Temperatur Problem.

Thanks to all of you! I replaced all the thermometers. And got the same result again. This just can't be right. The circulation fan is positioned to distribute air over the walls. So it's not even directed at the plants. The tent is 120 x 90 Homebox R120 and the exhaust system is from Spider Farmer in 4 inches and runs on level 5.

if it was sucking in air quickly it wouldn't lower the temperature, that doesn't seem likely to me. If all the thermometers in the tent measure the same, there may be a measurement error in the room, try changing your thermometers. The circulation fan will not reduce the temperature by 5 degrees, try to put the lights closer to the plant and get to at least 24 Celsius.

Try slowing down your exhaust fan, you may be drawing air through to fast if the fan is more powerful then is required.

Might be just fro fan moving air or were the thermometer is ideally measure close to canopy top might warmer right under light compared to next to fan

I don't get it either! There are three thermometers hanging in the tent. The one in the plants shows 19.00 degrees. The one on the back wall at plant height shows 21.00. The thermometer of the exhaust system also only shows 19.00 degrees directly in the plants. And when I measure the leaf temperature with infrared, it also shows 19.00 degrees. I just don't understand it.

looks like a measurement error. It is impossible for the tent to be less than the surroundings, with the lights on. Try a different thermometer