DIY with Quantum Boards

pop22

Well-Known Member
I'm running 4 QB304 at a total of 363 watts from the wall. All I have for an extraction fan is an 8" duct fan. My 4x4 tent is 10 degrees cooler than it was with a 345 actual watts Vipar piece of crap. Sounds like you don't have enough air moving through the tent, and if the tent is in a room without air conditioning, the room temps with ANY light will gradually rise as the heat builds in the room

How in the world do you guys cool these things down! These 2 qb 304 260w are cooking my tent!
 

robincnn

Well-Known Member
Hey guys! I just got my 260W QB304 kit assembled over the holiday weekend, and this thing is super nice! I have it hung in the tent now and it's a perfect fit. One thing I noticed when I was testing it out though is that it seems to max out at 240W from my smart plug.

Is it possible the potentiometer I soldered onto the Type-B Meanwell driver is limiting the total power? I seem to have a 10-240W usable range, and while I don't think I'd ever need more than that in my current tent, nobody likes feeling underpowered.

@robincnn, @Stephenj37826: Thoughts on what might be limiting the power?
Meanwell type A usually gives more power than type B. HLG Kits come with Type A as standard
HLG-240H-CxxxxA will go as high as 280-300 watts.
HLG-240H-CxxxxB will be max around 260-270 watts. A 100K pot will limit it to 100%. However pots have +-20% tolerance so a 100K can be as low as 80K or as high as 120K. For max just leave the Dim + and - Open then it gets around 105%-110%.
 

pop22

Well-Known Member
I'd go with the three 135 kits for the adjustability and spacing options.

Been lurking around for a bit and am thinking of purchasing some of these for a new grow measuring 6' wide x 2' deep x 9' high.

Would you go with two 265 kits or 3 135 kits?
 

coreywebster

Well-Known Member
I'm running 4 QB304 at a total of 363 watts from the wall. All I have for an extraction fan is an 8" duct fan. My 4x4 tent is 10 degrees cooler than it was with a 345 actual watts Vipar piece of crap. Sounds like you don't have enough air moving through the tent, and if the tent is in a room without air conditioning, the room temps with ANY light will gradually rise as the heat builds in the room
Or the extraction is limited by been vented into the same room and recirculating the warm air.
Or the thermometer is placed poorly and air circulation is poor.
Or tents is too small for the wattage.

See a lot of guys who think they can cut out extraction all together because they have LEDs.
@Bombaclatt5000
 

ttystikk

Well-Known Member
That would be way too much light IMO.
I don't think it's worthwhile to go over ~35w/sq foot of good LED if you arent gonna add CO2.
For example; I'm running four modules, each pulling 225W at about 55% efficiency, over a 24 sq ft trellis;
225x4=900W/24=37.5 watts per square foot and it's borderline too much.
 

frigginwizard

Well-Known Member
I'll get more g/square foot with 40 w/sqft than 30 w/sq
For sure, I didn't say no returns, I said diminishing.
I mean, you're making a case here for barely over the ~general number I said, and even that is widely variable based on how efficient the setup is. You would have to have your grow dialed in with a strain you have grown a lot before to even discern the difference between ~10% of your light.
 

ttystikk

Well-Known Member
The plants get used to the light if you give them a few days and the diminishing return is for g/watt I'll get more g/square foot with 40 w/sqft than 30 w/sq
Again, to a point of diminishing returns. See the graphic I posted above; the last little bit is costly in terms of both light and environmental control and doesn't return an awful lot for the trouble.
 

skunx818

Well-Known Member
Again, to a point of diminishing returns. See the graphic I posted above; the last little bit is costly in terms of both light and environmental control and doesn't return an awful lot for the trouble.

800-1000 is where i thought I should shoot for. And led gardener?'s video was showing 6 hundred something ?dead center 24" above.. I could be remembering wrong. And of course those numbers would go up when multiple boards are used. All speculation for me right this moment
 
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