MULTYRAMA GUIDA INGLESE 21-10-2009 12:57 Pagina 16
9.
10.
INSTALLATION TECHINIQUE
THERMAL INSULATION
Thermal insulation for central heating, air-conditioning and sanitary plumbing installations
Ruling 10/91, relevant to containment of energy consumption and the legislative decree DPR 412/93 imposes that pipes used in the realization of thermal systems be correctly covered by insulating material. Obviously, in the case of thermal installations and/or hot water sanitary plumbing systems insulation has the aim to avoid dispersion, while for air conditioning, besides avoiding increase in temperature of channelled fluid, impedes formation of condensation on the pipe’s surface due to humidity in the air. At an equal thickness of insulation, energy saving will, as a consequence, be far higher the more significant the insulating power of the insulation and just as less as the surface area of thermal exchange. The Legislative Decree 412/93 fixes the minimum thickness values of the insulation in function with its thermal conductivity and the diameter of the pipe to be insulated; the Decree states, moreover, that the thicknesses given in the following table be applied : CASE A
Fixed point at the base of
Fixed point in the column’s
column area
intermediary
equally, for systems placed in unheated localities (eg.
Garages, cellars, etc.) CASE B
multiplied for a reduced ratio of 0,5 per systems placed
internally in walls of a building’s perimeter. CASE C
multiplied for a reduced ratio of 0,3 for systems placed
in non-external structures, nor adjacent to unheated localities. Thermal conductivity of insulation w/m°K
Absorption of lenght with compensation ring in a direct conductor
External diameter of pipes <20
from 20 to 39
from 40 to 59 from 60 to 79 from 80 to 99
>100
0,030
13
19
26
33
37
40
0,032
14
21
29
36
40
44
0,034
15
23
31
39
44
48
0,036
17
25
34
43
47
52
0,038
18
28
37
46
51
56
0,040
20
30
40
50
55
60
0,042
22
32
43
54
59
64
0,044
24
35
46
58
63
69
0,046
26
38
50
62
68
74
0,048
28
41
54
66
72
79
0,050
30
44
58
71
77
84
The pipes supplied by Prandelli with insulation foresee the use of Expanded Polyethylene with closed cells and 6 and 10 mm thickness with external Polyethylene film as a barrier against humidity.
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Colori compositi
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