Ceiling fan
A ceiling fan is a mechanical fan mounted on the ceiling of a room or space, usually electrically powered, suspended from the ceiling of a room, that uses hub-mounted rotating blades to circulate air. Ceiling fans typically rotate more slowly than other types of circulating fans, such as electric desk fans. They cool people effectively by introducing slow movement into the otherwise still, hot air of a room. Fans never actually cool air, unlike air-conditioning equipment, they in fact heat the air due to the waste heat from the motor and friction, but use significantly less power (cooling air is thermodynamically expensive). Conversely, a ceiling fan can also be used to reduce the stratification of warm air in a room by forcing it down to affect both occupants' sensations and thermostat readings, thereby improving climate control energy efficiency.
Radiant cooling
Radiant cooling panels are generally attached to ceilings, but can be attached to walls also. They are usually suspended from the ceiling, but can also be directly integrated with continuous dropped ceilings. Modular construction offers increased flexibility in terms of placement and integration with lighting or other electrical systems. Lower thermal mass compared to chilled slabs means they can’t easily take advantage of passive cooling from thermal storage, but controls in panels can more quickly adjust to changes in outdoor temperature. Chilled panels are also better suited to buildings with spaces that have a greater variance in cooling loads. Perforated panels also offer better acoustical dampening than chilled slabs. Ceiling panels are also very suitable for retrofits because they can be attached to any ceiling. Chilled ceiling panels can be more easily integrated with ventilation supplied from the ceiling. Panels tend to cost more per unit of surface area than chilled slabs.