Piscataquis Community Elementary School - HVAC Upgrade

The scope of work for HVAC Upgrade includes the following items: 1) Remove all existing variable air volume (VAV) boxes in the second-floor classrooms and replace them with variable refrigerant flow (VRF) air handling units. Work to include duct modifications, refrigerant piping, condensate piping, electrical work, VRF controls and cutting / patching. VRF outdoor units to be placed on concrete pads, all refrigerant piping to outdoor units must be protected from ice / snow damage. 2) Existing air handling units (AHU) #1 and 8 shall be modified to provide outside air to the VRF air handling units. This work will consist of modifying fan speeds. Mechanical contractor shall work with owner's air balance and controls contractors to complete this work. In addition, the run-around heat recovery coils shall be cleaned, and the system fluid replaced. 3) Existing air handling unit AHU-2 shall be modified with a new encased cooling coil and drain pan / condensate piping installed in the supply air ductwork sized for 5,200 CFM. New refrigerant piping connecting the cooling coil to the outside condenser / compressor (CU) shall be installed. New CU shall be installed on a concrete pad, work to include electrical and cutting/patching. 4) Existing air handling unit AHU-3 shall be removed and replaced with a new, variable speed air handling unit complete with a direct expansion (DX) cooling coil, sized for 9,700 CFM, some existing duct modifications will be required. The existing return air fan shall be reused but will require a new VFD rated motor. New refrigerant piping connecting the cooling coil to the outside condenser / compressor (CU) shall be installed. New CU shall be installed on a concrete pad, work to include electrical and cutting/patching. 5) Existing air handling unit AHU-4 shall be modified with a new encased cooling coil and drain pan / condensate piping installed in the supply air ductwork sized for 3,850 CFM. New refrigerant piping connecting the cooling coil to the outside condenser / compressor (CU) shall be installed. New CU shall be installed on a concrete pad, work to include electrical and cutting/patching. 6) Existing air handling units AHU-5&6 shall have their cooling coils replaced with new R-410A refrigerant coils with new refrigerant piping to the roof and new outdoor condenser/ compressors mounted on the existing roof curbs, work to include electrical and cutting/patching. 7) Existing air handling unit AHU-9 shall be modified with a new encased cooling coil and drain pan / condensate piping installed in the supply air ductwork sized for 12,000 CFM. New refrigerant piping connecting the cooling coil to the outside condenser / compressor (CU) shall be installed. New CU shall be installed on a concrete pad, work to include electrical and cutting/patching. 8) Install a total of 3 ductless split systems in classrooms located on the 1st floor, work to include providing and installing equipment, refrigerant and condensate piping, electrical and cutting / patching. 9) Install modifications to the Nurse's Area ventilation including a wall mounted exhaust fan, work to include duct modification, electrical and cutting / patching. 10) Mechanical contractor (MC) shall be responsible for all demolition work, piping, ductwork, equipment installation, electrical, miscellaneous ceiling tile work, and cutting / patching. In addition, MC will be required to coordinate all his work with the owner's controls contractor and the owner's testing and balancing agent.

Division 23 -

Heating, Ventilating, and Air Conditioning (HVAC), Instrumentation and Control for HVAC, HVAC Air Distribution, Central HVAC Equipment.