Updated_SOW_for_Replacement_of_Chiller_2.docx

STATEMENT OF WORK

Replacement of Chiller No. 2 USDA Headquarters Complex Sub Central Plant 1400 Independence Avenue, S.W.

Washington, DC 20250

PART 1 –GENERAL

BACKGROUND

The USDA Headquarters (HQ) in Washington D.C. consists of two buildings – Whitten and South Buildings. The Sub Central Plant (SCP) is a standalone one story building located on the south side of the Whitten Building’s West Wing. The SCP is half underground with its main entrance on the north side. To access the SCP, one has to take the outdoor stair at the back of the Parking Lot 10A (see attached photos).

The SCP houses two chillers and each has its own cooling towers. A project in 2011 replaced Chiller 1 (the new Chiller 1 is a 400 ton York Centrifugal chiller with R134a refrigerant), its cooling towers, Chiller 2 cooling towers’ motors, two condenser and two chilled water pumps, water treatment system, and controls. The new pumps are all equipped with variable frequency drive (VFD); the towers (1A and 1B; 2A and 2B) have VFDs too. The new controls are direct digital type connected to a remote Building Management System (BMS; Johnson Controls Metasys). Also included in that 2011 project is a new free cooling system via Cooling Tower 1A and 1B, a standalone plate heat exchanger, and a separate condenser water pump. The free cooling mode is activated manually through a remote front-end of the Johnson Controls building management system (BMS) located in the Wing 2 Sub Basement of the USDA South Building.

The current Chiller 2 (Trane, 350 ton ice capable chiller) was replaced in 1995 in the Thermal Storage System (TSS) project. The TSS has its own glycol pumps and plate heat exchanger; Chiller 2 made ice at night for the TSS up until 2008. The TSS stopped running (due to economic reason and chronic glycol leaks); subsequently, Chiller 2 was used to generate chilled water only, up until 2011, when the new and more efficient Chiller 1 became the primary chiller and Chiller 2 was reduced to a backup role. Currently, the Building Operations Branch runs Chiller 2 occasionally to keep it in shape. Chiller 2 has outlived its life expectancy.

OBJECTIVES

1. Carry out the Chiller 2 replacement as a turnkey project utilizing a Design Build process.

2. Include provisions and or modifications of all related systems and works as needed for the new Chiller 2 to be delivered, set in place, and be fully functional.

3. Conform to the prevailing standard practices and codes in the Design Build process.

4. Removal of existing Chiller 2 can only begin approximately April 15, 2018 (when another source of chilled water becomes available as backup for Chiller 1) or later and completion of new chiller work by September 30, 2018. Chilled water at SCP must be available at all times during the construction.

PART 2 – EXECUTION

2.1 SCOPE OF WORK

This is a performance-based scope of work. The project shall meet the objectives above and the scope of work below in the replacement of Chiller 2 inside the USDA Sub Central Plant (SCP) located at 1400 Independence Avenue, SW, Washington DC, 20250.

2.1.1 DESIGN PHASE AND PRECONSTRUCTION PHASE- Include but not limit to the following:

· Site survey and review of relevant past project documents.

· Verify all information including those specified below prior to implementation.

· Interview Building Operations staff and Engineering staff as needed.

· Factor in design the impacts of existing site conditions and site constraints.

· Design mechanical, controls, electrical, plumbing and architectural for demo and new works.

· Use existing Chiller 1’s piping and control systems as model unless noted otherwise; Victaulic piping schedule 40 black steel for chilled water and condenser water systems is acceptable; butterfly isolation valves are acceptable.

· Rigging, hauling and providing access for equipment and materials deliveries and or removal and site protections; the entrance to the SCP is below the street level. Survey delivery path outside the SCP and inside; provide door removal/reinstall/repair including cutting wall opening/repairing wall if needed. Relocate/reinstall items in the way of the delivery path as needed. Adjust the existing chiller pad as needed. Remove/reinstall the steam/hot water convertor near the entrance if required for the chiller delivery.

· Construction drawings and specifications for the construction; coordination drawings; as-built drawings.

