collinsislee
Active Member
ive asked a few light questions already but im still learning and researching, would this setup be good for a closet set up? 6400k bulbs for veg, and 3000k for flowering High Tech Garden Supply
It depends entirely on the size of your closet and the efficiency of your ventilation system. A 400w HPS will generate an enormous amount of heat in a small closet area.
they are if you can rig a cool tube.... an expensive alternative, but imo, well worth the extra $100+/-. i have a friend who is running two 400w in a 2x6 closet, he does very well.It depends entirely on the size of your closet and the efficiency of your ventilation system. A 400w HPS will generate an enormous amount of heat in a small closet area.
Don't be fooled into getting a 400w HPS system just because everyone on here tells you to - they're NOT great in small spaces, where CFL's and T5's CAN offer a better alternative.
It's true cool tubes can offer 'some' heat reduction in enclosed spaces, but they're a waste of time, energy and money in terms of the light spread they offer. The internal (or external) reflector on cool tubes is pathetic in terms of the light spread it offers and what you gain by being able to use the cool tube low to the plant canopy you lose in terms of overall light spread.they are if you can rig a cool tube.... an expensive alternative, but imo, well worth the extra $100+/-. i have a friend who is running two 400w in a 2x6 closet, he does very well.
it is true that reflectors on the tubes suck, and i personally don't like to get my lights that close, as it cuts down on the area that is being lit. however, if you leave one end of the tube open, and you're using a strong enough fan (35$ 500cfm inline from hd) you won't have heat issues, not even from radiated heat. you see, light can pass through glass. heat cannot. this is why cars get so blasted hot in the summer with windows rolled up; the light hits objects in the car, and the light is changed into heat, which cannot escape.It's true cool tubes can offer 'some' heat reduction in enclosed spaces, but they're a waste of time, energy and money in terms of the light spread they offer. The internal (or external) reflector on cool tubes is pathetic in terms of the light spread it offers and what you gain by being able to use the cool tube low to the plant canopy you lose in terms of overall light spread.
The other problem with HPS's in cool tubes is the infra red heat emitted, you can ventilate inducted heat - but not radiated and that still goes to the overall heat buildup meaning you still have to have a separate ventilation system in addition to the fan used to cool the cool tube.
It's also more expense on top of the purchase price of the ballast, adding the cool tube AND fan to cool it.
In my opinion cool tubes are a waste of time money and effort and are just a fad.
For closet grows in small spaces a 250w HPS offers a far better alternative to a 400w, if CFL's and T5's aren't preferred.
Nonsense kp, what are you talking about?not even from radiated heat. you see, light can pass through glass. heat cannot. this is why cars get so blasted hot in the summer with windows rolled up; the light hits objects in the car, and the light is changed into heat, which cannot escape.
with hps, your intesity is much less than the sun, and radiant heat is not a problem. i used to have a pic of my friend licking his 1000w cool tube, but i can't find it.
this is true bg, uv and ir light can travel through glass. but, uv and ir are not heat. they are light. it is only when this light is absorbed that it is transferred to heat energy. the reason bulbs get so hot is because the tube itself contains burning gas that gets very hot. by using a cool tube, the heat that is produced from the burning gasses is sucked out through the exhaust. the reason that the glass bulbs emit heat is that the chamber inside of the glass gets hot, the so does the glass, then the glass becomes a radiator.Nonsense kp, what are you talking about?
How do you think the radiated heat gets out of the bulb in the first place? Yes, the GLASS bulb you claim IR heat can't escape from! Infra red wavelength OR Ultraviolet wavelenghs CAN AND DO pass through glass.
Metal halide bulbs with GLASS tubes emit radiated ultra-violet radiation - I know they emit it because I've seen the spectographs of them - exactly the same as infra-red heat from HPS's.
now, here's the thing; the light DOES pass through. the heat does not. glass is a very good insulator, and will heat up only when heat builds up inside of an enclosed space. when plants are sun poisoned, it doesn't mean they burnt from heat. they get bleached, kinda like when you go swimming and get a sunburn. it's not from heat.You might like to have a read of this -
HID's produce light by passing electrical current through different metal vapors, NO coating of phosphor in the way , but only gases which are controllable, safe and reliable can be used. So, the colours (different wavelengths of light) are severely constrained by the limited types of metal vapors that can be used. However, the radiation that is emitted is very INTENSE and often includes copious amounts of Infra Red for you to burn things with, like plant tops.
Now, also consider Infra Red heat is not effected by convection or conduction cooling technology, (electric fans and water cooled"cool tubes") it is radiation, not conduction or convection. This is why the INTENSITY of the (poor light quality) HID lamp can be used to cover large areas, if you bring the lamp too close you will radiate your plants with horrid IR heat, HID lamps and all ballasts must be kept a safe distance away from the plants to avoid IR radiation damage.
Source: PURple for the highest quality
Come on kp, those people that quote came from MAKE HID bulbs, are you now trying to tell me they're wrong?this is true bg, uv and ir light can travel through glass. but, uv and ir are not heat. they are light. it is only when this light is absorbed that it is transferred to heat energy. the reason bulbs get so hot is because the tube itself contains burning gas that gets very hot. by using a cool tube, the heat that is produced from the burning gasses is sucked out through the exhaust. the reason that the glass bulbs emit heat is that the chamber inside of the glass gets hot, the so does the glass, then the glass becomes a radiator.
i never said that, as a matter of fact, i agreed with you and them.Come on kp, those people that quote came from MAKE HID bulbs, are you now trying to tell me they're wrong?
infared light is a light wavelength. i use ir lights on my lizards. i point the bulb at the glass (and yep, you can feel the heat radiating, these bulbs are designed to emit heat) but, if you move your hand to the inside of the glass tank, you cannot feel the radiated heat at all. you can feel that the glass is slightly warm, but the light itself does not give off any warm sensations. the tank is not tinted in any way.Because if you are, we'll simply have to agree to disagree, because I don't agree with anything you've just written, and I KNOW Infra-red and Ultraviolet radiation does pass through glass and Infrared radiated heat IS heat and doesn't just heat up the bulb!
Our difference of opinion revolves soley around the affects of infra red wavelengths passing through glass and heating things up. Of course IR wavelengths passing through glass not hitting anything the other side isn't going to heat anything up - it's WHEN it hits an object that it creates heat.i'm not saying you're wrong about uv and ir passing through the bulb babe, i'm only trying to say that the heat factor of the lights is combated by cool air passing over the bulb when using a cool tube. it keeps the bulb cool, therefore the bulb does not radiate as much heat. and because the tube is glass, it will also help to insulate and sheild the plants from the heat the bulb puts out. this is why plants can be so close to the tube, there is no heat issue to worry about. the only problem you'll have by keeping the lights under 12'' is bleaching, which i mentioned before.