7/8 × 31-7/8 × 11
(580 × 810 × 280)
26-3/8 × 33-7/8 ×
12-1/4
(670 × 860 × 310)
33-1/8 × 37-3/8 ×
13-3/8
(840× 950 × 340)
Gross 25-1/4 × 37 × 16-1/2
(640 × 940 × 420)
28-3/4× 39 × 17-3/4
(730 × 990 × 450)
36-1/4 × 43-3/4 ×
18-1/8
(920 × 1,110 × 460)
Weight Net lb (kg) 75 (34) 79 (36) 106 (48) 155 (71)
Gross 84 (38) 88 (40) 115 (52) 166 (76)
Connection pipe
Size Liquid in (mm) Ø1/4 (Ø6.35) Ø1/4 (Ø6.35) Ø3/8 (Ø9.52)
Gas Ø3/8 (Ø9.52) Ø1/2 (Ø12.7) Ø5/8 (Ø15.88)
Method Flare
Pre-charge length
ft (m)
24.6 (7.5)
Max. length 82 (25) 98 (30) 164 (50)
Max. height difference
Indoor unit higher than
outdoor unit: 33 (10)
Outdoor unit higher
than indoor unit: 33
(10)
Indoor unit higher than outdoor unit: 49 (15)
Outdoor unit higher than indoor unit: 49 (15)
Indoor unit higher than
outdoor unit: 98 (30)
Outdoor unit higher
than indoor unit: 98
(30)
Operation range Cooling °F (°C) 5 to 118 (-15 to 48)
Heating -4 to 75 (-20 to 24)
NOTES:
• Specifications are based on the following conditions:
– Cooling: Indoor temperature of 80 °FDB (26.67 °CDB)/67 °FWB (19.44 °CWB), and outdoor temperature of 95 °FDB (35 °CDB)/75 °FWB (23.9 °CWB).
– Heating: Indoor temperature of 70 °FDB (21.11 °CDB)/59 °FWB (15 °CWB), and outdoor temperature of 47 °FDB (8.33 °CDB)/43 °FWB (6.11 °CWB).
– Pipe length: 24 ft 6 in (7.5 m), Height difference: 0 ft (0 m). (Between outdoor unit and indoor unit.)
• Protective function might work when using it outside the operation range.
• *1: Sound pressure level
– Measured values in manufacturer’s anechoic chamber.
– Because of the surrounding sound environment, the sound levels measured in actual installation conditions might be higher than the specified values here.
-5 -

Type Inverter heat pump
Model name WHU36SZA21S
Power supply 208/230 V ~ 60 Hz
Available voltage range 176—253 V
Fan
Airflow rate CFM (m3/h) 3,416 (5,800)
Type × Q'ty Propeller fan × 1
Motor output W 138
Sound pressure level *1dB (A) 61
Heat exchanger type
Dimensions
(H × W × D) in (mm) 37-15/16 × 39-11/16 × 1-11/16 (964 × 1,008 × 43.3)
Fin pitch FPI 16
Rows × Stages 2 × 38
Pipe type Copper
Fin type Type (Material) Aluminum
Surface treatment Blue fin
Compressor Type Rotary
Refrigerant
Type R410A
Charge lb oz 6 lb 15 oz
g 3,150
Refrigerant oil Type VG74 (POE)
Enclosure Material Steel sheet
Color White
Dimensions
(H × W × D)
Net in (mm) 41-3/8 × 37-3/8 × 13-3/8 (1,050 × 950 × 340)
Gross 47-1/4 × 43-3/4 × 18-1/8 (1,200 × 1,110 × 460)
Weight Net lb (kg) 192 (87)
Gross 215 (97)
Connection pipe
Size Liquid in (mm) Ø3/8 (Ø9.52)
Gas Ø3/4 (Ø19.05)
Method Flare
Pre-charge length
ft (m)
24.6 (7.5)
Max. length 164 (50)
Max. height difference Indoor unit higher than outdoor unit: 98 (30)
Outdoor unit higher than indoor unit: 98 (30)
Operation range Cooling °F (°C) 5 to 118 (-15 to 48)
Heating -4 to 75 (-20 to 24)
NOTES:
• Specifications are based on the following conditions:
– Cooling: Indoor temperature of 80 °FDB (26.67 °CDB)/67 °FWB (19.44 °CWB), and outdoor temperature of 95 °FDB (35 °CDB)/75 °FWB (23.9 °CWB).
– Heating: Indoor temperature of 70 °FDB (21.11 °CDB)/59 °FWB (15 °CWB), and outdoor temperature of 47 °FDB (8.33 °CDB)/43 °FWB (6.11 °CWB).
– Pipe length: 24 ft 6 in (7.5 m), Height difference: 0 ft (0 m). (Between outdoor unit and indoor unit.)
• Protective function might work when using it outside the operation range.
• *1: Sound pressure level
– Measured values in manufacturer’s anechoic chamber.
– Because of the surrounding sound environment, the sound levels measured in actual installation conditions might be higher than the specified values here.
-6 -

