2-4. Selection of pipe heat insulating material
Always insulate the refrigerant pipe to prevent condensation and water droplets by the refrigerant
pipe. For selection of pipe heat insulating material, refer to following items.
• Decide the thickness of the heat insulating material by referring to the recommended minimum
thickness in Table 1. (For installation condition T=32 °CDB, humidity≤70%, humidity≤75%, humidi-
ty≤80%, humidity≤85%)
Table 2-1 Size of refrigerant pipe and recommended minimum thickness of heat insulating material (In case a
heat insulating material which thermal conductivity is equal to or less than 0.040 W/mk is used.)
Recommended minimum thickness for heat insulating material
(mm)
Relative humidity
≤70%
≤75%
≤80%
≤85%
Refrigerant pipe
outside diameter
(mm [in])
6.35 (1/4)
8
10
13
17
9.52 (3/8)
9
11
14
18
12.70 (1/2)
10
12
15
19
15.88 (5/8)
10
12
16
20
19.05 (3/4)
10
13
16
21
22.22 (7/8)
11
13
17
22
25.40 (1)
11
13
17
22
• When the outdoor unit is installed in a higher position than the indoor unit, fill the connecting part
gap with putty, etc. to prevent the dew condensation water of the valve of the outdoor unit from
flowing to the indoors from the gap between the pipe and the heat insulating material.
• Liquid pipe and gas pipe should be completely insulated with same specification.
• In case not to insulate and not to seal refrigerant pipe completely, it will become the cause of wa-
ter leak.
• When an ambient temperature and relative humidity exceed 32 °CDB and 85% respectively,
strengthen heat insulation of refrigerant pipe. If necessary put a heat insulation on indoor unit cas-
ing. When not strengthening heat insulation of refrigerant pipe, the surface of the heat insulation
may be dewed.
• Since gas pipe becomes high temperature at heating operation for heat pump type, select the heat
insulating material which heat-resistant temperature is 120 °CDB or more.
• Make sure that pipe is covered completely by the heat insulation, not exposing to air. Inadequate
heat insulation may cause condensation.
• Do not cover heat insulation gas and liquid pipes together as figure below. It may cause conden-
sation and capacity drop by heat loss.
Gas pipe
Connection cable
Finishing tape
Liquid pipe
Heat insulation
Gas pipe
Liquid pipe
Heat insulation
- 189 -
2-4. Selection of pipe heat insulating material
2. Pipe design
SYSTEM
DESIGN
SYSTEM
DESIGN
Summary of Contents for AUYG18LVLB
Page 151: ...Part 2 OUTDOOR UNIT SIMULTANEOUS MULTI AOYG72LRLA AOYG90LRLA ...
Page 181: ...Part 3 SYSTEM DESIGN ...
Page 333: ...Part 4 OPTIONAL PARTS ...
