In 4, W. Boatwright said:

On Sun 27 Apr 2008 09:02:12a, Robert Allison told us...

If you invest in the special fixtures (I have been involved with
these mostly in can lights) and install them, you will come out
ahead financially. Although the dimmable on board ballasts cost
more than standard can lights, you only have to buy them once.

Coincidentally, that's exactly what I want to dim. I have 12 recessed cans
in my kitchen, each with a 23 watt conventional screw-in CFL. Full power
is ideal when I'm doing a lot of cooking and cleanup (which is usually at
night), but there are many times when I wish I could dim them when I don't
need that much light.

The bulbs that carry their own onboard ballast that makes them
dimmable are way more (about 20 bucks a piece) than standard
cfls. Since you are going to have to change them over the years,
you will save over and over by going with the dimmable fixtures.

Yes, I found out just how expensive when I first looked for the CFLs, and
didn't buy the dimmable units because of the price and the rumor? that they
didn't always perform well at dimming.

I suppose the best choice is to just bite the bullet and replace the cans
with dimmable models. I will have to find suitable retrofit models, as it
is a vaulted ceiling with no crawl space above to work from.

Keep in mind that fixtures with ballasts take a specific model or
limited range of specific models of pin-base ballastless CFLs.

I advise to get one that takes a more common and industry standard bulb,
such as 13 watt twintube (F13TT, AKA PL-13)
or 13 watt quadtube (F13DTT, AKA PLC-13)
or 26 watt quadtube (F26DTT, AKA PLC-26).

Any other bulb should be one that is available at home centers and is
available under the "Big 3" brands (GE, Philips or Sylvania - preferably
in the online catalogs of all 3, though model numbers may vary slightly).

Personally, I have been most impressed with CFL recessed ceiling
fixtures if they take 13 watt twintubes or doubletwintubes over 13 watts,
two bulbs per fixture, with the bulbs in a horizontal position. Also, I
have found 26 watt doubletwintubes to be nice and especially
impressively bright.

The more common sizes (13 watt twintube and 26 watt doubletwintube
especially) are available in different colors, though home centers
normally don't carry all available colors.

- Don Klipstein )