Statement of Work

Replace HVAC System Components

Visitor Center – Building 213

Fort San Cristóbal – San Juan National Historic Site 501 Calle Norzagaray San Juan, Puerto Rico

1. Project Title

Replace HVAC System Components – Visitor Center (Building 213)

2. Project Location

Fort San Cristóbal San Juan National Historic Site Visitor Center – Building 213

3. Background

The Visitor Center at Building 213 currently operates multiple aging HVAC systems that have experienced declining efficiency and reliability. Due to the coastal marine environment, the existing equipment is exposed to salt air corrosion, reducing its service life.

In addition, HVAC manufacturers have transitioned from R-410A refrigerant to new lower Global Warming Potential (GWP) refrigerants, such as R-454B and R-32, to comply with current environmental regulations. Because these new refrigerants require compatible system components, the existing interior air handling units (evaporator units) are not suitable for reuse with new condensing units. This project therefore includes replacement of both the exterior condensing units and the associated interior air handling units to provide complete, manufacturer-approved matched HVAC systems.

The new systems will improve energy efficiency, reliability, humidity control, and occupant comfort while ensuring compliance with current industry standards and manufacturer requirements.

4. Scope of Work

The Contractor shall provide all labor, materials, equipment, supervision, and services necessary to remove the existing HVAC systems and install complete new high-efficiency HVAC systems at the Visitor Center (Building 213).

Work shall include, but is not be limited to:

• Removal and replacement of all exterior condensing units.

• Removal and replacement of all interior air handling units (evaporator units).

• Replacement of all refrigerant piping.

• Replacement of refrigerant accessories required by the manufacturer.

• Replacement of electrical connections and controls as necessary.

• Startup, testing, balancing, commissioning, and operational verification of each complete HVAC system.

All equipment shall be furnished as factory-approved matched systems designed to operate with the manufacturer's specified refrigerant.

All work shall comply with manufacturer specifications, industry standards, and applicable Federal, State, and local codes.

The Contractor shall provide an on-site superintendent or foreman present at all times during active work.

5. Existing Condensing Units to be Replaced

Location Tonnage Manufacturer Model Number

Location #1 5 Ton Trane 4TTR3060E1000NA

Location #2 5 Ton Trane 4TTR6061C1000AA

Location #3 5 Ton Trane 4TTV0048A1000CD

Location #4 5 Ton Gree FLEXX60AC230V1A0

Location #5 5 Ton Gree FLEXX60AC230V1A0

Location #6 4 Ton Trane 4TTR3048E1000PB

Location Tonnage Manufacturer Model Number

Location #7 4 Ton Trane 4TTR3048E1000PB

Location #8 4 Ton Trane 4TTR3048E1000PB

Total HVAC systems to replace: 8

Each HVAC system shall include replacement of both the exterior condensing unit and the associated interior air handling unit.

6. Equipment Requirements

All new HVAC equipment shall meet the following requirements:

• Factory-matched condensing unit and indoor air handling unit.

• Compatible with current EPA-approved refrigerants (R-454B, R-32, or manufacturer's current approved refrigerant).

• Units shall be manufactured in the United States.

• Minimum SEER2 rating of 22 or greater, where commercially available for the equipment size.

• Electrical system: 208/230 Volt.

Minimum Warranty

• Seven (7) Year Compressor Warranty

• Five (5) Year Parts Warranty

Corrosion Protection

Due to the coastal environment, all exterior condensing units shall include:

• Anti-corrosion condenser coil coating.

• Components rated for saltwater environments.

• Corrosion-resistant cabinet construction.

Indoor air handling units shall be compatible with the selected condensing units and furnished with factory-approved evaporator coils designed for the specified refrigerant.

7. Installation Requirements

Condensing Units

• Install new exterior condensing units at existing locations.

• Replace all copper tubing with new copper tubing to accommodate new R-32 or R454B refrigerant.

• Replace all inline HVAC Receiver Drier Filter

• Each unit shall include breaker panel circuit labeling identifying the corresponding HVAC system.

• Each unit shall include a disconnect switch located in the immediate vicinity.

Disconnect switches shall be:

• Non-metallic

• NEMA 4X rated enclosure

• Mennekes brand or approved equal

Interior Air Handling Units

The Contractor shall remove and replace all existing interior air handling units.

Installation shall include:

• New factory-approved evaporator coils.

• New thermostatic expansion valve (TXV) or electronic expansion valve (EEV), as required by the manufacturer.

• New condensate drain connections and traps where required.

• New auxiliary drain pans and overflow safety switches where applicable.

• New condensate float safety switches.

• New air filters.

• New insulation as required.

• Reconnection to existing ductwork with modifications as necessary to provide proper fit and airflow.

Refrigerant Piping

All existing refrigerant piping shall be removed and replaced.

New piping requirements:

• New ACR Type L copper tubing.

• Tubing sizes shall be verified and matched to manufacturer requirements.

• Suction lines shall include all-weather insulation.

• Liquid lines shall be properly sized.

• Installation shall comply with manufacturer requirements for new refrigerants.

Piping Protection

• Refrigerant lines passing through floors or concrete walls shall be installed inside PVC conduit.

Electrical Work

• Remove existing electrical connections.

• Install new wiring between breaker panels, condensing units, and air handling units as required.

• Replace control wiring as necessary.

• All electrical work shall comply with the National Electrical Code (NEC).

Equipment Anchoring

Exterior condensing units exposed to open-air environments shall include:

• Corrosion-resistant wind anchoring systems.

• Rooftop equipment pedestals.

• Stainless steel tie-down hardware.

Units shall be mounted without roof penetrations.

8. Removal and Disposal

The Contractor shall:

• Remove all existing condensing units.

• Remove all existing interior air handling units.

• Remove existing refrigerant piping.

• Recover all refrigerants in accordance with EPA regulations.

• Dispose of equipment and refrigerants in accordance with all applicable Federal, State, and local regulations.

13. Deliverables

Prior to Notice to Proceed

The Contractor shall submit:

• Equipment product submittals for COR approval.

• Condensing unit and air handling unit specifications.

• Equipment dimensions and weights.

• Manufacturer documentation verifying matched-system compatibility.

Prior to Contract Closeout

The Contractor shall provide:

• Two (2) hard-bound Operation and Maintenance Manuals.

• One (1) hard-bound warranty manual.

• Equipment model and serial number list for all condensing units and air handling units.

• Documentation of system startup and commissioning.

• Documentation of training completion.