I have a question(s)... for over a year now, I've been thinking abt connecting a box of s9 miners up to the return on my central system.

I'd only be running it in the winter like that and close it up in the summer. But is there any pitfalls I should worry about? If my return is on the ceiling and the bpx is on the floor, the connecting duct will run straight up vertically. Would I need an inline fan or is it enough just to let the hvac pull the air on its own? Will I run into issues with airflow considering the 90 degree turn where the miner duct meet up w the main return duct?