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The single outlet system is designed to be installed either flush with the front of the BIS ULTRA 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 17).
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 16).
Figure 16
Figure 17
Figure 18
