23
DST
Series
3.0
Installation
•
General Combustion Air Requirements
Air Inlet Connection
(Flexible boot and band clamps are recommended)
Heater
High Wind Cap
(P/N: SWD-4)
Guidelines:
General
• No more than two 90 degree elbows are allowed.
• Allow for expansion. Use a 4 in. flexible hose to connect the duct to the burner control box.
• In humid environments, use insulated duct, PVC pipe or DWV (drain waste vent) to prevent
condensation on the outer surface.
• Do not draw air from attic space.
• A factory approved wall intake cap (P/N: WIV-4) must be used with horizontal outside intake
ducts. The wall intake cap (P/N: WIV-4) must be installed to prevent blockage. Locate the intake
where dirt, steam, snow, etc. will not contaminate or clog the intake screen.
• Separate air intake duct from vent pipe a minimum of 4 ft. Also, place vent pipe higher than
adjacent air intake duct.
Figure 3.10
•
Air Intake
Chart 3.2
•
Limitations for Length and Size of Combustion Air Intake Duct
4 in. 20 ft.
4 in.(single)/6 in.(dual) 20 ft.
5 in. 30 ft.
4 in.(single)/8 in.(dual) 30 ft.
6 in. 40 ft.
Air Intake Duct Size Max. Intake Length
Duct Size
Max. Intake Length
Single Heater Intake Dual Heater Intake
Consult factory for longer intake lengths.