A musty smell could be the result of mold. Sometimes, mold isn’t visible. Even when the mold is still a spore, it can be filtered out with an air purifier. It’s important to get to the root cause of mold. Old buildings and spaces that have water leaks or damage may be more likely to have mold. In any environment, a musty smell can be addressed with an air purifier. The best air purifiers for mold can reduce all musty smells in your home.