How to calculate PPFD for my build?

wietefras

wietefras

Well-Known Member
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

CobKits

Well-Known Member
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 ;)
wietefras said:
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.
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Big smo

Big smo

Well-Known Member
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

sixstring2112

Well-Known Member
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 :lol:
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 (:
 
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mahiluana

mahiluana

Well-Known Member
sixstring2112 said:
Bring your light over here,ill cool it
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Apes without undertrousers - where does this pissed up donald come from ???

Here in the Black Forest EU we still work like bongsmilie or even :spew: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. ???
 
G

George2324

Well-Known Member
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

CobKits

Well-Known Member
George2324 said:
whats currently the most efficient cob at 700ma and the most efficient at 1750ma?
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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
 
DankaDank

DankaDank

Well-Known Member
CobKits said:
no i dont like to talk efficiency %, its too misleading. too much bad data flying around.
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I think it should be standardized on this forum that efficiency be determined at Tj 50c and If mathematical calculated, show the LER used.
 
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Joe34

Joe34

Active Member
DankaDank said:
I think it should be standardized on this forum that efficiency be determined at Tj 50c and If mathematical calculated, show the LER used.
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Yep, thats true. this is what leads to the biased test results with diehard fanboys testing chips at 25tc vs 65tc
 
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