Desa (V)CB36N(E), (V)CB36P(E) operation manual Venting Installation

VENTING INSTALLATION

Continued

This appliance may be vented through a manu- factured chimney liner system if all are listed, inspected and approved by local codes and/or building authorities.

The examples shown in Figure 10 are typical of most B-vent installations and code practices.

WARNING: This gas fireplace andventassemblymustbevented directlytotheoutside.Theventing system must NEVER be attached to a chimney serving a separate solid fuel burning appliance.

Example 1: Shows the minimum allowable system height and lateral offset for a 60° or greater inclina- tion. Code specifies that offsets at 60° or greater are considered horizontal and must follow the 75% rule for lateral to total vertical system height. Codes also allows only one offset in the total system when at 60° or greater. The total vertical height in this example represents the minimum height of 8 feet and therefore the allowable lateral is 6 feet when the 75% rule applies. If the lateral length must exceed 75% then the system must be sized in accordance with the Category I venting tables.

Example 2: Shows multiple offsets each at 45° of inclination. Multiple offsets are permitted if they do not exceed 45° of inclination. The total lengths of the two offsets are not required to meet the 75% rule.

Example 3: Shows a single offset at 45° of inclina- tion and therefore the lateral length at 10 feet of offset does not have to meet the 75% allowable rule.

In each case the offsets must be supported and firestops must be positioned wherever the vent must pass through a sub-floor, ceiling joist or an attic overhang. The vent pipe must terminate vertically into a listed type vent cap and extend a sufficient height through an approved roof flash- ing, roof jack or a roof thimble. At all points the listed clearances must be maintained.

Vent terminations must be located in accordance with height and proximity rules of NFPA No. 54 or CAN/CSA B149. These rules apply to vents at 12" diameter or less and require a minimum height in accordance with the roof pitch and a minimum of 8 foot distance from a vertical wall or obstruction (see Figure 11, page 10).

If venting horizontally through a side wall be- comes necessary, a listed thimble approved for use with B-type vent must be used. Check with your local codes before venting through a side wall.

Some codes areas allow the use of existing B-type vent systems if the system is at or above the recom- mended diameter of the flue.

The flue connection must be made using listed B-type connectors and the existing system must be code inspected for damage and proper installation.

It is not recommended that this appliance be common vented with and existing gas burning appliance. However, if it becomes necessary to common vent the appliance. The venting system must be sized and configured in accordance with the common venting guides Appendix G of the cur- rent National Fuel Gas Code NFPA No. 54/ANSI Z223.1 and in Canada with CAN/CSA B149.

Note: Before connecting this appliance to an existing vent system or a common venting sys- tem consult with your local architect planner, or building official.

		Listed
		Vent Cap		Listed		Listed
				Vent Cap
						Vent Cap
	Maintain		Maintain
			Listed
	Listed		Clearance
	Clearance						Maintain
			Support Each	Maintain
							Listed
			Lateral At	Listed			Clearance
			Least Every	Clearance
		60	6 Feet	45
				12' Min.
8' Position						45°	10'
					Position
		6'
12' Min.	Firestop		Position	45	Firestop		12' Min.
			Firestop
		Maintain		Maintain			Maintain
		Listed		Listed			Listed
		Clearance		Clearance			Clearance

EXAMPLE 1	EXAMPLE 2	EXAMPLE 3
	Figure 10 - Typical B-Vent Configuration

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