St0ney

Why do incandescent lights suck?

We get asked this question about 1000 times a week so I did a bit or research for you all. Here is the problem with incandescent lights (and halogen, which is just a high pressure incandescent)... When electricity is used for lighting some of that electricity is used for creating the light and the rest is turned to heat. In the incandescent bulbs much more heat is produced then useable light, usually around 60-80% of the electricity used to power the incandescent is turned to heat not light. Fluorescents produce more light per watt used then any incandescent can ever do. HID (HPS in particular) produce WAY more light for every watt used. Let’s do some math:

150w incandescent = 2,550 lumens or 17 lumens per watt
150w halogen = 3000 lumens or 20 lumens per watt
150w of Fluorescents = 9,000 lumens or 60 lumens per watt
150w of Compact Fluorescents = 10,500 lumens or 70 lumens per watt
150w Metal Halide = 13,500 lumens or 90 lumens per watt
150w High Pressure Sodium = 16,000 lumens or 107 lumens per watt

Now since you're paying for each watt used wouldn’t you want that watt to put out as much light as it could? Using an incandescent bulb you are going to pay way more in electric costs then you would if you used a HID because you’ll need more watts for the grow to come out good. To produce killer bud you will need about 7,000 lumens per sq ft in your grow room. So, in a 5sq ft grow room you would need 35,000 total lumens (7,000 * 5 = 35,000) to reach the optimum 7,000 lumens per sq ft. To get 35,000 lumens you would need:

13.7 - 150w incandescent or 2,058 watts = 35,000 lumens
11.6 – 150w Halogens or 1750 watts = 35,000 lumens
3.8 - 150w Fluorescents or 583 watts = 35,000 lumens
3.3 – 150w Compact Fluorescents or 500 watts = 35,000 lumens
2.5 – 150w Metal Halide or 389 watts = 35,000 lumens
2.1 – 150w HPS or 327w = 35,000 lumens

Now according to our Grow Guide (lighting section): So, let's use me as an example, I pay $0.08 per KWH. Using our 5 sq ft grow room example above and shooting for 7,000 lumens per sq foot:

Incandescent lights
2,058w = $0.16 an Hr (2.058*0.08=0.16464) or $3.84 a day (0.16*24=3.84) or 115.20 a month (3.84*30=115.20) or 1,382.40 a year (115.20*12=1382.40)

Halogen lights
1750w = $0.14 an Hr or $3.36 a day or $100.80 a month or $1,209.60 a year.

Fluorescent lights
583w = $0.05 an Hr or $1.20 a day or $36 a month or $432.00 a year.

Compact Fluorescent lights
500w = $0.04 an Hr or $.96 a day or $28.80 a month or $345.60 a year.

Metal Halide
389w = $0.03 an Hr or $.72 a day or $21.60 a month or $259.20 a year.

High Pressure Sodium
327w = $0.03 an Hr or $.72 a day or $21.60 a month or $259.20 a year.

As you can see it adds up real quick. In one month of 24hr light I would spend $93.60 more to run incandescent lighting than I would for a HPS and in a year it would cost me $1,382.40 to run those same incandescent lights 24 hrs a day when it would only cost me $259.20 to run the HPS. That’s $1,123.20 more it would cost me per year to run an inferior light. Not to mention how much more it would cost to cool that same 5sq ft grow space running incandescent light over HPS.

So, as you can plainly see even if the light spectrum was correct and heat wasn’t a problem it would cost you WAY more to run incandescent/halogen lights than it would to run a HID. The money you save in just one month would almost pay for the HPS. When you break it down to cost per watt doesn’t it make more sense to buy the HID in the first place?

Any questions?

Incandescent lights.. More costly then we all thought.

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suburbanfarmer

Actually, incandescent lights have an efficiency of about 5%, which is absolutely horrible. Switching to fluorescent lights in houses would save billions every year. I don't see why the big manufacturers don't push those new compacts fluoros more- maybe it's because they last for a long time and don't have to be replaced as much? (less money for them)

Well, at least using incandescent lights will cut down on your heating bill :P