5
5. Refrigerant piping work
5.1. Refrigerant pipe (Fig. 5-1)
Maximum difference between heights of indoor unit and outdoor unit, the length of
refrigerant piping and the number of bends in piping are within limits shown below.
Models
(A) Pipe length
(B) Height
(C) Number of
(one way)
difference
bends (one way)
SEZ-A12AR
max. 20 m
max. 12 m
max. of 10
SEZ-A18AR
max. 30 m
max. 15 m
max. of 10
SEZ-A24AR
max. 30 m
max. 15 m
max. of 10
*1: Height difference limitations are binding regardless of which unit, indoor or out-
door, is positioned higher.
Avoid the following places for installation where air conditioner trouble is liable to
occur.
• Where there is too much oil such as for machine or cooking.
• Salty environment as seaside areas.
• Hot-spring areas.
• Where sulfide gas exists.
• Other special atmospheric areas.
• This unit has flared connections on both indoor and outdoor sides. (Fig. 5-2)
• Refrigerant pipes are used to connect the indoor and outdoor units as shown in the
figure below.
• Insulate both refrigerant and drainage piping completely to prevent condensation.
• Refrigerant adjustment … If pipe length exceeds 7 m, additional refrigerant (R410A)
charge is required.
(The outdoor unit is charged with refrigerant for 7 m pipe length.)
–
SEZ-A12AR:30g/m
SEZ-A18AR:50g/m
SEZ-A24AR:50g/m
Piping preparation
• Refrigerant pipes of 3, 5, 7, 10 and 15 m are available as optional items.
(1) Table below shows the specifications of pipes commercially available.
(2) Ensure that the 2 refrigerant pipes are well insulated to prevent condensation.
(3) Refrigerant pipe bending radius must be 10 cm or more.
Caution:
Using careful insulation of specified thickness. Excessive thickness prevents
storage behind the indoor unit and smaller thickness causes dew drippage.
Ø6.35
SEZ-A12:Ø9.52
SEZ-A18:Ø12.7
SEZ-A24:Ø15.88
1
2
b
(C)
(B)
(A)
a
Fig. 5-1
Fig. 5-2
Pipe length
7 m
maximum
No additional
charge required
Refrigerant
to be added
Additional
charge required
Exceeding
7 m
a
Indoor unit
b
Outdoor unit
1
Indoor unit
2
Outdoor unit
Pipe
For liquid
For gas
For liquid
For gas
For liquid
For gas
Outside diameter
mm
inch
6.35
1/4
9.52
3/8
6.35
1/4
12.7
1/2
6.35
1/4
15.88
5/8
Model
SEZ-A12AR
SEZ-A18AR
SEZ-A24AR
Insulation
material
Heat resisting
foam plastic
0.045 specific
gravity
Insulation
thickness
8 mm
8 mm
8 mm
8 mm
8 mm
8 mm
Min wall
thickness
0.8 mm
0.8 mm
0.8 mm
0.8 mm
0.8 mm
1.0 mm
