Statement_of_Work.pdf

CAPE HATTERAS NATIONAL SEASHORE

Outer Banks Group

STATEMENT OF WORK

REPLACE HVAC AT BUXTON DOUBLE KEEPERS QUARTERS

46379 LIGHTHOUSE RD BUXTON, NC 27920

PMIS 351878 A

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1.0 BACKGROUND AND EXISTING CONDITIONS

1.1 BACKGROUND

• The DKQ at 46379 Lighthouse Rd in Buxton, NC, is a museum located in what was once the double keepers’ quarters for the Cape Hatteras Lighthouse. This historic structure, built around 1854, measures about 90 feet by 36 feet and has roughly 4,238 square feet of interior space. The building’s front doors face south/southeast on the property. It features a brick piling foundation, wood framing, tongue-and-groove flooring and ceilings, and lapped board siding. Both the first and second floors have windows framed with wood trim and sills, along with additional storm windows installed on the exterior. There’s a covered wood porch in front and a smaller covered porch at the rear exit. Underneath, the crawl space varies from approximately 24 to 36 inches above ground level.

• Two small additions have been made since the original construction. The DKQ is part of the Cape Hatteras Light Station and is recognized as a historic site. Its HVAC system consists of seven geothermal heat pump units installed in individual closets across seven rooms, each closet measuring about 3 feet by 3 feet and featuring two wall returns (approximately 22 by 22 inches each). Six of the seven units include a pump. These units supply cooled air directly to their respective rooms. Some ground source piping is visible within the crawl space—three pairs are identified—but the full layout and circulation pattern of the pipes remains unknown, as do the number and depth of the geothermal wells supporting the system. The current HVAC setup was installed around 2002, after the DKQ was moved from its previous location to where it stands today.

1.2 EXISTING CONDITIONS

Currently, the Double Keepers Quarters building is being cooled by 6 portable floor units. These floor units were installed as a temporary repair are not sufficient to keep the building at a reasonable working temperature. The existing geothermal air conditioning system and all 7 package units are all turned off due to leaks and an inability to keep water in the system. Each of the seven geothermal package unit ground source heat pump units is locked out and tagged out for safety.

1.3 DRAWINGS – Building Sketches: The 4 Figures below provide a layout of the existing floorplans of the first and second floor, along with an overlay of the HVAC system ductwork installed in the first-floor ceiling and the second-floor attic space.

The below figures are for orientation purposes only and not meant to define the tasks for the scope of work.

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Figure 1 - First Floor Plan – 1985

Figure 2 – Second Floor Plan - 1985

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Figure 3 – First Floor Plan – 2006

Figure 4 – Second Floor Plan – 2006

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2.0 OBJECTIVES

2.1 Remove the old geothermal package units in the 7 closet spaces (4 downstairs and 3 upstairs) and replace them with 5 new (3 Downstairs and 2 Upstairs) traditional heat pump systems according to 2024 International Building Code, 2024 International Mechanical Code (IMC), American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) and ACCA standards, and Sheet Metal Air Conditional Contractors National Association (SMACNA) standards.

3.0 PLACE OF PERFORMANCE

3.1 The address for the Hatteras Light Station Double Keepers Quarters is 46379

Lighthouse Rd Buxton, NC 27920

4.0 TASKS/SPECIFICATIONS

4.1 Task 1: Demolition

1.1.2 Recover all refrigerant from 7 existing geothermal HVAC indoor units.

1.2.2 Disconnect all electrical lines from the disconnect switch at each heat pump. Existing disconnect boxes shall be removed. Wiring up to the existing boxes shall remain in place. Install new wiring that meets the requirements of each system being installed.

1.3.2 Remove existing meter and meter base from outside the building.

Coordinate meter removal and de-energizing the building with Cape Hatteras Electrical Cooperative (CHEC).

1.4.2 Coordinate with CHEC and upgrade the existing 200-amp service to a new 400-amp service.

1.5.2 Disconnect and remove geothermal water piping from the 7 units back to the ground level beneath the building. The existing pipes run through the closets and shall be cut out and pulled through the floor/ceiling inside of the closet space. Re-use this space for running refrigerant lines on the new HVAC systems being installed.

1.6.2 Cut and cap the pairs of old geothermal water loop lines approximately 4 inches above grade beneath the building in 3 places.

