On Mar 24, 2:55*pm, DerbyDad03 wrote:
On Mar 24, 3:24*pm, (Don Klipstein) wrote:
* The reason: *The fluorescent tubing gets hotter with the outer bulb
around it. *Fluorescent lamps only work well over a limited temperature
range, so the ones with outer bulbs are designed to work best at the high
temperature that they achieve.


Thanks for the reply, but your "reason" doesn't explain *why* they
start dimmer or take longer to warm up.

Your reason states 2 facts, both of which I agree with:

If you said something like "If they started brighter and heated up
quicker then the air inside the outer bulb would expand too quickly
and the bulb would explode" *that* would be a reason for the dim start
and the slow warm up.

I believe what he meant was that if they were designed to work
efficiently when cold, then when they heated up to the higher
temperatures caused by being enclosed, they would operate
inefficiently and herhaps burn out prematurely due to excess heat.

I use a defferent brand (what the local HD carries) and have replaced
every light in the house, inside and out, with various wattages and
colors of the same brand. I'm guestimating that they reach 90% of full
brightness within a fraction of a second...except for the two enclosed
floods I just recently bought (same brand), which take quite a while
to warm up. It's the type of bulb you bought, not the manufacturer.
They are working as expected.