a heat exchange apparatus is provided with an indirect evaporative heat exchange section . the indirect evaporative heat exchange section is comprised of a series of serpentine tubes , and an evaporative liquid is passed downwardly onto the indirect heat exchange section . the evaporative liquid is collected in a sump and then pumped upwardly to be distributed again across the indirect heat exchange section . an improved heat exchange apparatus is provided with an indirect evaporative heat exchange section consisting of a series of serpentine tubes comprised of tube runs both of normal and increased height between tube runs . a direct heat exchange section may be provided in the increased vertical spacing between tube runs .