Which architectural drawings would indicate the location of diffusers in a building?

Reflected Ceiling Plans are specifically designed to show the layout and design elements of the ceiling in a building, including the placement of items like diffusers, light fixtures, and other ceiling-mounted components. This type of drawing provides a visual representation from a viewpoint looking up at the ceiling, making it easier to identify where air diffusers, which distribute conditioned air, are located.

In contrast, Floor Plans primarily display the layout of rooms, walls, and other elements at the floor level, but do not typically indicate ceiling details or the placements of ceiling fixtures. Electrical Plans focus on the electrical layout of a space, detailing wiring and outlets, but they do not convey information about air distribution. Finally, Site Plans provide an overview of the entire site and its surroundings, including things like landscaping and building footprints, without any information related to the interior ceiling or diffuser locations.

Thus, Reflected Ceiling Plans are the most suitable and accurate for identifying where diffusers are situated in a building's design.