A method for obtaining a desired atmosphere within an interior space during an initial startup phase of a CAS is provided. The method includes a controller starting the CAS while keeping the air compressor OFF. The method also includes the controller calculating an atmosphere change rate while the air compressor OFF, and determining whether the interior space can reach a desired atmosphere set point with the air compressor OFF based on the atmosphere change rate. Further, the method includes the controller maintaining the air compressor OFF until the interior space reaches the desired atmosphere set point when the controller determines that the interior space can reach the desired atmosphere set point with the air compressor OFF, and switching the air compressor ON when the controller determines that the interior space cannot reach the desired atmosphere set point with the air compressor OFF.