Auto-learn Light Levels

[Andrew Millne]

What are people's thoughts on an "Auto-learn light levels" feature in Cortex?

I've been tweaking my light levels today and was thinking that using the difference in light levels between when the light is off and when it is switched on would be a good way of learning an optimum light level trigger. My thinking is there will be a sweet spot where turning on the light will increase the light level just enough to make a difference but during the brighter periods of the day relatively no difference at all.

[Paul_B]

Interesting thread. I've thought about this based on time of year as well. During the winter when outside light levels are low then you can cope with lower light levels indoors as well. The reverse is also when summer sunshine requires lights to come on earlier.

Of course this is just my observation

Paul

[Gumby]

Isn't this going to be rather dependant on relative position of sensor, natural light, artificial light and the position most in need of light (due to particular task performed)?

I guess you could use user demand (in terms of override/toggle requests) to help bias the system. But that raises a lot of other issues...

[chris_j_hunter]

yep, interesting ... suspect same goes for heating - ie: in Winter indoors can be cooler, in Summer indoors can be warmer ...

[Gumby]

Interesting thread. I've thought about this based on time of year as well. During the winter when outside light levels are low then you can cope with lower light levels indoors as well. The reverse is also when summer sunshine requires lights to come on earlier.

Of course this is just my observation

Paul

Kinda counter intuitive, since I would have thought the light needed for a particular task would not be seasonal, and if anything light would be needed sooner in winter due to reduced contribution from natural daylight.

Perhaps this is most relevant in entrance areas (or anywhere you might be wearing photosensitive specs)? Or due you think this is primarily a psychological factor, similar to the need for heating boost when it's cold outside?

[Paul_B]

Or due you think this is primarily a psychological factor, similar to the need for heating boost when it's cold outside?

My own experience suggests it is psychological and very similar to the heating boost. Just like climate control in the car, in winter the temp is set at 21 degrees in summer I set it around 18 degrees.

I guess it is quite a lot more complicated then first impressions may have you believe

[chris_j_hunter]

another factor would be age etc of people - grandma would almost certainly like it warmer & lighter ...

so looks like there's lots to go at with the tools Cortex provides !

Maybe with a Mir:ror & an RFID doll for each person, so they can tell Cortex when they're home, and it can set /do things accordingly - eg; reading lamp brightness according to who & when (day, month, year) ... ?

[toscal]

A lot more offices and museums are doing this. Using daylight to its maximum advantage can save on lighting costs. And more and more architects are considering lighting in the over all designs of buildings now.
But it does produce a few headaches in planning.
The main problem is the sensor placement, and control logic. Wrong sensor placement can lead to lights not coming on soon enough or too early and couple this with poorly designed logic control and you've got lights oscillating on and off. Another problem is type of sensor and control type. I know some systems just use a basic dawn dusk type controller and a relay. While others use actual light level sensors and some form of computerised controller.
Then as already stated depending on the task will also depend on light levels. There are actual light level guide lines for various situations, if you want I can post them here as a PDF file. Then the older you get the more light you need. But this is where it gets really tricky as the colour of the light also plays an important part, lower lights levels are possible with certain colours, can't remember which colours or colour temps work better.