B08_SOW.pdf

Performance Based Statement of Work Service Building HVAC Installations

Building #109 SAMMS ASSET 10021567

Service Building Maintenance offices 12311 Beech Forest Road Laurel, MD 20708

General Information Introduction Patuxent Research Refuge (PRR) is located along MD 197 in Laurel MD. The refuge is a unit of the US Fish and Wildlife Service, National Wildlife Refuge System. The refuge has a Service Building / maintenance staff offices, constructed in 1959, which is a one-story slab on grade 8,650 SQFT building. Area A is 5,452 sq feet and area B is 3201 sqft.

The building is served by two fuel oil furnaces with split system cooling units which need to be replaced.

The condensing units are single stage R-22 refrigerant units which are becoming prohibitively expensive to service. This statement of work requires removal and replacement of the furnaces, air handlers and condensing unit that serve two wings of the building. The air handlers are located in a dedicated mechanical room (room 21 on attached floor plan) with access to outside air. The building is separated into two zones for HVAC purposes and each furnace/ HVAC responds to its own hallway thermostat.

The current damper systems require physical switchover from summer to winter mode to prevent summer condensation damage to the heating systems.

The refuge wishes to convert to variable refrigerant flow, air source, inverter type heat pump technology with variable speed fan controls and multi stage compressor for both heating and cooling.

The current furnaces are fueled from a 1000 gallon heating oil tank which is to be disconnected as part of this contract. The damper system shall be modified so that the HVAC controls modulate the outside air dampers appropriately and include provision of at least 5% outside air.

Background:

In order to reduce heating costs PRR has long term plans to replace inefficient HVAC systems with newer systems. Most systems will be powered by solar energy, so efficiency and reliability, are paramount.

Scope In accordance with the work requirements below, the contractor shall remove the existing HVAC systems and install fully functioning, high efficiency systems at PRR’s Building #109

Work Requirements:

Technical requirements.

The contractor is responsible for:

1. The contractor shall be a licensed Mechanical Contractor in the state of Maryland.

All work and testing shall be in accordance with the 2021 International Mechanical Code (IMC). Duct work shall be performed in accordance with NFPA90B. Electrical work shall be in accordance with NFPA National Electrical Code / NFPA 70

2. Selective Demolitions; The contractor shall remove and legally dispose of:

• Existing furnaces, air handlers, condensing units, fuel oil piping and thermostats.

• Ductwork as necessary for installation of the new system

• Refrigerant piping serving the existing unit.

• Electrical cables and conduit serving the existing units may be reused if in good condition.

3. Maintain and protect existing facilities from damage during demolition work.

• Protect building structure and interior from weather and water leakage and damage.

• Locate, identify, shutoff or disconnect utility services prior to demolition.

• The contractor shall inspect the building and perform and submit load calculations (ACCA manual N) and confirm that the following specified system will be efficient and provide adequate capacity

4. All system components shall be inter-operative, including controls.

5. Field Measurements: On site field investigation and measurements shall be made prior to procurement of the HVAC units, to ensure that the proposed mechanical equipment will fit the site of the installation.

6. Upon completion of the installation, the HVAC system shall be complete and fully operational.

Perform startup operations with the presence of Refuge personnel.

The contractor shall provide cut sheets for Government approval for the following equipment (*) in advance of purchase.

The contractor shall install the following specified system in each area of the Service building.

BASE BID ITEM

Area A requires approximately 20 tons cooling.

Carrier Aero Indoor Air Handler Model 39MN (Indoor) Size 17W, or equivalent.

2” MERV 8 filtration, Quantity 6, - 20” x 20” Minihelic differential pressure gauge 1-2” W.C.

Direct Expansion Coil Carrier model 28ME or equivalent, intertwined row split (dual circuit) with 304 stainless steel drain pan, 16.93 SQFT coil area, ½” tube diameter, .0060 “ fin thickness, Aluminum fins with galvanized casing, R-410A refrigerant , 2 draw through, direct drive, 2208 RPM Class II supply fans, ECM Control Box, 208 Volts, 3 Phase 60 Hz, 8000 CFM with total cooling capacity 229 MB/ Hr and sensible cooling capacity of 174 MB/Hr, DX Coil Controller TCB-IFDMR01UP-UL (2), remote Controller

RBC-AWSU52-UL(2)

