What is Radiant Cooling for Zoos? Radiant cooling for zoos is an advanced hydronic climate control system that circulates chilled water through PEX tubing embedded in enclosure floors, rocks, or climbing structures. Unlike noisy forced-air AC, radiant cooling provides silent, draft-free, and energy-efficient temperature regulation, mimicking natural cool surfaces. It is the preferred solution for heat-sensitive animals like red pandas, polar bears, and penguins to prevent heat stress.