Fi
d
b
b il
&
h
B il
M
l
Finned copper tube gas boilers & water heaters – Boiler Manual
7
F
F
Figure 4
Horizontal Combustion Air and Venting for a Single Unit
Figure 5
Horizontal Combustion Air and Venting for a Multiple Units
When running horizontal combustion air and venting for single or multiple units, exhaust and combustion air terminals must be
installed on the same plane (outside wall) in order to prevent pressure diff erences due to prevailing winds. In cold climates, double-
wall or insulated inlet pipe recommended to prevent condensation.
16 FT
4.9 m
1/4 IN. PER FOOT
20 mm/m
1.5 FT
0.5 m
0
1
2
3
4
5
6
7
8
9
0
5
10
15
20
Horizontal Distance, X
Y ,
ec
nat
si
D l
aci
tr
e
V
2000 & Larger
1201 To 2000
901 To 1200
200 To 900
1000 BTU'S
1.5 FT
0.5 m
2 IN.
5.0 cm