2 Condensing units with 2 TXV, 12 and 8 Ton with c5 nozzles, even condensation versus evaporation, Refrigerant type 410A, Saturated suction temp 46 degrees Fahrenheit, Saturated Condensing Temp 119 degrees Fahrenheit. Model Toshiba / Carrier 3- phase Heat Pump (SMMS) Series Outdoor Unit MMY- UP2401HT9P-UL with modules 144 and 96 (MMY-MUP1441HT9P-UL and Model MMY-MUP0961HT9P- UL) Indoor Unit RBM-A1201UPVA-UL(2) or equivalent

Fan Model 39M1702VPEE-D size 17W, ECM direct drive plenum type (EBM-08) fan class II with Vertical orientation, 8000 CFM airflow, 2200 RPM. Controls programmable wired controller Model RBC-AWSu52-

UL (2)

Alternate Bid Item Area B requires approximately 10 tons cooling.

Carrier Aero Indoor Air Handler Model 39MN (Indoor) Size 08W, or equivalent.

2” MERV 8 filtration, Quantity 3, - 16” x 25”

Minihelic differential pressure gauge 1-2” W.C.

Direct Expansion Coil Carrier model 28ME or equivalent, intertwined row split (dual circuit) with 304 stainless steel drain pan, 7.64 SQFT coil area, ½” tube diameter, .0060 “ fin thickness, Aluminum fins with galvanized casing, R-410A refrigerant , 2 draw through, direct drive, 1930 RPM Class III, supply fans, ECM Control Box, 208 Volts, 3 Phase 60 Hz, 4000 CFM with total cooling capacity 110 MB/ Hr and sensible cooling capacity of 81 MB/Hr, DX Coil Controller TCB-IFDMR01UP-UL (1) , remote Controller

RBC-AWSU52-UL(1)

Condensing unit with 2 TXV, 3 Ton each, with G4/G3 nozzles, even condensation versus evaporation, Refrigerant type 410A, Saturated suction temp 45 degrees Fahrenheit, Saturated Condensing Temp 124 degrees Fahrenheit. Model Toshiba / Carrier 3 phase Heat Pump (SMMS) Series Outdoor Unit MMY- MUP1201HT9P-UL Indoor Unit RBM-A1201UPVA-UL (1) or equivalent

Fan Model 39M0802VPEE-D size 08W, ECM direct drive plenum type (EBM-06) fan class III with Vertical orientation, 4000 CFM airflow, 1930 RPM. Controls programmable wired controller Model RBC-AWSu52-

UL (1)

Contractor must verify piping length and calculate correct additional refrigerant charge.

Area Minimum Specifications

1. Energy efficient priority design 13.4 SEER (seasonal energy efficiency ratio) heat pump condenser with R410 refrigerant, Inverter driven variable speed rotary compressors and cooling fans.

2. fan coil compatible with R410 or R454b refrigerant, Variable speed Fan Motors, 208/230Volts AC 3 Phase, 60 Hz, Single piece cabinet insulation,

3. Wi-fi digital programmable thermostat

4. Condenser pump ups

5. Copper line set pressure test

6. Refrigerant filter dryer

7. Adaptive sheet metal, including any ductwork, insulation, or other components necessary for a complete reinstallation of the new air handler units.

8. Condensers shall be installed on existing concrete pad

9. High voltage disconnect may be reused if it meets the manufacturer’s specifications for the new condensing units. One additional outdoor disconnect will need to be provided and installed.

10. High and low voltage connections.

11. UV line cover protection

12. Condensate piping with float switch protection.

13. Minimum 2” pleated air filter with access door, or similar air filter. Air filter dimensions must provide manufacturers design airflow.

14. The HVAC system shall be in compliance with the following applicable performance standards:

Air-Conditioning, Heating, and Refrigeration Institute (AHRI), and the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE).

15. All electrical work shall be performed in accordance with the National Electric Code (NEC).

Notes

• All old equipment will be removed, disposed and recycled per federal and state laws

• Old units must have refrigerant removed per federal and state laws

• New air handler and condensing unit shall be installed in approximately the same locations as those removed.

• All work will adhere to local mechanical and building codes.

• If drywall or plaster needs to be cut, this contract does not include the patching which will be performed by the government.

• If mechanical room ceiling panels must be cut, an asbestos test must be conducted in advance.

• Work hours are 7AM to 3:30 PM

• Patuxent Research Refuge is a controlled access facility. Contractor employees must have identification. Employee names must be provided to COTR in advance of starting work.

• Contractor shall be required to pay Davis-Bacon Wage rates to all employees working on job.

Warranty The following minimum warranty periods must be included in the contractors pricing

• Labor for 2 years from date of installation

• Manufacturers limited parts 10 years

• Manufacturers limited compressor 10 years

• Installing Contractor is responsible for Warranty registration. Proof of registration required before final project payment is made.

