Armstrong International
IOM-706 V2.0
Flo-Direct Water Heater
Installing Intake Air Ducting
Page 16 of 45
Installing Intake Air Ducting
Note:
Do not
use manifold connected to other appliances.
Do not
run heater under negative air pressure.
Top must be solid metal.
Typical enclosure in
sheet metal box with
screen.
Roof
Provide
independent
support for duct.
Do not rest weight
on heater.
Bird screen
required.
Wall
Duct diameter must be at least
as large as intake diameter on
blower. 15% diameter increase
is recommended every 10 feet
removed from heater.
Material can be:
• CPVC
• Galvanized sheet metal
• Single wall stainless steel
