Also watch our old light transmission video using a LUX meter: th-cam.com/video/LfVgWkdg9Ow/w-d-xo.html Or read our In-Depth Article: greenhouseemporium.com/greenhouse-glazing-materials-best-for-light-transmission/
As far as we can say, the clarity of the polycarbonate sheets and the channel size must have played a role in this. The Riga greenhouses use quite translucent sheets while the 4mm generic polycarbonate was slightly less clear. When you look at the width of the channels between the walls, you can also see quite a difference. The 4mm has very narrow channels which could result in more light being blocked.
@@ghemporium that explanation actually makes sense. I'll make sure to check out the channels. Btw, in growing mary J, many of the better LED lights claim to having a 1.8 mol/joul rating. Would you want that type of intensity for any sun hungry crop?
@@dozyproductionss Now, we're rather talking about efficacy (PPE). As far as I understand it, µmol/J tells you how much usable light per Watt/Joule you get. A higher number is better as it provides more light per the same power spent. You can calculate PPF if you know the Wattage and PPE. For example, 1000W LED grow light with a 1.8 µmol/J rating will produce 1800 μmol/m²/s PPF. In veg stage, your plants only need 300-600 μmol/m²/s (less for seedlings) and 600-900 μmol/m²/s for flowering stage. This means the distance or a dimmer will help adjust the amount of light you'll give your plants during each stage. Hope this helps!
Hi. Your test is not consistent, you place the samples once parallel and once perpendicular (chambers of Pc), looking at the angle of the sun in 8mm Pc the light must pass through two walls to hit sensor but in 10mm Pc it must go throught 3 walls (including the inner walls of the chambers) in 16mm Pc it's passing 4-5 walls. This wouldn't be a problem if the sun was at its zenith. A similar situation is with LUX meter, light from further diodes on the led barr hit samples on sharp angle it would be more precise if you use one led bulb straight abowe sensor. Sorry for my english, I'm from far away :)
Thanks for pointing these things out! I didn't consider it and sure enough, you're right. It makes a difference which direction it's placed (I just went outside and tested it real quick). It's comments like this I love the most. I'm intrigued to test the polycarbonate panels again. Keep in mind, we did say it's not a scientific test. We are not in a place to avoid/prevent all variables.
Also watch our old light transmission video using a LUX meter: th-cam.com/video/LfVgWkdg9Ow/w-d-xo.html
Or read our In-Depth Article: greenhouseemporium.com/greenhouse-glazing-materials-best-for-light-transmission/
Any ideas why the 8mm polycarbonate resulted in better light transmission than the 4 AND higher ones?
As far as we can say, the clarity of the polycarbonate sheets and the channel size must have played a role in this. The Riga greenhouses use quite translucent sheets while the 4mm generic polycarbonate was slightly less clear. When you look at the width of the channels between the walls, you can also see quite a difference. The 4mm has very narrow channels which could result in more light being blocked.
@@ghemporium that explanation actually makes sense. I'll make sure to check out the channels.
Btw, in growing mary J, many of the better LED lights claim to having a 1.8 mol/joul rating. Would you want that type of intensity for any sun hungry crop?
@@dozyproductionss Now, we're rather talking about efficacy (PPE). As far as I understand it, µmol/J tells you how much usable light per Watt/Joule you get. A higher number is better as it provides more light per the same power spent. You can calculate PPF if you know the Wattage and PPE. For example, 1000W LED grow light with a 1.8 µmol/J rating will produce 1800 μmol/m²/s PPF. In veg stage, your plants only need 300-600 μmol/m²/s (less for seedlings) and 600-900 μmol/m²/s for flowering stage. This means the distance or a dimmer will help adjust the amount of light you'll give your plants during each stage. Hope this helps!
Hi. Your test is not consistent, you place the samples once parallel and once perpendicular (chambers of Pc), looking at the angle of the sun in 8mm Pc the light must pass through two walls to hit sensor but in 10mm Pc it must go throught 3 walls (including the inner walls of the chambers) in 16mm Pc it's passing 4-5 walls. This wouldn't be a problem if the sun was at its zenith. A similar situation is with LUX meter, light from further diodes on the led barr hit samples on sharp angle it would be more precise if you use one led bulb straight abowe sensor. Sorry for my english, I'm from far away :)
Thanks for pointing these things out! I didn't consider it and sure enough, you're right. It makes a difference which direction it's placed (I just went outside and tested it real quick). It's comments like this I love the most. I'm intrigued to test the polycarbonate panels again.
Keep in mind, we did say it's not a scientific test. We are not in a place to avoid/prevent all variables.