I grow organic,in my heated and dry walled garage-shop.I needed the space so i am growing on the floor this winter.I have 2 layers of felt paper,1 inch of foam and 1/2 inch of wood on my floor.so i don't get that frost type of cold.set heat on 61 degrees and leave it there all winter.(Temp at the soil,) lights on run an average of 68-70 and at lights off 62-64.I have not had any problems at all.they are all budding just fine.Next winter I hope to have them off the floor though.will it help any? don't know but will be easier to work with them when I can stand and do it.I keep a temp on my work tables as well and the temp there is not much difference at night than the floor only 1 degree.garage is 18 by 24 I leave the doors to the tent all the way open and just circulate the air in the tent around with 2- 8 inch fans on low ,one just above the soil the other near the top of plants. lights out the fans go off also.it can get smelly inside garage without the carbon filter running but I love the smell ( not even using one this year). No neighbors near me.I do not believe the soil it self get near as cold as the temp does at lights out.that would take more than 12 hours not sure though.not sure about plants producing heat at night that would be above my knowledge.I do know the colas seem to like it ( large and healthy ).do not have any pictures for you.hope to get some before chop in a couple of weeks and post on the t-5 site.please no trolling because I use t-5 and not led.The question was on temp not lighting and I adjust everything to what I use.Be blessed and good luck.