The 4x4 Grow Tent Club

Hey all. So im running a 630 watt cmh inside my 4 x 4 x 6 ft tent. Its an open hood style. My extraction is a 6" 440 cfm i believe. I had a passive intake. Which i then added a small 100 cfm inline fan to, in hopes of bringing in more cool outside air.... 6 inch clip fan shooting right at light fixture.. and another normal 16" stand fan.

Well the 6" extraction moves way more air than the intake can keep up too.. its helping a little but not as much as i had hoped...

My "lights on" temps are not horrible..
Hover around 78 - 82f. But the fan runs basically the whole 12hour cycle, which leaves my RH sitting at about 30%.. kinda low for first week of flowering cycle.

So iv pretty much come to the conclusion that im going to have to either run a small A/C unit..
Or switch over to an led light for my flower tent.. for at least June, july, aug and probably september..
Know what im sayin?

Anyway im just wondering what some of the people in here that are running higher watt HID kits. Do too help keep theyre enviroment right...

Any one chime in if they feel theyve been where im at.

By this point iv spent a fair bit to get growing. Just trying to avoid purchasing anything that wont help
 
If you’re not all ready, run your lights at night. 78-82 isn’t really something I’d worry about in most circumstances. Those small a/c units are cool but also cause the humidity to drop. I set up a humidifier right next to my intake and it helps bump up the rh a little. My last penny, LEDs don’t run cooler, that’s a marketing myth. If you replace your hid with the wattage equivalent led, the issues will be the same. Nothing beats an air cooled hood and unfortunately LEDs and cmh don’t have an option for those, unless you can make one.
 
Gadfly said:
78-82 isn’t really something I’d worry about in most circumstances.
Click to expand...

Or any, when the plants are receiving enough light-energy.
 
Well, sure, but that's a matter of personal preference, not plant health. In that specific instance, it might actually be the opposite of plant health, since it could be a sign that the plant is having trouble utilizing phosphorous because the temperature dropped below that at which the plant is able to operate efficiently.

Which, again, is the gardener's choice, of course. Everyone has their own priorities and such. Which is probably a good thing. . . .
 
Gadfly said:
If you’re not all ready, run your lights at night. 78-82 isn’t really something I’d worry about in most circumstances. Those small a/c units are cool but also cause the humidity to drop. I set up a humidifier right next to my intake and it helps bump up the rh a little. My last penny, LEDs don’t run cooler, that’s a marketing myth. If you replace your hid with the wattage equivalent led, the issues will be the same. Nothing beats an air cooled hood and unfortunately LEDs and cmh don’t have an option for those, unless you can make one.
Click to expand...
Amazing.. thats the kind of info i was out for... i wouldnt want to spend good money on a led.. to end up with same problem
Thnx a ton
 
captaincronik said:
Hey all. So im running a 630 watt cmh inside my 4 x 4 x 6 ft tent. Its an open hood style. My extraction is a 6" 440 cfm i believe. I had a passive intake. Which i then added a small 100 cfm inline fan to, in hopes of bringing in more cool outside air.... 6 inch clip fan shooting right at light fixture.. and another normal 16" stand fan.

Well the 6" extraction moves way more air than the intake can keep up too.. its helping a little but not as much as i had hoped...

My "lights on" temps are not horrible..
Hover around 78 - 82f. But the fan runs basically the whole 12hour cycle, which leaves my RH sitting at about 30%.. kinda low for first week of flowering cycle.

So iv pretty much come to the conclusion that im going to have to either run a small A/C unit..
Or switch over to an led light for my flower tent.. for at least June, july, aug and probably september..
Know what im sayin?

Anyway im just wondering what some of the people in here that are running higher watt HID kits. Do too help keep theyre enviroment right...

Any one chime in if they feel theyve been where im at.

By this point iv spent a fair bit to get growing. Just trying to avoid purchasing anything that wont help
Click to expand...
What about using a swamp cooler (evaporative AC)? It should drop your temp a few degrees while adding humidity. I think they’re cheaper than portable AC units too.
 
Gadfly said:
LEDs don’t run cooler, that’s a marketing myth.
Click to expand...

LMAO. Seriously? It's a scientific fact an LED produces more light and less heat when current is applied to it than an incandescent lamp. Please keep your troglodyte opinions to yourself, there are impressionable individuals around.
 
