watts vs distance (qb 132)

If you have the money, twice the number of boards at half power (37.5 watts) is a great idea. Plus you can double your grow space in the future if you want. You could put half the boards in the new space and run them at the full 75 watts. Just need to make sure to get dimmable drivers that can put out the full 75 watts per board.

 

simple and probably the least expensive way to get full power and full easy dimming would be a Meanwell LRS-350-36 driver. Runs $32.00 at Mouser.com. has a pot adjustment built in you could use for some dimming but I think i better solution and real easy and works great is to add a PWM controller for dimming.

 

Yes, but if you have to add the $22 for the pwm controller that makes it $54. In that case, it's only slightly more expensive to use the HLG-240h-36A for three boards, and it has very good dimming already built in.

 

Yes, the hlg-240 is only a little bit more but you don't HAVE to use the PWM controller, most people using the set up are not, I simply saw where somebody else had added one and thought it was neat so decided to do it also.
Also, perhaps I am wrong, but I do not think you can get the full 75 W per board using the HLG-240. Wouldn't you only get 60w/per on that driver? I very well may be wrong - I'm still trying to get my head straight on the drivers, wiring, making sure you pick a driver that is correct for the board or strip and all are different!the higher power ability of the lrs-350-36 gave more power than the hlg-240-36 and was less expensive.
The best option I saw was the hlg-320-2100 to run 4x qb132 but it's pricey at around $90
So far I'm very happy with the LRS – 350-36 except for the added fan noise of the unit's built in fan.

 

Yes, if you added 4 boards to the HLG-240-36A it would be 60 watts per board, but if you do three like I do, you can run the boards at full capacity. 3 boards and 75 watts is 225 Watts, so the 240 watt driver seems perfect. You can dim it very low, and you can blast them a little higher than 75 Watts if you want to. For most people, I guess groups of three boards is inconvenient, but for my situation, I'm using a 2 x 6 tent and two 2 x 3 tents, so they are perfect in groups of three.

 

if you are doing three, I can see that than but for groups of four there are bigger/better options

 

Yes. The hlg-320 would do. Not sure if they have an elg version at that wattage.

Here's something that is extremely useful. It has every meanwell driver made and all of their wattages.

MEAN WELL LED Power Supply

 

Everything u said is 100 percent correct. Except i dont hear both of my lrs-350-36 driver fans. They dont kick on til bout 34 volts. They can b dimd just as easy as hlg a &b by adjusting the volts Phillips head and using multi meter. I love my 8 qb132's with 2 lrs-350-36 . can run em at 60watts or 75. Got 89.5 efficiency for lrs drivers while hlg drivers are 93-94 efficient but for 35 buck a driver il b ok with the slight loss with my lrs. Where else can u get almost 600 true watts of sum of the best lighting on market (HLG)for 275 bucks? That was my total.then another 25 bucks in alum angle from my job as a machinist. The framing a sinch since i work using all metals daily. The wiring on other hand was intimidating til i got on here and asked couple guys who helps alot of people on here with quantums. Then the wiring is now a cinch sense i was able to mount mine on a 4x4 alum frame and see em glow like 8 little square suns. Lol. Without fan blowing across fixture the lights themselves run bout 90 degrees with my temp in room staying bout 84. With fan on the boards run like at 78-80 degrees and room perfectly around78-80 with all 8 running at max. Just trying to share my info with whoever it may help and to say u hit the nail on head bout everything u said. I reserched quantums/cobs for 4-5 months b4 i bought my 8 132's. My fixture has room for me to add sum qb 96 elites . they have the added reds for flowering and can b ran high wattage for a little light. But nice to meet u dude✌

 

I have the lrs-350 on my 4x qb132's and the driver fan kicks on and I plainly hear it. it's not that loud or invasive and if the driver was in the tent at the lights I very well may not hear it over the noise of the the two reg fans and the air filter fan, but it's mounted on the outside of the tent and it's in a quiet bedroom so everything can be heard, same as i can still hear the fans running INSIDE the tent.
It's not overly loud nor bad at all, but compared to the hlg-240 I have running my 2x 288 boards it is, since the hlg driver is dead silent without a fan. on the other hand the hlg driver is hot as hell to touch it - i mean seriously frickin' hot, the the lrs driver barely ever goes above ambient room temp even being run at 100% 18/4 schedule she never feels warm. I'm glad for the little light to tell me it's actually on! lol
If i'm foliar feeding while the lights are on i'll dim them down with the pwm dimmer I have attached and you are correct, with the lrs driver dimmed down I don't recall the fan usually kicking in. I can't say definitely that it never turns on at dimmed levels, but I don't recall hearing it doing so.

 

Yea now it makes sense on y ud hear fans running. Mine r inside room but like u said i only hear fans blowing across room. And yes ur correct my fans dont run when they are dimd down to 33-34 volts. I just hook up a multimeter when i dim or brighten lights and just watch the volts. Nice chatn with u bro i dont have any pics of room or anything yet but wil b up and going real soon as im just sprouting seeds for first grow indoors but done 2 harvests a yr outdoors for 20 yrs. First indoor attempt. Nice 2 meet u✌