WHITFIELD_HALL_HVAC_RTU_REPLACEMENT.docx

MISSISSIPPI UNIVERSITY FOR WOMEN

WHITFIELD HALL

HVAC ROOFTOP UNIT REPLACEMENT

SCOPE OF WORK

1. Project Intent Provide all labor, supervision, engineering coordination, equipment, materials, tools, rigging, crane services, transportation, permits, temporary protection, testing, startup, commissioning, disposal, and incidentals required for a complete turnkey replacement of the two existing rooftop HVAC units serving Whitfield Hall. The work shall include removal of the existing units and installation of two new 25-ton packaged electric/electric rooftop units, identified as RTU-1 and RTU-2, complete and operational.

2. Basis of Design and Major Equipment The attached proposal and submittal identify two Trane Foundation packaged rooftop units, model EDK300A3S0A**07 (or approved final configured model), 25-ton nominal cooling capacity, 208-230V/60Hz/3-phase, R-454B refrigerant, Symbio 700 controls, two-speed supply fan, and field-installed auxiliary electric heat.

Quantity: Two (2) rooftop units, tagged RTU-1 and RTU-2.

Nominal cooling: 25 tons per unit.

Design airflow: approximately 9,000 CFM per unit.

Electrical: 208-230V, 60 Hz, 3-phase. Submittal indicates MCA 177 A and MOP 200 A without electric heat; with electric heat at 230V, MCA 200 A and MOP 225 A. Contractor shall field verify the actual serving electrical system and final nameplate requirements before procurement and installation.

Heating: 72 kW field-installed electric heater per unit, two-stage heating.

Accessories: manual outside-air damper, condenser coil hail guard, options module, and specified filters.

Approximate unit envelope: 4.94 ft high x 7.24 ft wide x 10.26 ft long.

Published operating weight range: approximately 1,938 to 2,519 lb; final shipping/operating weight, accessory weight, center of gravity, and rigging points shall be confirmed from approved submittals before the lift.

Factory startup by an authorized Trane service technician is included in the equipment proposal and shall be coordinated as part of the project.

3. Mandatory Preconstruction Field Verification No dimensions, capacities, connection locations, curb conditions, electrical characteristics, controls interfaces, or crane assumptions shall be accepted solely from drawings or submittals. The Contractor shall perform a complete site investigation before ordering fabrication-dependent materials and before mobilizing for the crane lift.

Verify existing RTU manufacturer, model, serial number, capacity, voltage, phase, MCA/MOCP, heater size, airflow arrangement, control voltage, disconnecting means, and all existing accessories.

Measure and document each existing roof curb, roof opening, supply opening, return opening, curb height, curb orientation, unit footprint, service clearances, and all roof penetrations.

Verify whether the new units will set directly on existing curbs. If dimensions or openings differ, provide properly engineered curb adapters/transitions suitable for the new equipment, preserving weather integrity and required clearances.

Verify structural condition and capacity of existing curbs, roof framing, supports, decking, and attachment points to support the new units, curb adapters, accessories, and all applicable gravity, wind, seismic, and service loads. Obtain structural engineering review when required.

Verify existing supply and return duct dimensions, condition, insulation, liner, flexible connections, transitions, fire/smoke dampers where applicable, and available space for modifications.

Verify condensate drain size, routing, slope, traps, supports, termination, and roof penetration condition.

Verify power source, feeder conductors, raceways, breakers/fuses, disconnects, grounding/bonding, available fault current where applicable, and compatibility with final unit nameplate MCA/MOCP and electric heat load.

Verify existing BAS/controls, thermostat or space sensor wiring, interlocks, smoke detection/shutdown interfaces, fire alarm interfaces, occupancy scheduling, outside-air requirements, and any remote alarms or monitoring.

Verify roof access, staging areas, crane setup location, crane travel route, outrigger placement, underground utilities, overhead utilities, landscaping, sidewalks, roads, building setbacks, nearby structures, and required barricade/exclusion zones.

Verify the lift radius, roof elevation, required boom length, unit pick weight, rigging configuration, center of gravity, landing orientation, and whether any obstructions affect the lift.

Photograph and document existing conditions before work. Promptly report conflicts or concealed conditions to the Owner before proceeding.

4. Submittals and Coordination Submit final equipment data, electrical data, dimensions, weights, clearances, rigging information, curb/roof opening information, accessories, controls data, and installation requirements for review before installation.

Provide curb adapter/shop drawings and duct transition details when required by field verification.

