Desa CGB35N Installing Heater, Continued, VENTING HEATER continued Proper Size Vent, Vent Types

INSTALLING HEATER

Continued

VENTING HEATER (continued)

Proper Size Vent

To safely vent heater, the vent connector pipe must be the same diameter as the draft hood outlet on the rear of the heater. Pipe that is too small can cause flue gas to spill from the heater. Fasten vent connector to the draft hood outlet with a sheet metal screw.

Vent Types

Prefabricated or Masonry All-Fuel Chimney - This is a masonry chimney or a residential-type prefabricated chimney. Only use prefabricated chimneys listed by Underwriters Laboratories (UL), Inc.

Type-B Vent - These vents are made of noncombustible, corrosion resistant material. They are certified by a nationally recognized testing agency. Type-B vents are double-walled pipe. Clearances to combustible construction must be in accordance with the listing of the particular type-B vent. Type-B vents are currently listed as B-1, B-1 1/2, and B-2.

The illustrations below show both vent types. The illustration shows typical construction of each type of venting system. Minimum clearances and lengths are added to the illustrations.

	Terminate at least 5' above draft hood.
	If vent extends over 5' above roof,
	support with guy wires or braces.
	Vent Cap
	Must Be At
	Least 2 Feet
	Above
	Highest Point
	Within 10
	Feet.
	Maintain Listed
	Clearance of Vent
	Support If
	Necessary
	Lock Joints
5'	6"
	Min.
Min.
	Lock Joints
	Heater
	Vent
	Connector

Seal Around

Collar and

Flashing

Lock

Joints

Position Support

Firestop Laterals

Maintain Listed

Clearance of

Vent53"

Min.

Vertical Vent

Heater

10

Prefabricated or Masonry	Type-B Vent
All-Fuel Chimney

Figure 5 - Typical Construction of Venting Systems

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