iroh is a peer to peer networking technology so the project example of controlling a fan isn't so much about the fan but rather that it's controllable from anywhere through an esp32 microcontroller that can maintain a resilient connection endpoint even through power cycles and so on. I think iroh was posted about on HN a few weeks ago and I had a similar reaction of like...what in the world is this blog post even saying haha. But I found their docs page and found it pretty fascinating learning! https://docs.iroh.computer/what-is-iroh
I use a fan with an on/off button.