Headaches, sore throat, coughing, Asthma attacks, and difficulty breathing are a few of the symptoms that can be brought on by some air purifiers. Yes, that's right. Your air purifier may actually aggravate many of the health issues you hoped it would solve.

Higher ef ciency filters (MERV 9-12) will work even better, and a true high ef ciency filter (MERV 13-16) can reduce indoor particles by as much as 95 percent. Filters with a High Ef ciency Particulate Air (HEPA) rating, (or MERV 17-20) are the most efcient.

Expensive air filters usually use higher-quality materials, such as metal or plastic. If you are looking for a cheap air filter that needs to be replaced often, then you should buy a low-quality one. At the end of the day, it is important to consider your needs before making a purchase.

Second Nature began in 2012 as a company called FilterEasy. The mission was simple: make replacing air filters as convenient as possible. In time, co-founders Thad Tarkington and Kevin Barry made it happen. The whole process of changing out air filters is, let's face it, rather dull.