So here I am after a 1 week absence, I've changed the 3 panels by the new one (the Phlizon 1500w, still not the best but you know...), and results are much better. We can see that the plant suffer a little from lack of water despite the fact that a friend come over to watering. I had some problems with the temperature of the box, because the new led panel was heating to much. But I wasn't able to extract the air to cool down the box because the humidity would decrease too.
P.S : I'm using a sprayer to increase the air humidity, but I have to do it a lots of time, and it's useless if I turn on the air extraction.