Quote:
Originally Posted by ton80
The key variable in mold formation is relative humidity (RH) not absolute humidity. A garage does not generally have moisture generators such as showers etc, It is generally hotter than the ambient temperature so it usually has a lower RH than the outside air even when the outside air has a higher absolute humidity. The garage can have a higher absolute humidity than your house but a lower Relative Humidity. In Florida there usually are no cold surfaces in the garage that cause high RH unlike partially underground garages in the Northern states. Put a temp/RH measuring device in your garage to see for yourself. The same is true of your attic space. The attic is a good place to dry herbs.
To decrease RH you can increase the temperature thereby raising the dewpoint or reduce the moisture in the air inside your home. These are the reasons that running a standalone dehumidifier will lower the RH quickly. Running the AC alone to reach the RH setpoint when equipped will drive the inside air temp lower along with the RH by condensing and removing moisture in the air exchanger.
I agree with your use of dehumidifier for extra protection and agree with your setpoints. We never had a problem using these settings during our snowbird years.
An unoccupied home set at 80F for AC usually will have RH less than 60% except for long periods of cool rainy weather when the temp does not cause the AC to run. Air circulation is necessary. Keep room doors and closets open.
Some definitions
Absolute humidity is a measure of how much water is present in air inside a closed space. Maximum humidity at a given air temperature is basically the dewpoint. If the air gets cooler or there are cool surfaces drops of water will condense on the cooler surface.
Relative humidity is a measure of how much water is present in the air versus the maximum water that can be carried at a given temperature. Relative humidity is expressed in percent. As stated previously, a relative humidity of 60% is often recommended as a maximum allowable relative humidity to avoid mold formation.
|
Thanks for the very informative post.