Abstract: A window-based HVAC interface system is provided as a convenient solution for installing and interfacing to a ventilation system in a new building or for upgrading an aging HVAC system in an existing building. The HVAC interface system may be optionally integrated with a window. The HVAC interface system includes separate but connectable components, including a hooded vent unit extending from the interior of a room, through a wall or window structure to the exterior, and connected thereto, a plenum box disposed in the room interior. The plenum box is configured to facilitate connection to an HVAC system such as an HPAC unit. The hooded vent unit may be provided as a portion of an integrated window assembly.