Regarding the sealed enclosures, about 3 years ago we began replacing the incandescent bulbs in the stable with CFLs. Most fixtures are Vapor Tight units meant for wet locations, and out of 18 bulbs, we've had 3 fail so far.
The bulbs above the aisle (20+', a PITA to change) are PAR types in unenclosed ceramic sockets mounted on 4"X4" boxes, and out of 22 bulbs, we've had 3 failures.
The bulbs are typically switched on and off several times during the day. The stalls have large windows, but trees surround the barn, so natural illumination is subdued.
The conventional CLFs take a couple of minutes to reach full brilliance, and the reflector models about 5 minutes. But we have useable illumination within a second of the switch being thrown.
Changing bulbs used to be a constant chore. Now it's been several months since I was up on a ladder.
We haven't noticed any difference in the electric bill that we can attribute to the CFLs, but we run fans in the stalls during the summer and heated water buckets during the winter. Yeah, the horses are spoiled!
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