Bridgelux Vesta 2750 Supplemental Grow Light Test & Build

[PeteR_1]

I'm not a "Grower", just a gardener looking to extend the beginning and end of my growing season indoors, have been using standard 3000K, 5000K and T8 household LED bulbs, and recently purchased a Linear LED High Bay fixture (5000K Lumileds) specifically for ripening potted figs (Ficus carica) indoors in the fall. My initial "exposure" in 2015 to LED Grow Lights was from internet info posted by BML (now Fluence), they used spectral wavelength for objective comparisons of different "Light Recipes" (currently a fan of Valoya and their use in horticultural academic research). At the time T8 Fluorescent proved most practical and cost effective, with LED T8's and A19's (Globes removed) replacing my T8 Florescent a year later.

2ft x 8ft east facing indoor grow area with Fig (Ficus carica) plants.

Now, just purchased eight (8) Bridgelux 2750G, 560 mm strips and five (5) TRP (Thomas Research Products - Hubbell) 75 watt drivers from Digikey (for testing / prototyping) after Reading through several informative and enlightening Bridgelux Vesta 2750 discussions, received them in only two (2) days from placing the order and the prototype was built within the next two days. A perforated 18 by 26 Aluminum Sheet is used for the prototype but a solid aluminum Sheet / Bun Pan will be used for the final product...
LED Strips BXEB-2750G... https://www.digikey.com/product-detail/ ... ND/7899252
75W LED Driver... https://www.digikey.com/product-detail/ ... C3000-D-ND
100K Ohm Pot... https://www.digikey.com/product-detail/ ... ND/4733104
Perforated 18x26 Aluminum Pan... https://www.culinarydepotinc.com/winco- ... -sheet-pan
Solid 18x26 Aluminum Pan... https://www.culinarydepotinc.com/winco- ... -sheet-pan



The Vesta 2750 prototype is a modular "Supplemental" Grow light to cover a total area of 2ft x 8ft (16 sq ft / ~ 1.6 sq m) next to an East facing window. The plan is to create two to three (2 - 3) modular grow lights similar to Commercial DLC Listed Linear High Bays or a Nextlight Core. A Watt Meter (Kill A Watt P3) and Lux Meter (Benetech GM1010) will be used to measure the Lux (PPFD) and adjust / set the 100K Ohm Pots to an adequate spectrum and intensity / Density (respectively), for "Day-Neutral" plants.

Linear High Bay... https://greenlightdepot.com/collections ... 2196998187
https://cdn.shopify.com/s/files/1/0931/ ... 5685830816
@ 28000 Lm * 0.015 PPF/Lm = ~ PPF 420 (umol/s)

Nextlight Core... https://nextlight.com/index.php?route=p ... uct_id=116
@ PPF 380 (umol/s) / 0.015 PPF/Lm = ~ 25000 Lm


Using the basic sizing formulas;
Generic Lumens to PPF (PPF/Lm) Factor:
0.014 = 5000K 80 CRI
0.015 = 4000K 80 CRI
0.016 = 3000K 80 CRI

Generic "Plant PPFD Requirement":
100 - 200 PPFD (~ 6700 - 13400 Lux)= Seedlings - Cuttings (up to 24% Blue)
300 - 500 PPFD (~ 20100 - 33500 Lux) = Vegetative - Flowering (up to 20% Blue)
600 - 800+ PPFD (~ 40200 - 53600 Lux) = Fruiting / Flowering (up to 15% Blue)

Formulas;
Req'd PPFD * Area (sq m) = Req'd PPF
Req'd PPF / LED's PPF/W = Req'd Watts

We get;
Req'd PPFD 500 (umol/m2/s) * 1.6 (m2) = PPF 800 (umol/s)
800 (umol/s) / 2.1 PPF/W (132 LM/W x 0.016 PPF/Lm) = 381 Watts

Preliminary calculations for module, approximately 18 in x 24 in (40 cm x 60 cm) with eight (8) BXEB-TL-2750G 560mm strips;
a. 8 strips @ 750mA & PPF 39 (umol/s) each = 150 Watts total & PPF 312 umol/s (actual 360 umol/s @ strips)
* b. 8 strips @ 1000mA & PPF 52 (umol/s) each = 200 Watts total & PPF 416 umol/s (actual 480 umol/s @ strips)
c. 8 strips @ 1500mA & PPF 78 (umol/s) each = 300 Watts total (requires Heatsink) & PPF 624 umol/s (actual 660 umol/s @ strips)

Preliminary measurements @ 150 Watts after 2 hrs run time are;
Driver Input;
120 VAC
165 Watts
0.96 PF

Driver Output;
23.98 VDC
3.1 Amps

IR Thermometer;
25.4°C Room Temp.
35 - 37°C Rear Strip Temp.
40°C LED Driver Tc Temp.

