Low noise fans are designed for multiple-task ventilation. This means that you can ventilate multiple areas or multiple rooms with just one fan. For example, you can place inlets over the shower, tub, toilet and/or vanity in a single bathroom and still use just one fan. In recent years, homes have become more airtight and energy efficient. While this lowers the cost to heat and air-condition a home, it also retains pollutants that can be hazardous to its occupants. One way to improve the air quality of the home is through whole-house ventilation with a Panasonic WhisperLine(tm) fan, which removes "stale" air and provides fresh air on a slow, continuous basis.