Desa GVB35N 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.

5'

Min.

Vent Cap	Seal Around
	Collar and
Must Be At	Flashing
Least 2 Feet
Above
Highest Point
Within 10
Feet.
Maintain Listed		Lock
Clearance of Vent
		Joints
	Position	Support
	Firestop
Support If		Laterals
Necessary
Lock Joints	Maintain Listed
	Clearance of	53"
6"	Vent
		Min.
Min.
	Vertical Vent
Lock Joints
Heater	Heater
Vent
Connector

10

Prefabricated or Ma-	Type-B Vent
sonry All-Fuel Chimney

Figure 5 - Typical Construction of Venting Systems

100353