If daylight enters the room, this may in many
cases completely or partly replace the electric lights at certain times.
Lights can often be switched off when nobody is
in the room.
It is cheapest to turn off the lights manually, but this does not always
this works satisfactorily.
You can use presence-controlled lighting and ventilation operation by
using motion detectors or presence detectors,
which turn off and the stop the systems.
Energy consumption can often be reduced by 20-80% by the presence- or
Occupancy and motion detectors respond to changes in heat radiation and
motion that occurs when someone staying in a room. When the room is
empty, the light is turned off.