Raypak 751 manual Condensing Heat Exchanger Category

Fig. 27: Horizontal Thru-Wall Direct Venting/Combustion Air with Add-on

Condensing Heat Exchanger (Category IV)

	Venting	Certified Venting	Vent Size	Maximum Vent	Combustion Air	Air Inlet	Max. Air
Model					Intake Pipe	Size	Intake Length
	Category	Material	(inches)	Length (feet)
					Material	(inches)	(feet)
		UL 1738 Certified		35	Galvanized		35
ADB-751	IV	Venting Material e.g.	8	Subtract 10 ft per	Steel	6	Subtract 10 ft
w/CHX		AL29-4C Stainless		elbow, Max. 3	PVC, ABS		per elbow,
		Steel PVC*, CPVC*		elbows	CPVC		Max. 3 elbows
		UL 1738 Certified		35	Galvanized		35
ADB-1001	IV	Venting Material e.g.	10	Subtract 10 ft per	Steel	6	Subtract 10 ft
w/CHX		AL29-4C Stainless		elbow, Max. 3	PVC, ABS		per elbow,
		Steel PVC*, CPVC*		elbows	CPVC		Max. 3 elbows
		UL 1738 Certified		35	Galvanized		35
ADB-1501	IV	Venting Material e.g.	12	Subtract 10 ft per	Steel	8**	Subtract 10 ft
w/CHX		AL29-4C Stainless		elbow, Max. 3	PVC, ABS		per elbow,
		Steel PVC*, CPVC*		elbows	CPVC		Max. 3 elbows

*Contact the manufacturer for details.

**If the boiler is direct vented, a 6 to 8 in. adapter must be installed at the blower inlet.

Table Q: Horizontal Thru-wall Direct Venting with Add-on

Condensing Heat Exchanger

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