How to calculate PPFD for my build?

[wietefras]

Reflectors lose light. Where would this extra light be coming from? Malocan tested a 4x4 tent and noticed a loss of 20% on average when mounting the reflectors.

Only the small edge next to the open door was there less light from the bare cobs since that was going outside the tent. Like CobKits stated, when there is no reflective material to bounce the light back, you would need reflectors. Otherwise it just loses light.

Especially anything more than 20 inch from the edges/walls has no benefit from reflectors anyway since most of the light from the bare COB would fall on the plants directly. No reflection needed.

 

[CobKits]

also depends on tent size. in a 2x2 where a lot of it is hitting the walls you'll suffer a fair amount of reflective losses from the walls alone

my tent is a 5x9 so a lot of the light from the middle cobs hits the canopy directly

but rereading your post, you basically said that

Especially anything more than 20 inch from the edges/walls has no benefit from reflectors anyway since most of the light from the bare COB would fall on the plants directly. No reflection needed.

 

[Big smo]

Reflectors absorb light as the walls on a tent absorb light. I don't understand how Our plants would see a loss or more of a loss with them vs a tents walls. It just seems like common sense the plants would see much more light. My par meter agrees.

 

[sixstring2112]

Its vero funny to see you citiots acting creetarded over the lense losses vs gains.but the glaring creeality is still the fact or lack of grows with the dubious luminous. Wish i had a Marz Bar,im hungry
No i won't take apart one of my fixtures so you can run your secret tests on my db and dd bin golden nuggets, jerry got what your after @coberto.all'z i can figure is i think im @ about 207 lpw with my dd bin cree @ 30w per chip and they are bright as fuck,but the jerrys still out on that shizzle

 

[sixstring2112]

Oh and thats no reflectorz or silly lenses.its the naked les is best

 

[CobKits]

all'z i can figure is i think im @ about 207 lpw with my dd bin cree @ 30w per chip

would love to see pics of your water cooled rig!

 

[sixstring2112]

Bring your light over here,ill cool it

 

[CobKits]

plenty cool here my friend. maybe not michigan cold but cold enough for me!

 

[mahiluana]

Bring your light over here,ill cool it

Apes without undertrousers - where does this pissed up donald come from ???

Here in the Black Forest EU we still work like or even to have liquid cooling.

Can i see more of your personal cooling methods please ?

Can you cool down my 50 W chip + driver @ 1,5A/45°C - to 55,5 W ???

How many °C of reduction does that mean for junction temp. ???

 

[George2324]

whats currently the most efficient cob at 700ma and the most efficient at 1750ma?

Or could someone help me understand how to work out the efficiency of a cob from the data sheet?

 

[CobKits]

whats currently the most efficient cob at 700ma and the most efficient at 1750ma?

probably citi 3618 gen 6 at both currents
but at 700 mA its only slightly more efficient than the next few cobs and not worth the $45-$50 pricetag. these chips are best used above 150W

 

[George2324]

What would you say is the next best without the price tag then?

Cheers for your input

 

[CobKits]

What would you say is the next best without the price tag then?

Cheers for your input

i think 1212 gen 6 and luminus cxm22 are the best for the price

so 1212 below 50W
luminus 40-80W
1825 75-150W
3618 150+W

 

[George2324]

Sorry for bugging you but would you be able to give me the efficiency % for those specs?

Cheers

 

[CobKits]

no i dont like to talk efficiency %, its too misleading. too much bad data flying around.

 

[sixstring2112]

You got that right

 

[DankaDank]

no i dont like to talk efficiency %, its too misleading. too much bad data flying around.

I think it should be standardized on this forum that efficiency be determined at Tj 50c and If mathematical calculated, show the LER used.

 

[George2324]

no i dont like to talk efficiency %, its too misleading. too much bad data flying around.

What statistics do you use the determine which cob is most efficient then?

 

[Joe34]

I think it should be standardized on this forum that efficiency be determined at Tj 50c and If mathematical calculated, show the LER used.

Yep, thats true. this is what leads to the biased test results with diehard fanboys testing chips at 25tc vs 65tc

 

[George2324]

Yep, thats true. this is what leads to the biased test results with diehard fanboys testing chips at 25tc vs 65tc

So a cob is more efficient if you have a heatsink that runs a lot cooler?