Deliverables:

The contractor shall provide all labor, material, technical knowledge and expertise to meet the necessary requirements. The contractor shall remove and properly dispose of all old equipment and materials and leave the site without any debris around it. All disposal receipts are to be submitted to COR. The contractor may dispose of clean scrap metal in the facilities metal recycling dumpster. Area must be clean of all rubbish caused by the installation of equipment. Provide all Installation, Operations and Maintenance Manuals to the Refuge.

Special considerations

1. Normal working hours for Facility Staff are from 7:00 AM to 3:30 PM Monday through Friday except for Government holidays and special events.

2. Building is a working office building.

3. If possible, work should be accomplished Monday-Friday.

Project Safety

The Contractor shall be responsible for strict compliance with all provisions of Occupational

Safety and Health Administration (OSHA) requirements 29 CFR 1910 and 29CFR 1926 during performance of the work.

View of Air Handlers

Area A Heating unit on top and Cooling Coil on Bottom.

Area B Heating Unit

Area B HVAC cooling unit

Manufacturers label on Area A Condensing unit.

Manufacturer’s LABEL Condensing Unit Area B

Exterior view of condensing units

Guiding Specifications

Heat Pump

Variable Refrigerant Flow Outdoor Units

Size Range:

Nominal Cooling Capacity Range: 72,000 to 480,000 Btu/h

Nominal Heating Capacity Range: 81,000 to 540,000 Btu/h

Toshiba Carrier Model Number:

MMY-UP---1HTP—UL

MMY-UP---H1HTP--UL

Part 1 - General

1.01 SYSTEM DESCRIPTION

A. The heat pump variable refrigerant flow system is a two-pipe system consisting of a single or multiple outdoor units, multiple indoor units of various types and capacities, individual or central indoor unit controls with on/off temperature settings, all connected by fully insulated refrigerant lines utilizing factory supplied, fully insulated, branching kits. Indoor units are connected to condensate piping that shall be terminated to the nearest drain point.

B. The system shall be fully capable of providing heating or cooling as requested by the individual indoor zones that can consist of single or multiple indoor units. The heating priority shall be the default factory setting and can be changed to cooling, majority or a single zone priority.

C. The maximum number of connected indoor units shall not exceed 74.

D. The total connected indoor unit capacity shall range between 50 and 200% of the outdoor unit capacity based on indoor unit type & size selected.

1.02 QUALITY ASSURANCE

A. Units shall be listed by ETL (Engineering Testing Laboratory) and be evaluated in accordance with UL standard 60335-2-40, 3rd. edition.

B. Units shall be listed in the AHRI directory.

C. All units shall meet the Federal minimum efficiency standards and be tested per AHRI 1230

Standard.

1.03 DELIVERY, STORAGE, AND HANDLING

A. Units shall be shipped in one piece and shall be stored and handled per unit manufacturer's recommendations.

B. Units shall be supplied with a base rail that provides openings for moving the unit by fork truck or rigging the unit by crane.

1.04 WARRANTY (For Inclusion by Specifying Engineer)

Part 2 - Products

2.01 EQUIPMENT

A. General:

Factory-assembled, single piece air-cooled outdoor unit. Contained within the unit enclosure shall be all factory wiring, piping, controls, and the multiple inverter-driven twin rotary compressors.

1. The maximum sound pressure rating for a single module shall not exceed 64 dBA sound pressure in cooling and 67 dBA in heating and for multiple modular systems the sound pressure numbers should not exceed 66 dBA and 71 dBA. Sound pressure ratings are measured at a distance of 3 ft out and 4 ½ ft up from the side of the outdoor unit.

2. The outdoor unit shall include an oversized accumulator and a liquid tank for proper heating performance while allowing the indoor unit PMV (pulse modulating valve) metering device to shut off completely when a zone is satisfied.

3. The outdoor unit shall be protected by a high-pressure switch, high-pressure sensor, low-pressure sensor, fusible plug, PC board, and inverter overload protector.

4. The outdoor unit shall be capable of operating in cooling mode down to -10F ambient air temperature and down to -22 F wet bulb ambient air temperature in heating.

5. The outdoor unit shall include a total oil management system that balances oil between compressors within a module, replenishes compressor oil to the compressors in a module from the oil separator if required, and allows oil and refrigerant to move between multiple modular units if required, even if one of the units is not running.

