The Extreme 3500ti introduces variable speed fans to WhisperKOOL’s most advanced and powerful self-contained cooling system. Utilizing variable speed fans this high capacity unit can maintain optimal cellar condi- tions while operating at a quiet 57 decibels. The Extreme is designed to fit between standard wall studs for simple “through-the-wall” installation with minimum modification to existing wall structures. Extremes are acceptable for mounting through an exterior wall and can operate in a 110Â°F exhaust environment. The ti Series includes our most advanced controller utilizing Advanced System Protection Technology. This features a series of strategically placed monitoring probes, which ensure efficient performance and long cooling unit life. This system is designed to maintain 55Â°F in a cellar up to 800 cubic feet in size.