Hi Sue! Welcome back, I don't recall hearing from you for a while.

The "2700K" and similar numbers are the color temperature. It may seem like a paradox, but the higher the number the "cooler" (more bluish) the light. The 2700K lamp will be very close to incandescent color, and the 5000K lamp more like blue-sky outdoor light.

A common shorthand is to combine the first digit of the CRI (color rendering index, an indication of how well the lamp helps you distinguish colors) and the first two digits of the color temperature.

So, from the number CF13LD/E/827, I'd guess that what you have now is a compact fluorescent 13 watt lamp, 2700K color temperature, 80+ CRI (probably 82). I don't know what the LD and E stand for. The manufacturer's website might explain it, if you're really that interested.

I can't absolutely guarantee it, but the spare you identify as "CF13DD/E/827 - 13 Watt - 4 Pin G24q-1 Base - 2700K" sounds like it should work just fine.

G24 lamps are just starting to get established. A greater variety of spares should be available at home centers in the next couple of years. With luck you won't have to order online next time.

If I *want* a warmer color, am I fine to get one with a higher number?

It's interesting that the G24 seems a bit new. The lamp I got had a flange/tab on one side of the base, and it blocked the lamp from fitting into the socket. We had to break it off w/ a pliers. I'm wondering if the light fixture wasn't manufacturered properly to spec. I'd assumed it was the odd-brand lamp that they included w/ the fixture.

But now I'm thinking it's the fixture itself, bcs all the recognizable-name brands show that same tab on their lamp bases.

(and aren't you impressed that I know that "lamp" is the electrician's term for the bulb, and NOT for the fixture? ;-) )

Actually what most people perceive as "warmer" (yellower as apposed to blue) tones are lower color temperatures. The really higher color temperatures are as close to "daylight" as you are going to get with these things.

Ah--great, thanks!

You're not likely to find many warmer than 2700K. I've seen a few CFs in the 2500-2550 range, but they're pretty uncommon.

Your statement that you had to break off a tab on the lamp concerns me. What brand is the fixture, and where did you get it?

I don't remember. It didn't seem any more "fly by night" than anyone else's.

And the guy from the electrician's was the one who broke the tab off. I pressed him on the idea that it might not be as safe, and he assured me it would be fine. I would never have done that, if left to my own devices; I'd have put the old fixture back and started over.

I was crabby about the stupid light anyway, bcs I thought I'd ordered one w/ a different pin system (for which I already had the expensive bulbs), but when we opened the box, it was different. I didn't want to pay for the electrician to come twice, so I decided not to return the fixture but just go ahead.
Then when he got to the very end and was putting in the bulbs, he discovered that the tab keeps them from fitting. Once he broke that off, they fit very snugly and everything aligned perfectly. They don't get jiggled much, and as I said, they fit well.

I think he and I both assumed that the off-brand bulb was the problem, not the fixture itself. But now that I am finally looking for the replacement bulbs (time to stock up--they haven't burned out, not by a long shot), I see that they all look the same as the photo on the off-brand bulb's box.

(and I don't remember if that tab we took off was reflected in the photo on the box or if it was extra--I may see if I can get up there w/ a ladder to check)

I doubt there is anything off standard or out of spec with your bulb. You probably had a "G24Q-2" base lamp instead of a "G24Q-1" base lamp, or vice versa.

I was looking for the difference between 13w and 18w G24 fixtures, and I've found some information.

http://www.hugeinventions.com/faq/g24lamps.html

This basic FAQ is the basic difference between 2-pin and 4-pin lamps and the nib configurations. It seems like the difference may be in the ballast, but all of my searching for ballast information leads me to wholesalers and importers. I can't tell if there's any problem jamming an 18 watt bulb into a 13 watt fixture. I'm trying to increase the wattage on a fixture I have, and I don't want to replace the whole darn thing just to get more light. That's not very "green" either.

I also found more information than you could possibly need on your lamp labeling.

http://www.energyrating.gov.au/library/pubs/2009-ref-manual-lighting.pdf

Go to page 122 of the .pdf, or search the document for "G24", and it will tell you everything about the ANSI and NEMA labeling conventions for fluorescent lamps.

Huh, my wife is a plant grower (legal stuff) and it's not that hard to find CFs in the 4000-5000K range.