Abstract: A heat exchanger including upper and lower header tanks, a vertical baffle in the lower header tank defining first and second longitudinal chambers, a check valve, two tube rows, and a coolant inlet to the first chamber and outlet from the second chamber. The baffle includes a by-pass hole therethrough. One tube row includes a plurality of vertical tubes extending between the upper header tank and the first chamber of the lower header tank, and the other tube row includes a plurality of vertical tubes extending between the upper header tank and the second chamber of the lower header tank. The check valve creates a leak-proof seal during standard operating mode to prevent pressure release from the header tank and creates an air path between the header tank and the environment during draining mode to allow vacuum relief from the header tank.

Abstract: The effectiveness of an evaporative cooler is increased in a construction having a housing (10) provided with an air entrance (18) and an air exit (20) together with a substantially closed air flow path (32) extending between the entrance (18) and the exit (20). A body (34) of evaporative cooling media is within the housing (10) and extends across the air path (32). The body has an upper end (39) and upstream and downstream sides (46), (38). A water distribution plate (54) is located above the body (34) and has an elongated edge (60) which contacts the body (34) along the entire length of the edge (60) at a location at or closely adjacent the upstream side (46). A spring (78) biases the edge (60) against the body (34) and a water distribution header (64) overlies the water distribution plate (54) and directs water onto the plate (54) as a plurality of merging streams.