Mechanically, three existing 100% outside air units were completely removed and replaced with new packaged DX 100% outside air units. The new units were installed at their original locations and reconnected to the existing ductwork. New freezeproof hoses bibs were introduced on each roof in the vicinity of the HVAC units, connecting to existing domestic water piping below. Testing and balancing was conducted for the outside air and energy recovery exhaust duct systems, achieving balance for each zone in accordance with calculated airflows. The new HVAC units were equipped with CO2 sensing to facilitate demand-controlled ventilation (VAV operation) per FBC-Energy Conservation standards. All building HVAC controls were upgraded to the new Honeywell BAS system, ensuring integration with existing controllers via BACnet, in alignment with the existing campus system and district objectives. The new HVAC systems were equipped with on-board packaged controllers featuring BACnet integration capabilities. Electrically, no upgrades to the existing system capacity were required. Necessary modifications were made to the existing power system to accommodate the outlined mechanical work. New performance specifications were developed to extend the existing lightning protection system to cover the new mechanical units.