Lennox P1BRENTW-A Installation Instructions Manual page 19

The single outlet system is designed to be installed either flush with the front of the
BRENTWOOD or extended out slightly from the face of the fireplace (if installing with a
brick or thick facing for example). To extend the double outlet system, it will be necessary
to purchase two adjustable lengths (7B26ZL2A). To extend the single outlet, it is necessary
to install the insulation strip provided with the system. A maximum of 3 ½" (89 mm) of
extension is provided by the single outlet system (see figure 16).
When installing the double outlet system, the hot air outlets can be installed in the same
room as the fireplace, or one or both of the outlets can be installed in adjacent or upper
rooms. Installing the ducts at different elevations will tend to exhaust more heat out of the
higher outlet (figure 15).
Figure 15
17
Figure 16
Figure 17