HVAC System Repair and Replacement Services. Inspect the current HVAC system, advise LCRA on a recommended approach to repair and/or replace the current HVAC system, and execute the selected approach. After an initial assessment of the current HVAC system, LCRA has identified multiple approaches to remedy the recent malfunctions, which are listed below. Approach #1: Replace the existing system with roof mounted package units. Approach #2: Replace the existing system with an individual ductless split system. Approach #3: Replace the existing system with individual RTUs. Approach #4: Repair and upgrade the existing system.