Lighting Grow Northern Live Tech Talk

[Corgy]

I don't understand, my friend was planing on connecting 4 together then just plug them straight into the wall via the plug and grow. 4 HS1's is only 300w ? I don't know, what am I missing ?

You can connect up to 16 HS1's in a daisy chain

http://www.grownorthern.com/wago-distribution-t-piece.html

 

[MikeyB420]

I was wondering on my dog walk this morning ........................................................

Sorry Bro, couldn't resist!

Good points as always in your post!! Although, the more I look at the 'Luminous efficiency' figure of 43% quoted by GN, it knocks HPS into a cocked hat!



MikeyB.

 

[GrowNorthern]

Does anybody have a link to a picture showing the surface of the diffuser from the HS1?

Rilla.

Here is a picture of a Holographic diffuser (on the left) and a traditional diffuser (on the right)

The micro-structured surface of the diffuser needs to be be examined under an electron microscope, here are some examples.

 

[User K]

Nice

 

[GoeRilla]

Thank´s

Rilla.

 

[Xagor]

Can you give more info about what the diffusor does? Or what your trials show?
It reminds me of a cool tube, which takes away valuable light, seems counter intuitive to me.
When I look at the leds, they seem tightly clustered + height above plants, the light already seems nicely mixed.

Maybe TaNg can get 3gpw in a test without it?
Just wondering, never saw one of those on these $$$$$ professional led grow panels

cheers

 

[puffman420]

Here is what the diffuser does - these pics are from another site


without diffuser

with diffuser

 

[TaNg]

Here is what the diffuser does - these pics are from another site


without diffuser

with diffuser

Great post bro the pictures demonstrate the necessity of the Holographic diffuser perfectly,plus max rep.

 

[Xagor]

Nice pics.
But isnt it a bit an illusion? Reminds my of my camera, if you focus a bright spot in the mddle, everything gets darkend around like that, when in reality everything seems much brighter to the eye.
Or is the HS built like that? If so, if you have the headspace, you could just put it higher or not?

 

[GrowNorthern]

Can you give more info about what the diffusor does? Or what your trials show?
It reminds me of a cool tube, which takes away valuable light, seems counter intuitive to me.
When I look at the leds, they seem tightly clustered + height above plants, the light already seems nicely mixed.

Maybe TaNg can get 3gpw in a test without it?
Just wondering, never saw one of those on these $$$$$ professional led grow panels

cheers

The holographic diffuser is used to create even distribution of spectra and intensity across the target coverage area from a single point or multiple points of illumination. The problem with led grow lights that only use secondary optics is there relative intensity distribution in the beam angle. Take a look at this example

See how a large portion of the relative intensity lies at around 20° degrees with a peak at 0°. These are light intensity hotspots and we have found that not only do these account for a large volume of wasted reflected light but these hots spots also cause light-induced molecular damage and other consequential plant health issues.


This can be seen with most cluster/modular LED grow lights like our previous series. Depending on the power density and distance to the canopy, they generally tend to have a very high central intensity (which also has hotspots with in that central intensity) and a secondary intensity. Though that central intensity can produce great PAR readings when measured at a single location this doesn't tell us the quality and quantity of growth we can see spanning the full coverage area or the damage that these hotspots can cause to plants.

The secondary optics we use are from LEDIL- a producer of high efficiency polymer optics. The beam angle of the HS1 optics is 20-24 degrees (depending on whether the LED is the rebel or rebel es), if applied like you suggested without the diffuser this will cause significant damage to any plants underneath and a tiny coverage area that is just slightly larger than the area of the module without a holographic diffuser (as seen in the previous reply to this post). Here is the relative distribution on the narrow optics we use.

The use of a narrow beam angle optic in comparison with a an optic with a wider beam angle has 2 main benefits. Firstly the optics transmission efficiency is higher in the narrower angle (73%-wider angle, 88.3% narrow angle) and secondly you can use any holographic diffuser in conjunction that has a wider beam angle than the secondary optics. This means we can not only produce a homogenous distribution of intensity across the beam angle but we can also interchange the beam angle using our magnetically removable diffusers. That said your right in thinking using a tertiary optic like the holographic diffuser does decrease the efficiency of light delivered to the plants compared to just using primary optics. Though by using a more efficient primary optic with a narrower beam angle we make up much of the difference but now the light is also distributed homogeneously across the beam angle. Compared to traditional diffusors (see the previous GN post) the holographic diffuser's micro-structure greatly reduces reflection making ordinary polycarbonate transmit light as upto a 92% efficiency compared to the 70%+- traditional diffuses.


The only other "$$$$ LED grow lights" that can offer similar uniformity to the HS1 are the illumitex models. If you examine their LED package you will find a similar optical system for removing hotspots. In the illumitex array the semiconductors are not encapsulated by a silicone dome but by the optical system and their diffuser is a traditional (injection molded) type which is part of the primary optic. The package they produce has similarities between the HS1 optical system and the optical system in the modular series. Though hotspots are removed/reduced from the distribution of a single LED array, the arrays also need to be spaced out accordingly to prevent hotspots forming from two arrays in conjunction. Our optical system doesn't need this spacing as it performs like a single illumitex array but with a larger power density, coverage and a more homogeneous spread of light.