watsongreenthumb
Active Member
sounds like you have it pretty well dialed in, what sort of lights are you using in that space? I found that I can run the fan a lot harder and still keep the temperature up around 80-81 in the tent using 4x 315 cmh, have also done some testing using 4x 240w quantum boards in there, fan does not run nearly as much and have to lower the idle speed of the fan or it will drop the temps to just a few degrees above the rest of the basement, down to 75-76, too cool for optimal growth.My tent is fairly small... the rough equivalent of a 4x4, though it's 5x3 (to fit the space I have.
But yes, I have the T6 for exhaust up above (in tent), with a Terrabloom filter in front of it, then it ducts out the tent and to a basement level window (about 4' of ducting).
I have the S6 down at the bottom as an intake (outside the tent, with a bit of duct on each side of the fan). For that setup I need the S6 to run damped back a bit so it doesn't create positive pressure in the tent. I use MERV13 filter fabric over the open intake duct to not only filter the dust/dirt out of the air, but to reduce the airflow to keep the negative pressure. Depending on if I use 1 layer or a couple layers I can damp down the intake airflow though the fans are using the same settings with the Controller 67.
This with the 67 gives a reasonable amount of control over the grow environment, given I don't have AC. During the winter I have a small in-tent humidifier, then during the hotter weather when it's humid I run dehumidifiers in the 'lung room' (actually the whole basement level) where I want to control humidity up or down seasonally and not just for plants...we have a music room/studio space that holds my guitars, basses, amplification gear and electronics; a fairly decent ceramics studio & a large room for storage. I try to keep that floor in the 40-45 range which is comfortable for instruments, ceramics drying as well as giving the tent drier air when the fans kick in stronger.
In terms of running an in-duct with really cold air...that may cause you humidity issues. Cold air meeting hot creates condensation, so something to consider. Also, I use a backdraft damper on my exhaust duct at the window. That guarantees that cold air doesn't enter my exit, should weather conditions and air pressure push cold air in my exit.
Either way, the only time I really have difficulty in controlling conditions is the middle of summer when you're just dealing with lots of ambient heat and humidity.
I like your use of merv 13 filter fabric on the intake side, I may build a box that I can fit whole filters in and then run some ducting to the bottom port on either side of the tent. I think that would work great If I decide to get an intake fan.
I had not considered the condensation aspect of venting my sealed flower room in the winter, but your absolutely right, the cold air coming in through the duct would drop the first air it hits below the dew point and create condensation. When I tried this years back it didnt get cold enough in that area for that to happen but up here it absolutely does. Will need to ponder how best to overcome that issue, thanks for the feedback!
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