@darnell @baldand I would like to do this with my #homelab
Hotspot Energy makes a device that captures heat from HVAC for hot water heating. Capturing heat from computers is very much off-label but should be possible. See https://www.hotspotenergy.com/residential-heat-recovery-water-heaters/
Linus did something similar to heat his pool: https://youtu.be/4ozYlgOuYis