I'm finding that I struggle a lot with sleeping and doing certain things that necessarily lead me to believe that my bedroom has bad air flow. My bedroom is in the basement of my house, has no windows, and exactly one doorway in the opposite corner from my bed. We do have a vent system but it's old and doesn't have A/C, only heating, which we never use, so it's basically a static non-variable.

I always keep a fan on blowing in air from the door at night, but of course that doesn't help. What can I do to fix this problem? I need to be able to breathe better.