An apparatus for cooling ventilation air for a building, includes a radiating panel having an emissive surface for use on the building such that the emissive surface of the panel is directed skyward and exposed to ambient air. The radiating panel defines an air collection space between itself and the building and has a plurality of air openings for the ambient air to pass through the openings to the air collection space. A passageway extends between the air collection space and an interior of the building and is located for passage of cooled ambient air from the air collection space into the interior of the building. A fan is located for moving the cooled ambient air from the air collection space through the passageway to the interior of the building.