Can somebody please check my math?

Putting together a grow closet. The "closet" is an IKEA wardrobe with interior dimensions of 22" deep, 36" wide, 6' tall. Before I pull the trigger on the bulb order, I wanted to make sure I had it about right:

42W CFLs, 6500K, 2800 lumens each.

Closet is 22x36 = 792 sq.inches = 5.5 sq.feet.

Shooting for 7500 lumens / sq.ft, so 5.5 x 7500 = 41250 lumens.

41250 lumens / 2800 lumens/bulb = about 15 bulbs

So fifteen 42W CFLs in a 2'x3' space? Yes? No? 630W total.

Went with 42W bulbs because higher wattages have few lumens per watt, and get expensive quickly. Would have needed 10 85-watt CFLs (850W total) to make the same number of lumens, and the bulbs cost twice as much!

Seems like a lot of bulbs, is all.

--Bud

should work well

bro, those 42 watt lights get hott, your better off using a 250 watt hps

ive got 85 watt 2700K that are 5700 lumens each. im running 9 of them. 765 watts in 5 square feet. 51300 lumens divided by 5 = 10260 lumens per square feet. These bulbs are about the same lumens per watt than those 42 watt ones.

stonesour said:

ive got 85 watt 2700K that are 5700 lumens each. im running 9 of them. 765 watts in 5 square feet. 51300 lumens divided by 5 = 10260 lumens per square feet. These bulbs are about the same lumens per watt than those 42 watt ones.

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I'm having trouble finding high-wattage bulbs for vegging that have good lumens per watt. I've seen those 5700 lumen 85W bulbs for flowering; I'll probably go that way when the time comes, but for vegging I'm looking for 6500K bulbs.

--Bud

this will help you for awhile - the 7500 lumens per square ft is the recommended amount of light for flowering. you only need half that for vegging.

also a 400 watt hps light will provide the same amount of light as your 15 cfl's with less energy and heat.

Bud Manstrong said:

I'm having trouble finding high-wattage bulbs for vegging that have good lumens per watt. I've seen those 5700 lumen 85W bulbs for flowering; I'll probably go that way when the time comes, but for vegging I'm looking for 6500K bulbs.

--Bud

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I have the exact same bulbs in 5000K i use for vegging. Same wattage, same lumens.