Blue Ridge KIT-BMPK12 User manual

Concealed Duct Plenum Kits
User Guide
KIT-BMPK12
KIT-BMPK18
KIT-BMPK2124
Thank you for purchasing a ductboard plenum kit from Alpine Home Air Products. These kits
consist of two pre-cut pieces of ductboard material, from which you can make a Supply and
Return plenum for your Blueridge Concealed Duct unit. These kits are correctly sized to fit the
unit you purchased.
What you will need:
● Blueridge concealed duct kit
● Ductboard knife (serrated edge)
● Foil tape
● Mastic

Box contents:
1. Supply/Return ductboard with V-trench cuts.
2. Ductboard end cap piece
Color legend:
Red - Guide line for separating Supply and Return
Green - Insulation removed to leave a 2” overlap of backing only

Step 1. Using a serrated knife, cut to separate the Supply and Return plenums. Using the
pre-marked line will give you a 30” Supply and an 18” Return. You can make your own marks
and change the length to suit your particular installation.
Step 2. Lay out the Supply plenum with foil backing side down. Fold along the V trench cuts to
create a box shape. Align the backing-only lap joint as shown to create a box with rectangular
shape.
Step 3: Use foil tape to close up the plenum. Be sure the joint is as depicted above, and the
resulting plenum shape has 4 right angles.
Step 4: Attach the end cap by inserting the insulation side into either end of the supply plenum.
If the fit is too tight, use your serrated knife to bevel the insulation until you get a nice snug fit all
the way around. Use the backing overlap to make a good taping surface and secure with foil
tape. You now have a 5 sided supply plenum, ready to attach to the supply opening of your
concealed duct unit.
Step 5: Repeat Steps 2 and 3 to create a Return Plenum. Return plenums do not have an end
cap.
Step 6: Use the serrated knife or ductboard hole cutting tool to cut holes for attaching duct
takeoffs.

Step 7: Attach duct takeoffs according to the table below. Insert the tabbed end of the takeoff
into the plenum and bend the tabs to make a secure fit. Finish with tape and mastic for an
airtight seal.
Air handler model
# of takeoffs
Diameter takeoff
BMKH12CD1
Up to 2
6” takeoff
BMKH18CD1
Up to 3
6” takeoff
BMKH21CD1
Up to 3
7” takeoff
BMKH24CD1
Up to 4
7” takeoff
Step 8: Attach the Supply plenum to the concealed duct, fitting around the flange. Attach with
foil tape, seal with mastic. Option - use sheetmetal screws into the flange for a more secure
attachment. Still use tape and mastic for air sealing.
Step 9: Attach the Return plenum over the return opening. There are no flanges on the return
side, but the Return plenum is the same size as the unit chassis, and can be taped on directly.
We recommend that you remove the filter screen and reattach further upstream in a location
you can access for maintenance, such as the return register.
Note: Ductboard is subject to minor tears and dents in shipping, or while being worked. These
can easily be patched with foil tape. A good, airtight plenum is the most important
consideration.