The request of staff for City Council is to review and consider for approval the attached deductive change order in the amount of ($21,697.00) and final pay request in the amount not to exceed $37,543.92 from Air Mechanical and Service Corporation (AMSCO), for the replacement of the HVAC system at City Hall.

As City Council is aware, the City Hall system is the oldest remaining HVAC system in operation.  The majority of the HVAC system components appear to be original to the building built in 1989.  The newest component is the chiller that was installed in 2007. Subsequent to the Library Renovations project, Volt Air Consulting Engineers was tasked by staff to perform a system evaluation on the existing City Hall HVAC and identify deficiencies. The deficiency analysis recommended the replacement of the existing system as all components have met their useful life except for air handling units (AHU) four and five and the two split systems installed in the Technology Services area.

The scope of work for the project included:

1.     The upgrade of the existing direct digital controls (DDC) system.  This system upgrade converted the HVAC system into a total automated system where one central computer can control system operations of components, collect data for trend implementation, monitor system for failures, and submit automated notifications of the failures for the appropriate remediation to the system.  

2.     The replacement of the existing 76-ton air cooled chiller included piping, valves, and support systems. 

3.     Pump replacements included variable speed pumps with the addition variable frequency devices or VFDs.

4.     The replacement of AHU one, two, and three including ductwork in the mechanical room.