In one aspect, the invention is a lighting assembly comprising a housing defining an internal space within the housing, and an ambient space surrounding the housing, a light source within the internal space; a high capacity desiccant within the internal space, the high capacity desiccant being nonregenerating at temperatures of up to about 50 degrees Celsius and about 11.0% relative humidity; and a diffusion tube having a first opening proximate to the internal space and a second opening proximate to the ambient space, the diffusion tube providing gaseous communication between the internal space and the ambient space.