Youtuber fixes PC cooling with air ducts [video]

It's interesting. I remember seeing the air duct on CPU in Dell servers a long time ago, I wonder if they still do that.

Also, it would have been nice for the author to try each duct individually, so as to better understand their role in temperature reduction on every devices. Would the CPU air duct indirectly help the GPU by reducing the box temperature overall?

Finally, I wish he also measured the impact on energy consumption.