36
5-3. Insulating the Refrigerant Tubing
Tubing Insulation
●
Standard Selection of Insulation Material
Under the environment of the high temperature and high
humidity, the surface of the insulation material is easy
to become c
ondensation
. This will result in leakage and
dew drop. See the chart shown below when selecting the
insulation material. In case that the ambient temperature and
relative humidity are placed above the line of the insulation
thickness, the condensation may occasionally make a dew
drop on the surface of the insulation material. In this case,
select the better insulation efficiency.
* However, since the condition will be different due to
the sort of the insulaton material and the environmental
condition of the installation place, see the chart shown
below as a reference when making a selection.
Standard Selection of Tubing Insulation
Sort of insulation material
Polyethylene heat resisting
material
Upper limits of usage
temperature
Gas tubing : 120 °C or above
Other tubing : 80 °C or above
Calculating condition
Thermal conductivity
of insulation material
0.043 W/(m · K)
(Average temperature 23 °C)
Refrigerant temperature
2 °C
Two tubes arranged together
40
10
20
30
40
50
50
60
70
80
90
100
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
10
20
30
40
50
40
50
60
70
80
90
100
40
50
60
70
80
90
100
40
50
60
70
80
90
100
40
50
60
70
80
90
100
40
50
60
70
80
90
100
40
50
60
70
80
90
100
o6.35
o15.88
o25.4
o19.05
o22.22
o9.52
o12.7
Ambient temperature [°C]
Ambient temperature [°C]
Ambient temperature [°C]
Ambient temperature [°C]
Ambient temperature [°C]
Ambient temperature [°C]
Thickness
30mm
Thickness
30mm
Thickness
30mm
Thickness
30mm
Thickness
30mm
Thickness
30mm
Thickness
20mm
Thickness
20mm
Thickness
20mm
Thickness
20mm
Thickness
20mm
Thickness
20mm
Thickness
10mm
Thickness
10mm
Thickness
10mm
Thickness
10mm
Thickness
10mm
Thickness
10mm
Ambient relative humidity [%]
Ambient relative humidity [%]
Ambient relative humidity [%]
Ambient relative humidity [%]
Ambient relative humidity [%]
Ambient relative humidity [%]
Liquid tube
Gas tube
Insulation
00_291827_2WAY_Eng.indb 36
2017/7/5 13:41:34
