Why do you need a dehumidifier for your apartment to decrease the humidity in the home? As can cause many problems in your life. Often it can lead to the cause mould, mildew and dampness. Moisture in the air can also lead to rooms feeling stuffy and smelling musty, less evidence of the potential health problems of damp environments often harbour dust mites, the leading cause of asthma. You can find the five best dehumidifiers for the apartment.