KNOW THIS: If post mitigation levels show less than about 2.5 picoCuris per liter after a reduction from over 6, look out. You may expect humidity and mold issues within a few months unless you turn the radon system off and do not use it at all. If a post mitigation test shows radon levels of between 0.5 and 1.75 pCi/l, the radon system is probably delivering even more hot, humid air than the air conditioner can handle, and you can expect humidity and mold problems even sooner. If you acquire and use a hygrometer, you will quickly learn of the high humidity mold risk, especially in the months of March, April and May as well as September, October and November. CORRECT AUTOMATIC SYSTEM OPERATION IS CLEARLY PREFERRED.