Spiral CFL compared to PL-L

Lets start with what we hear on the forums...


Quotes mostly from Knna who is pretty meticulous about keeping data...and uses PL-L

"Type L CFLs not only are more efficients than any screw in CFL, but the light use is way better: evenly distributed and lower optical losses due some tubes blocking the light of other tubes as happen on typical multitubes CFLs."

"As a rule of thumb, the higher the wattage of each single tube of the CFL, the better: for compact CFLs (not PLL style), spiral ones, which are build with a single tube, are more efficients. The prefered shape is of the PLLs, a single tube bended by half, resulting on the higher energy efficiency and the lower optical losses."

"About heat, just slighty less than same wattage of other CFLs (yep, ive used screw in CFLs before: more than heat, the difference is yield per watt, way better for the PLL)."

"Depending of the strains, i got 0.4-07g/w with those lamps." <-- in reference to PL-L 55 watt


Ok, now with CFL Spiral...

Lifeless rubbermaid grow... 168 watt CFL = 110-112g = 0.6g/w How are CFL spirals so inefficient compared to PL-L? If the spiral shape is blocking so many lumens...why is this not apparent in yields?


Knna says he gets about 2 ounces per 110 watts of PL-L, However, Lifeless gets 4 ounces from 168 watts. (4 X42 watt CFL's) That would mean in order for Knna to get 4 ounces, he would need to use 220 watts of PL-L.

For micro growers, this is important, as PL-L seems to be an alternative. But, are they worth the inconvenience (i.e. have to be ordered...ballast wiring...etc)?

The gram per watt yields are pretty close for PL-L to be exceedingly more efficient than spiral CFL as some would have you believe.

Anyone have any evidence to the contrary?

reference:

http://www.icmag.com/ic/showthread.php?t=51381&page=1&pp=15&highlight=lifeless

i dont think its that simple. dont you have to take vegging time and pot size into consideration?

yeah it is kinda pointless to make that comparison..... why not take some light meter readings from both styles and work from there?

If you look at the square foot of each grow, and the effective distance of CFL light, you should be able to draw some conclusions. Nevertheless, the point is that the g/w isn't all that different considering the supposed inefficiency of CFL spiral...

Knna -> "While L CFLs gives about of 75-80% of lm avalaible of the initial total emission, typical CFLs may be a little over 50% of initial emission due the large optical losses."

That is a 25-30% difference in lumen loss that I am not seeing in yield loss from spiral CFL growers.

I'd rather this thread not be about what people "think", but about what can be calculated.


Given what Knna says about spiral lumen loss, I'd expect Lifeless's yield to be about 0.175 - 0.21g/w which it isn't.

inefectualize said:

yeah it is kinda pointless to make that comparison..... why not take some light meter readings from both styles and work from there?

Click to expand...

Pointless? Not exactly. We are talking about g/w and how the optical lumen loss effects yield...not lumen intensity. I believe you are not understanding what I am talking about.

I am not talking about measuring whether or not the lumens are being lost comparatively (which they likely are due to the spiral design), but it seems that whatever lumens that are lost are not showing to adversely effect yield...unless you consider lifeless's yields from 4 42 watt CFL's at 4 ounces to be subpar considering it is a higher g/w compared to Knna's result.

the only way to get a true comparison is to build two cabs- one with spirals and one with PLL's. same size cabs and run the same wattage in both. run clones of the same girls in each with the same veg time, give each the exact same amounts of water and nutes and medium. no other variables other than bulbs.

comparing two different growers most likely growing two different stains is comparing apples and oranges.

I suppose really I am expecting Knna to reply. Obviously the circumstances that requires that exacting detail are unlikely.

However, stating a lumen optical loss of 25-30% from spirals should result in a similar drop in yields regardless of how you set up the grow. It is strange that no one who has replied has paid any attention to this.

There was NO 25-30% g/w loss in Lifeless's grow...or any other for that matter. I hate to have to state the obvious...but here on these forums, when doing comparisons...we have to work in averages.

To put it more simply...

IF PL-L are 25-30% more efficient than spirals due to optical lumen loss...THEN you should see a g/w AVERAGE that is correspondingly 25-30% higher than Spiral.

Are there any math people here who understand this?

there are just so many variables when comparing two different peoples grows and how wet the buds were when they were weighed .... can you give some other spiral compact grows that post similar g/watt yield? Someone should build two rubbermaid tubs and do one with spirals and one with the same wattage of linear cfls.....im thinking the difference will not be significant in either direction....to me i love all styles of cfls, it is just that different shapes have different applications...

You are correct...there are a lot of variables...which is why we use average. ie The avg yield is 0.5g/w. Like the bell curve. Yes, there are other grows which avg approx 0.6 g/w under CFL spiral. And the average yield is roughly 1 ounce per 42 watt spiral CFL. (Not including Dr Bud which would be not the average grower )

Garden Knowm on rollitup has a book out on growing with CFL. He grew 3 plants with 8 42 watt CFL spirals for a total yield of 8 ounces...which is approx double what lifeless pulled using 4 42 watt CFL. ( approx 0.66 g/w)

I have also seen grows where people are pulling roughly 2 ounces from 2 42 watt CFL spirals in a PC tower.

2 ounces is about what people yield using the 2ft 4 bulb T5 lights (which are about 110 watts) and almost 4 ounces for the 2ft 8 bulb version (220 watts). So, you see ... while some pull more...and some pull less...the average for spiral CFL is about 0.5 - 0.6 g/w. The average for T5 tubes is around 0.6 g/w as well.

I can post links if you like. But the point isn't bashing PL-L at all. I am trying to understand if there is a reason to use them over CFL spiral with regards to increasing yields.

From what I have seen...the difference in yield is small if any. From what I can tell from the average of different CFL type grows, the yields doesn't vary much. I am asking if any PL-L users have seen the same, and what their average yields are.

For a 25-30% gain in efficiency, we should see higher than 0.6g/w yield.

imho, the difference with the various types of CFLs and t5s is mostly based on how they are used, and not the light themselves. they all put out relatively similar amounts of light, but are designed for different uses. if the grower takes notice of this, and applies them correctly, youll have similar results with both styles

the difference from cfl/t5 to t8 or t12 is much more pronounced