Watts Aerco Modulex EXT Series Technical Application Manual page 11

Modulex EXT Vent and Combustion Air Application Guide
7. When terminating the combustion air through the roof:
a) Combustion air inlet must be 3 ft. below any vent outlet within 10 ft. See Figures 6 and 7.
b) Combustion air inlet must also face away from the vent outlet. See Figure 6.
Figure 6: Combustion Air Roof Termination Locations
8. All inlet air ducts must be sealed air tight.
9. When using sealed combustion, the combustion air inlet and vent outlet must be located on the
same surface (same wall, roof, etc.). See Figures 7. This is required so that equal pressure zones
are acting on both the air inlet and vent outlet. This makes the installation a balanced vent system,
which helps maintain stable combustion characteristics.
10. For outdoor installations, a downward facing 90° elbow should be added to the inlet air connection
and covered with a bird screen. See Figure 8.
Figure 7: Sealed Combustion Air Inlet and Vent Outlet Locations (Wall & Roof)
TAG-0054_0F
GF-136–V
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Phone: 800-526-0288
Page 11 of 28
09/25/2017