How do you keep a hospital running while replacing all of the infrastructure components? You need an exceptionally solid plan. The Medical Center, a 700,000 ft2 hospital located in Columbus, Ga., developed an 18-phase strategic master plan enacted over a seven-year period. The target ENERGY STAR rating after all of the infrastructure projects are completed is 75 (up from 24). This article discusses Phase 2, which included converting the existing chilled water plant from a constant volume primary secondary system to a variable primary system.