PPFD @ center
928 umol/s/m2 @ 9 in (23 cm) - 58000 Lux
160 umol/s/m2 @ 24 in (60 cm) - 10000 Lux

References:
BXEB-2750G topic... viewtopic.php?f=15&t=761
75W LED Driver topic... viewtopic.php?f=15&t=747
EB Gen3 2700K 90CRI Performance topic... viewtopic.php?f=32&t=5575
Vesta 2750 performance topic... viewtopic.php?f=32&t=4277&hilit=bridgel ... t&start=50
DLC LIsted LED Grow Lights w/ Posted Spectrums... https://www.designlights.org/horticultu ... ng/search/
Easy Estimate of PPFD from Lux... https://www.biorxiv.org/content/biorxiv ... 0.full.pdf

[LEDG]

Dang, nice write-up! References even! Takes me back to my book-learnin' days.

I agree on switching the heat sink over to something solid. The more surface contact the better. Love the baking/electrical fusion going on here. What's your take on the drivers? Well-built?

[PeteR_1]

@LEDG ,

Thanks. Just like to provide corroborating info for any discussions...

The TRP LED Drivers appear to be well build, also TRP appears to be a division of Hubbell a large manufacturer of electrical components. The 75W is rated and working at 88% Efficiency, ~ 82 Watts input, ~ 75 watts output. Will be ordering a 200 - 240 Watt MeanWell LED Driver rated at ~ 92% Efficiency for one of the two production light fixtures (future comparisons)...

[PeteR_1]

Vesta 2750G LED Strip Comparison at Various 2700 : 5000K Ratios

Some of the reasons for choosing the Bridgelux Vesta 2750G strips are;
Good Wavelength distribution, IMO only missing adequate ~ 400 - 430nm range typical for most PC White LEDs.
Tuning capability along with Dimming for tailored spectrum and density / intensity.
The actual "Spectrum Wavelength Distribution" posted by @TEKNIK
PPE (Efficiency) over 2.0 umol/Watt
Readily availible and moderate price for testing and (ab)use.

Spectral Wavelength Distribution of several Commercial Grow Light

Compared to Fixed Spectrum Wavelength distribution of Commercially available Grow lights the Vesta 2750G can be easily "Tuned" for typical Vegetative, Full Cycle or Flower Spectrum.

Simple Wiring Diagram for utilizing 2700K (Flower) 5000K (Veg) and 3800K (Full Cycle) Spectrum on a single LED Driver

A single dimmable LED Driver can be wired in parallel with two switches for 5000K or 2700K, or 3800K with both switches "On", for Vegetative, Flower or Full Cycle respectively...


Hubbell... https://www.hubbell.com/hubbellindustri ... /p/2056667
Valoya... https://www.valoya.com/wp-content/uploa ... 2020.2.pdf
Atrium... https://cdn.shopify.com/s/files/1/0001/ ... 26.pdf?103
Fluence, Gavita, HydroFarm PhotoBio, etc... https://www.designlights.org/horticultu ... ng/search/
Samsung Strip... viewtopic.php?f=32&t=5741&p=22975&hilit ... sts#p22975
Bridgelux Gen3 90 CRI... viewtopic.php?f=32&t=5575

[TEKNIK]

I didn't know anyone was studying my tests results with such detail.
I will have a solution for those seeking spectrum in the 430nm range soon that will be very affordable and also blend in with a strip build really well.
It will be part of a new range I'm doing and can be controlled really easily. All of the new range will have the same forward voltage so it can be operated from one driver with the choice of adding a controller.
Colors about to be released are 4000K CRI95, PC red, 660nm and 730nm.
I'm still testing the 660nm but performance is hitting over 3.5m/joule. Others will be much lower in performance but still really good value for those that want to DIY or add onto a pre assembled light.
My system is really easy to install and set up.

[PeteR_1]

@TEKNIK

Its not really studying , just organizing and using the info provided by the forum community and internet to make informed decisions. Thanks for taking the time to share your expertise and knowledge.

IMO as a gardener, Light Recipes and Spectral Wavelength Distribution should and can be treated "objectively" like prescriptive fertilizer N-P-K and Micro-nutrient ratios. Understanding and following the established prescribed application rates and methods usually leads to success, regardless of personal preferences.

Looking forward to the products and info on supplemental Blues and PC Reds since I already have 3000K and 5000K LEDs which are still functional.

[PeteR_1]

Eight Vesta 2750G 560mm strips and MW XLG-240-H-AB Driver prototype...

Preliminary measurements XLG-240-H-AB @ 240 Watts after 1 hr run time are;
Driver Input;
119 VAC
262 Watts
1.00 PF

Driver Output;
48.89 VDC
5.0 Amps

IR Thermometer;
27.4°C Room Temp.
40°C - 44.5°C Rear Strip Temp.
51.5°C LED Driver Tc Temp.

PPFD @ center
1360 umol/s/m2 @ 9 in (23 cm) - 80000 Lux
1037 umol/s/m2 @ 12 in (30 cm) - 61000 Lux
425 umol/s/m2 @ 24 in (60 cm) - 25000 Lux
238 umol/s/m2 @ 36 in (90 cm) - 14000 Lux

XLG-240-H-AB... https://www.digikey.com/product-detail/ ... D/10300463

From these preliminary measurements will need to add two (2) more Vesta 2750G 560mm strips, for a total of 10 strips to reduce LED temperatures and individual strip milli-Amp current at Driver's full output...