I don't think we have ever had a moisture problem inside the chamber. We decided at the beginning to keep the room the chamber is in as cool as possible since compressed air is 'warmer' than non-compressed air. So, we figured to start out with very cool air. If it is very cool outside, we open the window. We have a fan sitting near the compressor and turn it on blowing toward the compressor sometimes just to make sure the circulation is good and the air is cool. Then, we nearly always prop the chamber open with a rolled up yoga mat between sessions.
In the beginning, I found being in the chamber quite warm (due to compression), but over time, I have relaxed so much (I guess) that it is very cool inside to me and I wear long pants, a long-sleeved t-shirt, and warm socks inside. Others still experience it as being very warm, thus the installation of the circulation fan INSIDE the chamber as discussed earlier.
So, using fans, fresh air, A/C cooling, propping open, we just haven't had any internal moisture problem.