World's Slowest 15W CFL's

CFLs slowness is a real PITA in most applications and is really hindering their acceptance. I'm trying to convert to LED bulbs wherever possible. But LED prices still hurt and the brightness is not there yet.

Anyways, I am using CFLs throughout the house anyway and found that over-sizing them (in terms of wattage and light output) appears to help remedy the slowness.

Of course, oversizing defeats the purpose of having CFLs but in places like bathroom it's the only way to see anything in dark. If I use 40W light output CFL, I'll be out of bathroom before it reaches the full brightness, LOL. So I stepped up to 60W. By the way, Phillips CFLs are not fast either.

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This is a CFL with an outer bulb. Those generally start dimmer and take longer to warm up.

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.

- Don Klipstein ( snipped-for-privacy@misty.com)

I use a CFL as well as a string of LED holiday lights in my bathroom. The LED lights are usually enough.

I've been using CFL's for a long time now, since they were first readily available. I've had the best luck with Sylvania. GE performs OK for me, but the Menard's brand (FEIT?) and the L of A are pretty sad.

I can understand how someone whose first experience with CFL's is with L of A would have a negative opinion of CFL's in general, because their products really suck. FEIT isn't much better.

OTOH -- if Sylvania products aren't doing it for you, odds are nobody's will.

Have you tried maybe using a single 13w Sylvania CFL in there instead of a spot?

DA wrote:

Don,

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:

1 - The tubes get hotter due to the outer bulb 2 - They are designed to work best at their final operating temperature

They are also white, they are also made of glass, they also contain mercury.

All of these facts are true, but they don't explain *why* they take so long to warm up and acheive maximum output.

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.

Is something like that the case?

Cfl spots take a long time to get bright unlike regular cfls, at 0f its 6 minutes.

re: if Sylvania products aren't doing it for you, odds are nobody's will.

I have CFL's in many other fixtures, including ceiling lights on three stair landings, inside closets, etc. In all other cases, the initial output is adaquate and full output is achieved in a realtively short time (

I hope it never gets down to 0F in my kitchen! It'll be cold *and* dark!

The problem is that 15 watts only produces about 51 BTU/hour of heat, minus whatever fraction of the electricity becomes light instead.

It takes a couple of minutes for 40-50 BTU/hour to get the tubing up to the temperature it works best at. It's not just the tubing - the tubing won't fully warm up until the outer bulb and the air in it also have an increase in temperature.

What could be done to speed this up:

1. Have the ballast circuitry provide increased power during warmup. This will both increase light output and speed up the warmup process.

One problem with this is that the filaments at the ends of the tubing only work properly in a certain power range, and otherwise wear out quickly. Another is the cost of such a feature, including detection of need for increased power, and smoothly reducing the power to normal as the bulb warms up.

1. Make the tubing of thinner glass and the bulb out of thinner material. However, that would make them break more easily.

- Don Klipstein ( snipped-for-privacy@misty.com)

See what outdoor CFLs do outdoors when it's cold! I have seen Philips SL/O ones take 5-10 minutes to reach full brightness at 5-10 degrees F. Some CFLs also start with a very reddish color of a neon-argon mixture that is mostly neon when they are very cold.

- Don Klipstein ( snipped-for-privacy@misty.com)

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.

I include one real light bulb so I can see until the others warm up. It seems to be about 30 seconds, but i haven't measured all of them.

My first CFL burned out a couple weeks ago. I'm going to call the Canadian Football League and complain.