Roberts Gorden TF-380, TF-350, TF-300 Outside Combustion Air Supply, Vertical Outside Air Supply

TF-SERIES INSTALLATION, OPERATION AND SERVICE MANUAL

9.13 Outside Combustion Air Supply

IMPORTANT: If the building has a slight negative pressure or corrosive contaminants, such as halogenated hydrocarbons, are present in the air, an outside combustion air supply to the heater is required. Seal all combustion air pipe joints.

For TF-120 4" (10 cm) single wall pipe or for TF-160/200/250/300/350/380 5" (13 cm) single wall pipe, PVC pipe, aluminum flex duct, or equivalent may be used for outside air supply.

9.13.2 Vertical Outside Air Supply

Use of optional outside combustion air is not recommended with unvented heaters.

The air supply duct may have to be insulated to prevent condensation on the outer surface. The outside air terminal must not be more than 1' (31 cm) above the vent terminal.

9.13.1 Length Requirements

Follow the constraints listed on Page 38, Section 9.6.

Description	Part Number
Vent Cap 5" (13 cm)	90502301

Minimum of

2’ (0.61 m)

42