Nice concept! Wanted to know is there an option to run it without heat ie summer times? If not there would be alot of down times harder to get ROI.
Mining generates heat, so not wanting heat is always down time.
Now you've reminded me of my only hands-on experience I had with mining. It was at least 2-3 years ago, 2017 if I am not mistaken, where Altcoin mining was really popular. I was using my standard PC, which was then upgraded with two GPUs for the sake of mining, the software being used was Nicehash.
The profit back then was pretty decent, I was mining from early August or September till the winter months, February if I remember correctly. The heat it was generating during winter could potentially act as a small heater for sure. As you can imagine, having a desktop PC, running 24/7, with overclocked GPUs, it generated quite a lot of heat.
The amount of heat that your computer generates depends on the graphics cards that are installed in it. If you have 2 video cards GTX 1060, then the heat will not be too noticeable.
If you have 2 video cards GTX 1080 Ti, then this is a potential heater for half a kilowatt.
This is not enough to heat the room, but it is enough to warm your feet in winter.