John Grabowski wrote:

"sid" wrote in message
...
Finishing my basement and I need to calculate the number of can lights
needed to install in the drop ceiling. Dimensions are approx 21' x
22' and 7'7" high. I read one post recommending a can light every
4' and another every 6'. I want the space to be lit enough for work
space or food prep, but most of the time I intend to dim them down to
reading, PC, or TV watching levels.

Any suggestions on how to calculate the number and placement of cans ?


*It depends on the size of the recessed light and the bulb that you
intend to use. For bright even lighting with a 4" diameter can you will
need to space them closer together. A 6" can with an R40 bulb can have
nice even illumination 6' apart. As someone else suggested multiple
switches can be helpful for the different uses of the space that you
anticipate. Don't plan on using dimmers with CFL's. There aren't many
choices out there and I haven't heard of any that give satisfactory
results.

Do you want even lightning at the floor, or at work surfaces (like at a
book)?

If your work area is lit by just one can you will get shadows on the
work from your hands/body. For doing work (like food prep)I would want
light from multiple cans at the work height. That requires a lot more
cans than even illumination. IMHO it is one of the problems of using
recessed lighting. Recessed lightning is more of a problem in basements
because the ceiling height is usually lower.

The light spread from the can depends on the bulb, trim and how far
recessed the bulb is.

You could buy a couple cans, vary the spacing, and look at the results.

--
bud--