PAR question

GreenBean 420

GreenBean 420

Well-Known Member
I’m using the Photone app with a diffuser to measure my PAR after watching that YouTube video. Yes not ideal but seemed great to me.
My question is. I had my SonoFarm 2000s at 36in from seedlings (7days old). Dimmed to 80% and was reading 360 PAR. I just lowered them to 24in in hopes of getting the canopy temp up a couple degrees. Dimmed to 60% at the same PAR. As long as my PAR reading is the same (correct for that growth stage etc) it doesn’t matter how close the lights are correct? Obviously the light spread becomes more concentrated and less spread out so not too close to soon but just wanted clarity that that was the case. Thanks y’all!
 
Rocket Soul

Rocket Soul

Well-Known Member
GreenBean 420 said:
I’m using the Photone app with a diffuser to measure my PAR after watching that YouTube video. Yes not ideal but seemed great to me.
My question is. I had my SonoFarm 2000s at 36in from seedlings (7days old). Dimmed to 80% and was reading 360 PAR. I just lowered them to 24in in hopes of getting the canopy temp up a couple degrees. Dimmed to 60% at the same PAR. As long as my PAR reading is the same (correct for that growth stage etc) it doesn’t matter how close the lights are correct? Obviously the light spread becomes more concentrated and less spread out so not too close to soon but just wanted clarity that that was the case. Thanks y’all!
Click to expand...
Te real question is whether your app is doing reliable measurements, keep a look out for signs of light stress.
 
C

ComfortCreator

Well-Known Member
GreenBean 420 said:
I’m using the Photone app with a diffuser to measure my PAR after watching that YouTube video. Yes not ideal but seemed great to me.
My question is. I had my SonoFarm 2000s at 36in from seedlings (7days old). Dimmed to 80% and was reading 360 PAR. I just lowered them to 24in in hopes of getting the canopy temp up a couple degrees. Dimmed to 60% at the same PAR. As long as my PAR reading is the same (correct for that growth stage etc) it doesn’t matter how close the lights are correct? Obviously the light spread becomes more concentrated and less spread out so not too close to soon but just wanted clarity that that was the case. Thanks y’all!
Click to expand...
No you may be overlooking some details.

The heat mostly comes from the driver that powers the lights. The rest comes from the lights themselves. As you turn down the lights, the heat produced by the driver and the lights goes down.

To increase heat, raise lights higher, turn up power higher, and use a fan or 2 to blow the heat indirectly down towards the canopy. You have to produce the heat (driver being run at 75%+) and then blow it towards the targeted area (fans).
 
GreenBean 420

GreenBean 420

Well-Known Member
ComfortCreator said:
No you may be overlooking some details.

The heat mostly comes from the driver that powers the lights. The rest comes from the lights themselves. As you turn down the lights, the heat produced by the driver and the lights goes down.

To increase heat, raise lights higher, turn up power higher, and use a fan or 2 to blow the heat indirectly down towards the canopy. You have to produce the heat (driver being run at 75%+) and then blow it towards the targeted area (fans).
Click to expand...
Ah this makes sense. Yeah the temp hasn’t changed much lol. Thank you!
 
Roy O'Bannon

Roy O'Bannon

Well-Known Member
Can you actually get leaf temps to change with an led like a SF1000-4000, If is just the heat from the driver? Then a heater could do it right?
I thought the leaf temp diff came for the ir light frequency in the filament or gas filled lights?
 
1

1212ham

Well-Known Member
GreenBean 420 said:
I’m using the Photone app with a diffuser to measure my PAR after watching that YouTube video. Yes not ideal but seemed great to me.
My question is. I had my SonoFarm 2000s at 36in from seedlings (7days old). Dimmed to 80% and was reading 360 PAR. I just lowered them to 24in in hopes of getting the canopy temp up a couple degrees. Dimmed to 60% at the same PAR. As long as my PAR reading is the same (correct for that growth stage etc) it doesn’t matter how close the lights are correct? Obviously the light spread becomes more concentrated and less spread out so not too close to soon but just wanted clarity that that was the case. Thanks y’all!
Click to expand...
As Comfortcreator said, raise the lights and increase power for more heat. Reducing air flow through the tent is a primary way to retain heat. Insulation helps, I've been know to put blankets and bedspreads over the tent and even built a cabinet with 1" foam insulation and that raised temps much higher than the same size tent, at least 10° F.
 
Last edited:
C

ComfortCreator

Well-Known Member
1212ham said:
Where did you ever get that idea? The heat mostly comes from the LED's. A typical Meanwell driver has around 94% efficiency, that means 94% of the electric energy powers the LEDs and 6% is converted to heat by the driver.
Click to expand...
I get the idea from using the equipment and observing how it works. I offered good practical advice you agree with but want to say what exactly, I'm wrong the drivers dont produce a ton of heat? Lol ok. Do you grow?

Meanwell doesnt claim 96%, and sure doesn't claim that at full power.

"...The power supplies do not have a constant efficiency; it varies with various factors such as the environmental and load conditions. The supplies achieve their maximum efficiency when operated at 50% of their load. In fact, the manufacturers guarantee the maximum efficiency only when the supply is run at 50% load...."

So try sitting on your meanwell driver at full power or hold your hand on it. The reason some put drivers outside their space is because they produce so much heat.

Above 75%...as I said before, the drivers get very hot. If you own a driver above 120watts you know this.
 
C

ComfortCreator

Well-Known Member
So if I quote meanwell saying their max efficiency is running 50%, and that same quote had a graph showing it fell off on both sides...lower efficiency on either side of 50%....would you guys bother to check or just say whatever lol?
 
Southernontariogrower

Southernontariogrower

Well-Known Member
my lights diodes are best run at 105 degrees, lose less intensity over time, lower temp causes degradation of leds at a faster rate the lower the running temp. Dont make sense to me but what company claims. Osram diodes, look up charts. Believe drivers run better at 100% too. But nothing to back up beliefs yet, havent looked either.
 
GreenBean 420

GreenBean 420

Well-Known Member
Thanks for some added info y’all. I have raised the lights back to 36in and cranked them back to 80%. The temp has gone up from 68-69 to 72-73. With the small fan up top blowing down on the top of the panels and I believe pushing the heat downward. I will try today with the fan off and see if the temps move up or down. I am tracking everything with AC infinity app so it’s pretty easy to watch changes lol
 
C

ComfortCreator

Well-Known Member
salmonetin said:
im curious about that quote and graph....are we talking about same or similar drivers?....
Click to expand...
Well both graphs were from Meanwell, but my reference was an older set of models. Efficiency is as high as the graph shows, I was wrong on that.

But the practical advice was correct, and imo the driver sure as heck produces a ton of heat but I cant quantify it in reference to the boards. I can only assume I am wrong or off base. That's how I learn, I get it wrong sometimes.
 
You must log in or register to reply here.
Top