IDEA: energy saving adaptive illumination

Hi,
currently the interior lighting design aims to provide suitable illumination in a space for all purposes. Typically and depending on the size of the space one or more light sources are distributed in a room providing somewhere between minimal and maximal tolerable ambient lighting.

This can be very wasteful for sparingly used rooms and areas where most of the illumination is not used at all. A more economical approach adapts the light to the task and usage at each part of the room. Open floor space, audio visual equipment and comfort chairs do typically require not as much light as a work table or reading chair. Statically by using multiple light sources spread evenly accross the work area requiring good illumination and spread sparingly for ambient illumination the light is more usage directed.

However, most of the work area is not in use all the time. Hence the exposure is not as resourceful as one might want. Also, light fixtures and fittings tend to be embedded in the building or room. Hence, adaptation to a new layout or function of a room is sometimes difficult. Optionally, mobile light sources such as desk lamps are used. Manual attention is required to ensure that the desk light is only switched on when used.

A more useful approach for the illumination is to combine a dimmer controlled light source with a motion sensor. Unlike motion sensitive lighting used for security purposes around properties our motion sensor adapts the lighting level on the amount of movement and the length of time it takes place. Hence, a person sitting statically in a chair will be exposed to little light. Heavy activity, such as playing, working or cleaning result in more motion and thus get granted more illumination.

Sufficient light sources can therefore be distributed in the room for all activities. However, given the self dimming effect combined with the motion sensor only a fraction of the total output is required at any time. Hence, a suitable and sizeable power saving can be achieved.

Unfortunately, motion sensor cannot give sufficient information to detect if someone is reading or knitting for example as opposed to using the remote to switch the TV channel. Some manual adjustment of each light sources should be possible to tune the sensitivity locally to a task. A simple laser pointer could be sufficient to signal to a suitable sensor at the light source that a change of brightness is required.