Testing Hans panel: 56watt Cree xp-e/ Lumiled rebel power==== Let's talk efficiency

Originally Posted by PSUAGRO.

Yeah Ive looked at it real close now and it seems to pull the air above it and push it out the sides of the fan housing and flowing over the back of the panel( acting like a flat heatsink?)and to the sides, but not into the interior.........sorry Franjan for the bad info lol......

It's all good P. If you don't mind me thread crapping a bit, here's how someone who seems to really know about cooling thinks. This is from "Power Supplies for LED Driving" by Steve Winder (Copyright 2008 by Elsevier Inc.) and is being used in compliance under section 107 of the Copyright Act of 1976.

"When several devices on a circuit board generate the heat, a solution could be to use a
fan to blow air across the circuit board. Cooler air from outside the equipment can be
blown over warm components to reduce their temperature. Airflow will reduce the
effective thermal resistance of the air interface.

Careful placing of cooling fans can make a big difference to the performance. Large
objects like electrolytic capacitors will tend to block the flow and may steer the cooling air
away from areas of the PCB. If the air flows in the direction of heatsink fins, it will be more
effective. Air flowing across the fins will only cool the front and rear fins, see Figure 14.7.
14.7 - Copy (2).png
If mounting a fan at the top of equipment make sure that the air flows upwards,
with the fan blowing air outwards, so that the fan aids the natural buoyancy of the
hot air. Fans mounted in the side of equipment are much more effective if two
fans are used, one on either side of the enclosure. In a wide enclosure, both fans
could be mounted on the rear panel; one fan should blow in and the other should
blow out so that air circulates around the components inside.

Fans do have a reliability issue, so consider adding a fail-safe mechanism in case the
fan fails to operate. A fail-safe mechanism should monitor the temperature of
sensitive components on the circuit board. Driving the LEDs at a lower power or
turning them off when the temperature rises too high may be a solution."

Until someone convinces me otherwise that's how I'm looking at fans and cooling right now .

Originally Posted by PetFlora

A trip to Hans' website should ease your mind. Keep in mind his light is not designed for > 2.5ft plants. I have an F1 cross of an Indica/Sat that is mostly indica that is barely 26". It would be perfect to grow using Han's light. I attempted to pollinate her; pollen is 2 weeks old, keepin fingers crossed for some seeds

I tired a private source for autos. They simply would not sex until I dropped the light to 12/12

Yeah I agree with this, don't think this panel is designed for growing "trees"............It's definitely beneficial to use a scrog/sog under this little guy(IMO)...
As for AF's, well we know how I feel about them

Originally Posted by FranJan

It's all good P. If you don't mind me thread crapping a bit, here's how someone who seems to really know about cooling thinks. This is from "Power Supplies for LED Driving" by Steve Winder (Copyright 2008 by Elsevier Inc.) and is being used in compliance under section 107 of the Copyright Act of 1976.

"When several devices on a circuit board generate the heat, a solution could be to use a
fan to blow air across the circuit board. Cooler air from outside the equipment can be
blown over warm components to reduce their temperature. Airflow will reduce the
effective thermal resistance of the air interface.

Careful placing of cooling fans can make a big difference to the performance. Large
objects like electrolytic capacitors will tend to block the flow and may steer the cooling air
away from areas of the PCB. If the air flows in the direction of heatsink fins, it will be more
effective. Air flowing across the fins will only cool the front and rear fins, see Figure 14.7.
14.7 - Copy (2).png
If mounting a fan at the top of equipment make sure that the air flows upwards,
with the fan blowing air outwards, so that the fan aids the natural buoyancy of the
hot air. Fans mounted in the side of equipment are much more effective if two
fans are used, one on either side of the enclosure. In a wide enclosure, both fans
could be mounted on the rear panel; one fan should blow in and the other should
blow out so that air circulates around the components inside.

Fans do have a reliability issue, so consider adding a fail-safe mechanism in case the
fan fails to operate. A fail-safe mechanism should monitor the temperature of
sensitive components on the circuit board. Driving the LEDs at a lower power or
turning them off when the temperature rises too high may be a solution."

Until someone convinces me otherwise that's how I'm looking at fans and cooling right now .

Post away my friend, we are all here to learn something new............So Apache Tech has it figured out with their panels, they have two fans mounted on the side drawing air out(i think)........well we will know for sure when puffenuff gets his new toy any day now.......I want pics puff!!!!ha

Originally Posted by PSUAGRO.

Yeah the fan just sits on top and circulates air over the metal backing/ no vent holes!!/ seems illogical to me..........who knows if it holds up...

Surly there is some spacers lifting the fan 5-10mm or so.

I think even if the fan is not very useful, it serves a purpose, it prevent users mounting the panel directly on the wall or a wooden plate, blocking all passive cooling.

Remember we are taking something that's general and is applying it a very closed space, in this blow direction debate.

Reversing the flow in the standing rectangle would take energy to counteract the rising hot air flow.
In the box matching our lamps the space is so small it doesn't matter. And cooling directly on the
LED has first priority vs. using extra power on fan's

Also he's got a much larger fan blowing directly at the heatsink, so it's kind of a silly argument

Should be getting the call today that my order is ready for pickup. Screw shipping across town, saving the extra cash on delivery and picking it up from the factory, a benefit of dealing locally. Ended up with a killer deal on it. I'll let you guys know as much abojt the fans as possible without voiding the warranty. From what they told me, the second fan isnt even.needed and is only there as a precaution in case the other fan fails. I thought it was interesting that they said they are testing 3w and 5w models but are still trying to find a way to effectively cool them while driving the leds the way they like to (100%). Think I mentioned it before, the fans are not the most important aspect of thermal management.

Originally Posted by Rasser

Surly there is some spacers lifting the fan 5-10mm or so.

I think even if the fan is not very useful, it serves a purpose, it prevent users mounting the panel directly on the wall or a wooden plate, blocking all passive cooling.

Ding ding........you're right as usual Attachment 2191480001.jpg........id say a 5mm spacer

Originally Posted by Rasser

Remember we are taking something that's general and is applying it a very closed space, in this blow direction debate.

Reversing the flow in the standing rectangle would take energy to counteract the rising hot air flow.
In the box matching our lamps the space is so small it doesn't matter. And cooling directly on the
LED has first priority vs. using extra power on fan's

Yeah personally id prefer it pulling the air away off the flat backing.....but I think it's irrelevant in my space as you stated...

Originally Posted by puffenuff

Should be getting the call today that my order is ready for pickup. Screw shipping across town, saving the extra cash on delivery and picking it up from the factory, a benefit of dealing locally. Ended up with a killer deal on it. I'll let you guys know as much abojt the fans as possible without voiding the warranty. From what they told me, the second fan isnt even.needed and is only there as a precaution in case the other fan fails. I thought it was interesting that they said they are testing 3w and 5w models but are still trying to find a way to effectively cool them while driving the leds the way they like to (100%). Think I mentioned it before, the fans are not the most important aspect of thermal management.

Can't wait for pics........As for the fans not being an important aspect to thermal management.....well that debatable


Day 5 still nada on germination............002.jpg.........ZZZZZZZZZZZZZZZZZZ

Originally Posted by bassclef

Also he's got a much larger fan blowing directly at the heatsink, so it's kind of a silly argument

Ha .................^^^^This is also true