Carrier 58ZAV ÐConfined Space Air for Combustion and, ÐSupply Air Connections

			DUCTS TO
		OUTDOORS
					1 SQ IN.
					PER 4000
					BTUH*
	VENT THROUGH ROOF
	(CATEGORY I)
		12″ MAX		D	12″￿
		1 SQ IN.	A RETURN	VENT	MAX
		PER 2000			F
RETURN		BTUH*	AIR	THROUGH
	12″ MAX			ROOF
AIR				(CATEGORY I)	1 SQ IN.
	1 SQ IN.				PER 4000
					BTUH*
SPACE	PER 1000	DUCTS		CONFINED SPACE
	SPACE				1 SQ IN.
	BTUH* IN DOOR	TO			OUTDOORS
INTERIOR	OR WALL	OUTSIDE
	UNCONFINED
HEATED
	6″ MIN				PER 4000
					BTUH*
	(FRONT) †
		1 SQ IN.
	1 SQ IN.		B	E	G
		PER 2000
	PER 1000	BTUH*			12″￿
	BTUH* IN DOOR	12″ MAX		C	MAX
	OR WALL			12″ MAX
	12″ MAX	SUPPLY AIR		DUCT
					1 SQ IN.
				TO
SUPPLY AIR				OUTDOORS	PER 4000
					BTUH
		*Minimum dimensions of 3 in.

*Minimum opening size is 100 sq in. with minimum dimensions of 3 in.

†Minimum of 3 in. when type B-1 vent is used.

NOTE: Use any of the following combinations of openings:

A & B C & D D & E F & G

			A93387					A93388
Fig. 3ÐConfined Space: Air for Combustion and				Fig. 4ÐConfined Space: Air for Combustion and
Ventilation from an Unconfined Indoor Space					Ventilation from Outdoors
	→Table 2ÐMinimum Free Area Of Combustion Air Opening
	AIR FROM UNCON-	OUTDOOR AIR THROUGH			OUTDOOR AIR THROUGH		OUTDOOR AIR THROUGH
58ZAV	FINED INDOOR
		VERTICAL DUCTS			HORIZONTAL DUCTS		SINGLE DUCT
FURNACE	SPACE
INPUT	Free Area	Free Area of	Round		Free Area of	Round	Free Area of	Round
(BTUH)	of Opening	Opening and Duct	Pipe		Opening and Duct	Pipe	Opening and Duct	Pipe
	(Sq In.)	(Sq In.)	(In. Dia)		(Sq In.)	(In. Dia)	(Sq In.)	(In. Dia)
46,000	100	11.50	4		23.0	6	15.33	5
69,000	100	17.25	5		34.5	7	23.00	6
92,000	100	23.00	6		46.0	8	30.67	7
115,000	115	28.75	7		57.5	9	38.33	7
135,000	135	33.75	7		67.5	10	45.00	8

*Free area shall be equal to or greater than the sum of the areas of all vent connectors in the confined space. Opening area must be increased if other gas appliances in the space require combustion air.

Step 3ÐSupply Air Connections

DOWNFLOW FURNACES

Connect supply-air duct to supply-air opening on furnace. The supply-air duct attachment must ONLY be connected to furnace supply/outlet or air conditioning coil casing (when used), when installed on non-combustible material. When installed on combus- tible material, supply-air duct attachment must ONLY be con- nected to an accessory subbase or factory approved air condition- ing coil casing. DO NOT cut main furnace casing to attach supply side air duct, humidifier, or other accessories. All accessories MUST be connected external to furnace main casing.

HORIZONTAL FURNACES

Connect supply-air duct to supply air opening on furnace. The supply-air duct attachment must ONLY be connected to furnace

supply/outlet or air conditioning coil casing (when used). DO NOT cut main furnace casing to attach supply side air duct, humidifier, or other accessories. All accessories MUST be connected external to furnace main casing.

Step 4ÐReturn Air Connections

Do not install the furnace on its back or sides. Safety control operation will be adversely affected. Never connect return-air ducts to the back of the furnace. A failure to follow this warning can cause a fire, personal injury, or death.

The return-air duct must be connected to return-air opening provided as shown in Fig. 1. DO NOT cut into casing sides or back

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