I'm pretty religious about swapping out my HVAC filter every month. When I pay rent, I change the filter. That's just how I do it. Living in a beach town means the wind is pretty much always blowing, and in my case, it's blowing in from the Gulf. The means sand and dust are a constant. And at this particular moment, it's peak pollen season here! If I leave anything outside for a day or two, it's yellow.