DW.....I`ve never run anything but vertical bare bulbs , so I wouldn`t know the difference in brightness from horizontal reflectors , and for the record ..........with bare bulbs ALWAYS wear welder`s glasses in the rooms light`s on per sticky by Mr C.......but........
My lumens were measured by digital meters and not speculated on .......3' away from a bulb sideways is not optimal.........induces stretching and increased internodal spacing for the most part from what I ran over the yrs.....
Good luck...DHF......
That said, I don't think watts/sq ft calculation works quite the same for vert. We normally caluclate based on a flat footprint and a reflector. With no reflector, I have to believe the bulbs energy is disbursed more efficiently.
Hey Bob.........I`m at the beach on my laptop watchin it rain , so I can`t give yas a straight answer either right now , but it`s stored on my desktop at the farm........
I do know my meter never measured "Lux" , but rather Lumens and footcandles....I also know the conversion from light per sq ft on lumens and footcandles to Lux is the difference between a sq ft and a sq meter measurement......but......
I used "Eye" hortilux bulbs and Lumatek ballasts for as many lumens as I could blast at their ass sideways.......around 90,000 +/- per bulb as I remember correctly.......Been a few yrs since I used said meter and once shit was dialed , it went in storage.....
This watts per sq ft vertically versus horizontally has been debated and argued over for yrs , but seeing your post about 20 watts per sq ft of vertical canopy being optimum , directly coorelates with my walls/shelves/racks bein in the 22-24 sq ft range , and with 4 of em around 3-600`s on top of each other....
Approximately 90+/- sq ft of vertical canopy sideways on all 4 walls with 1800 watts per room , but.....in only 36 sq ft of actual room area relating to the minimum 50 watts per sq ftg requirement on horizontal floor grows.....Things that make yas go hmmmm........
Coincedence ?........Prolly not.....
Started out with pre-vegged , pruned , and shaped , month old 18-20" plants and they finished at about 10-12" from the bulbs hangin through hortinova netting around 30" long from top of coco in the smartpots......
Goin home for Thanksgiving and will dig up those numbers for yas Bob , although if my math`s right with my setups that were around 270 cu ft with around and lil over 270,000 lumens in the room, it would stand to reason that 1000 lumens and lil more per cu ft is the proper number for dialed conditions IMO.......
What`re your thoughts Bob.......
Take care and good luck.....DHF............
This is very interesting but now it's time for the reaaallllyy stupid questions. Why is vert better? Is it because less light is wasted on reflectors? A reflector is very efficient. Flat white reflects 95 to 98% of light. Are your grows 5% better? 10%? 15%? 20%? What increase do you get from vert with the same lights and strains but vert instead of horizontal? Could it be that the plant hit from the side absorbs more light? I wonder why none of you are starting with smaller bulbs when the plants are small and moving the plants to larger ones when the plants are bigger.
If the reason that verts are better is because the light is hitting more leaf area horizontally couldn't you do a 180 degree vert with a reflector. (No one faint. It's just an idea) In my case where I grow a 180 vert would be convenient. Put the reflector on the cabs door. No one be mean. I'm trying to get a handle on this. I want to know what is the basis for this being more efficient. If you know that you can make it better.
? A reflector is very efficient. Flat white reflects 95 to 98% of light.
one thing I remember from earlier in this thread is... the reflector also is/becomes a 'heat sink', holding heat while reflecting it.
This is very interesting but now it's time for the reaaallllyy stupid questions. Why is vert better? Is it because less light is wasted on reflectors? A reflector is very efficient.....
apparently they are 135% better....Flat white reflects 95 to 98% of light. Are your grows 5% better? 10%? 15%? 20%? What increase do you get from vert with the same lights and strains but vert instead of horizontal?