Bathroom exhaust fans remove moisture from the home to help keep relative humidity levels down. This is important for discouraging condensation and the growth of mold, mildew, and dust mites. Continuous or intermittently operating exhaust fans can also be part of a whole-house ventilation strategy. ENERGY STAR certified ventilation fans provide better efficiency and comfort with less noise, and in some cases, have controls for spot exhaust and continuous ventilation. They feature high-performance motors and improved blade design, providing more effective exhaust and longer life.