[magicalhippo]

A few years back I had to temporarily move back to my parents while getting a new place. It had been years since I'd used my room, and it had been neglected a bit.

First days I started coughing a lot when staying the room for a bit, and I woke up quite stuffy in the morning. Got me an air purifier with HEPA filter and let it run at max setting while at work. After running it a few days like this, I didn't have any more issues.