Dimensions
Models: WHU09CTA21S and WHU12CTA21S
Unit: in (mm)
Display panel
24-7/16 (620)
1-7/8 (48)
24-7/16 (620)
13-1-16 (331)
10-13/16 (275)
2-7/16 (62) 22-7/16 (570)
Air outlet Air outlet
Air inlet
Liquid pipe Gas pipe
a: Ceiling openings
a: Ceiling openings
24-7/16 (620)
20-7/8 (530)
20-1/4 (515)
24-7/16 (620)
2-1/16 (52)
Electric box Drain pipe
2 (51)
3-11/16
(93)
5-7/16 (138)
5-1/16
(128)
1-5/8 (41)
3-1/8 (79) 5-3/16 (131)
8-7/16 (215)
a: Ceiling openings
Cassette grille (Option [Grid type]) in (mm) 22-5/8 to 23-1/4 (575 to 590)
-7 -

Installation space requirement
Provide sufficient installation space for product safety.
Unit: in (mm)
3/8 (10) or more
(4-Suspension Bolts)
M10 or W3/8 (Locally purchased)
Nut (Locally purchased)
Washer (Accesary)
3/8 (10)
Surface of ceiling
9-5/8 (245)
4-15/16
(110)
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
120 (3000)
or more
Piping connection
Service access door
Piping connection
Service access door
Piping connection
Service access door
- 8 -

Models: WHU18CTA21S and WHU24CTA21S
Unit: in (mm)
33-1/16 (840)
29-7/8 (760)
a: Ceiling openings
a: Ceiling openings
29-7/8 (760)
Liquid pipe Gas pipe
37-3/8 (950)
19-5/16 (490)
18-13/16 (478)
20-1/2 (520)
37-3/8 (950)
Display panel
Electric box
33-1/8 (841)
5 (127)
4-1/32 (102)
4-5/16 (110)
7-1/8 (180) 5-1/8 (130)
1-3/4 (45)
4-5/8 (118) 4-1/32 (102)
9-3/4 (248)
Drain pipe
a: Ceiling openings
Cassette grille (Option [Grid type]) in (mm) 33-7/8 to 35-13/16 (860 to 910)
-9 -

Installation space requirement
Provide sufficient installation space for product safety.
Unit: in (mm)
3/8 (10) or more
9-3/4 (248)
*1/4 (7)
*indicates the dimension between
lower face of indoor unit and
surface of ceiling.
4-1/32
(102)
1-3/4 (45)
Surface of ceiling
W-Nut (Locally purchased)
Washer (Accesary)
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
120 (3000)
or more
Piping connection
Service access door
Piping connection
Service access door
Piping connection
Service access door
- 10 -

Model: WHU36CTA21S
Unit: in (mm)
33-1/16 (840)
29-7/8 (760)
a: Ceiling openings
a: Ceiling openings
29-7/8 (760)
Liquid pipe Gas pipe
37-3/8 (950)
19-5/16 (490)
18-13/16 (478)
20-1/2 (520)
37-3/8 (950)
Display panel
Electric box
33-1/8 (841)
5 (127)
4-1/32 (102)
4-5/16 (110)
7-1/8 (180) 5-1/8 (130)
1-3/4 (45)
4-5/8 (118) 4-1/32 (102)
11-3/4
(298)
Drain pipe
a: Ceiling openings
Cassette grille (Option [Grid type]) in (mm) 33-7/8 to 35-13/16 (860 to 910)
-11 -

