The outside temperature of the intake air is 46F. When I tried to put the extraction to 100% with the lights on, the temp fell to 77F inside, and humidity was at 40%. The plant’s leaves temperature was also a little bit below 77F, though some of them still had a bit more than this. This was with the wet towels now in the room and the humidifier running.
The exahust goes out of the room and outside. There is no air cooled reflector at the lamps. Also, I didn’t put the fan to blow on the lamp, because I saw somewhere about the wind burn when the fan blows directly at the plants.
I was not exhausting 24/7 before, because I wanted to get the humidity up. But then there will be no CO2 in the room, so I’m still trying to find out the best route to take.
Now I will leave it on at all times when the lights are on (and at 10% when it is dark, because of the cold outside air).
I might put the lights still a little bit higher, to lower the temperature a bit more. The thing is, I was scared the plants will then start to grow too much and will be too tall for the room in the end stage.
It’s a lot of things to consider, so I will try to utilize what you guys told me.
So, now I know the temperature of the plant is the most important thing, and then the rest.
Also thank you all for your comments and help.