Demolition, construction, changing ΔT, two chiller plants, changing piping designs, adjusting makeup water pressure, incorporating thermal storage ... these are but some of the hurdles and goals the project team has faced during a major retrofit at the Centers for Disease Control in Atlanta. In short, site limitations and economics pointed to connecting the chiller plants and investing in thermal storage, but that just scratches the surface of this critical work. If you think your chiller retrofit is involved, read this and feel better.