Luminare W rating

[76nemo]

Stupid question I didn't have a definete answer for.....


I know you construction guys will know. I pondered about CFL's in a flush mount globe light. 60W rating/twin fixture. I was asked about CFL's placed in a closed globe. Globe rated for 60W's. Can we use the actual wattage rating for CFL's as we do incadescents?

Haven't dealt much with CFL's, not in this matter anyway/globes. We're not to calculate the equivelant, but thee actual draw with CFL's,......correct in closed luminare fixtures???

 

[hurk27]

I would believe you would go with actual wattage. and since a CFL produces more lumen's per watt then a incandescent with allot less heat, I would think heat would not be a problem, but there is one thing to consider, many CFL's are not rated for use in enclosed or recessed fixtures, also if they get to hot they wont last long, but if you look you can find some that are, I know Menard's sells Sylvania that are rated for recessed/enclosed fixtures we use these on shower trims, because most home owners are unhappy with the amount of light you get with a 40 watt A-19 bulb, and if you put in anything higher it will trip the protector in the can, so we use the Sylvania CFL minnie 100 watt equivelant which is only 23 watts actual.

 

[76nemo]

I would believe you would go with actual wattage. and since a CFL produces more lumen's per watt then a incandescent with allot less heat, I would think heat would not be a problem, but there is one thing to consider, many CFL's are not rated for use in enclosed or recessed fixtures, also if they get to hot they wont last long, but if you look you can find some that are, I know Menard's sells Sylvania that are rated for recessed/enclosed fixtures we use these on shower trims, because most home owners are unhappy with the amount of light you get with a 40 watt A-19 bulb, and if you put in anything higher it will trip the protector in the can, so we use the Sylvania CFL minnie 100 watt equivelant which is only 23 watts actual.

Thanks Wayne, I was hoping someone would understand the question. I have a friend that was sick of his lighting scenario in his kitchen. He has a bar, alot of accents and hardwood in there now. What he mainly realized was he was sick of warm white. I put three new 60W globes in the kitchen on a new feed. I stuck one 23W/100W equivelant cool white CFL in each fixture and he was amazed in the difference in lighting. Me personally, I hate warm white, a bedroom maybe, otherwise.....NAH!!!

Being a twin fixture he asked if he could put another 23W in each one. That's when I went blank, thus my question. It just so happens that with these fixtures, the CFL rest against the heavy glass globe and it acts as a heat sink. I'd like to stick another one in and get a temp reading inside the globe if anyone is interested.

Anyone else have an issue with premature failures with CFL's in globes? What's in there now is just temp.. I know for a fact he wouldn't mind changing them once a year, am I asking too much???

 

[Dennis Alwon]

There is no legitimate answer since most fixtures say that they are listed as incandescent luminaires. You install a fluorescent and you void the listing. I have seen premature failure very often with CFL installed inside an enclosed fixture.

 

[jumper]

There is no legitimate answer since most fixtures say that they are listed as incandescent luminaires. You install a fluorescent and you void the listing. I have seen premature failure very often with CFL installed inside an enclosed fixture.

Okay, so I voided the listing on a few hundred fixtures.

I have used CFLs in enclosed fixtures for quite awhile now with pretty good success.

I use these 13w T2 spirals, they are approved for enclosed fixtures.
http://www.satco.com/new-cfl-product-sheets.aspx

 

[broadgage]

If the fixture is rated for a 60 watt lamp, then the FIXTURE cant come to any harm from a 60 watt flourescent lamp, since the heat produced will be no more than intended.

The LAMP might well suffer from short life owing to overheating, many types are only for open or well ventilated fixtures.
For example an enclosed fixture with a 60 watt incandescent might reach 200 degrees internal temperature, and suffer no harm as lamp and fixture were designed to be used thus.
Now fit a 60 watt CFL in the same fixture, the temperature cant exceed the 200 degrees reached with the incandescent, therefore the fixture cant be damaged. The LAMP however is unlikely to survive for long at such temperatures.

In practice however a 60 watt CFL wont fit in any common enclosed fixture intended for a 60 watt incandescent.
A 60 watt CFL is a very large one with a light output equall to about 250 watts incandescent.

I have found that a good rule of thumb for use of CFLs in enclosed fixtures is not to exceed one third of the stated maximum wattage.
For example, fixture listed for 60 watt incandescent, dont exceed 20 watt CFL, that still gives an increased light since a 20 watt CFL is roughly equivalent to a 75 watt incandescent, maybe a bit more.

A lot depends on ambient temperature, for example a 30 watt CFL might be acceptable in a 60 watt listed fixture outdoors in a cold climate, but not in a kitchen.

 

[LarryFine]

I have always recommended the actual wattage, and not the "equivalent", as one of the main advantages of CFL's.

I also agree about using CFL reflectors in shower cans, and with the face of the bulb right up against the trim lens.

If people complain about the slow brightness increase at turn-on, I mention what a great feature it is late at night.


"Not always right, but never in doubt."

 

[walkerj]

I would not count o a CFL lasting long in an enclosed fixture unless it is designed for the heat build-up.

I have the downlight CFL lamps in a few places in my house and the long start-up time is my biggest problem with them.

 

[Volta]

I worry less about the life of the CF lamp than the socket holding it.

The ballast-generated heat may be closer to the lampholder than when the heat was radiated from the glass of an incandescent lamp.

I don't much use them in existing fixtures.

 

[LarryFine]

. . . the long start-up time is my biggest problem with them.

It's a great feature late at night.

 

[76nemo]

The Sylvania 20W CW Insta-On's are excellent

 

[iwire]

the long start-up time is my biggest problem with them.

It's a great feature late at night.

I agree with Larry, I have CFLs in my bathroom and first thing in the morning I appreciate the delay in full brightness.

 

[76nemo]

I still stand on my opinion on warm whites,..... night lights are one thing. All other general lighting,....CW all the way!!!

 

[Electric-Light]

Given the same wattage, CFLs will run hotter. Incandescent can shed a way a good amount of its energy in the form of radiant infrared energy. CFLs depend more on convection.

 

[CPorter]

The heck with CFLs. Don't last long enough, hate cool white and warm white, much prefer 4100K lamps. I'm changing to LEDs now that the price is coming down. In the places I've used them I have already exceeded the standard CFL life and the units with LM-70 and LM-80 tests show I may not have to change them this decade.