A safety barrier heat exchanger for a heating appliance such as a fireplace or furnace is provided. The safety barrier heat exchanger includes a housing configured for attachment across the viewable opening of a fireplace or a barrier window of a furnace, and a plurality of optically transparent, semi-transparent or translucent safety barriers secured within the housing in spaced apart relationship to define a tortuous or serpentine passageway through which a forced bulk flow of ambient air is passed across a viewable opening or barrier window more than one time. Also provided are fireplace systems comprising the safety barrier heat exchanger.