That’s great for you. My QB that draws 280 watts will bring my tent up around 20 degrees above the ambient. The driver heats up to around 150 and the board itself was around 100 with driver removed. With my old 400 watt hps—which actually pulls more than 400 watts—I can keep my tent 2-4 degrees above ambient just using an air cooled hood. It is unfortunate that you couldn’t figure out how to make them work.

A watt drawn from either an hps or led will produce the same amount of heat. Unless you’re privileged to some kind of information I am not, how do you explain magical led watts being cooler?

Assuming I too live in the real world, my experience conflicts with yours. There are variables I’m sure being overlooked as some get very emotional when talking led/hps. I am however very open to any “scientific facts” that anyone would like to provide. I’m humble enough to read.
 
Anyone here use a light mover? I have a rectangular LED panel that I want to move side to side over my 4x4 canopy. I found some online, but I wanted to know if anyone would recommend a specific brand/model. Thank you
 

(PDF) Internal heat gain from different light sources in the building lighting systems

PDF | EU directives and the Construction Law have for some time required investors to report the energy consumption of buildings, and this has indeed... | Find, read and cite all the research you need on ResearchGate
www.researchgate.net

LEDs produce considerably less heat and more light per watt than any other available light source.

my guess is without the cool tube your ventilation is inadequate. I have no problems keeping 500+wall Watts of mixed led lighting cool in mine. Currently 69°f in the room 70.5°f in the tent. The board only tent which is 480 Watts is only 69°f leaf surface temps sitting at 73 and 72°f respectively.

during building construction different light sources are calculated differently in regards to heat load.

Screenshot_20190425-124304.png
 
Well at least you brought something this time. :thumb: Cute try.

1. I did noticed what’s missing in that study, NO HID data to compare, which is what we’re are discussing. Or am I just way confused. :hmmmm: You’re using a comparison of different light out of context from the conversation and my earlier statement. Maybe I wasn’t clear enough that we are not discussing growing with mom’s old reading lamp.

2. It’s discussing internal heat and power consumptions of indiviual bulbs of different wattages, and not with HID.

3. The bulbs they use in that study are all different wattage. They use averages of what is assumed would be used in each circumstance. Understand? Yes captain obvious, a 12 watt led will be cooler than a 100 watt incandescent—thanks science!

4. Also, you have Michigan climate problems, not SoCal where heat is a regular issue. I’ve been doing this a very long time, sometimes on a large scale, and feel very much at home running ducting. But I’ll take your pro tips under consideration, maybe enjoy a little chuckle.

5. I am always suspicious of results produced by the companies that are selling the products, like in the video you posted. Aren’t you?

6. What would happen if I put that same bunny at that same distance under my QB? I think we all could figure that out quickly. Can you?

I admit that I have no experience with cobs. However, you are conveniently leaving out other factors, like drivers, the CORRECT form of lighting to compare, unbiased demonstration, physics, and the laws of thermal dynamics.

1 watt of electricity produces the same amount of BTU’s regardless of the source. This is what I said, and it’s also the same reality you’re dancing around.

If you want to watch videos produced by the people selling you stuff and form an opinion, that’s you. I’m just looking for truth and sharing my experience.
 
The bunny was for giggles. There is more than enough relevant and published data available to illustrate the point.

The screen shot shows a portion of heat load calculations. Different types of light sources introduce different heat loads. The halogen bulb refers to hid lighting. With a coefficient of .82 w/w every watt of power applied creates .82 watts Or approximately 2.8 btus of heat.
LEDs have a coefficient of .08 w/w.

The calculations are used by countless engineers throughout the developed world. To insist that all light sources create the same amount of heat is inaccurate.
 
I'm no scientist, but:

Are y'all doing these temperature tests inside a fully-enclosed, well insulated space? Are you accounting for both the heat produced by the electrical devices and that from all those photons impacting on things within that enclosed space (regardless of the type of technology that is producing those photons)?

Are you accounting for perceptions? If you have a rock small enough to cover with your hand and one larger than your head, and they're both sitting there at 350° (and assuming equal densities, I suppose?), it's easy, you sort of get that the larger item has more heat. But what if the two objects are at different (perhaps significantly different) temperatures? What's hotter, the flame from a candle or that from a propane torch? What if there's one torch and 2,500 candles?

I know which I'd rather be sharing a telephone booth with ;) .
 
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