Provide crane/lift plan showing crane type and capacity, setup location, outrigger reactions/support, lift radius, boom configuration, pick weights, rigging method, swing path, exclusion zone, and sequence of lifts.

Provide project schedule and proposed outage/shutdown duration. Coordinate all work with the Owner to minimize disruption to Whitfield Hall.

Coordinate required roof access and roof warranty requirements with the Owner and roofing manufacturer/contractor, if applicable.

Obtain all permits, inspections, utility coordination, and code approvals required for the work.

5. Demolition and Removal Coordinate shutdown of RTU-1 and RTU-2 with the Owner before disconnecting equipment.

Lock out/tag out all electrical and control energy sources in accordance with applicable safety requirements.

Disconnect electrical feeders, controls, condensate piping, duct connections, and other services necessary for removal.

Recover and manage refrigerant and other regulated materials from existing equipment in accordance with applicable requirements; do not vent refrigerant.

Protect roof membrane, curbs, duct openings, building interiors, finishes, and occupied areas from weather, debris, dust, and water intrusion during removal.

Use the project crane and qualified rigging personnel to remove the existing rooftop units. Existing units shall not be dragged across or loaded onto the roof in a manner that can damage the roof system or structure.

Remove obsolete curb components, duct transitions, wiring, controls, piping, supports, and accessories only as required for the new installation.

Legally dispose of or recycle removed equipment, refrigerant, metals, packaging, and debris unless the Owner directs that specific items be retained.

6. Crane, Rigging, and Lift Operations Crane services are an integral part of this scope. The Contractor shall furnish a properly sized mobile crane, qualified operator, riggers, signal person(s), lifting beams/spreader bars where required, slings, shackles, tag lines, cribbing/mats, traffic control, barricades, and all other equipment necessary to safely remove the existing RTUs and set the new RTUs.

Crane selection shall be based on verified pick weights, maximum working radius, roof elevation, boom length, site access, and manufacturer load charts. No crane capacity shall be assumed from nominal unit weight alone.

Confirm final unit weight, accessory weight, center of gravity, approved lifting points, and rigging instructions from the final equipment documentation. The submittal specifically requires verification of weight, connections, and dimensions before installation.

Establish and maintain a controlled lift/exclusion zone. Coordinate pedestrian and vehicle detours and restrict access below the lift path.

Locate and protect underground utilities and evaluate pavement/soil bearing capacity at crane and outrigger locations. Provide outrigger mats/cribbing sized for anticipated reactions.

Do not perform lifts in weather or wind conditions exceeding crane, rigging, or equipment manufacturer limits.

Provide temporary weather protection for roof openings during the lift sequence and do not leave openings exposed if work is interrupted.

Repair any damage to roofing, pavement, landscaping, sidewalks, building components, or other property caused by crane or rigging operations.

7. Roof Curb, Structural, and Weatherproofing Work Verify existing roof curb and opening compatibility with the new downflow units. The submittal indicates a downflow application and depicts roof-opening/clearance requirements; actual field conditions govern.

Provide new curb adapters, structural supports, transitions, blocking, reinforcement, attachment hardware, and flashing as required for a secure, level, code-compliant installation.

Maintain manufacturer-required service and condenser-air clearances. Coordinate all nearby walls, parapets, piping, equipment, and roof features.

Provide continuous weatherproofing at curbs, adapters, penetrations, and modified roofing. Roofing work shall be performed in a manner compatible with the existing roof system and warranty requirements.

Seal all supply/return interfaces air-tight and water-tight. Provide gasketing and flashing recommended by the equipment/curb manufacturer.

8. Mechanical Installation Set, align, level, anchor, and secure each new RTU in accordance with approved submittals, manufacturer instructions, and applicable codes.

Modify and reconnect supply and return ductwork as required. Provide transitions, reinforcement, supports, flexible connections where appropriate, insulation, vapor barrier, and sealing to match or exceed existing system performance.

Install the field-installed 72 kW electric heater, manual outside-air damper, hail guards, options module, and all other specified accessories.

Install new condensate drain connections, traps, vents, supports, insulation where required, and positive drainage to the existing approved termination point.

Provide and install new filters. Confirm filter access and serviceability.

Seal unused penetrations and restore all affected insulation and weather barriers.

Maintain access to service panels, disconnects, controls, filters, coils, drains, and other service components.

9. Electrical Work Provide all electrical labor and materials required for complete operation of each unit, including feeders, conductors, raceways, fittings, disconnects, overcurrent protection, grounding/bonding, terminations, supports, labeling, and weatherproof connections as required.

