MCA
Pro
45/65/90/115
MCA-Pro ISM Rv.4.1 2/2017
46
4.8.4 Lengths of the air/flue gas pipes
Type 2: Sealed combustion systems applications
Vertical or horizontal venting systems for both, the flue
gases and combustion air operating at two different
pressure zones or vent terminal locations.
Combustion air supply
Flue gas outlet
i
• Flue gas vertical termination must be
tapered with a bird/rodent screen.
• Horizontal breeching proportions shall be
kept to a minimum.
• Horizontal sections of the venting must slope
downward towards the boiler ½" per linear
foot (42mm/m) and adequate vent support
must be provided.
• Horizontal sections in the air supply must
slope away from the boiler towards the supply
opening and incorporate a drain connection if
the route rises from a lower point.
• The maximum combined length L as seen in
the drawing can be found in the table.
Conventional chimney application with sealed air (two pipe system) and different pressure zones
MCA
Pro
Vent ø
Max.
length
Number of elbows 90˚ and equivalent feet/meters
1
2
3
4
5
6
7
8
in
mm
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
35
3
80
131
40
118
36
105
32
92
28
79
24
66
20
52
16
39
12
26
8
45
3
80
131
40
118
36
105
32
92
28
79
24
66
20
52
16
39
12
26
8
65
3
80
108
33
95
29
82
25
69
21
56
17
43
13
29
9
16
5
3
1
65
4
100
131
40
115
35
99
30
83
25
67
20
51
16
34
11
18
6
2
1
90
4
100
131
40
115
35
99
30
83
25
67
20
51
16
34
11
183
6
2
1
115
4
100
131
40
115
35
99
30
83
25
67
20
51
16
34
11
18
6
2
1
Conventional chimney application with sealed air (two pipe system) and different pressure zones
MCA
Pro
Vent ø
Max. length
Number of elbows 45˚ and equivalent feet/meters
1
2
3
4
5
6
7
8
in
mm
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
ft
m
35
3
80
131
40
127
39
123
38
119
36
115
35
112
34
108
33
104
32
100
30
45
3
80
131
40
127
39
123
38
119
36
115
35
112
34
108
33
104
32
100
30
65
3
80
108
33
104
32
100
31
96
29
92
28
89
27
85
26
81
25
77
23
65
4
100
131
40
127
39
122
37
118
36
114
35
110
34
105
32
101
31
97
30
90
4
100
131
40
127
39
122
37
118
36
114
35
110
34
105
32
101
31
97
30
115
4
100
131
40
127
39
122
37
118
36
114
35
110
34
105
32
101
31
97
30
4. Installation
Combustion
air supply
Flue gas
outlet
L = Maximum length
Max. Length :
*
*
* with a 4" to 3" adaptor
Содержание MCA Pro 115
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