Installation space requirement
Provide sufficient installation space for product safety.
Unit: in (mm)
3/8 (10) or more
11-3/4 (298)
*1/4 (7)
*indicates the dimension between
lower face of indoor unit and
surface of ceiling.
4-1/32
(102)
1-3/4 (45)
Surface of ceiling
W-Nut (Locally purchased)
Washer (Accesary)
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
60 (1500)
or more
120 (3000)
or more
Piping connection
Service access door
Piping connection
Service access door
Piping connection
Service access door
- 12 -

Models: WHU09SZA21S and WHU12SZA21S
Unit: in (mm)
11 (250) 11-1/4 (285)
Electric box
Air outlet
12-3/8 (314)
5-7/8 (150)
2 (50)
20-1/8 (510) 4-3/8 (10) × 5/8 (17) Hole
Drain pipe
Air inlet
3 (76)31-7/8 (810)
4-3/8 (112)
1-3/8 (35)
13-1/4 (338) 12-1/4 (310)
6-5/8 (167)
22-7/8 (580)
11-3/4 (297)
5-3/4 (146)
5-7/8 (148)
Gas pipe
25°
Liquid pipe
-13 -

Model: WHU18SZA21S
Unit: in (mm)
14-1/2 (368)
12-3/16 (310)
1-7/16 (36)
13-7/16 (341)
4-7/16 (11) × 11/16 (17) Hole
2 (50)
12-1/8 (309)
Drain pipe
Air outlet
Air inlet
4-5/16 (109)
6-7/16 (164)
4-7/8 (123)
4-15/16 (125)
Gas pipe
Liquid pipe
26-3/8 (670)
12-7/8 (327)
33-7/8 (860)
21-3/8 (542) 6-5/8 (168) 3 (76)
12-1/4 (312) Electric box
- 14 -

Model: WHU24SZA21S
Unit: in (mm)
6-1/8
(155)
2-5/8 (66)
4-1/8
(105)
37-3/8 (950)
7-1/4 (185) 22-7/8 (580)
33-1/16 (840)
16-1/4 (414)
1-5/8 (41)
14-15/16 (380)
13-3/8 (340)
4- Ø5/8 (Ø15) Hole 2-3/4 (70)
Drain pipe
13-9/16 (344)
40-7/8 (1,038)
3-1/2 (88)
Air outlet
Air inlet
Gas pipe
Liquid pipe
Electric box
90°
-15 -

Model: WHU36SZA21S
Unit: in (mm)
4- Ø5/8 (Ø15) Hole
Air outlet
40-7/8 (1,038)
6-1/8
(155)
2-5/8 (66)
3-1/2 (88)37-3/8 (950)
22-7/8 (580)
7-1/4 (185)
1-5/8 (41) 41-5/16 (1,050)
4-1/8 (105)
13-3/8 (340)
14-15/16 (380)
16-1/4 (414)
2-R 5/16 (7.5)
2-1/2 (65)
Air inlet
Drain pipe
13-9/16 (344)
Gas pipe
Liquid pipe
Electric box
90°
- 16 -

Installation space
Models: WHU09SZA21S, WHU12SZA21S, WHU18SZA21S,
Provide sufficient installation space for product safety.
CAUTION
Keep the space shown in the installation examples.
If the installation is not performed accordingly, it could cause a short circuit and result in a lack of
operating performance.
-17 -
¢Space requirement
WHU24SZA21S, and WHU36SZA21S

Refrigerant circuit
Models: WHU09SZA21S, WHU12SZA21S, and WHU18SZA21S
ECS
D
1
3
4
5
6
10
8 9
Cooling cycle
Heating cycle
2
7
List of components
1 Compressor
2 Suction temperature sensor
3 Discharge temperature sensor
4 4-way valve
5 Outdoor heat exchanger
6 Ambient temperature sensor
7 Coil temperature sensor
8 Electric expansion valve
9 Stop valve (Liquid)
10 Stop valve (Gas)
- 18 -

Model: WHU24SZA21S
ECS
D
1
3
5
6
8
12
10 11
Cooling cycle
Heating cycle
4
7
HP
2
9
List of components
1 Compressor
2 High pressure switch
3 Discharge temperature sensor
4 Suction temperature sensor
5 4-way valve
6 Outdoor heat exchanger
7 Coil temperature sensor
8 Defrost temperature sensor
9 Ambient temperature sensor
10 Electric expansion valve
11 Stop valve (Liquid)
12 Stop valve (Gas)
-19 -