groar's lighting thread - Page 2

groar · 10-26-08, 05:13 AM

I bought a few CFL yesterday, for our house and my parents in law's house.

For the living room we bought a 20w (100w equiv) 6500°K CFL. It's rated at 1090 lm (lumen) while the 2700°K one is rated at 1150.

For the bed room we bought a 15w (75w equiv) 6500°K CFL. It's rated at 760 lm while the 2700°K one is rated at 800.

For my bedside table we bought a 9w (45w equiv) 6500°K CFL. It's rated at 405 lm. It replaces a 5w (25w equiv) 2700°K, if I prefer the light quality of the newer one, I find it a little bit too strong for late evening and soon morning. I may swap with my wife's bedside table who is reading much more in bed then I do.

In my stock I found one with the lumen rate written on it : a 8w (35w equiv) 2700°K rated at 290 lm.

For my parents in law's chandelier we bought 6x5w (25w equiv) 2700°K rated at 180 lm.

Denis.

toyobug · 10-27-08, 11:35 AM

groar- did you buy the ones that look like natural light?

groar · 10-27-08, 04:12 PM

Quote:

Originally Posted by toyobug

groar- did you buy the ones that look like natural light?

Yes, we bought the 6500°K bulbs ie "natural" lights, while 2700°K are more "artificial" lights.

I didn't noticed the real price differences as we wanted to buy "natural" lights, but from what I remember it was at most 10% more expensive, while the choice was 10 times smaller...
The web site of the store currently gives me only "404 not found"...

Except the price a little bit more expensive and the lumens a little bit smaller, others specifications (life, dimensions...) are the same between the 2700°K and the 6500°K CFL I have.

Denis.

toyobug · 11-06-08, 08:57 AM

good info groar. I plan to change to CFLs the 1st of DEC.

groar · 11-07-08, 10:00 PM

I spent a couple of minutes this afternoon in my bulb store. On LED only a subset of one brand indicate the lumens of their LEDs. They were all 1W and composed of 20 LEDs. Here they are :

yellow : 7-10 lm
green : 30-45 lm
red : 8-12 lm
blue : 7-10 lm
white : no stock...
multiple colors : no stock...

I was also surprised to see so much difference... I simply copied what was written on the packaging.

Denis.

toyobug · 11-08-08, 12:04 AM

very interesting

Daox · 11-08-08, 08:45 AM

Yeah, I too have seen the major difference in lumens between colors. Its odd. I wonder how they measure lumens...

GenKreton · 11-09-08, 12:40 PM

To measure lumens from a light source you typically use a photometer which counts photos. It has a defined size on the collector, you measure a precise distance from the source, and you need to know the directionality of the light (simply defined as the percentage of a sphere for elementary cases) to get your unit of lumens. So lumens has no accounting for the frequency of light.

Daox · 11-10-08, 06:04 AM

Excellent. Thanks.

10-26-08, 05:13 AM	#11
groar X-Frenchy: very Join Date: Sep 2008 Location: Toulouse, France Posts: 153 Thanks: 0 Thanked 2 Times in 2 Posts	CFL and lumens I bought a few CFL yesterday, for our house and my parents in law's house. For the living room we bought a 20w (100w equiv) 6500°K CFL. It's rated at 1090 lm (lumen) while the 2700°K one is rated at 1150. For the bed room we bought a 15w (75w equiv) 6500°K CFL. It's rated at 760 lm while the 2700°K one is rated at 800. For my bedside table we bought a 9w (45w equiv) 6500°K CFL. It's rated at 405 lm. It replaces a 5w (25w equiv) 2700°K, if I prefer the light quality of the newer one, I find it a little bit too strong for late evening and soon morning. I may swap with my wife's bedside table who is reading much more in bed then I do. In my stock I found one with the lumen rate written on it : a 8w (35w equiv) 2700°K rated at 290 lm. For my parents in law's chandelier we bought 6x5w (25w equiv) 2700°K rated at 180 lm. Denis. __________________ Earth absorbs 1.8 t CO2/head/yr, while a French generates 6.2 t CO2/yr To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. kg saved 06/08-08/09: 1816.9+382.9 (ecodriving / 1420mi not driven) = 2199.8 To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. (2.66 kg/l diesel) kg saved by 3kWc photo-voltaic solar panels : 187 kg/yr To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. (59.1 g/kWh) Radioactive wastes saved by 3kWc photo-voltaic solar panels : Long life (>100,000 years) : 2.85 g/yr (0.9 mg/kWh) Short life (<300 years) : 31.7 g/yr (10.0 mg/kWh) Based upon "official" French figures...

11-07-08, 10:00 PM	#15
groar X-Frenchy: very Join Date: Sep 2008 Location: Toulouse, France Posts: 153 Thanks: 0 Thanked 2 Times in 2 Posts	LED and lumens I spent a couple of minutes this afternoon in my bulb store. On LED only a subset of one brand indicate the lumens of their LEDs. They were all 1W and composed of 20 LEDs. Here they are : yellow : 7-10 lm green : 30-45 lm red : 8-12 lm blue : 7-10 lm white : no stock... multiple colors : no stock... I was also surprised to see so much difference... I simply copied what was written on the packaging. Denis. __________________ Earth absorbs 1.8 t CO2/head/yr, while a French generates 6.2 t CO2/yr To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. kg saved 06/08-08/09: 1816.9+382.9 (ecodriving / 1420mi not driven) = 2199.8 To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. (2.66 kg/l diesel) kg saved by 3kWc photo-voltaic solar panels : 187 kg/yr To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. (59.1 g/kWh) Radioactive wastes saved by 3kWc photo-voltaic solar panels : Long life (>100,000 years) : 2.85 g/yr (0.9 mg/kWh) Short life (<300 years) : 31.7 g/yr (10.0 mg/kWh) Based upon "official" French figures...

11-08-08, 08:45 AM	#17
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Yeah, I too have seen the major difference in lumens between colors. Its odd. I wonder how they measure lumens... __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-10-08, 06:04 AM	#19
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Excellent. Thanks. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

10-27-08, 11:35 AM	#12
toyobug avid DIY'r Join Date: Sep 2008 Location: MS. Gulf Coast Posts: 154 Thanks: 0 Thanked 1 Time in 1 Post	groar- did you buy the ones that look like natural light?

11-06-08, 08:57 AM	#14
toyobug avid DIY'r Join Date: Sep 2008 Location: MS. Gulf Coast Posts: 154 Thanks: 0 Thanked 1 Time in 1 Post	good info groar. I plan to change to CFLs the 1st of DEC.

11-08-08, 12:04 AM	#16
toyobug avid DIY'r Join Date: Sep 2008 Location: MS. Gulf Coast Posts: 154 Thanks: 0 Thanked 1 Time in 1 Post	very interesting

11-09-08, 12:40 PM	#18
GenKreton Lurking Renovator Join Date: Sep 2008 Location: Cambridge, MA Posts: 29 Thanks: 0 Thanked 0 Times in 0 Posts	To measure lumens from a light source you typically use a photometer which counts photos. It has a defined size on the collector, you measure a precise distance from the source, and you need to know the directionality of the light (simply defined as the percentage of a sphere for elementary cases) to get your unit of lumens. So lumens has no accounting for the frequency of light.