first set up 40x40x140 very limited space. Ok to have used cable ties? And no ducting on the outflow jus flowering back into tent
At first glance I think you may run into some heat issues. If warm air isn't being exhausted it will turn your tent into a convection oven. So maybe be prepared for that and have a backup plan if the tent is hotter then you expect. Cable ties are fine, I even use zip ties
I plan to leave the doors open The outflow from the fan isn't warm? Or should I put a outflow duct on leading out the tent to be safe? I've yet to add a fan to blow air
If you don't have plants in there, do a test run. Get a thermometer and see what your temps are after 12 hours. Maybe put a bucket of water under the light to get a feel for what your humidity will be like too. I run 2, 1000 watt hps in an 8x8x8. So I'm sure you won't have the temp issues I had.