· Factory startup and report

· Commissioning and training

· Requirements for disassembly and reassembly of chiller if needed; they shall be performed by the factory’s representatives

· Demo and removal of existing chiller and associated items

· Ensure hangers, supports, and protections for equipment and piping are structurally sound

Equipment and materials (including information mentioned in attached photos):

Chiller (Basis of Design is York YMC2 Chiller): 350 nominal ton cooling capacity, hermetic oil free permanent magnet type compressor centrifugal water chiller with latest refrigerant which will not be phased out by 2030, 480/3/60 power supply and three phase sensing motor overcurrent protection, single phase protection, all internal power and control wiring, over temperature protection, IEEE 519 filter, Ashrae 90.1 compliant, BACnet communication, service suction isolation valves, buy American compliant, initial refrigerant and oil charge, microcomputer graphical display control panel with safety and operating controls, compressor overspeed test at 15% over design condition, insulation, all shipping costs and dissembled and reassembled costs, factory test and report costs, flow switch, high efficiency type (minimum 0.52 kW/Ton at 100% load with 85F/1195gpm condenser water supply and 42F/956gpm chilled water leaving), part load operation down to 10% or better, variable speed drive (VFD) with harmonic filter standard complied with IEEE 519, isolation valves, temperature and pressure gauges, thermal insulation, flow sensors and flow switches, 1” thick Neoprene vibration isolation pad for all floor support points. Chiller size shall fit existing space and allows sufficient service clearance. Adjust existing concrete pad as needed. Operating parameters and sequence of operation shall be similar to those of Chiller 1 (see attached reference Chiller 1 Replacement project in 2011).

Chiller warranty: include five (5) year parts and labor warranty for the entire unit including refrigerant.

Shipping and Rigging: include all needed dissembled and reassembled work if required. The work shall by performed by factory’s representatives and shall include refrigerant leak test.

Controls: modify the existing Direct Digital Controls (DDC) controls (installed by Johnson Controls in 2011) to work with the new chiller and associated piping. Provide removal and reinstallation works as needed. Replace broken and or outdated controls with latest. All devices shall be compatible to BACnet DDC system and be integrated with the existing Johnson Controls Metasys Building Management System (BMS). All 2011 control devices and automatic valves appear to work normally and shall be reused if possible. Survey and interview building engineer to confirm. Provide flow meter for condenser water loop. (Note: the 2011 project, new DDC controls and automatic control valves were installed for both chillers so that Chiller 2 can also be controlled remotely from the BMS. In addition, the 2013 BMS’s server was replaced in May 2017 and the 2011 Metasys software was upgraded to Version Release 8.1 in 2017). Provide calibrations and name plates or tags for all control items. Provide shop drawings and as-built drawings. Provide commissioning to demonstrate the chiller and associated equipment are functioning properly. Provide training as specified below.

Provide a new laptop loaded with latest Metasys software and needed apps for working with the BMS. Laptop shall be Dell Inspiron 17 5000 Non-Touch or equivalence, with at least the following features: 17” screen, 16 GB RAM, 1 TB hard drive, wireless mouse, Window 10, and latest Microsoft Office.

Sequence of Operation: the current sequence of operation is that one chiller works as lead and the other as lag. The lag chiller will automatically take over when the lead chiller fails to hold set points. See attached Chiller 1 Replacement project document for the complete details including automatic valves, pumps and towers operations.

Refrigerant Monitor: Replace the existing refrigerant leak detection system (see photo) which was installed in 2011 with one that will work with the Chiller 2’s refrigerant type.

Chemical Feed Tank: replace (see photo)

Piping:

· Existing Chiller 2’s direct chilled water piping loop conveys glycol fluid: remove glycol fluid and all glycol piping within the upper section of the SCP (see attached SK-1 diagram); cap off remaining glycol pipes at wall; dispose glycol according to local regulation.

· New chilled water piping: remove sections going to the plate heat exchanger of the thermal storage system as needed. Provide new pipes between new chiller and chilled water mains, including all needed valves, fittings, and all other piping components similar to those of the Chiller 1 system (see attached SK-1 drawing).

· Condenser water piping: replace all condenser water piping, which was not replaced in the 2011 project (see SK-1), up to the two chain valves east of the wall of the cooling tower enclosure; replace control valve V-10 if it can’t be reused and replace the DDC inserted flow meter.

· See the attached demo and new construction approximated pipe lengths and fittings. This is for reference only. Contractors shall verify and include the correct quantities in their bids and or actual construction.

