Nordyne RC 92+, RL 90+ installation instructions Vertical Venting, Vent Protection

4.Insure the combustion air inlet pipe (for a 2 pipe installation) has a 90 degree termination elbow as shown in Figures 21 and 22.

Vent Configuration to
Provide 12" Minimum
height above
Snow Level.	12" Min.
	19" Max.
Outside	Support	12" Above
Wall
		Normally
		Expected
	1/2"	Snow
		Level
	Armaflex
	Insulation or
	Equivalent
	(If Required)

Figure 21. Alternate Horizontal

Vent Installation

Note: A combustion air intake must be provided with an elbow opening downward. The screen provided with the furnace must be installed in the elbow to prevent entry of debris or creatures.

When the vent pipe must exit an exterior wall close to the grade or expected snow level, a riser should be provided as shown in Figure 20.

Table 6 describes the maximum length of flue pipe that can travel through an unconditioned space or an exterior space. The total vent length must not exceed the lengths noted on Table 5.

Vertical Venting

Figure 23 shows the proper installation and clearances for vertical vent termination. The roof penetration must be properly flashed and waterproofed with a plumbing roof boot or equiva- lent flashing. Termination spacing requirements from the roof and from each other must be per Figure 23.

	Maximum Flue Pipe Length in
	Unconditioned and Exterior Spaces
Winter Design	Without Insulation	With Insulation
Termperature (°F)	(feet)	(feet) ‡
20	45	70
0	20	70
-20	10	60

‡= Insulation thickness greater than 3/8 inch, based on an R value of 3.5 (ft*°F*hr)/(BTU*in)

Table 6. Vent Protection

Exhaust Vent
Option B
Mounting Kit
Faceplate Secured			Exhaust Vent
to Wall with Screws	18" Min.		Option A
Combustion	36" Max.	8" Min.
Air Inlet
Exhaust Vent
Option C
		18" min.
	18" Min.	36" max.	Grade
			Level
	36" Max.	12" Min. to	or Normal
7" Min.			Snow
		Normal Snow Level
		Inlet	Exhaust

Figure 22. Exhaust and Combustion Air Pipe Clearances

25