Here are a few topics from one of your previous post that I wish to address (hopefully) for your benefit as well as any that might be following along.
...I have a squirrel fan to dump out extra heat. It helps that my ambient temp in the basement is cool...
...I have read up on how to control the speed of a fan. In my mind, resistance causes heat... heat causes fire...
...The reason we use a fan is not so much to toughen up the plants(even though it does) but to keep the air circulating so mildew, mold and rot doesn't move in...
I hope that squirrel fan (squirrel cage blower?) is in the same room as your grow and exhausts to the outside. If so, and you have close neighbors, at some point you may have to consider a carbon filter for odor control. Of course, if you have a permit to grow, forget the filter. It's cool (pun intended) that your grow is in the basement.
I'm glad you're reading up "on how to control the speed of a fan" and you are correct about the "resistance causes heat" thingy (though friction also causes heat in a motor). Without getting too technical, your three speed motor is actually three motors in one, each with a different number of windings, each winding being wound with a different size wire. I just want you to have the fan set at the proper speed (usually high), and used with the proper variable speed controller.
Being in a basement can cause high humidity levels, especially on or after a rainy day, and I would suggest you get one of these digital humidity and temperature monitors
as mold and mildew, love high humidity. I just bought one and it's a nice, inexpensive little unit that shows current levels as well as the previous twenty four hour highest and lowest levels for both temperature and humidity. This will show you if you will need a dehumidifier for your basement. It's the least expensive unit I could find and if you don't have a Walmart close, can be shipped to your home. In my case, I found the humidity was too low, which spider mites love, so I purchased a humidifier.
As to Sir Ganga's thoughts on air temperature stratification, I agree that we humans use ceiling fans to break up this condition. Ceiling fans are reversible so as to pull cooler air from the floor during the summer and push warm air down during the winter, in the center of the room (where most activities take place) with the opposite happening against the walls (where little activity take place), though I have seen fan installers install them and run them in the incorrect direction for the season.
Where I disagree with Sir Ganga is his reason for doing so vs. your reason for doing so, as you have stated "The reason we use a fan is... to keep the air circulating so mildew, mold and rot doesn't move in..." I know that Sir Ganga uses four tons of A/C in his grow and you do not. I also know that Sir Ganga uses active bulb cooling (Re: BEGINNING A NEW ERA!) but know (from previous conservations) that you plan to use passive cooling for yours.
So, let the heat do it's thing and rise and exhaust it with your blower and get a thermometer/hydrometer to get an idea of what conditions you'll be dealing with.
That's all for now folks and best regards to all following this thread,