Bryant 355CAV Air Ducts, General Requirements, Ductwork Acoustical Treatment, Downflow Furnaces

	Table 1 – Opening Dimensions (in./mm)
FURNACE	APPLICATION	PLENUM OPENING		FLOOR OPENING
CASING	(APPROVED FACTORY SUPPLIED CASED COILS AND COIL BOX:
WIDTH	CD5, CKR, CAPVP, CARVP, CAPMP, CARMP, CNPVP, CNRVP, AND	A	B	C	D
	KCAKC)
	Upflow Applications on Combustible or Noncombustible	16 in./	24-1/8 in./	16-5/8 in./	24-3/4 in./
	Flooring (KGASB subbase not required)	406 mm	613 mm	422 mm	629 mm
	Downflow Applications on Noncombustible Flooring (KGASB	15-7/8 in./	19 in./	16-1/2 in./	19-5/8 in./
	subbase not required)	403 mm	483 mm	419 mm	498 mm
17 ½ in.
	Downflow applications on combustible flooring (KGASB sub-	15-1/8 in./	19 in./	16-3/4 in./	20-3/8 in./
445 mm	base required)	384 mm	483 mm	425 mm	518 mm
	Downflow Applications on Combustible Flooring with Factory	15-1/2 in./	19 in./	16-1/2 in./	20 in./
	supplied cased coil or Factory supplied coil box (KGASB
		394 mm	483 mm	419 mm	508 mm
	subbase not required)
	Upflow Applications on Combustible or Noncombustible	19-1/2 in./	24-1/8 in./	20-1/8 in./	24-3/4 in./
	Flooring (KGASB subbase not required)	495 mm	613 mm	511 mm	629 mm
	Downflow Applications on Noncombustible Flooring (KGASB	19-3/8 in./	19 in./	20 in./	19-5/8 in./
21 in./	subbase not required)	492 mm	483 mm	508 mm	498 mm
	Downflow applications on combustible flooring (KGASB sub-	18-5/8 in.	19 in./	20-1/4 in./	20-3/8 in./
533 mm
	base required)	473 mm	483 mm	514 mm	518 mm
	Downflow Applications on Combustible Flooring with Factory	19 in./	19 in./	20 in./	20 in./
	supplied cased coil or Factory supplied coil box (KGASB
		483 mm	483 mm	508 mm	508 mm
	subbase not required)
	Upflow Applications on Combustible or Noncombustible	23 in./	24-1/8 in./	23-5/8 in./	24-3/4 in./
	Flooring (KGASB subbase not required)	584 mm	613 mm	600 mm	629 mm
	Downflow Applications on Noncombustible Flooring (KGASB	22-7/8 in./	19 in./	23-1/2 in./	19-5/8 in.
24-1/2 in./	subbase not required)	581 mm	483 mm	597 mm	498 mm
	Downflow applications on Combustible flooring (KGASB	22-1/8 in./	19 in./	23-3/4 in./	20-3/8 in./
622 mm
	subbase required)	562 mm	483 mm	603 mm	518 mm
	Downflow Applications on Combustible Flooring with Factory	22-1/2 in./	19 in./	23-1/2 in./	20 in./
	supplied cased coil or Factory supplied coil box (KGASB
		572 mm	483 mm	597 mm	508 mm
	subbase not required)

355CAV

AIR DUCTS

General Requirements

The duct system should be designed and sized according to accepted national standards such as those published by: Air Conditioning Contractors Association (ACCA), Sheet Metal and Air Conditioning Contractors National Association (SMACNA) or American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) or consult The Air Systems Design Guidelines reference tables available from your local distributor. The duct system should be sized to handle the required system design CFM at the design static pressure.

When a furnace is installed so that the supply ducts carry air circulated by the furnace to areas outside the space containing the furnace, the return air must also be handled by a duct(s) sealed to the furnace casing and terminating outside the space containing the furnace.

Secure ductwork with proper fasteners for type of ductwork used. Seal supply- and return-duct connections to furnace with code approved tape or duct sealer.

Flexible connections should be used between ductwork and furnace to prevent transmission of vibration. Ductwork passing through unconditioned space should be insulated to enhance system performance. When air conditioning is used, a vapor barrier is recommended.

Maintain a 1-in. (25.4mm) clearance from combustible materials to supply air ductwork for a distance of 36 in. (914.4mm) horizontally from the furnace. See NFPA 90B or local code for further requirements.

For a furnace not equipped with a cooling coil, the outlet duct shall be provided with a removable access panel. This opening shall be accessible when the furnace is installed and shall be of such a size that the heat exchanger can be viewed for possible openings using light assistance or a probe can be inserted for sampling the air stream. The cover attachment shall prevent leaks.

Ductwork Acoustical Treatment

Metal duct systems that do not have a 90 degree elbow and 10 ft (3 m) of main duct to the first branch take-off may require internal acoustical lining. As an alternative, fibrous ductwork may be used if constructed and installed in accordance with the latest edition of SMACNA construction standard on fibrous glass ducts. Both acoustical lining and fibrous ductwork shall comply with NFPA 90B as tested by UL Standard 181 for Class 1 Rigid air ducts.

Supply Air Connections

Upflow Furnaces

Connect supply-air duct to 3/4-in. (19.0mm)flange on furnace supply-air outlet. The supply-air duct attachment must ONLY be connected to furnace supply-/outlet-air duct flanges 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.

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 combustible material, supply air duct attachment must ONLY be connected to an accessory subbase or factory approved air conditioning 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. Supply air opening duct flanges must be modified per Fig. 22.

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,

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