1.7.2 Remove two existing electrical panels in the electrical closet at the restrooms.

1.8.2 Remove all 7 indoor geothermal package units, pumps and associated geothermal components. Do not damage adjacent flooring, closet spaces, floors or walls. Remove and dispose of all existing thermostats, louvers, grills/return grills, registers, and exterior electrical disconnects.

1.9.2 Carpentry and wood framing materials and all demolition necessary to remove the existing geothermal systems are included.

4.2 Task 2: Provide five new multi-stage split HVAC systems

2.1.2 Mark the locations of the four corners of five HVAC stands and submit the marked areas for park approval.

2.2.2 Build one outdoor HVAC stand as a mockup and submit the mockup for park approval.

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2.3.2 Provide five new outdoor HVAC stands in the location shown on the attached drawings below (figures 5 & 6). The 5 new stands shall consist of all pressure treated 4x4 posts, 2x4 joists, 2x6 board platform floor with no walls, approximately 24 inches above ground level. Provide approximately 24” clear space in between each of the five units. Provide approximately 12” clear space from the edge of the porch and edge of the restroom wing. Provide approximately 36” set back from the rear of the building.

2.4.2 Install the new outdoor compressor units on the new stands.

2.5.2 Provide new 400-amp disconnect and new meter base. Coordinate new meter installation with CHEC.

2.6.2 Provide two new 200-amp electrical panels inside the electrical closet with associated breakers to serve the existing branch circuits and the new HVAC. New panels shall be QO type with visible trip indicator.

2.7.2 Reconnect existing building branch circuits to one of the new 200-amp panels. Label this panel as Panel “A”. Label branch circuits at each breaker in Panel A.

2.8.2 Install the other 200-amp panel adjacent to the first panel. Connect new HVAC equipment to the second panel and label this panel as Panel “B”.

Reuse existing wiring from geothermal indoor units to the new panel for the indoor air handlers. Provide new conduit and wiring from Panel B to new disconnects for each new outdoor heat pump.

2.9.2 Provide 4x4 wood posts adjacent to the platform on which to mount the subpanel and two new GFCI outlets.

2.10.2 Provide and install two 20-amp duplex GFCI outlets in a weatherproof box on the centrally located wooden stands (One in each location) This location is to be approved by the COR.

2.11.2 Provide new disconnects and liquid tight cable between the new disconnects and each new outdoor heat pump.

2.12.2 Provide 5 new indoor air handler units in the existing identified HVAC closets.

2.13.2 Provide new copper line set with UV protected insulation sized according to manufacturer instructions.

2.14.2 Remove and replace all existing ductwork inside of the 5 HVAC closets with new R8 insulated ductwork to code with insulated sheet metal transitions that are properly sized for the new unit.

2.15.2 Provide new return duct to meet the size of the new return filter grill openings. Filters shall be located at the return registers. Return duct shall be sealed directly between the return grill and the return box.

2.16.2 New indoor air handlers shall match the serial number series for the outdoor heat pump unit.

2.17.2 Provide each system with condensate drain traps, and a shut-off Safe-T Switch.

2.18.2 New HVAC units shall meet or exceed a 16 SEER rating.

2.19.2 New outdoor units shall have anti-corrosion technology made for coastal environments.

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2.20.2 Downstairs units shall include one 2.5 ton and two 1.5-ton units. The movie room shall have a 1.5-ton unit. The main building shall have a 2.5-ton unit. The north end single story addition shall have a 1.5-ton unit.

2.21.2 Upstairs units include a 3-ton unit, and a 2-ton unit, The 3-ton unit is in the main portion of the building. The 2-ton unit is located at the south end.

2.22.2 Provide duct dampeners to adjust airflow to each room. The duct dampener shall be within reach.

2.23.2 Provide all new digital thermostats in each closet.

2.24.2 Provide remote sensor on the closet wall adjacent to the return air grill.

2.25.2 Provide new duct wrapped with R-8 insulation, sealed per ACCA and

SMACNA standards as needed.

2.26.2 Provide insulated round flexible duct from all new main metal duct to each supply grille. Maximum length of any round flexible duct shall be 8 ft including the bends.

2.27.2 Replace all 7 return openings on each closet. New openings and new filter grills shall fit the preexisting 22”x22” return opening. Provide 12 new filters for each return grill.

