Lumens Per Watt

**fredsgrow** · 03-05-2010, 08:07 PM

23 watt CFLs tend to be the most efficient "economy bulbs." Most will put out roughly 1600 lumens (69 lumens/watt) whereas 42w lamps put out 2600 or so (61 lumens/watt). I think I'll have a pretty healthy grow with 6-8 CFLs in a 3.4 sq ft area with 1-2 plants. If you're going much larger than that you'll want HID lighting, CFLs are really only good for small numbers of plants you want to keep small for whatever reason

**kennewickrockerguy** · 03-05-2010, 11:24 PM

I plan on 8 - 85 watt 6500K for veg 4200 lumens each in a 2 x 5 x 7ft tall room. I hope thats a good start.

**stumps** · 03-05-2010, 11:55 PM

8x85w is going to put off some heat. you'll need good venting for the heat. At 45.00 a pop on lights you would be money ahead to get a 400w hid. lol with that said you would be good with the cfl's in your room size. before you buy lights you need to come check out my little grow.

**supertiger** · 03-06-2010, 01:10 AM

Originally Posted by stumps

8x85w is going to put off some heat. you'll need good venting for the heat. At 45.00 a pop on lights you would be money ahead to get a 400w hid. lol with that said you would be good with the cfl's in your room size. before you buy lights you need to come check out my little grow.

It's also an overly expensive and an inefficient way to setup a grow room of that size. Get a 48" T5 HO, 8 bulb light fixture. It's under $220 including bulbs and will outperform your 680 watts in lumens and the heat will be 80% less. So why would you buy those CFLs? Honest question, why do people invest so much money in hot CFLs beyond a PC style grow when T5 HO are so much better? Your 4200 Lumens x 8 lights = 33,600 lumens. And your using how much watts? 680? And what cost for plugs and fixtures? The 8 bulb T5 HO consumes 432 watts and puts out 40,000 lumens @ $220.

CFLs should stick to PC grows or anything around 2' x 2' or less. Go get a T5 HO fixture. Spend your saved money on great ventilation.

**stumps** · 03-06-2010, 02:18 AM

I've never really looked into
T5's. guess I should. Yes the 2x was messing me up. the tubes would be a good idea for that space.

**bubblegoogles** · 03-07-2010, 05:54 PM

Small CFL's are less efficient than large ones. The best a spiral cfl can do is 61-63 lumins/watt the U type cfl ( 105 watts and upto 300 watt) are at 65 lumins/watt there is a new player in cfl's called the rosebud which puts out 75 lumins watt simply by the shape of the tubes allow more light to come out of the inner tubes it also runs cooler because of larger air gaps. check out pics. These are cheap too! they are $35 ea. at enviro-techlighting.com.

**supertiger** · 03-07-2010, 07:52 PM

That still doesn't beat the 92.59 lumens per watt you get with HO T5's.. Not to mention the significantly reduced heat. Like up to 90% less heat.. CFLs cost more and provide less.

**stumps** · 03-07-2010, 08:21 PM

Can you get 54w tubes that are higher or lower then 5000k??

**bubblegoogles** · 03-07-2010, 09:04 PM

Actually it's cheaper to go with the cfl's still. T5 at 432 watts is $220 the rosebuds are $35 ea and are 105 watts ea and use a standard lamp base. 4 rosebuds are $140 and give you 32000 lumins@ 420 watts. The heat is not as warm as the normal spiral cfls they feel about the same heat as T5's.

**supertiger** · 03-08-2010, 12:10 AM

Originally Posted by bubblegoogles

Actually it's cheaper to go with the cfl's still. T5 at 432 watts is $220 the rosebuds are $35 ea and are 105 watts ea and use a standard lamp base. 4 rosebuds are $140 and give you 32000 lumins@ 420 watts.

And is that a complete setup or do you still need 2 110v to E27 lamp plugs and 2 Y's? Does that include a reflector? To reach 40,000 lumens you would need 5 bulbs, plus 5 reflectors, plus the adapter plugs etc.. Performance can't be compared unless as I said before, your using a very small grow area. (Like 2' x 2' or less)

The reason performance can't be compared is because although your small little CFL may put out 8,000 lumens, it's only doing so from a very small source point, which means light intensity will drop off and the CFL will cover a much smaller area compared to the 4' T5 which is throwing 5,000 lumens accross 4 feet.

Best advice is to get a light meter which 99% of CFL growers fail to do. If you looked at a side by side comparison of a 4' 8 bulb T5 HO lamp and 5 of those rosebud CFL's in a 2' x 4' area, you would find the light meter shows multiple pockets of significantly reduced light compared to the 4' T5's.

I hope that makes sense.