· General requirement for piping: reconnect existing relief line to chiller, fittings, etc., for a fully functional chiller. New piping and valves shall be compatible to those of existing Chiller 1. All pipes shall be scheduled 40 black steel. Relief line shall be copper. Reuse existing electric control valves, if possible, to achieve sequence of operation mentioned in the controls section above. All other valves and piping components such as isolation valves (butterfly), strainers, vibration isolators, check valve, balancing valves, vents and drains, thermometers and pressure gauges, unions, etc., shall be replaced with new. Provide tabs for all insertion controls and or instrumentation. Provide flange connections for all flanged valves and or fittings. Notice the ceiling height and items overhead when designing pipe and or equipment hangers. Hanger rods can be reused if they are suitable, but hangers shall be new.

Insulation: equipment and piping insulation shall match those of existing Chiller 1 or better. Piping insulation shall be covered with PVC jackets and shall have metal shields between hangers/supports and jackets. Include insulation of components which are excluded by the chiller manufacturer.

Labeling: meet ANSI &ASME pipe marker standards and existing color scheme in SCP. Provide pipe markers, equipment name plate, and valve tags. Pipe markers shall be pre-printed wrap around type with arrow banding tapes. Equipment tags shall be engraved on heavy duty plastic. Valve tags shall be brass with chain. Control equipment shall have name tags.

Painting: paint bare piping and insulated piping to match those of Chiller 1. Paint floor area where it is affected by demo and new works. Paint all items that are disturbed by demo or new works.

Electrical: provide power wiring including power for control equipment (note: power for existing Chiller 2 was modified during the 2011 Chiller 1 Replacement project; see attached 2011 project). Provide step up transformer and wiring as required to work with the new chiller.

Plumbing: as needed

Flushing: protect piping materials from dust during delivery, storage and installation; clean new piping prior to installing.

Testing: provide functional field tests for chiller and controls. Submit reports.

Water balance: provide condenser and chilled water balance and reports. Water balance shall be performed by an independent water balance company.

Commissioning and Training: provide commissioning for chiller and controls to demonstrate that the chiller 2 system is working as designed. Submit reports. Provide trainings on chiller (1 hour), refrigerant monitor (1 hour) and controls (1 hour) to Building Operations staff including training materials.

Other Requirements:

· Removal and disposal of refrigerant and glycol in demo works.

· Replace and or relocate existing evacuation ductwork as needed.

· Include all needed ancillary works to achieve a turnkey project

· Designer shall conduct one inspection when the chiller is delivered, one when it is set in place, one during key piping installation, and one final inspection to create punch list. Copy the government on the inspection reports.

2.1.2 CONSTRUCTION PHASE - include but not limit to the following:

The Contractor shall provide all management, supervision, labor, equipment, tools, insurance, fees, permits and supplies to provide a fully operational Chiller 2.

Perform works as designed and the following:

· Survey site and provide construction kickoff meeting

· Include but not limited to the specific chiller, the approximate pipe lengths that tie into the existing pipe mains and the new 208/480 step-up transformer addressed in this SOW. New chemical feed tank system, refrigerant monitoring system, controls sequencing, remote lap top and other miscellaneous items including insulation, painting, electrical, etc.

· Make safe and protect existing items from damages during construction

· Submit the factory’s chiller testing result for approval prior to shipping

· Hold weekly meeting with COR and submit meeting minutes (by email)

· Progress inspections, punch list inspection and final inspection.

· Paint floor area impacted by new work

· Provide electrical work

· Provide mechanical work

· Provide controls and programming

· Provide works as needed to restore items removed and relocated during deliveries of chiller and materials

· Permits as required

· Complete punch list items

2.2 PROJECT COMPLETION ACCEPTANCE CRITERIA

· Complete the works as per design and specifications

· Complete works within approved period of performance

· Complete items on the final punch lists created by the contractor and by the government

· Ensure damaged items, if any, as a result of demo and new works have been repaired

· Submit approved as-built documents, approved shop drawings, warranty certificates, and operation and maintenance manuals

· Demonstrate successful chiller performance

· Complete required trainings

PART 3 – SPECIAL CONSIDERATIONS

3.1 Period of Performance: Six calendar months for Design and Build; removal of existing Chiller 2 must begin after April 15, 2018 (approximated) when GSA chilled water is available to back up Chiller 1; new Chiller 2 must be operational by September 30, 2018.