4.3 Task 3: Install Quiet Fence

3.1.2 Install approximately 35 linear feet of white louvered aluminum panel

HVAC quiet fence screening that is made for HVAC sound damping in both areas where new condenser units are installed. This fence must be removable in sections for maintenance of HVAC units. The panels should be roughly 5 to 6 feet tall and designed for high wind speeds greater than 90 MPH and sustainable in coastal environments. The screening fence shall be placed in front of the HVAC condenser units and around the end of all new condenser units to reduce noise levels inside the building and provide a visual barrier for park visitors.

3.2.2 See Figure 5 below for fence placement

3.3.2 Material must be approved by COR prior to purchase and installation

4.4 Task 4: Install rafter vents

4.1.2 Temporarily remove the insulation in the attic

4.2.2 Add attic rafter vents (baffles) between the rafters

4.3.2 Install new R30 insulation so that it fits snugly against the baffles.

4.4.2 Install new R30 type insulation in locations where necessary, even if none is pre-existing

4.5.2 Insulate all attic access doors

4.5 Task 5: Install new ductwork and grilles

5.1.2 Provide an additional new duct opening and R8 insulated metal duct from the existing duct trunkline to the restroom. Install two new HVAC supply grilles in the restroom, ensuring all work is completed in accordance with ACCA and SMACNA standards. Provide insulated round flexible duct from new main metal duct to each new supply grille. Maximum length of any round flexible duct shall be 8 ft including the bends.

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4.6 Task 6: Provide two new Fresh Air Delivery Systems in the attic

6.1.2 Furnish and install two (2) 350 cfm capable dehumidifiers with secondary drain pans and associated drain line piping to remove the condensate water.

6.2.2 Units shall be in the attic to deliver positive ventilation for the building.

6.3.2 Both units shall be installed within the attic space for the conditioning of the outside air before entering the building envelope.

6.4.2 Sante Fe Ultra 120 or equivalent.

6.5.2 Piping shall exit via the existing upstairs ducts.

6.6.2 Intake air must be prefiltered with an easily accessible air filter.

6.7.2 Unit duct will discharge into the upstairs ceiling via two (2) 14 x 14 aluminum grills

4.7 Task 7: Provide Start-up, testing, and balancing for newly installed systems.

7.1.2 Provide a date and time for the Start-up of these new 5 units. Coordinate with the Contracting Officer Representative (COR)

7.2.2 Provide all Operations and Maintenance Manuals specifically for the exact type, brand, and model numbers of the new HVAC units installed, thermostats, and attic fans.

7.3.2 Provide at least a one-year warranty covering all parts and service.

5.0 SUBMITTALS

5.1 Product Data. Provide all product data sheets, initial operating conditions for the items below, including dimensions for equipment and ducting.

5.1.1 Outdoor heat pump units

5.1.2 Indoor air handler units

5.1.3 Duct material

5.1.4 Insulation

5.1.5 Digital Thermostats

5.1.6 Attic Fan

5.1.7 Fresh Air Delivery system and components

5.1.8 Electrical panel and associated parts

6.0 DELIVERY / STORAGE AND HANDLING

6.1 Ensure that all materials are delivered to the project site following issuance of the notice to proceed. All items must be in original containers with seals unbroken and labeled with manufacturer's name, product brand name and type, date of manufacture, approval or listing agency markings, and directions for storing and mixing with other components.

6.2 Use and storage of a work trailer can be coordinated with the COR.

7.0 OTHER UNIQUE REQUIREMENTS:

7.1 The units and all materials shall be stored and handled according to the manufacturer's recommendations.

7.2 Remove, cut, alter, replace, patch and repair existing work as necessary to install new

AC units. Existing work to be altered or extended and that is found to be defective in

PMIS 351878 A Replace HVAC at Buxton Double Keepers Quarters P a g e | 9 any way, shall be reported to the COR before it is disturbed. Materials and workmanship used in restoring work shall conform in type and quality to that of original existing construction. This is a historic structure, and all modifications not specifically listed on this scope of work must be approved by the COR prior to making the alteration or repair.

7.3 60 Day Period of Performance

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Figure 5 – Downstairs Plan

Figure 6 – Upstairs Plan