Why not just buy some bigger drives instead of so many? Are you really going to populate with 48x 3-4TB drives?

That's an inefficient use of electricity, heat and money.

In my old house we exhausted the heat out a window in the summer with a Dayton fan and 6" ducting , in the winter we circulated it to supplement a pellet stove.

Now in my own house servers are in basement along with my hybrid hot water heater.