LED boards with heatsinks or without?

Hello everyone! I am considering buying QB-like boards from AliExpress. And I really need advice from experienced growers.
My task is to make additional artificial lighting in the spring-autumn period (temperate continental climate) in a greenhouse near my mother-in-law's country house. Tomatoes, strawberries and all that. It is also possible in the future to switch to year-round use.

There are 2 lots, 288 lm281b+ boards (unknown bins) at $16 and 288 lm301h boards (unknown bins) at $40. Both rated 120w. Heatsinks are also available for ~$15 each. All prices are inclusive of delivery.

I have a choice:
use lm301h boards 2 per 240w driver (120w each) with heatsinks which will cost $110 plus driver,
or try using lm281b+ without heatsinks 4 per 240w driver (60w each) which will cost $64.
Drivers in all cases will be used by MW XLG 240 at ~$48 each.

I tested 301h boards with heatsinks, when ~120W is applied to each, they evenly heat up to ~60-70°C. The measurements were taken with a thermal imager, so they may not be super accurate.

Unfortunately I have no experience with boards with lm281b+ LEDs.

Based on the above, I have a few questions.


Will the lm288b+ boards be able to work with a power supply of 50-60w without heatsinks? Approximately what temperature will be on LEDs at ambient temperature from +10 to +30 °C.


How much in terms of efficiency per watt will be the difference between the two types of boards? lm301h at 120w and lm288b+ at 50-60w (half power). At least approximately.
Electricity costs approximately $50-$65 per 1000 kW/h. It is planned to install LEDs with a total power of about 3kW ($1320 with lm301h or $768 with lm281b+).

Two old sayings that still hold true are buy once-cry once and the more options the better.

Buy the most powerful lights-drivers and best heat sinks you can afford at this time.
You will then hopefully have plenty of light and cooling now, with room to expand if needed.

Can't really tell you anything about those leds, but I run lm301b boards without heatsinks. They are 44*29cm and I run them at 80w per board.

The more diodes your spread your watts out over, the less heat they produce and the more efficient they are.
Under-driving the diodes is awesome if you can put the money in on extra panels up front.

If you throw out the idea of efficiency gains and just go with heat and light, you are going to get AT LEAST the same amount of photons from 4 boards on a 240 driver as you would with 2, but those photons will be distributed much more evenly over your canopy. The diodes will last longer too because of the lower temps.
Only issue you might run in into is airflow around the boards as you can easily create a "wall of boards" up there. You can figure that out.

I like the LM301 line vs LM281s because I have never seen a spec sheet on the 281s. The 301 is the gold standard of while light diodes for AG right now. Eventually, something will replace it, but pretty sure it won't be the 281s.

If trying to save a buck, the 301B is basically the same thing as the 301H.
For flower, get the 3000nm if using "white" only LEDs. The 3500 has significantly less red (to the naked eye.)

Kingbrite sells their LM301b QB288 bare boards for $29 US + shipping (the 301H is $31, and I conside that the equivalent of "top bin" selection on the B's.)
Their pricing on components is basically perfectly worked out so that you don't lose anything by mixing and matching.
For example:
The price of a 480 watt driver is the same as (2) 240 watt drivers.
If you wanted to run eight QB288s on heat sinks with a single 480 watt driver, you could order that specific setup and not lose a penny.

The difference between the 480 and the 240 is that the 480 allows you to dim the driver all the way down to zero. The 240 watt drivers only go down to ~30%, so you can't use the 0-10v dimmer feature to turn them off.
This is important for some people because it prevents the inrush current surge which draws high amperage compared to the normal running load.

As you are dimming the boards down, you reach a point where the decrease in output is not detectable with the naked eye, but you can see the watts continue to go down significantly.
I can't remember what the bottom output of the 240 watt driver was. Either 17 or 30 watts @ a 110 volt wall outlet.

Contact Vicky Song at Kingbrite and ask her to price you out a deal with shipping on whatever you want.

BTW: if you think you might want heat sinks some day, go ahead and buy them. $15 for the 2 QB board is cheaper than you can buy sheet aluminum for at the local hardware store, and it is pre-drilled/cut. If you ask for screws, Vicky will throw them in for free.