Hi, I’m planning my grow tent and for some reason I’m stuck on ventilation. The amount of information from different sources on the web is crowded and I have read about at least three different ways to calculate appropriate fan size in relation to tent size. I’m planning on using a simple passive exhaust system for my small tent, with a carbon filter of course. Who doesn’t want a carbon filter? I realise the many benefits of good ventilation, and since it seems every system needs to be tweaked for optimal performance, I guess what I’m looking for is some kind of general key aspects to consider. One of those that I have read about might be negative air pressure. If I manage to create negative air pressure using the least amount of fan power, am I good then? Too much power would dry the air out and waste electricity, and too little power would not reach negative pressure. Or is there any other aspect I should focus on instead? Also, in order to reach this sweet spot of air flow, I can’t see how I can do this without a gradual controller that can reach the perfect level. But using a controller seems to be something reserved for professional growers, and I am surprised it is not considered essential. For instance. A local European vendor of complete tent systems with lighting and ventilation, sells a grow tent that is roughly 2x2x5 feet with LED lights. The fan they have in the system far exceeds the various calculations I have made based on the internet. One such calculation is 2x2x5x1.33. The fan they are selling moves around 4 times this amount of air per minute, and there is only two settings on the fan. No way to gradually try to tweak it. Maybe the vendor is crazy, but when I look at different fans on the market, the one they sell looks like the smallest one that isn’t a fan made for computers or something silly. Am I overdoing this? Is a small tent always going to have a too large fan and that’s fine? Is a gradual controller not that important? Please someone, help me navigate ventilation in a grow tent.
if u r doing a similar size tent then all u need is a good high out put 4'' inline fan (150-200cfm) and filter, if it turns out to be too much get a solid state speed controller.!!