Does single-phase immersion cooling require significant changes to existing infrastructure? 

Retrofitting for single-phase immersion cooling does not require significant infrastructure changes, but different levels of integration are possible. At the basic level, racks are replaced by pods while retaining existing power distribution and air-cooling infrastructure. For higher efficiency, CDUs can be connected to an existing or upgraded chilled or warm water loop, increasing power density and freeing up capacity thanks to lower energy consumption.