ADAAG Manual

Mounting Height

ADAAG specifies a signal height 80 inches above the highest floor level within the space or 6 inches below the ceiling, whichever is lower. (This can be measured to the centerline or to the bottom edge of the appliance). The 80 inch height is based on research indicating it to be the most effective for a 75 cd lamp. It is also consistent with the minimum headroom clearance required for protruding objects. However, photometric calculations of lamp intensity for mounting heights of 80 and 96 inches show only nominal differences and can be practically considered to be equivalent. In multi-purpose facilities where bleacher seating, athletic equipment, backdrops, or other moveable elements may at times be deployed or in libraries, convention centers and other building types where devices would not be visible when installed at the specified height, optimal signal placement may require study and the development of alternative intensity and placement calculations as an "equivalent facilitation" which permits departures from ADAAG specifications if equal or greater access is provided. What is most important is that strobes, whether projecting from walls or suspended from ceilings, be at least 6 inches below the ceiling plane to minimize smoke obscuration.