Robson Elementary Cooling Tower Replacement, Mesa, AZ

Scope of work: Mechanical Demolition: Remove two existing cooling towers, two centrifugal separators, two condenser water pumps, and associated condenser water piping, cold water piping, drain piping, floor sink, chemical treatment, concrete pylons, and structural supports from the Tower Yard. Remove approximately 25’ of the existing west 10’-0” tall masonry Tower Yard wall. Remove approximately 300 sq ft of existing sidewalk and corresponding 25’ of handrail. Mechanical: Provide 2 new 130-ton cooling towers, centrifugal separators, two new 390 GPM condenser water pumps, and 2 new cooling tower fan VFDs in the Tower Yard. Provide new 6” diameter condenser water supply and return piping from the new cooling towers to the remaining underground condenser water piping stub-ups in the existing Tower Yard. Provide 4 new 6” diameter, 120v/1ph motorized valves in the condenser water piping to the cooling towers. Provide new 1" copper water piping from existing Mechanical Room to the new cooling towers in the Tower Yard. Provide new water meter tied into the EMS, new pressure reducing valve and new backflow preventer. Provide new cooling tower drain piping, centrifugal separator piping, and floor sink. Re-install existing chemical treatment tanks, pumps, and controllers. Provide new Circon EMS Controls including Loytec Linx Energy Control Management System front end and graphics with Loytec LWEB-900. Provide new Distech 650 Central Plant Controller with scroll wheel. Provide new controllers, wiring, conduit (minimum 3/4" diameter), and programming to control the new cooling towers, motorized control valves, pump, centrifugal separators, VFDs, and vibration switches. Integrate the new controls into the existing Circon EMS Control System. Upgrade the existing Circon EMS front end as required to accommodate the new cooling towers, motorized condenser water valves, vibration switches, pumps, centrifugal separators VFDs, etc. Provide commissioning to ensure proper operation of the new equipment and controls. Provide approximately 220 sq ft of new 4” thick 2000 psi concrete sidewalk dowelled into the existing sidewalk and provide 30’ of new handrail. Electrical Demolition: Remove disconnects/starters, corresponding conduit, and wiring back to source from cooling tower, VFD, pumps, centrifugal separators, motorized valves, etc. Electrical: Provide new starters, disconnects, Panel CT, conduit, and wiring to power the new cooling towers, VFDs, pumps, motorized valves, sensors, lights, receptacles, and controls. Tie new Panel CT into the existing MMC with new fuses. Panel CT to power all the new equipment in the Tower Yard. Structural: Provide a two new approximately 8’x8’x3’ tall structural framing stands to support the new cooling towers in the Tower Yard. Provide 12” tall housekeeping pads under each cooling tower. Provide 4” tall housekeeping pads under each centrifugal separator and pump. Provide approximately 45’ of new 16”x16”x8” thick, 10’ tall masonry wall to extend the cooling tower enclosure 10’ to the west. Fill the new 450 sq ft Tower Yard expansion with 4” thick 2000 psi concrete slab to match the elevation of the existing sidewalks and slope towards the gate. Fill in openings in existing Tower Yard slab with new 4” thick 2000 psi concrete slabs dowelled into the existing slab. Deadline for questions is August 20, 2021 by 2:00pm. Bonds