I use GE, Lg imported dehumidifier which I hand carried from for all my paying guest rooms as they all have large screen TV sets in their rooms. 6 years ago, I had an issue in 2 rooms where I had to bear a loss of around 3 lacs Indian rupees, and another 4. 5 lacs on my Yamaha Clavinova digital keyboard where it short circuited on the Mother board due to heavy condensation. For the past 4 years I keep them on and specially for 3 months in the rainy season, and had not got any moisture problems.
The only draw back is to throw away the condensed water every 4 - 5 hours depending on the humidity levels. It is tiresome, so I made and arrangement as to keep it near a sink platform and made a system where water droplets drains continuously and directly in to sink. I do visit the rooms once in a day now.
As for my music room where I also have many other electronics, basically 3 Yamaha electronic organs, and 1 upright piano, I use the Air Conditioning throughout the monsoons with tonnage 0.75 tons tuned to a degree of 23 degrees centigrade. I can see the amount of condensed water draining at a constant speed. This really has stoped peeling of the mirror finish piano. Secondly I could hardly play the piano in the monsoon, as all the hammer keys used to get stuck and would not play very well. Now I am tension free. Remember my room has 2 Air conditioning unit. I brought this low tonnage one as to avoid heavy electric bill for my 8 meter by 7 meter room. The other Air Cool 1.5 tonnage I rarely use when I have visitors.
Let me also mention that my humidity meters read for this rainy season on an average of 86% to 92%. So imagine what will happen to the electronics .
please see as attached today’s humidity while I am posting this reply on the forum