The contractor will be working around an occupied building and must plan the work accordingly. The normal working hours is from 6 am to 6 pm, Monday thru Friday excluding weekends and holidays. Except as very loud noise producing activities like outdoor jack hammering and core drilling and work, the remaining work can be accomplished during normal working hours. Any work requiring power outages must be scheduled two weeks in advance. Although no outage of chilled water production is specified earlier, chilled water outage-if must have-shall be coordinate with the COR at least one month in advance. Also work that would affect the day-to-day operation of the facility, for example, a mobile boom crane or boom truck blocking executive parking, if necessary, will be performed after hours or on the weekends.

All changes and time extensions must be approved by the contracting officer beforehand.

3.2 Codes, Standards, and Regulations: as a minimum, the design and build shall conform to the following codes and standards:

· GSA Facilities Standard P100

· Leadership in Energy and Environmental Design (LEED)

· Ashrae 90.1 Energy Standard for Building Except Low-Rise Residential

· Ashrae 15 Safety Standard for Refrigeration System

· International Mechanical Code (IMC)

· National Electric Code (NEC)

· National Fire Protection Association (NFPA)

· ANSI & ASME Pipe Marker Standards

· ASME B31.1

· Tubular Exchanger Manufacturer Association (TEMA)

3.3.2 Quality Control:

· All work shall be done based on the final approved drawings and specifications. Work shall commence only after the shop drawings have been approved. Contractor shall coordinate inspections, tests, punch list, final inspection, and training through the COR. Any rejected work shall be corrected to the satisfaction of the Government at no additional cost to the contract.

· Submit factory test report of the new chiller for approval prior to shipping

· Provide chiller startup report

· Include commissioning of chiller and control systems

· Obtain necessary permits for activities impacting sidewalk and street traffic with the DC government

3.4 Coordination: coordination for outages 2 weeks in advance; outages and work impacting government’s normal business must be performed after normal hours or weekends. Chilled water outage, if unavoidable, must be limited to the shortest time possible like less than one hour and must be conducted in the weekend.

3.5 Delivery: coordinate with COR in advance to avoid impacting Parking Lot 10A. Delivery impacting Parking Lot 10A must be conducted before or after normal hours or on weekends. Equipment and materials stored on site are at contractor’s risk.

3.6 Cleaning and Disposal

· Avoid accumulation of debris on site. Remove debris daily. Keep work place clean after each shift. Daily broom sweep construction area. Protect floor inside SCP and lawn outside SCP. Repair damages as required.

· All removal and disposal shall meet Federal, State and local government laws and regulations.

· Provide final cleaning at end of project

· Impact to lawn area outside the SCP is unavoidable. Contractor shall include in the work to repair and one re-seed of the lawn at the end of the project.

3.7 Safety and Fire Prevention

Observe all normal rules governing safety on construction projects and shall comply with OSHA and all other Federal, State, and Local construction regulations, and as directed by the COR. Workers, supervisors, and visitors to the job site shall wear hard hats and other applicable safety equipment. Temporary electrical service shall be coordinated with the COR. Material Safety Data Sheets for all compounds used shall be provided to the Government prior to those compounds being brought into the facility. The contractor shall obtain a burn permit from the USDA prior to performing each of the welding, soldering, torch or open flame works. The burn permit shall be kept at the site where work is being performed for the period granted. Provide a fire watch and items, such as fire extinguisher and fire blanket, etc., that are required by burn permits.

3.8 Security Requirements: comply with USDA security regulations for identification passes for all workers.

3.9 Parking: no parking is provided by USDA on site. Schedule all deliveries with COR to avoid impacting Parking Lot 10A.

3.10 Submittal: submit the following -

Contractor shall provide design drawings, specifications, and shop drawings to Government for final review prior to start of any construction (besides O/M manuals and project close-out package). Provide three hard copies and one electronic copy unless noted otherwise.

The above are the minimum submission requirements and the government may request additional submittals as deemed necessary. The government review time for each submission will be about one week.

· Submit 95% design package (drawings and specifications), drawing in half size.

· Meet with government project team to present the 95% design

· Resolve and incorporate government comments.

· Provide one pre-final check set drawing in half size for government’s review prior to issuing the 100% package for construction; the electronic drawing files in the final package shall be in both AutoCAD and PDF. Provide three half size copies of final set.

· Shop drawings are required for equipment, materials, layouts and wiring diagrams (all trades), and sequence of operations. Designer shall review and approve construction shop drawings before the government’s review.

· Submit construction schedule and schedule of value; payment for equipment can only be invoiced after it is delivered to the site.

· Submit daily report (via email; in doc or pdf file); include digital photographs of key events) to government’s Contracting Officer Representative (COR)

· Submit meeting minutes (by email)

· Invoices shall follow closely with the percentage of accomplished works; invoice will be processed monthly via the government’s Invoice Processing Platform (IPP) website; provide draft copy for COR’s approval prior to uploading into IPP.

· Submit two (2) copies of O/M manuals (binders and electronic copy) with warranty information and contact phone numbers.

3.11 Warranty and Post Construction Services:

Contractor shall provide 12 months materials, parts, and labor warranty for the works or as per the manufacturer’s warranty period, whichever is greater from the signed date indicating satisfactory completion of the contract including punch list items.

The chiller itself shall have five (5) year part and labor warranty for the entire unit including refrigerant. Warranty services shall be provided within 24 hour.

In addition, provide one four-hour onsite control service within the first year after the project ended, of a Johnson Control tech, to trouble shoot, adjust and or modify the control program and or graphics of the Chiller 2 system when requested by the government, for items not related to warranty work.

3.12 Other Misc. Requirements

· Conduct pre-proposal meeting and site walk-through

· Conduct design kickoff meeting

· Conduct preconstruction kickoff meeting

· Factor in existing conditions in the proposal

· The project is implemented for the Office of Operations by the Facilities Management Division/Engineering Branch. The COR will be designated after the contract award.

3.13 Project Close-Out

All necessary training shall be conducted prior to project close-out.

Submit O&M and as-built documents/drawings for equipment, piping, power wiring and control wiring including sequence of operations (two hard copies and one digital copy).

PART 4 – REFERENCES

4.1 ATTACHMENTS: Items 1 through 4 are not enclosed with the scope of work due to the document sizes. The pdf copies are available upon request. Their hard copies are available on site for review and copy. These documents are for reference only.

1. Replacement of Chiller 1 System March 29, 2010 drawings

2. Replacement of Chiller 1 System March 29, 2010 Specifications

3. Replacement of Cooling Tower 2 Project 4-ME-98 in 1998

4. Thermal Energy Storage System for SCP Plant Project number 93-A/E-39 in 1994

5. New Construct. Pipe Lengths (estimated; contractor shall take its own measurement)

6. Demolition Pipe Lengths (estimated; contractor shall take its own measurement)

4.2 PHOTOS and Sketch SK-1 (Note: Some required work actions are noted on photos and SK-1 Drawing)

USDA Headquarters (HQ) in Washington, DC

Aerial View of the USDA HQ Buildings

Outdoor stair leading from Parking Lot 10A to Sub Central Plant entrance. Air intake louvers to indoor cooling towers were covered with plywood during the 2011 construction.

View of Parking Lot 10A (looking West) and top of stair to SCP

Delivery of Chiller 1 in 2011 (for information)

DDC Controls during 2011 Chiller 1 Replacement project

Front end graphics for condenser water loops during the 2011 project

Front end graphics for both Chillers 1 and 2 during the 2011 project

Existing Chiller 2. Pink and white are glycol piping and blue is chilled water piping. Existing overhead crane system can be used during the installation (must be field-verified by contractor)

Existing Chiller 2’s power panel

Pink, white glycol piping to be removed. Blue piping to be modified as needed

Brown condenser piping (of existing Chiller 2) to be replaced. The red control valve V-10 (as seen here) can be reused if it is in good working condition. The DDC flow meters (not in this picture) in the condenser water and glycol loop are to be replaced if they can’t be reused.

Replace existing MSA refrigerant sensing system with a one that works with the new chiller’s refrigerant type.

Replace the chiller 2’s existing chemical feed tank and its piping and insulation.

A view of the Sub Central Plant entrance as seen from inside the plant during the 2011 construction. A steam/hot water heat exchanger is seen in the middle.

A view of Sub Central Plant interior after the 2011 construction as seen from the entry door. Chiller 2 is hidden behind the VFD cabinet on the left. Relocate/reinstall/repair the orange steam/hot water convertor maybe required to facilitate the chiller delivery.

Sample of a mechanical drawing from the Chiller 1 replacement project; it is not legible here but is available in pdf file or Acad file. The entire 2011 drawing set (in AutoCAD or pdf) including electrical work is available for reference and use.

Sketch SK-1 Existing Chiller Plant Piping Diagram Note in red is added for information only. A thorough site survey is required to determine the extent of work.

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