Bryant 581A Iii. - Field Fabricate Ductwork, Iv. - Make Unit Duct Connections, Flue Hood Location

III. STEP 3 — FIELD FABRICATE DUCTWORK

On vertical units, secure all ducts to roof curb and building structure. Do not connect ductwork to unit. Use flexible duct connectors between unit and ducts as required. Adequately insulate and weatherproof all ductwork located outdoors, joints, and roof openings with counter flashing and mastic in accordance with applicable codes. Insulate ducts passing through unconditioned space, and use vapor barrier in accor- dance with the latest issue of SMACNA (Sheet Metal and Air Conditioning Contractors National Association) and ACCA (Air Conditioning Contractors of America) minimum instal- lation standards for heating and air conditioning systems.

Ducts passing through an unconditioned space must be insu- lated and covered with a vapor barrier.

A minimum clearance to combustibles of 1 in. for the first 24 in. of ductwork is required for all units with electric heat. Cabinet return-air static shall not exceed –0.35 in. wg with economizer or –0.45 in. wg without economizer.

IV. STEP 4 — MAKE UNIT DUCT CONNECTIONS

Unit is shipped for thru-the-bottom duct connections. Duct- work openings are shown in Fig. 1, 4, and 5. Duct connections are shown in Fig. 6. Field-fabricated concentric

ductwork may be connected as shown in Fig. 7 and 8. Attach all ductwork to roof curb and roof curb basepans. Refer to installation instructions shipped with accessory roof curb for more information.

WARNING: For vertical supply and return units, tools or parts could drop into ductwork and cause an injury. Install a 90 degree turn in the return ductwork between the unit and the conditioned space. If a 90 degree elbow cannot be installed, then a grille of sufficient strength and density should be installed to prevent objects from falling into the conditioned space.

V.STEP 5 — INSTALL FLUE HOOD AND WIND BAFFLE

Flue hood, screen, and wind baffle are shipped secured under main control box. To install, secure flue hood and screen to access panel with screws provided. See Fig. 9. The wind baffle is then installed over the flue hood.

NOTE: When properly installed, flue hood will line up with combustion fan housing. See Fig. 10.

NOTE: Do not drill in this area; damage to basepan may result in water leak.

Fig. 6 — Air Distribution — Thru-the-Bottom (581A180, 240 Unit Shown)

NOTE: Dimensions A, A’, B and

B’ are obtained from field-supplied ceiling diffuser.

Shaded areas indicate block-off pans.

Fig. 8 — Concentric Duct Details

WIND BAFFLE

INLET LOUVERS

	FLUE
	SCREEN
NOTE: Do not drill in this area; damage to basepan may result in water
leak.
Fig. 7 — Concentric Duct Air Distribution	Fig. 9 — Flue Hood Location
(581A180, 240 Unit Shown)

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