B. Unit Cabinet:

1. Unit cabinet shall be constructed of pre-coated steel, finished on both inside and outside.

2. Unit access panels shall be removable with minimal screws and shall provide full access to the compressors, fan, and control components.

3. Compressors shall be isolated in a compartment and have an acoustic wrap to assure quiet operation.

4. The outdoor unit control panel shall include a sliding window to access adjustable controls and an LED display for setup and diagnostics.

5. Unit cabinet shall be capable of withstanding 1500-hour salt spray test per ASTM-B117-16.

C. Fans:

1. Outdoor fan shall discharge air vertically and be driven by a DC inverter variable speed motor with 64 steps that is capable of running down to 60 rpm.

2. Outdoor fan motor shall be totally-enclosed with permanently-lubricated bearings.

3. Motor shall be protected by internal thermal overload protection.

4. Fan blade shall be non-metallic and shall be statically and dynamically balanced.

5. Outdoor fan shall be protected by a raised non metallic protective grille.

D. Compressors:

1. Each outdoor unit module shall be equipped with two inverter-driven twin rotary compressors with full range control to an accuracy of 0.1 Hz.

2. Compressor shall be totally enclosed in the machine compartment.

3. Compressors shall be equipped with factory mounted crankcase heaters.

4. Internal overloads shall protect the compressor from over-temperature operation.

5. Motor shall be suitable for operation in an R-410A refrigerant atmosphere.

6. Compressor assembly shall be installed on rubber vibration isolators.

7. To maximize compressor reliability, multiple compressors within a module shall be started and operated in variable patterns to ensure equal run time on all compressors.

8. To ensure maximum efficiency throughout the system operation range, no compressor is required to run at maximum speed under any condition.

E. Outdoor Coil:

1. Coil shall be constructed of aluminum fins mechanically bonded to seamless copper tubes, which are cleaned, dehydrated, and sealed.

2. The coil configuration shall be 4-sided and fully separated from the machine compartment for more effective heat transfer and sound isolation.

3. The coil fins shall have a factory-applied corrosion resistant blue-fin finish.

F. Controls and Safeties:

Operating controls and safeties shall be factory selected, assembled, and tested. The minimum control functions shall include the following:

1. Controls:

a. Compressor speed to match the refrigerant flow and capacity with the system requirements.

b. Outdoor fan motor speed for higher efficiency and lower sound.

c. Oil control for improved system reliability and comfort

d. Pulse modulating valve control for precise control of the refrigerant distribution and accurate capacity management to avoid starving any units.

e. Control of compressor staging to maximize reliability and minimum run time on all compressors.

f. Module control of compressor operation, compressor speed, and outdoor heat exchanger surface to maximize efficiency and sound level and reliability across the entire operating range of the system.

g. Control of the outdoor heat exchanger surface (main vs sub heat exchangers) for maximum efficiency and comfort.

2. Safeties:

The following safety devices shall be part of the condensing unit:

a. High-pressure switch

b. Fuses

c. Crankcase heater

d. Fusible plug

e. Overcurrent relay for the compressor

f. Thermal protectors for compressor and fan motor

g. Compressor time delay

h. Oil recovery system

i. Oil level sensor

j. Overcurrent sensor

k. Compressor suction and discharge temperature sensor

l. Compressor suction and discharge pressure sensor

G. Electrical Requirements:

1. All sizes shall utilize 208/230-3-60 or 460-3-60 (V-Ph-Hz) field power supply.

2. Multiple systems shall have separate field power supply to each module.

3. Two-core, standard, shielded low voltage cable shall be required for communication between outdoor and indoor unit.

4. All power and control wiring must be installed per NEC and all local electrical codes.

H. Refrigerant Piping and Line Lengths:

1. Piping connections shall be from the front or the bottom of the unit. The unit shall be capable of operating with maximum connected refrigerant line lengths up to 3937 (ft) actual based on total system capacity and refrigerant amount.

2. The outdoor unit shall have the ability to operate with a maximum height of 361 ft between the outdoor and the lowest indoor unit.

3. The maximum distance between the outdoor unit and the furthest fan coil shall not exceed

623 ft actual or 771 ft equivalent. No line size changes or oil traps shall be required.

4. The system shall be capable of operating when the height difference between the upper and the lower fan coil is 131 ft.

I. Auxiliary Refrigerant Components:

1. All field-supplied copper tubing connecting the outdoor unit to the indoor unit shall use factory-supplied branching kits consisting of either Y joints or headers to ensure even refrigerant flow.

2. To ensure piping flexibility, the system shall allow having Y joints or headers downstream of another header.