If you live in a New York City apartment, chances are your heating and cooling runs on a ductless mini split system. They're compact, efficient, and increasingly common across Manhattan, Brooklyn, and Queens. But there's one thing most people never think about: when was the last time yours was actually cleaned? Unlike a window AC that you can take out and rinse off, a mini split's internal components — the evaporator coil, blower wheel, filters, and drain line — accumulate du