21
Marvair Wall Mount Heat Pump I&O Manual
11/2021 New
For units with electric heat, a 1” clearance around the duct extensions is required. The duct extensions must be made of
galvanized steel with a minimum thickness of .019” as per the NFPA standards 90A & 90B.
Figure 4 - Heat Pump Wall Mounting Detail
2.7 Mounting the Unit
1. For wiring into the back of unit, locate the lower of the two knock-outs on the wall side of the Heat
Pump. Drill a one inch hole in the building wall to match this opening. Allow sufficient clearance to
run 3/4" conduit through the hole and to the unit.
2. Apply a bead of silicone sealer on the wall side of the mounting brackets on the Heat Pump. Circle
the mounting holes with the silicone bead.
3.
Using an appropriate and safe lifting device
, set the Heat Pump on the bottom support bracket
mounted on the wall. You must stabilize the unit on the bracket with the lifting device or by some
other means - the bracket alone is not sufficient.
4. Make sure that the duct flanges are properly aligned with the wall opening. Adjust as necessary.
5. Note the holes in each side bracket. Using the holes for guides, drill holes through the wall with a
3/8 inch drill bit. Insert the 3/8" bolts or lag screws through the brackets. Tighten the bolts to secure
the unit.
6. Apply a bead of silicone where the top flange and side brackets contact to the structure wall.
7. Fasten the top flange to the wall using #10 x 1/2 inch sheet metal screws.
8. On the inside of the structure, wall sleeves must be installed in the supply and return air openings.
The sleeves should be trimmed to fit flush with the inside wall. For units with electric heat, a one
inch clearance is required around the duct extensions. The duct extensions must be constructed of
galvanized steel with a minimum thickness of .019” as per the NFPA standards 90A & 90B.
9. Check the fit of each sleeve to its mating flange for possible air leaks. Apply silicone sealer to close
any gaps. Install the air return and supply grilles.
10. To minimize sound transmission, a latex based, insulating foam seal may be applied between the
duct extensions and the frame for the wall openings. NOTE: DO NOT USE THE FOAM ON ANY
UNITS WITH ELECTRIC RESISTANT HEATERS.
