4120--Equipment: Replace AHU-24

Scope of Work: • Coordinate all work with the Contracting Officer (CO), Contracting Officers Representative (COR) and Engineering Operations Supervisor (EOS). • Conduct T&B at AHU and each floor to determine airflow prior to replacement and after replacement. • Lock and tag out all electrical service to unit. • Lock and tag out all CW and steam supply to the unit. • Disconnect existing BAS and Fire Alarm circuits from unit. • Remove existing AHU-24 blower and coil compartment and dispose of material. • Remove existing humidifier steam piping back to first shutoff valve. • Remove and replace existing pneumatically operated 3-way CW control valve with new 2-way DDC operated CW control valve. • Remove and replace existing pneumatically operated steam preheat control valve with new DDC operated steam preheat control valve. • Install new AHU-24, reconfiguring CW and steam line connections as required. • Insulate all CW and steam piping. • Plumb in new condensate drain lines to existing floor drains in the space. • Connect new controls to Siemens Desigo BAS, including the update of existing graphics, alarming points and updating trends. • Provide and install SA and RA/OA temp and humidity sensors. • Provide and install SA static pressure sensors. • Commission the new AHU to prove the sequence of operations, alarms, trends, and unit shutdown for any safeties (i.e., LTD, smoke/fire, High static pressure of low static pressure. • Provide four (4) hours of training to HVAC Shop maintenance personnel on maintenance, operation and control for new AHU-24. • Provide a minimum one (1) year warranty of all parts and labor. • Contractor responsible for removal of all construction debris/material. • The project must be performed by a contractor that has the capability and capacity to perform all tasks. A New AHU-24 blower/coil assembly must fit current footprint. Expect delivery within 90 days of award.

Division 22 -	Plumbing, Common Work Results for Plumbing.
Division 23 -	Heating, Ventilating, and Air Conditioning (HVAC), Instrumentation and Control for HVAC, HVAC Air Distribution, Central HVAC Equipment.