We've spent the last several months testing window air conditioners and portable air conditioners and found that while window units cooled rooms faster, it wasn't that much faster. Traditionally, the standards for window a/c units were higher, but as of this year, portable a/c units aren't too far behind. Window a/c units sometimes have a "dry" setting which dehumidifies but portable units automatically do so because of how they work. The Best Portable A/C UnitsWhen to Consider a Window Air ConditionerIf you want quiet operationHave you ever passed by a window a/c unit on the street while it's running? The (DOE) and the Environmental Protection Agency (EPA) have tested window a/c units and held them to a higher standard of energy efficiency.