Germicidal lighting

Apparatus for disinfecting air of a room, the apparatus comprising:

• a ceiling fan having a rotatable fan blade;
• a fixture configured to be suspended into the room from a ceiling;
• a light-emitting diode (“LED”) that:
• is configured to emit germicidal light that is incident on the ceiling;
• is part of an LED array that is disposed in the fixture such that the LED does not rotate with the fan blade;
• and
• has an upper surface corresponding to a plane;
• and
• an opaque surface defining a perimeter;
• wherein:
• absent reflection off an environmental object, the apparatus does not emit germicidal light below the plane;
• if the germicidal light emitted by the LED propagates outward along the plane and is incident on the opaque surface, the opaque surface interferes with such germicidal light;
• and
• the LED is disposed inside the perimeter.