Samsung F Series Gen3 LED Strips Build (using double row variant strip)
Currently my 4 X 2 veg tent has a 4 X 54W T5 bulb fixture that uses 216 watts, yielding approximately 20 000 lumens. I replaced this with the new Samsung F series Gen3 strips. I ordered two of the SI-B8R521560WW strips from DigiKey. They cost about $26 USD each. The 5000K strips are rated at 9300 lumens each using 2 rows of LM 561C LEDs, for a total of 18 600 lumens, which is close enough to the stated output of my T5 fixture (my T5 bulbs have probably dimmed with age anyway). The 2 LED strips combined use about 103 Watts, about half of the equivalent T5 setup.
Materials:
2 X 24 inch aluminum flat bar (⅛ inch thick)
#6 Self drilling/self tapping screws
2 X SI-B8R521560WW Samsung LED strips
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LED Power Supply ( I used a 24V power supply and a separate constant current driver module from eBay. Meanwell HLG-150H-48A would work fine also)
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18 gauge solid wire
Steps:
- Cut bar into desired length. I used 1.5 inch wide flat bar since the double Samsung strip is 39mm wide. I made it slightly longer than the strip to have attachment points for hanging it. No sag noticed in the bar.
- Attach strips using self tapping screws. I drilled first then drove in the screws. It would be best to include a nylon washer so that the screw doesn’t accidentally make an electrical connection on the strip itself. No TIM, no greases, no glues. Easy.
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- I connected the wires into the on-board connectors and set the system for 48V, 2.24A (I used a parallel connection for the two strips). No soldering needed. You will need to use the ammeter function on your multimeter to set the current.
Before:
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After:
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I think this is the way to go in the future. I get 180 lumens per watt with very little construction effort, no expensive heat sinks and no soldering. You can also use these strips for flowering. Just order the 3000K strips and use more of them. These are more efficient than fluorescent bulbs and HPS/MH bulbs while being easier and cheaper to assemble than COBs.
In the future I would just use some office supply clips to secure the strips to the aluminum (you can see one of the clips in one of the images above).
The LEDs do actually get hot, and strip itself gets hot enough that you can only put your fingers on it for a few seconds. I checked and the aluminum seems to max out at 130F (55C). I guess fingers act to draw away heat at a rate that feels too hot. Samsung's specs are measured at 65C so I'm not overheating the LEDs. Still, some extra heatsinks or fan probably wouldn't hurt. These lights will be great in the summer, as total heat is reduced without impacting light output. However, in the winter I may need some seedling heat mats to keep the temperature high enough.
The light comes from one small area, so the light output is more glaring than a diffuse set of T5 bulbs. Not sure if the plants care.
The currents on these particular strips are non standard at 1.12 A each. I used my own power supply components. If you wanted to use a Meanwell, you could use a HLG-150H-48A and adjust the current down. It would be nice if there were inexpensive strips that used standard currents, like 700mA, 1050mA, or 1400mA.
These strips are designed for retrofitting into existing fixtures, so they use standard 2 foot and 4 foot lengths. Nice.
Others have had great results mounting small strips on cookie sheets, which are cheap and easy to get heatsinks as well.
Final:
Lux reading 12 inches from T5 lights: 22 100 lux, 238 W total system power (ballasts, etc)
Lux reading 12 inches from Samsung hard strips: 28 900 lux, 130 W total system power (LED driver, etc)
More light at half the wattage!
