I am not disputing your observations about blowing air on moisture. However, your solution has no scientific basis as a method of remediation without fully evaluating the psychometric properties of the air in question.
This is my point .Moisture does not disappear.
Just because you can’t see it, does not mean it’s not there.
There are several solutions to the problem once the actual cause is evaluated and determined.
Blowing air as well as opening a window or door may make the condensation go away but neither is desirable or effective as a long-term solution. Blowing air on a bathroom mirror after taking a shower works and works best when you add heat. Adding heat changes the psychrometric properties of the air. This is what I am referring to. Simply moving air will not guarantee moisture removal. Changing one of the psychometric properties of air will.
We have not determined this! It may very well be! I can give you a laundry list of possible causes.
The point I’m trying to make is that we must determine the source of the moisture, determine the quantity and evaluate the best means to prevent the occurrence of condensation under all potential conditions. Recommending to a client that they can mediate a moisture problem by simply turning on the ceiling fan may result in an opposite effect. Without further evaluation increasing air movement may increase moisture condensation (which I’m trying to point out). Additionally, the client may not be comfortable with the ceiling fan running all the time in the heating season. It may be a child’s room and may cause health issues.
I am not saying that moving the air in the house will not change the condensation condition. There is a high probability that there will be air in other parts of the house/room with different psychrometric properties. What I am saying is that it is not a definitive conclusion to the issue. By not determining the source and quantity of the moisture in the house and simply recommending turning on the fan is not going to hold up under the scrutiny of litigation.
The majority of times that I have found cold spots at the ceiling/wall juncture it is simply a matter of putting the insulation back where it belongs or installing batt insulation properly so air convection does not occur. As in this photograph where a ceiling repair was made and the insulation was never put back.
In this case would you recommend turning on the ceiling fan forever or replaced the insulation?