This unit was designed to circulate air in a room or closet where warmer air accumulates to another area in the home. Often times when components are installed in a closet, or even in the room where they are installed, the entire room or closet requires venting to circulate the warmer air. This unit is perfect for room to room venting and can be easily retrofit.
This system will usually be installed on a wall adjacent to a hallway or larger area in the home and air will simply be moved from the closet, directly through the wall, to the adjacent area. This method of cooling helps to better circulate the air in the home and during cooler months, the warmer air is effectively used in heating the home and in warmer months, HVAC systems are designed to 'reprocess' warmer air and conditioning air that is simply heated is significantly more efficient than cooling and dehumidifying air which would be the case if venting to the outside or to attics. When venting outside, that air is replaced by air from the outside or most commonly and worse, air from the attic. This air can be hot, humid, and smelly so you should NEVER vent to the outside or to the attic.
If you are considering this product and are in the construction phase (no sheetrock installed), consider using it with the Wall Duct Boxes as this allows you more flexibility with the placement of the unit since you would be moving air through tubing instead of simply from one side of a wall to the other. You may also consider venting to the HVAC return system or using the system specifically designed for return systems - the Ceiling Vent System (VS-CVS).