Field verify existing feeder and overcurrent protection adequacy against final unit nameplate data, particularly the increased electrical requirement associated with the 72 kW electric heat. Replace or modify components as necessary to provide a code-compliant installation.

Verify voltage and phase before energizing equipment and confirm phase rotation.

Provide local disconnecting means as required and coordinate mounting with manufacturer access requirements.

Remove or abandon obsolete electrical components only in an approved and code-compliant manner; identify all circuits and update panel directories where affected.

10. Controls, BAS, and Life-Safety Interfaces Reconnect or replace space sensors, thermostats, control wiring, and associated low-voltage components required for full operation.

Integrate the Symbio 700 controls with the existing building automation system to the extent required by the existing system and Owner standards. Verify communication protocol, points, addressing, schedules, alarms, occupied/unoccupied operation, and trend requirements before final configuration.

Verify and restore all existing smoke detector, duct detector, fire alarm, emergency shutdown, or other life-safety interlocks serving the units.

Demonstrate correct sequence of operation for cooling stages, electric heat stages, fan operation, outside-air damper, safeties, alarms, and shutdown interlocks.

11. Refrigerant and R-454B Considerations The specified units use R-454B refrigerant. The Contractor shall follow the final manufacturer installation instructions, applicable mechanical/electrical codes, refrigerant safety requirements, and all requirements associated with the unit's factory refrigerant leak detection and mitigation system. Personnel performing refrigerant work shall be appropriately qualified.

Do not disable, bypass, obstruct, or improperly relocate factory leak-detection components.

Verify required clearances, airflow pathways, electrical components, and field-installed accessories are compatible with the manufacturer's R-454B installation requirements.

Perform leak checks and commissioning procedures required by the manufacturer before turnover.

12. Startup, Testing, Balancing, and Commissioning Complete all manufacturer pre-start checks before requesting factory startup.

Coordinate factory startup by an authorized Trane service technician for both units. The equipment proposal includes one 8-hour factory-startup trip; the Contractor shall coordinate site readiness so the included visit can be used efficiently.

Verify supply fan rotation, belt alignment/tension, motor operation, airflow, external static pressure, filters, dampers, condensate drainage, refrigerant operation, electric heat stages, compressor staging, safeties, phase monitor, and controls.

Measure and document operating voltage and amperage on major loads and confirm operation within manufacturer requirements.

Test and balance air quantities as necessary to restore the intended building airflow. Adjust fan speed/sheaves and outside-air damper as required within equipment limitations.

Verify heating and cooling discharge-air performance and confirm occupied spaces are receiving appropriate airflow.

Test all BAS points, alarms, schedules, and life-safety shutdowns.

Correct deficiencies identified during startup, testing, or Owner review before final acceptance.

13. Protection, Safety, and Site Management Comply with OSHA requirements and all Owner safety, access, hot-work, lockout/tagout, fall-protection, and site-control requirements.

Provide fall protection and safe roof access for all personnel.

Protect building occupants, roof surfaces, interior finishes, landscaping, vehicles, and adjacent property throughout the work.

Maintain housekeeping daily. Keep access routes, exits, fire lanes, and emergency access clear.

Coordinate noisy work, shutdowns, crane operations, and any work affecting building occupancy with the Owner in advance.

Provide temporary cooling or other temporary measures only if specifically required by the Owner or contract documents; identify any such requirement before pricing.

14. Closeout and Owner Turnover Provide final startup reports, test and balance data, controls/BAS verification, inspection approvals, and commissioning documentation.

Provide operation and maintenance manuals, approved submittals, wiring diagrams, parts information, filter sizes, recommended maintenance requirements, and manufacturer warranty information.

Provide as-built documentation showing significant field modifications to curbs, ductwork, electrical service, controls, and condensate routing.

Label units RTU-1 and RTU-2 and label associated disconnects/circuits to match Owner records.

Provide Owner training covering normal operation, controls, alarms, filter service, electric heat, shutdown procedures, and basic maintenance.

Clean the work area and roof, remove debris and temporary protection, and repair all construction-related damage before final acceptance.

15. Contractor Responsibility and Completeness The Contractor shall provide a complete, functional, code-compliant installation whether or not every minor component is specifically enumerated in this scope. Items reasonably inferable as necessary for the replacement, connection, support, weatherproofing, electrical service, control, startup, testing, and safe operation of the two rooftop units shall be included. Any discrepancy discovered during field verification that materially changes the work shall be brought to the Owner's attention before procurement or construction.

16. Reference Equipment Data

Whitfield Hall HVAC Rooftop Unit Replacement - Scope of Work