Customer approved proposal to replace three systems. With Daikin systems. Upon installation removed original systems. Removed defective air handler deck and defective return plenum on 4 ton system. Fabricated new return air plenum and installed. Added support before installing new air handler deck. Removed UV light to reuse on new system. Installed new air handlers, heaters, float switches, thermostats and condensers. Transitioned new air handler to existing supply duct. Nitrogen purged lines during soldering process. Pressure tested lines. Pressures held. Evacuated system. Wired up each system and thermostat. Started and checked operation. Systems running as per manufacturers specifications.