A 75W PAR30 bulb is going to be the same heat output whether it is halogen or regular incandescent. The halogen capsule is actually inside the larger bulb.

The PAR30 halogen isn't going to consume anywhere near that power or generate an appreciable amount of heat. The biggest issue here is that some of them don't have the best ballast design and can cook themselves to death in a tightly enclosed fixture. You won't know unless you try .

The second paragraph above should start out with...
"The PAR30 CFL isn't going ..."

thanks for the quick response ronnatalie.

To clarify then, incandescent and halogenn are equally safe an dthrow off the same amount of heat. Is there a real advantage to the halogen...or a negative?

I think I understood you to mean I could use a PAR40....in the can...they will be open....worst case it wont last? I already have 6 of these suckers in a box on my shelf from last year...never used. Again, Par40 cfls...look like they will easily fit the 6" in can....just want to be safe....I think they should be brighter...ratings compared to 90w vs 65w I think....

As far as the fixture is concerned, 75 watts incandescent is the same heat regardless of halogen vs. regular. The filament burns hotter in the halogen, but that's inside the quartz element that is inside the "fake bulb" that they put around it to make it a PAR40.

The advantage is that you get more light out of them because it burns hotter, the halogen cycle keeps the hotter burning filament from burning out faster. The quartz envelope keeps the bulb small enough for this all to happen.

for th enon dimmable 4 cans I think I will try the PAR40 cfs. It seams they should throw mre light (allbeit after 30 secnds or so), they should be brighter than a comparable PAR30 cfl, and mre economical.

I then need t buy 9 dimmable incandecsents or hallogens. Which do you think I should go with...regular, hallogen...any partuclar brand..

Halogens are also incandescent. They'll cost you a little more for slightly better light output but cost more, otherwise about the same.

The point about halogens is that they are brighter for the same wattage. So you can use a lower-wattage bulb. Like a 45w halogen for a 60w incandescent.

I'm not sure, but I don't think halogens like being run at reduced voltage. It lessens their lifespan.

weedmeister is correct, halogens can be run dimmed but lessens their lifespan. To counter than, you can run them a full blast once in a while to start the chemical reaction inside the bulb of halogens.