Thermo Pride OMD-70 - Manual (Page 15)

All installations and services must be performed by qualified service personnel.
If the combustion air passageway cannot terminate outside of the skirting or enclosure, a
permanent opening with a minimum of 50 square inches of unobstructed infiltration (free
area) for ventilation air must be provided for adequate combustion. This permanent opening
must be located no less than 12 inches from the bottom of the enclosure or skirting.
Figure 3.
Slit the corners of connector duct down to the top of the base assembly. If metal projects more
than 1-inch above the top of the base assembly, trim the flanges down to 1-inch. While the top
of distribution duct is being pulled up with one hand, bend down each side of the connector
duct tightly to the base assembly with the other hand. This assures a tight connection between
the base assembly and the connector duct and that the distribution duct will be full size. Use
high temperature tape and/or high temperature silicone caulking on all joints and seams to
minimize air leakage. Secure the base assembly to the floor with two screws in the front
flange.
2. Cottage Base Model: OMCCOT-BASE
The OMCCOT-BASE cottage base (Figure 1B) is required for a freestanding cottage base
installation. The cottage base is designed to permit the installation of an 8-inch x 12-inch register
in each of the two side panels and the rear panel. This allows combustion air to be drawn from
outside, or inside, the structure whichever is appropriate, or permissible. See section G.
COMBUSTION AIR for further details regarding combustion air requirements.
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