Nortek B6BV Series, Installation Instructions Manual

6

NotE:

 Downflow installations require the use of a plenum 

connector (or its equivalent) if the supply air ducts pass 

through the floor of the structure. This factory supplied 

accessory must be installed in the floor cavity and attached 

to the supply air duct before the downflow unit is installed. 

Available plenum connectors for all B6BV air Handlers are 
listed in 

Table 1 (page 7)

. All return air in downflow 

applications must enter through the top of the unit.
Position the air handler on top of the plenum connector and 

secure together with sheet metal screws. The screws must 

penetrate the sheet metal cabinet and plenum connector. 

Tape or seal all seams if required by local code.
Plenum Connector Installation

The plenum connector is designed for use with trunk ducts 

having a minimum width of 12”. If sufficient space is not 

available to adequately bend and secure duct tabs it may 

be necessary to attach the connector to the duct using 

sheet-metal fasteners and seal with an approved foil tape.

The connector may be field constructed but must meet 

requirements as listed in the unit installation instructions.
1. Measure and mark the outline of the cut-out on the 

floor. See 

Figure 3 (page 7)

 for cutout dimensions.

ImpoRtANt! 

Cut-outs in the floor and  ductwork must 

be carefully located to avoid misalignment of the air 

handler and supply / return air ducts.

2. Cut out the floor opening.

 NotE:

 To allow some clearance for installing the plenum 

connector, cut the opening 1/16” larger than the actual 

cutout drawn.

3. Center the plenum connector in the floor opening with 

bottom tabs resting on top of the supply air duct.

4. Mark the cut-out area on the supply air duct by tracing 

around the connector tabs of the plenum connector. 

Figure 2. Installation configurations

Return

Air

Return

Air

UPFLOW

DOWNFLOW

AIR HANDLER INStALLAtIoN

These Installation procedures are suggested for typical 

air handler installations. Since all installations are different 

from each other, the sequence of these steps may 

differ from the actual installation. 

only qualified HVAc 

technicians should install this air handler

.

The B6BV series air handler is shipped ready for vertical 

upflow installation and is approved for attic, basement, 

alcove/closet or crawlspace installation with zero clearance 
to combustibles. See 

Figure 1 (page 4)

 for required 

installation clearances. 

this appliance is approved only 

for indoor use.

•  remove the shipping carton and user’s manual from 

the equipment.

•  The unit must be leveled at installation and attached to 

a properly installed duct system.

•  The surface that the air handler is mounted on must 

provide sound physical support of the unit.

•  The air handler must be installed so that all electrical 

components are protected from water.

•  If a louvered door is installed across the front of this 

unit, the appliance must be mounted flush or behind 

front edge of finished wall.

Upflow Installations

All air handlers are factory shipped, ready for upflow 

installation. All return air must enter from the bottom of the 

unit when installed in the upflow configuration. A typical 
upflow unit is shown in 

Figure 2

.

Position the air handler on top of the return air duct and 

secure together with sheet metal screws. The screws 

must penetrate the sheet metal cabinet and duct. Tape 

or seal all seams if required by local code.
To attach the supply air duct to the air handler, bend the 
perforated flanges (

Figure 4 (page 7)

) upward 90° 

with a pair of wide duct pliers. Position the duct on top 

of the air handler and secure together with sheet metal 

screws. Make sure the screws penetrate the sheet metal 

casing and flanges. Tape or seal all seams if required by 

local code.

NotE:

 If an upflow pedestal mounting stand is fabricated 

in the field, the stand must be constructed strong 

enough to support the unit with all accessories installed 

(approximately 130 lbs. for B-cabinet models and 200 lbs. 

for C-cabinet models). The construction of the pedestal 

stand must also allow for at least 235 in

2

 free opening 

(300 in

2

 for C-cabinet models) in the application. Field 

fabricated upflow pedestal mounting stands must be 

constructed of noncombustible materials. Position the air 

handler on top of the mounting stand and secure together 

with sheet metal screws. The screws must penetrate the 

sheet metal cabinet and duct. Tape or seal all seams if 

required by local code.

Downflow Installations

B6BV air handlers can be converted to downflow operation 

by flipping an upflow unit 180°. A typical installation of 
the unit in a downflow application is shown in 

Figure 2

.