Abstract: An airflow window system that includes at least three glazing layers positioned roughly parallel to each other to define at least two internal airflow cavities within the window system. A first of the glazing layers is adjacent a first of the airflow cavities, a second of the glazing layers is adjacent a second of the airflow cavities, and a center glazing layer is between the first and second glazing layers and separates the first and second airflow cavities. Airflow cavity openings are located adjacent the uppermost and lowermost extents of each airflow cavity, and airflow is enabled through the first airflow cavity between the openings thereof and enabled through the second airflow cavity between the openings thereof. The window system operates as a crossflow heat exchanger capable of supplying fresh outdoor air to an enclosed indoor space, while thermally tempering the incoming fresh air with outgoing indoor air.