Hello all. I just put a tent up in the basement and trying to get things dialed in. Ambient temp where the tent is low 60s. Lights on I can maintain about 79-83 degrees in tent, but I have to constantly run the exhaust fan on lowest setting otherwise it jumps up to over 90 degrees. I can only manage about 35%rh even with a humidifier in the tent. Also the tent body itself blows up like a balloon. When I open the zipper air rushes out. I’m just learning about vpd and am looking for help or advice in this regard. Is the temp disparity inside/outside tent causing this internal pressure?
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Increase exhaust from the top of the tent. Increasing airflow may help.
I wouldn’t bother, particularly given that you have other problems to deal with. Just keep humidity in the proper range. I don’t know many experienced growers who bother chasing VPD.
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Why is your tent blowing up when you have exhaust fan running?
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You’re not exhausting in reverse? I had mine hooked up backwards at first. 
I ended up putting mine outside on top of the tent.
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Sorry about that @SausageMahoney
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@Tmac845 you might be able to put humidifier on outside of tent next to intake
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It was hooked up backwards 
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Growing in basement kind of sucks if you’re not in the right climate.
You want your exhaust to run all the time, espn while lights are on. Even if it has to be on low is better than it shutting off. Open you passive intake at bottom and see if you can set fan speed to hold about 80⁰F while lights are on. It’s okay if it drops during lights out. You just want to keep your leaf surface temp up while lights are and keep steady flow of fresh co².
You’ll probably deal with low rh in the winter and high rh in the summer. Just manage to the best of your ability with the resources you have.
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Yes, I can only get rh up to about 35 with a humidifier in the tent. Basement rh is low 20s. Gonna add another humidifier and see what happens. Can hold temps at 80 with light on with fan on lowest setting.
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Your best shot would be to get a large humidifier and run it in the room that your grow space draws air from. Putting small humidifiers in your tent is only usually good for small increases.
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It’s a basement so it’s pretty large space compared to the tent. So you’re saying it’s more effective / easier to raise the humidity in the basement than inside the tent?
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Yes. It’s mostly due to the volume of moisture going into the air and what will fit into a tent and still have room to grow in. The small humidifiers people run in tents would be plenty big enough to get moisture up within the volume of the tent. But most are exhausting their tents and drawing in fresh air constantly. But if you have a unit that’s large enough to hit target moisture levels in your lung room all of your intake air will already be at desired rh and volume of air in the room won’t swing as much being cycled through your tent or grow space.
Makes sense. I’m in Connecticut in the middle of winter so it’s very dry, and cold. Very cold the last week or so, and it’s going to stay that way for a while. It was in the 50s in the lung room (basement) last night. I think it’s not worth it to heat and humidify my whole basement right now. I’ve got a smaller 3x3 tent that I can run in an upstairs bedroom for a few months until the weather breaks.
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