This is an Air Handling Unit mechanical component replacement project. The existing Air Handler is original to the facility, installed in 2001. It is located in a mezzanine with pull down stair access from the hallway below. The DX Condenser is located at grade and the DX piping runs through the attic. The DX system is R-22. There is also a hydronic heating coil (reheat position) in this unit. Several components of this system are to be worked on with this project. Due to the recent code changes to allowable refrigerants, it is not permissible to retrofit an A2L (R454b/R-32) DX coil into an existing air handler. Therefore, the design concept is to convert the AHU to a chilled water coil and install an air cooled chiller exterior to the facility. The selected Contractor would be required to work closely with City Engineering Staff to ensure that the installation meets maintenance and operational requirements of the owner. City Engineering staff have prepared a performance specification and selected equipment to be used. The Contractor would be required to complete the detailed design and submit the plan to City Building Inspection for permitting (following IBC 2021 requirements). Schematic drawings have been provided and include: − Design assist. This document outlines the general basis of design for the refurbished air handling system and associated coils. Contractor shall review and submit a detailed design for City Approval. Collaboration with City Staff would be expected prior to approval of a final design. − General demolition scope of the existing DX Condenser, DX Piping, DX Coil/drain pan, Hot Water Coil and Humidifier. − General refurbishment of the AHU sheet metal and prep for new coil installation. − General install for a new Chiller, Chilled Water Coil, Chilled Water Piping and Piping Components and Hot Water Coil and Piping Components per details. − Include Pipe Insulation, Controls and Test and Balance (Air Handler, Chilled Water System and Hot Water Coil/Secondary Pumps)
