Built a new enclosure for an L3+ to run at home. After initially modelling in CAD, I decided to knock together a quick proof-of-concept using some scrap MDF. It works so well, I'm not sure I'm going to bother building another until I actually have another miner to run.
Inside it's mostly just bare MDF, but I rolled up a little bit of loose fabric in a couple of the corners and glued it down for sound-deadening and to help direct airflow. I'm also 3D printing some louvers to help reflect sounds back into the enclosure while maintaining airflow, I don't think it's really necessary. It works pretty well - definitely not louder than an air-conditioner. Temps are stable and about the same.
Here's a video of me demoing it:
