SATPC0028772 Tab 04 SOW.pdf

Scope of Work

400 area Bunker 1 HVAC

July 21, 2022

Introduction The Propulsion Test Office of the NASA White Sands Test Facilities (WSTF) supports various NASA programs including Fleet Leader testing and qualification testing of reaction control engines and other propulsion components. The data acquisitions and control systems (DACS) is an integral part of the test systems, providing test article controls, data collection, analysis, and archiving. A portion of the DACS hardware is installed in 400 area bunkers. The DACS hardware requires constant thermal conditioning during operation to ensure system reliability and data quality.

The current bunker HVAC units are beyond their normal economic life cycle. Critical spares and replacement components are no longer available. Existing HVAC units utilize R-22 refrigerant that is now illegal to produce and will be illegal to use starting in 2030.

Purpose The purpose of this document is to define the requirements to replace the HVAC unit in WSTF’s Propulsion Test Office’s 400 area bunker 1.

System Overview.

400 area consists of two bunkers. The main access to bunker 1 is through a blast door which 42”x64”. The HVAC unit is located in a separate room, with in bunker 1, that has two access doors WxH.

Chilled air is pushed through a raised floor in to the DACS equipment installed in the bunker. The return ducting is installed in the ceiling. The condenser is located outside.

Piping is installed in the concrete to connect the condenser to the reset of the HVAC system located inside the bunker. HVAC control and monitoring is conducted from the controller room located above the bunkers.

Onsite Access

The bunkers are located on a federal facility within a hazards test area with restricted access. Access to support pre and post bid activities can/will be arranged. At a minimum all personnel must follow area hazardous warnings, site protocols, and be cleared by security to access the site. Farther guidance will be provided per visit request.

Technical Challenges

This project will have three specific issues that will make the change out difficult.

1. The installation and removal shall be scheduled around area operations.

Removal and installation efforts most be completed per area with in a two week period.

2. HVAC is installed in cramped mechanical rooms located in the bunker with limited access. Getting the old equipment out and the new equipment in will require dissembling the old equipment into small sections and craning the items out. The new units must be modular and able to fit through both the HVAC room and bunker blast doors. Restricted access to the blast door will require a crane to remove and install the HVAC hardware.

3. Were applicable the existing piping, conduit, ductwork, and power maybe reused. Reuse of existing infrastructure must be assets and final written approval obtained by WSTF.

Examples

a. Reusing the existing power and fuses

i. Concerns: MMC fuse ampacity may need to be changed. The new units should be more efficient so ampacity should go down eliminating the need to replace wire and conduit.

b. Reusing the existing lines running through the block house reinforced concrete walls.

i. Concerns: Lines shall be flushed to a level were the refrigerant can be switched from R-22 to 410A (they use different oils that are not compatible) and will hold pressure (410A runs at much higher pressures than R 22).

Requirements

General

Procure and install one HVAC unit for the 400 area bunker 1 DACS room capable of maintain an operating temp for the DACS components of 70°F ±20°.

Single fault failures should be minimized where possible. Critical spare parts should be kept on hand where single fault failures can’t not be minimized. Critical parts on each system shall be interchangeable. Critical parts are defined as high dollar items with a long lead time.

Heat Loads

Maximum heat load is estimated to be 16.23KW. Nominal heat is estimated to be around 9KW.

CFM

System shall have a capacity of 8000 cfms.

Cooling Capacity

System shall have a colling capacity of 10-ton.

Refrigerant

Replacements units shall use a sustainable approved refrigerant such as but not limited to 410-A. HVAC’s system that required the use of R-22 shall not be permitted.

Monitoring and Controls

Each system shall have capability to be controlled and monitored locally as well as from the blockhouses.

WSTF

Shall install a computer or vender supplied controller in BH control room for bunker HVAC controls and monitoring. Make all connection to the communication back bone.

Vendor

Install vendor supplied software on WSTF computers or vender supplied controller.

Provide training to WSTF personnel on the use of the software. If applicable the contract shall include licensing for up to four users.

Software

Software shall allow for remote control of the system. Single system log-in will be utilized.

HVAC industry standard protocol such as but not limited to ASHRAE BACnet open protocol shall be utilized.

The software shall display the following:

• Supply air temperature

• Return air temperature

• Required set temperature

• % of outside air supply

• Display system error messages and warnings

The Software shall control the following:

• Initiation of automated process to maintain the set temperature

• Initiate shutdown (emergency and standard)

Software shall log the following including date/timestamps:

• error messages and alarms

• Limits exceeded

• User inputs

• set temperature changes

• shutdowns and start-ups

Demolition of existing units and prep for new units:

The overall goal is to have a minimal impact and to carry out the more difficult and complex items first as these items may present problems that require time for recovery.

This being the case the replacement of the air handlers and verification of the integrity of the refrigerant lines should be the top priority.

Once a window is found to carry out the replacement the bunker will be shut down for all operations so the swap out can take place. This includes shut down of all DACS controls and other electrical cabinets. All work from system shutdown to startup must be completed with in a two week period. Bunkers operate independently of each other therefore installation between bunkers can take place at separate times.

WSTF

Carry out LOTO and yellow lock control for the equipment to prevent someone from trying to turn on equipment during the work.

Vendor Recover all R-22 refrigerants from the system in accordance with EPA requirements.

WSTF may elect to keep this to keep other R-22 units operational or may not keep the refrigerant in which case the vendor will dispose of or recycle the refrigerant in accordance with EPA requirements. The proper documentation will be generated and supplied in either case.

Cut and temporarily cap the refrigeration lines to prevent contamination at both the AH unit and the condenser. Later, those will be flushed and check for integrity. Cut and remove the condensate drain lines to the floor drain for the AH unit.

WSTF

Disconnect electrical and control wiring for air handler system. After disconnected replace red LOTO install the proper yellow locks and tag. Remove conduit and wire as needed for removal of the AH unit.

Prep area for removal of air handler. This will involve removal of the door for the mechanical room, staging equipment to move gear out of the room and to outside (where it can be craned out). Also, there may be a need to move some equipment cabinets out of the way (if possible) to get equipment out. The route needs to be clear before removal begins.

Break the existing air handlers up into pieces with a safe fast method. More than likely this will be cutting units apart with Sawzalls. The units are not to be salvaged (with maybe the exception of the fan motor). Cut the units up into sizes that will fit through the personnel door and can be transported outside. With all the sharp edges proper PPE will be required and the pieces need to be wrapped so they do not damage any items or hurt anyone during movement and handling. Clear the Mechanical room as reasonable quick as possible. Maintain existing duct work for connection to the new unit.

Note: The flex connectors on the 400 AH units are suspected to be asbestos. All flex connectors will need to be removed by environmental prior to AH demolition.

Environmental will need to do a completed assessment to determine if any other asbestos is present.

Vendor

Remove Condenser. Disconnect the electrical feed (verify it is secure LOYO/yellow lock) and control wiring and move out of the way. Remove the condenser from its position and set aside to provide good access to the refrigeration lines.

Test lines for integrity. Cap the lines at both ends (both suction and discharge) with a connection at one end (on each line) for a valve and a pressure gauge. Charge both lines with dry nitrogen up to 500 psi and verify both lines are leak tight. Decay test over 24 hours with compensation for temperature (record starting pressure and temperature and finish pressure and temperature at finish). If the line indicates leaking stop, remove valve/gauge assembly and cap. Abandon in place. If the lines are leak tight flush lines out to remove all residual R-22 mineral oils. Flushing fluids will need to be approved and a WWIPS generated prior to this step. Prep lines for use for 410 A by flowing dry GN2 through the lines to remove any flush fluids in the lines. Maintain clean. Temporarily cap when done.

Contingency item (added cost over base bid) Vendor would install new line set and WSTF will install bunker wall penetrations.

In the event the refrigeration lines cannot be reused then new refrigeration lines will be needed. These runs in 400 area will be more difficult and cannot go the same route as the existing lines as they are buried. In the event new lines are needed they will need to be exposed and run over to the pipe rack along the retaining wall then piped down by the blast door at the bunker. It may be easier to move the condenser and rerun electrical instead of leaving the new condenser in the old condenser location. That will need to be determined and decided at the time. We will need to core drill the concrete wall by the door and install sleeve for the refrigeration pipe to run through. WSTF would make any needed wall penetrations into the bunker and the vendor will run all refrigeration lines (including needed supports) from the condenser to the AH unit. If lines are run, they shall be properly sized for the length of the run and the size of the unit. The lines will be type ACR L copper tubing complying with ASTM B280 or ASTM B819. Fittings will be silver soldered. Install p-traps as needed to maintain the refrigeration oils at the condenser unit. After the lines are installed, connected to new equipment and leak checks insulate the lines with sun resistant Armaflex insulation and then wrap with aluminum jacketing to protect the insulation.

Install the new AH unit in the mechanical room (both areas).

WSTF

Will provide a crane and personnel to get material down to the bunker. them to the mechanical room and the vendor will assemble the modules in the mechanical room into the complete functional AH unit and make connections to ducting, refrigeration lines and install the needed condensation drains to existing floor drains.

Will change out the overcurrent protection in the MMC bucket. WSTF will also provide a communication back bone connection for the one board AH unit controls to provide control and monitoring capabilities from the BH control room.

Vendor

Sheet metal adapters with flex connectors, as needed, will be fabricated and installed by the vendor. The vendor will also be responsible electrical connections.

Final connections to the condenser and the AH unit. Calculate the needed oil and 410A refrigerant charge that will be needed for the system based on the equipment used, length of lines, size of lines and the configuration (height of condenser above AH unit coils. Make two name plates (Phenolic) with the information on the oil charge and the refrigerant charge required and place one on the condenser (at the service valves) and one on the AH unit (at the connection of the lines to the DX coil).

Pneumatically leak check the lines using dry nitrogen. Hold the leak check over time (minimum 4 hours) and check. Calculate variance in pressure due to temperature changes as needed. Also bubble check all sweated and mechanical fittings. Once the system is determined to be leak tight vent the nitrogen and evacuate the system to no less than 300 microns (high vacuum preferred). Once vacuum is pulled stop the vacuum pump and valve off monitoring the vacuum to look for signs of decay.

Service the unit with the proper quantity of refrigeration oil and 410A refrigerant. Run the system with local control to charge the system and verify proper system operation by monitoring the suction/discharge pressures, RA temp, SA temp and overall system operations. The amount of oil and refrigerant used will be documented and provided to WSTF and for EPA reporting purposes.

Condenser considerations

The location of the condenser units will depend on the reuse of the existing refrigeration lines. If the existing lines can be used the condenser will be placed in the same location as the old condenser. If the lines can’t be reused then the new lines and condenser shall be relocate to the northeast side of the tech support building near the pipe rack on the retaining wall to keep the new lines as short and easy to route as possible.

If the condenser must be relocated

WSTF

• Shall prep the area and move the condenser into the new location.

• Relocate all power and control wiring to the new location.

Vendor

• Shall install the refrigerant lines

• Make all final connections

Smoke Detection WSTF will also provide circuits, connections, and sensors for return air smoke detection. The smoke detectors will provide an activation signal to the WSTF fire alarm/annunciation system if smoke is detected. This fire alarm connection may occur later.

The vendor shall incorporate and install the WSTF supplied smoke detector in the RA duct work and also have provision in their operational software to turn the AH unit off (specifically the supply fan) in the event smoke is detected. This provision will include connections at the CPU at the air handler to receive the signal from the smoke detector and shut the unit off locally. If this shut down happens the software will alarm and the remote operation terminal in the BH control room.

Documentation Upon completion vendor shall supply all source code, programming, drawings, parts lists, wiring lists, operators manuals, maintenance manuals, etc. for all hardware to WSTF. Any changes after commissioning and during warranty period shall be coordinated with vendor. Changes made after warranty period should still be coordinated with vendor.

Standards Electrical Systems

All electrical systems shall comply with the latest NFPA regulations and the current revisions of WSI PROP-0038, "Installation of Electrical Systems in Hazardous

Locations” and WM-SAF-0002, “Operational Safety”. The Electrical NFPA Classified Location boundaries are depicted on drawing 459-15180.D for the 400 area systems.

Environmental and Procurement Standards

These units must be procured and installed in accordance with all Federal, State, and local regulations. These units must meet all federal, state and local environmental compliance and energy efficiency requirements.

Additional Standards

Work shall comply with applicable standards and codes for Mechanical and Electrical work including but not exclusive to:

1. ASHRAE – American Society for Heating, Refrigeration and Air Conditioning Engineers

2. SMACNA- Sheet Metal and Air Conditioning Contractor’s National Association

3. UMC – Uniform Mechanical Code

4. UPC – Uniform Plumbing Code

5. NEC – National Electrical Code

6. EPA - EPA Stationary Refrigeration and Air Conditioning Regulations

Life Cycle Industry standard off the shelf components with a minimum of 10 year service life must be used.

Energy Compliance Hardware must comply with Federal Energy Management Program (FEMP) for energy efficient products. Energy Star rated components are preferred. Approval by WSTF’s energy management compliance office shall be required before awarding bid.

Warranty Warranty terms and conditions must be clearly documented. At a minimum the Vendor shall provide a 1-year warranty on installation labor and materials. None consumable components such as compressor, condensers, blow motors, etc shall have a minimum of 5 year warranty.

Commissioning The new system shall be commissioned once work is completed. This commissioning will include a complete exercising of the system and verification all sensors, actuators, controls and major components function correctly and as designed.

This will include, but is not limited to, suction/discharge pressures, RA and SA temperatures and expected delta temp, air flow, timing for system, system lockout timing, compressor heater functions, expected ampacity of system components, duct smoke detector operation and unit shut down/alarm, set point verifications (for temperature), software function for monitoring and control, alarm functions and all other check outs needed.