A chill mold is used to cool molten material to form a casting. A support holds the chill mold so that a bottom of the chill mold is elevated. A baffle is arranged to divert a generally horizontal flow of cooling air upwardly to impinge the bottom of the chill mold. A plurality of chill molds may be aligned generally in a row, and at least one fan may be arranged at an end of the row to direct the flow of cooling air underneath the chill molds. The size and the vertical position of the baffles may be varied along the row, so as to generally equalize convective cooling rates among the chill molds in the row.