The majority of my time in the basement was under LED. Quantum Boards, to be precise. Two 31"x31"x71" tents, each with a 250 watt fixture. My basement is unfinished and quite drafty at the sill, so Michigan winters will bring the ambient temps down into the high 40's. I partitioned off a 10'x20' area with three layers of plastic drop-cloth, and added a space heater within the area, outside the tents. I also insulated the bottoms of the tents from the concrete floor, though I never tried insulating the top or sides. I just barely managed to squeak by, usually with very unhappy plants. There were a couple of sweet spots, from late April through early June, and from mid September through early November - but the growing schedule was never dialed in tight enough to consistently take advantage of that. The rest of the year was either bitterly cold or suffocatingly humid. It's really more the humidity than anything that drove me upstairs. The second time you lose half your harvest to rot, you start questioning the original plan. The wife and I aren't crazy about having the grow in our bedroom (though we love the white noise from the exhaust fans!), but it's better than the alternative. Now we just need to keep all visitors away from our room, which has proved to be tricky. Someday I'll build a proper, climate-controlled grow-room in the basement, and show the weather who's boss, but for the time being, my tail is firmly between my legs...
Sounds like you might have a better space to begin with, so hopefully you'll be able to dial in those temps just right. Best of luck!
