Looking through the front vents or louvers a white foam can be viewed. This material commonly referred to as Styrofoam is Expanded Polystyrene (EPS). This material is used to form the air ducts that direct the airflow and also act as an insulator. It is a necessary component of the unit and can not be removed.
The EPS-formed air ducts are not completely airtight so sunlight from the outside may be visible.