AHU Coil Replacement

Located in the heart of Downtown Denver, 1801 California Street is a 54-story, 1.3 million square foot high-rise building, originally completed in 1983. The building’s air handling units (AHUs) are situated on the 14th and 40th floors. In recent years, building management observed elevated supply air temperatures, prompting a detailed investigation into the HVAC system. It was discovered that, over 40 years of service, the coils had accumulated sludge, which obstructed water flow and significantly reduced cooling capacity. To address this issue, a comprehensive coil replacement project was initiated on the 14th floor AHUs.

The project involved the replacement of 30 coils per unit, each with a cooling capacity of 800 tons per AHU. The replacement work was carried out in phases, with five coils replaced at a time, ensuring that the system remained operational throughout the process. Only the specific coil bank being serviced was taken offline, minimizing downtime and maintaining optimal building performance during the replacement.