Balanced air for a healthier home

For most homes, 40 to 50 percent relative humidity keeps people comfortable and discourages mold and dust mites. In cold weather you may need to drop toward 30 to 40 percent to stop condensation on windows.

Measure first with a small hygrometer. If readings sit below about 35 percent, especially in winter, a humidifier helps. If they climb above 55 to 60 percent, with musty smells or foggy windows, a dehumidifier is the better tool.

Both bring in fresh air while recovering heat from the air they exhaust. An ERV also transfers some moisture, which suits humid or very dry climates, while an HRV moves heat only and fits colder regions well.

An affordable monitor that tracks particulates and humidity is useful for spotting trends and problem rooms, even if it is not lab accurate. Use it to compare before and after changes rather than treating the exact number as gospel.

Rinse the tank daily, and do a proper clean with white vinegar every few days during heavy use. Standing water grows mold and bacteria fast, and a dirty unit will spread that straight into the air you breathe.