Space-Ray LTU Series Installation And Operation Instructions Manual page 45

In multiple heater applications multiple heater applications, the combustion air intake may be ducted individually or common ducted in the
multiple heater applications multiple heater applications
same configuration as shown for venting in Section 17.0). For combustion air intake duct sizing, please refer to
the Vent Sizing Table Vent Sizing Table and use the diameter indicated, based on the number of heaters per duct.
Vent Sizing Table Vent Sizing Table
Vertical
Through the roof
Through Sidewall
-44-
Horizontal
Form #43155010
Sept 2011