I am running autos in a 2.3x2.3x5 foot tent. I currently have one vent open but the AC Infinity S4 struggles to keep humidity at 45% even though lung room is 35 percent. I was thinking of opening another side vent. In general is there any consensus on how many vents to open?
If your fan is turned high and you’re able to turn it down and still keep temps in check turn it down some and it will keep more humidity in the tentor try a humidifier close to the passive air vents suck more humidity in but I would try lowering the speed on the fan first
Do you want RH that low? A RH of 45% during late flower you are looking at temps 60 - 70F.
If you are trying to increase RH, exhaust back into the tent room / lung. Or supplement it as suggested by JJ
It is late flower. Should I raise to 50%? The tent is full to the brim 27x27x 63 inches with 4 plants. 50 percent would be easier to maintain
This a VPN chart from ScynceLED. You can download the complete chart from their site.
The salmon color represents flower stage. You can see from the chart when temps are 75 - 79F, room RH should be 55 - 65%. I like this chart because it is straight forward and based on tent / grow room metrics. Other charts are more complicated and based on ± leaf temps. In any case it gives you info as to where temps and humidity intersect to provide optimum growing environment based on the crops growth stage
VPN stands for Vapor Pressure Deficit.
Thank you. When you pointed out that the RH was too low for my temperatures I looked for VPD charts on this site. I actually book marked it to remind me this morning. The one you provided is easier for a starter grower. If I I can have higher humidity during flower my life will be easier. My online fan was always struggling to keep RH that low This is the more advance one I found here. VPD charts and vague explanation
That is from DimLux. I have those saved as well but more than I need. My approach is try to get close to Scyneled chart. At least in ball park. In late flower you are better to be on the dry side in order to avoid bud rot problems. It does not sound like that would be an issue for you.