A chiller includes a main condenser that has a refrigerant condensate sump with an internal weir or standpipe that maintains at least a minimum liquid seal between the outlets of the main condenser and a heat-recovery condenser. An optical waveguide is formed in a surface portion of the substrate. The multimedia system directs the presentation of the sub-narratives by interfacing with presentation components for each media type through a custom interface component for that media type that implements a common application interface.