Monessen Hearth 36CDVXTRN Vertical Sidewall Applications, Maximum number of 90 elbows is three

needs to have an immediate rise before going hori- zontal. NOTE: Be careful not to distort the outer flex as this will affect the performance of the fireplace.

6.Secure the collar to the firestop by bending the tab out on the firestop and running a screw through the tab and collar.

7.From outside the house, slide the termination onto the collars sticking through the firestop.

8.Secure the termination to the house with the four (4) screws provided. Be sure to seal around the termi- nation and house cladding.

Vertical Sidewall Applications

Since it is very important that the vent- ing system maintain its balance between the combustion air intake and the flue gas exhaust, certain limitations as to vent configurations apply and must be strictly adhered to.

The Vent Graph shows the relationship between vertical and horizontal side wall venting and will help to deter- mine the various dimensions allowable.

Minimum clearance between vent pipes and combustible materials is 1” (25 mm) on top, bottom and sides unless otherwise noted.

When vent termination exits through foundations less than 20” below siding outcrop, the vent pipe must flush up with the siding. It is always best to locate the fireplace in such a way that minimizes the number of offsets and horizontal vent length.

The horizontal vent run refers to the total length of vent pipe from the flue collar of the fireplace to the face of the outer wall.

Horizontal plane means no vertical rise exists on this portion of the vent assembly.

•The maximum horizontal vent run is 20 ft. (6.1 m) when the vertical vent rise is 7¹⁄₂ ft. (2.3 m). (Fig. 26)

Vertical Dimension	Maximum
	20 ft. (6.1m)
7¹⁄₂’ Minimum When
Horizontal Run is
20’	7TDV90
7.5'
(2.3m)
	7TCDV90
CFM141

Fig. 26 Maximum number of 90° elbows is three (3).

CDVX Series Direct Vent Gas Fireplace

•The maximum number of 90° elbows per side wall installation is three (3).

•If a 90° elbow is used in the horizontal vent run (level height maintained) the maximum horizontal vent length is reduced by 36” (914 mm). (Fig. 27) This does not apply if the 90° elbows are used to increase or redirect a vertical rise. (Fig. 28)

Maximum

3' (914mm)

		7TCDV90
			CFM142
Fig. 27	Maximum horizontal vent run.
			7 ft.
		B	(2134 mm)
	A	10 ft.
		(3048 mm)
		90° Elbow = 3 ft.
		A + B = 17 ft. (Max.)
7 ft. 6 in.
(2286 mm)
			CFM147
Fig. 28	Maximum vent run with elbows.

Example: According to the chart the maximum horizontal vent length in a system with a 7.5’ (2.3 m) vertical rise is 20’ (6 m) and if a 90° elbow is required in the horizontal vent it must be reduced to 17’ (5.2 m). In Figure 28 Dimension A plus B must not be greater than 17’ (5.2 m).

•The maximum number of 45° elbows permitted per side wall installation is two (2). These elbows can be installed in either the vertical or horizontal run.

•For each 45° elbow installed in the horizontal run, the length of the horizontal run MUST be reduced by 18” (45 cm). This does not apply if the 45° elbows are installed on the vertical part of the vent system.

•The maximum number of elbow degrees in a system is 270°. (Fig. 29)

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