***Replaced invoice # 252839296. (MY)*** Made the following changes to the three split systems ductwork for proper zone control and balance. Relocated (2) thermostats. Relocated (6) supply grills and (1) return grille. Removed (1) supply grille from the #1 system. Removed the break room supplies from the #2 system. Added the break room supplies to the #3 system. Built and Installed filters frames in systems #1 & #2 to secure the bottom filters to prevent air from bypassing.