A04_-_SOW_(Updated_5_8_2026)_0001.pdf

SECTION C – STATEMENT OF WORK

Mackay Island National Wildlife Refuge, Quarters #30

684 Knotts Island Road, Knotts Island, NC 27950

C.1 SCOPE OF WORK

The Contractor shall provide all labor, materials, equipment, and supervision necessary to remove and replace the existing second-floor HVAC system at Quarters #30, Mackay Island National Wildlife Refuge.

The work includes furnishing and installing one complete, fully functional split-system HVAC system (cooling and heating).

C.2 APPLICABLE STANDARDS

All work shall comply with:

• OSHA Standards

• EPA Refrigerant Regulations

• National Electrical Code (NEC)

• Local and State Mechanical Codes

C.3 SYSTEM REQUIREMENTS

The Contractor shall provide one complete matched HVAC system meeting the following:

• Cooling Capacity: Approximately 2 tons (±25% based on load calculation)

• Efficiency: Minimum 14.3 SEER2

• Heating: Propane furnace, 40,000–60,000 BTU/Electric Emergency Heat (Heat Strips):

Provide electric resistance heat strips with a capacity of approximately 10,000–15,000 BTU’s (as required to match system capacity and load calculation).

• Minimum 80% AFUE

• Refrigerant: A2L or code-compliant

C.4 INSTALLATION REQUIREMENTS

• Remove and properly dispose of existing equipment - Contractor shall disconnect, remove, and dispose of all existing HVAC equipment associated with the second-floor system, including but not limited to the outdoor condensing unit, indoor coil, furnace/air handler, refrigerant piping, condensate components, and associated appurtenances as required for a complete system replacement. Prior to removal, Contractor shall recover all refrigerant in accordance with EPA regulations and document proper handling. Contractor shall safely disconnect electrical and fuel connections and cap or secure all utilities to prevent hazards.

All removed equipment and materials shall be transported offsite and disposed of or recycled in accordance with all applicable federal, state, and local environmental regulations. Contractor shall take care to protect existing structures, finishes, and adjacent systems during removal and shall repair any damage caused by demolition activities at no additional cost to the Government. Work areas shall be left clean, free of debris, and ready for installation of new equipment.

• Install new outdoor unit on pad - Contractor shall furnish and install the outdoor condensing unit on a stable, level, and code-compliant mounting surface. Contractor shall utilize an existing pad if suitable, or provide a new pad constructed of precast concrete or other approved material, sized appropriately for the unit and site conditions. The pad shall be level, adequately supported, and elevated as necessary to prevent water intrusion, vegetation interference, and soil settlement. The outdoor unit shall be securely anchored as required by manufacturer instructions and local code, including wind-load requirements where applicable. Contractor shall maintain minimum manufacturer-recommended clearances on all sides to ensure proper airflow and serviceability. All refrigerant lines, electrical conduit, and control wiring shall be properly routed, supported, and protected from physical damage and environmental exposure. Installation shall ensure proper drainage around the unit and shall not adversely impact adjacent structures or utilities.

• Connect to existing ductwork and utilities - Contractor shall connect the new HVAC system to existing ductwork, electrical service, and propane supply as required for a complete and operational system. Contractor shall inspect all existing ductwork for condition, sizing, leakage, and airflow restrictions. Any deficiencies that would prevent proper system performance shall be corrected, including sealing leaks, repairing damaged sections, reinforcing connections, and modifying duct configuration as necessary to achieve proper airflow and system balance. Contractor shall provide new insulation or replace deteriorated insulation on ductwork and all associated components in unconditioned or exposed areas.

Insulation shall be properly secured, sealed, and installed to prevent air leakage, condensation, and energy loss. All utility connections (electrical, refrigerant, condensate, and gas) shall be installed in accordance with applicable codes and manufacturer requirements, and verified for safe, leak-free operation.

• Insulation of Refrigerant Lines and Exposed Surfaces - Contractor shall provide new insulation or replace deteriorated insulation on all exposed refrigerant lines and associated components. Insulation shall be UV-resistant (for exterior applications), sealed at all joints, and installed to prevent condensation, energy loss, and deterioration in outdoor conditions.

• Refrigerant Line Set Cleaning/Preparation - Contractor shall inspect existing refrigerant line set and either properly clean and flush using an approved flushing agent or replace the line set as required to ensure compatibility with the new system and refrigerant. Final installation shall meet manufacturer requirements and be free of contaminants, moisture, and debris.

• Install condensate drain and safety controls - Contractor shall provide and install a complete condensate management system for the HVAC unit, including primary and secondary drain lines, traps, and safety devices, in accordance with applicable codes and manufacturer requirements. The primary condensate drain shall be properly trapped, sloped, and routed to an approved discharge location to ensure continuous drainage without standing water. Where the unit is installed above finished spaces or in an attic/closet, Contractor shall install a secondary (emergency) drain pan with a separate drain line or approved overflow device. Safety controls shall include a float switch or equivalent shutoff device installed in the secondary drain pan or primary drain line to automatically shut down the system in the event of blockage or overflow. All piping shall be properly supported, secured, and protected from physical damage, freezing, and UV exposure where applicable. Installation shall prevent air leakage, water damage, microbial growth, and nuisance conditions, and shall be verified for proper operation during system startup.

• Provide thermostat and electrical connections - Contractor shall provide and install a new thermostat compatible with the installed HVAC system, including all required low-voltage wiring, controls, and accessories necessary for full system operation. Thermostat shall be programmable for residential applications and shall be capable of controlling both heating and cooling functions. Contractor shall coordinate thermostat location with the Government to ensure proper placement for accurate temperature sensing and accessibility.

Contractor shall provide all electrical connections required for a complete and operational system, including line voltage power to the outdoor unit and indoor equipment, low-voltage control wiring, and interconnections between system components. All electrical work shall comply with the NEC and local requirements. Contractor shall install properly sized conductors, overcurrent protection, disconnect switches within sight of equipment, and grounding in accordance with code and manufacturer requirements.

All wiring shall be neatly installed, supported, and protected from physical damage and environmental exposure. Contractor shall verify proper voltage, phase, and amperage prior to energizing equipment. Upon completion, Contractor shall test and demonstrate proper thermostat operation, system staging (if applicable), and safe startup and shutdown of the HVAC system.

C.5 SUBMITTALS (SD-03 PRODUCT DATA)

The Contractor shall submit:

• Manufacturer product data for HVAC system

• Equipment specifications

• Load calculations (Manual J or equivalent)

• Warranty documentation

C.6 TESTING AND COMMISSIONING

• Verify refrigerant charge

• Confirm airflow and temperature split

• Test heating and cooling operation

• Ensure no leaks (refrigerant, gas, condensate)

C.7 PERIOD OF PERFORMANCE

90 days from Notice to Proceed.

Work hours: Monday–Thursday, 7:00 AM – 4:30 PM.

No work on federal holidays.

C.8 ACCEPTANCE CRITERIA

• System operates properly in all modes

• No leaks present

• Adequate airflow achieved

• Site restored to original condition

C.9 WARRANTY

• Minimum one-year labor warranty

• Manufacturer warranties transferred to Government