VA Cheyenne AHU Replacements

Apogee was tasked with the replacement of air-handlers AHU-1 and AHU-23 at the VAMC in Cheyenne, Wyoming. The project involved a comprehensive approach that began with a thorough site investigation to assess existing conditions and verify as-built drawings. The demolition phase included the removal of the existing AHUs, associated piping, and selective ductwork in both the north penthouse and rooftop areas. Temporary heating, cooling, and ventilation systems were implemented to maintain comfort in areas previously served by AHU-1 and AHU-23 during the transition.

In terms of architectural work, the design included enlarging intake and exhaust openings to accommodate new systems and installing louvers for proper ventilation. Wall patching and painting were done to match the existing finishes once the old ductwork was removed. Fire protection work involved relocating existing fire sprinkler heads as necessary for the new ductwork installation and adding new sprinkler heads in the penthouse to meet safety standards.

The MEP engineering scope focused on the installation of a new modular semi-custom air-handler with a capacity of 23,000 CFM, positioned near the existing AHU-23. This new unit features a fan wall system for both supply and return air, chilled and hot water coils for cooling and pre-heating, and a pre- and final filter box system with MERV 17 filters. The air-handler also includes dehumidification capability using a reheat coil and a humidification system. New ductwork was installed in the penthouse area to connect the new AHU to the existing duct network, with all ductwork cleaned and sterilized upon completion. Piping was re-routed from the main chilled and heating water lines to the new AHU, and a new heating water pipe loop was installed to provide heating to the new unit and future AHU replacements. Existing controls were modified to integrate the new air-handler, adding DDC points. Additionally, terminal air boxes in the surgical suite areas (1, 2, 3, and 4) were upgraded to allow for airflow turn-down during unoccupied hours via both scheduling and occupancy sensors.

Cost estimates were provided with each project submission, ensuring that the project remained on budget throughout the process. This comprehensive upgrade improved the facility’s HVAC efficiency and reliability while maintaining stringent operational standards.