Fi
d
b
b il
&
h
B il
M
l
Finned copper tube gas boilers & water heaters – Boiler Manual
7
F
F
Figure 1
Hoizontal Air Intake an Venting for a Single Direct Vent System
Figure 2
Horizontal Air Intake and Venting for Multiple Direct Vent Systems
When running horizontal combustion air and venting for
single or multiple units, exhaust and combustion air ter-
minals 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.
5 FT
1.5 m
1.5 FT
0.5 m
2 IN.
5.0 cm
4001 & LARGER
2001 TO 4000
1001 TO 2000
500 TO 1000
MBH
FT
m
15
4.6
20
6.1
5
1.5
10
3.1
kW
146 TO 293
293 TO 586
586 TO 1172
1172 & LARGER
16 FT 4.9 m
1/4 IN. PER FOOT
20 mm/m
1.5 FT 0.5 m
1000 BTU’S
