How Many Days Should You Use a Dehumidifier?

A dehumidifier can bring excess humidity under control.

As Long as You Need

50 percent humidity or lower is acceptable to avoid mold.

Mold cannot grow in a humidity level below 50 percent; therefore, 50 percent humidity or just below is acceptable in most living spaces. There is no set limit on the number of days a dehumidifier should be used since most dehumidifiers will automatically turn themselves off when the desired humidity level is reached or the tank becomes full. Otherwise, it is acceptable to let it run for 24 hours a day for as long it takes to lower humidity to the desired level.

Be Aware of Size Requirements.

If you have a dehumidifier too small or to large for the space you are seeking to dehumidify, you could be wasting time and money. If the unit is too small, the water tank will fill up multiple times without ever actually getting the humidity level below 50 percent. If the tank is too large for the area, and you try to get the humidity level below 40 percent, you will be wasting electricity. You usually cannot dehumidify much below 40 percent.

Bottom Line

If you are sure that your dehumidifier is the correct size for the area, you can run it for as long as it takes for the tank to fill or the dehumidifier to automatically turn off when the desired humidity setting is reached. There is no limit on the number of days to use one.

References

• Allergy Consumer Review: Dehumidifier Q&A
• Energy Star: Dehumidifier Basics