Valued Resident,

As summer progresses, we want to ensure that your living environment remains comfortable and free from issues related to high humidity and mold growth.

We have noticed that residents may experience these problems, particularly during the months of June, July, and August.

The Thermostat Fan Setting Behind It

One significant factor contributing to high humidity levels in your home is the setting of your thermostat fan.

If the fan is set to “Constant ON,” it can lead to an excessive influx of outside air, which overwhelms the air conditioner’s ability to manage moisture.

This setting can create conditions conducive to mold growth and other indoor air quality issues.

It will also increase your energy bill since the amount of outside air infiltration is approximately three times greater with the fan on as with the fan off.

Key Recommendations

Change the Thermostat Fan Setting

Please switch your thermostat fan setting from “Constant ON” to “AUTO.” This adjustment will synchronize the fan with the air conditioning compressor, allowing for more efficient moisture management.

Monitor Humidity Levels

Aim to maintain indoor humidity levels below 60%. If you notice persistent humidity or condensation, please contact us for further assistance.

Report Any Issues

If you observe any signs of mold or excessive moisture, report them immediately so we can take appropriate action.

Thank You

By following these recommendations, you can help ensure a healthier living environment and avoid potential issues related to mold and humidity.

Thank you for your attention to this important matter.


If the setting change does not fix it, the building is usually the cause, whether that is uncontrolled ventilation or a mold problem that has already taken hold. Call 615.373.2498 or request an evaluation.