formulas for wattage / room space?

K

kdt15

Active Member
Lets say in a 10x10 ft room, 100 square foot.

How much wattage is required to grow efficiently if the entire 10x10 foot was used as a canopy for plants? I recall seeing a few formulas but wasnt sure if they were accurate, depending on the type of lighting used. ive also seen some articles indicating some other odd conversion with 4sqft/plant to factor in before doing the total wattage calculation, which didnt make much sense when i read it.

thanks
 
Gilbertslab

Gilbertslab

Member
HID rule of thumb:

250watt = 2'×2' coverage
400watt = 3'×3' coverage
600watt = 4'×4' coverage
1000watt = 5'×5' coverage

Or

The formula for the “Watts per Square Ft.” method is 50 to 75 watts per sq. ft.. The optimal spot is right in the middle of that which is basically 65w. This is considered the Sweet Spot.

Experts will correct me if I'm wrong.
 
Last edited:
K

kdt15

Active Member
thanks, i do recall seeing 50-75 so thats good to hear.

anyone have values for other lights?
 
Underground Scientist

Underground Scientist

Well-Known Member
kdt15 said:
thanks, i do recall seeing 50-75 so thats good to hear.

anyone have values for other lights?
Click to expand...
Yeah, I've been a bit of a CMH junkie lately, and for a 315w CMH, it's well known they cover a 3'x3' area very well, a 4'x4' is known to be pushing their limits.

So it seems the common recommendation for CMH would be 315/9 = 35w/sf

I bet 9 in a 10x10 would cover it.

I believe COB LED has a lower Watt/sf requirement. I want to say 40/sf, check GroErr's thread for verification on that one.
 
Mcgician

Mcgician

Well-Known Member
If you are in any state that's "legal" you're up against guys using gavitas every 26-28" 3_4' away. They're also using commercial properties/ warehouses which only cost ~.13 Kw. If you're residential in one of these states, you're looking at a HUGE uphill battle in order to compete. Residential prices vary, but here in Cali, we get RAPED via tiered billing/usage. Unless you have a good network which can move your stuff, and have one of the best strains ever, save your money, time, and effort and just grow for yourself.

If you're absolutely intent on making it happen and rolling the dice, my advice would be to use 6 gavitas in that space. Hopefully in a room that has 14 foot ceilings as well.
 
V

VegasWinner

Well-Known Member
kdt15 said:
Lets say in a 10x10 ft room, 100 square foot.

How much wattage is required to grow efficiently if the entire 10x10 foot was used as a canopy for plants? I recall seeing a few formulas but wasnt sure if they were accurate, depending on the type of lighting used. ive also seen some articles indicating some other odd conversion with 4sqft/plant to factor in before doing the total wattage calculation, which didnt make much sense when i read it.

thanks
Click to expand...
Veg 25 to 35 watts per square foot. Flower 50 watts per square foot.
 
K

kdt15

Active Member
Mcgician said:
If you are in any state that's "legal" you're up against guys using gavitas every 26-28" 3_4' away. They're also using commercial properties/ warehouses which only cost ~.13 Kw. If you're residential in one of these states, you're looking at a HUGE uphill battle in order to compete. Residential prices vary, but here in Cali, we get RAPED via tiered billing/usage. Unless you have a good network which can move your stuff, and have one of the best strains ever, save your money, time, and effort and just grow for yourself.

If you're absolutely intent on making it happen and rolling the dice, my advice would be to use 6 gavitas in that space. Hopefully in a room that has 14 foot ceilings as well.
Click to expand...
Yeah tiered California sucks. Do have plans with commercials buildings but also want to do some home room in large scales, so going led. Never heard of gavita, will look into it.
 
You must log in or register to reply here.
Top