I second Japan tbh, a country that has invented both video games to talk to women and a dedicated word for living in your childhood bedroom as an adult and like, just the worst culture that like half the guys in my city seem to be in love with…

like, revolving sushi is good but at WHAT COST

the food…

For gasses, you should monitor co and gas, carbon dioxide alarms are uncommon outside of industries where we have a lot of carbon dioxide stored. Without a better idea of the space it’s hard to suggest a ventilation solution.

They make large diameter vent fans for buildings that are designed to run on a widely varied DC source like a solar panel, those can be really useful.

As the other reply says, you need a large volume of air slowly so a large diameter slower fan is good. You can get flexible duct work anywhere they sell construction supplies :3

oh, smoke alarm and fire extinguisher too! people are always smoking in abandoned buildings, burning them down