I hope you are v3nting the air outdoors.
Not yet, but I will be. The vents are installed through the house wall but I still have to run all the hvac and build the air exchanger system. Basically a HRV with a bypass mode. those things are freaking expensive, so I'll be building my own. Just need to source out a place I can buy a bunch of tin metal squares for cheap for the core.
Since my system is stand by it does not produce much hydrogen though, so all this is more a precaution than necessity.
No free NAS but I did build a file server:
The expansion modules I wont be actively using though, they use too much power and the drives are proprietary, my UPS is only 750w. I turn it on once in a while to do a full environment backup, then turn it off.
Looking at that old pic makes me realize how far I've come with this project so far.