RG CTH3-150 - Manual (Page 41)

SECTION 8: V ENTING
35 of 71
8.11 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.
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.
Use of optional outside combustion air is not
recommended with unvented heaters.
8.11.1 Length Requirements
Follow the constraints listed on Page 32, Section 8.6.
8.11.2 Vertical Outside Air Supply for Single Heater Installation
8.11.3 Horizontal Outside Air Supply for Single Heater Installation
Description Part Number
Vent Cap 4" (10 cm) for 80,000 Btu/h
and 115,000 Btu/h models
90502300
Vent Cap 5" (13 cm) for 150,000 Btu/h
and 200,000 Btu/h models
90502301
SIDE VIEW
Band Clamp
(Recommended)
Flex Hose
(Recommended)
Vent Cap W
all
For 80 and 115 models,
4" (10 cm) Single Wall Pipe.
For 150 and 200 models,
5" (13 cm) Single Wall Pipe.
Burner
4"
(10 cm)
Min.
SIDE VIEW
Description Part Number
Vent Cap 4" (10 cm) for 80,000 Btu/h
and 115,000 Btu/h models
90502300
Vent Cap 5" (13 cm) for 150,000 Btu/h
and 200,000 Btu/h models
90502301