bulb sizes: BR-40 vs R-40?

[woger151]

I want to replace some recessed flood light bulbs in my basement den with CFL equivalents.

The information label on the reflector says it takes BR-40 (and the bulb in there now has the shape of a BR-40).

There aren't that many choices for CFL BR-40, however, and I'm wondering whether "R-40" is the same thing as BR-40. I've looked around on the web and can't find anything about this.

TIA,

S

[TKM]

The lamps are physically equivalent in terms of reflector diameter; but may be different in overall length (usually called "MOL" or maximum overall length in lamp manufacturers spec. sheets.). The "40" refers to the diameter of the lamp in 1/8 of an inch (yes, it's an odd way to measure lamps; but that's what it is.

So, an R-40 reflector lamp is 40/8 = 5 inches in diameter.

The BR-40 has the same reflector diameter, but has a bulge in the glass near the lens. That doesn't change the optics of the bulb significantly, but it does create more volume inside the bulb. Most BR-40 lamps are 6 1/2 inches from lens to tip of base; but check that dimension in any "R" or "BR" lamp that you buy as a replacement since MOLs can vary and a longer lamp may look glaring and ugly if it sticks out the bottom of shallow "can" fixtures.

While there aren't many listings for BR-40 CFLs, there are enough to find replacements for your standard lamps and BR-40 CFLs are made by the major manufacturers such as GE.

TKM

[RBM]

What you really need to be aware of is that many CF- reflector flood equivalent lamps won't seat properly in the recessed fixture socket. Depending upon the make and model of the recessed fixture, and CF lamp, internal fixture parts can interfere with the lamps ability to be completely screwed down, and of course, you assume the lamp is defective when this happens

[Kevin Ricks]

I might add that all of the CF reflectors, at least the ones I have, take a long time to come up to full brightness ~2 min. or so. And they don't seem to last as long as the non reflector type.

Kevin

[Wayne Boatwright]

On Tue 05 Aug 2008 06:15:16a, Kevin Ricks told us...

@k37g2000hsf.googlegroups.com...

Well, not *all* CFL reflectors. I have 12 23W R40s in recessed cans in my kitchen. They were purchsed nearly two years ago and are used for the better part of the day and evening. They reach full brightness in ~30 seconds. We have had no problems. I don't recall the brand, but the were purchased at Home Depot.

The said poart about CFLs in general is that there don't seem to be any standards that manufacturers follow that would insure consistency across the board.

[woger151]

Thanks for all the responses---very helpful. I'll buy one CFL bulb and try it out before buying lots of them.

Cheers,

S

[TKM]

Any CFLs marked "Energy Star" have to conform to some rather extensive performance specifications involving life, light output, color, etc. See:

Further, samples of the lamp have to be tested on a regular basis and the manufacturer has to provide a toll-free telephone number on the package in case of consumer problems. The dimensions of CFLs are standardized, including the bases too, according to ANSI C78.901-2001. But, some CFLs don't fit into the "can" type downlights because the fixtures (and their sockets) are older than the standard.

The reason for the slow warm-up of some CFLs is that they use an "amalgam" for temperature control. That improves light output in hot fixtures. Amalgam lamps are a good choice for can fixtures as they are usually enclosed and/or surrounded by insulation.

TKM

[Wayne Boatwright]

On Tue 05 Aug 2008 06:16:28p, TKM told us...

Thanks for all that information. I was unaware. I don't know if our lamps are Energy Star compliant. I do know that our recessed can fixtures are brand new and well-ventilated. We had no trouble with the lamps fitting the sockets in the fixtures.