Selection Of Pipe Heat Insulating Material - Fujitsu AOU48RLXFZ Design & Technical Manual

2-4.

SELECTION OF PIPE HEAT INSULATING MATERIAL

● Always insulate the refrigerant pipe to prevent condensation and water droplets by the
refrigerant pipe.
● Decide the thickness of the heat insulating material by referring to the recommended minimum
thickness in Table 1. (For installation condition T=90°F DB (32°C DB),humidity≤70%,
humidity≤75%, humidity≤80%, humidity≤85%)
● 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
water leak.
Table1 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/(m·k) is
used. )
Relative humidity
Refrigerant 6.35 (1/4")
pipe 9.52 (3/8")
12.70 (1/2")
Outside
15.88 (5/8")
diameter mm
19.05 (3/4")
(in.)
● When an ambient temperature and relative humidity exceed 90°F DB (32°C DB) and 85%
respectively, please strengthen heat insulation of refrigerant pipe. If necessary put a heat
insulation on indoor unit casing. 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 heatpump type, please
select the heat insulating material which heat-resistant temperature is 248°F (120°C) or more.
Gas pipe
Connection cable
Liquid pipe
Heat insulation
● 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 above figure. It may cause
condensation and capacity drop by heat loss.
Recommended minimum thickness for heat
insulating material (mm)
≤70% ≤75%
8
9
10
10
10
Finishing tape
- (06 - 16) -
≤80% ≤85%
10 13 17
11 14 18
12 15 19
12 16 20
13 16 21
Gas pipe
Liquid pipe
Heat insulation
6. SYSTEM DESIGN