Attachment 1_SOW Replace Air Cooled Chiller Raleigh NC_Redacted.pdf

Statement of Work

Replace 60 Ton Air-Cooled Chiller

Plant Science Facility Raleigh, North Carolina

Asset ID: 664500B011

12/08/2022

Table of Contents

Statement of Work Page 3

Contractor Requirements Page 4

Chiller Specifications Page 5

Project Schedule Page 10

Project Contacts Page 11

Pictures Page 12

Statement of Work: Provide all personnel, equipment, tools, materials, supervision, and quality control necessary to perform removal and disposal of the existing Air-Cooled Chiller; and to furnish and install a new Air-Cooled Chiller as defined in this Statement of Work (SOW).

This requirement will be awarded on a Lowest Price – Technically acceptable basis. The contractor shall provide a technical proposal and detailed cost estimate for the entire project as specified in this statement of work. Descriptive literature and written specifications for the equipment in the proposal must be included with the bid. The detailed cost estimate shall provide a breakdown showing the equipment, labor, general conditions, etc.

Project Objective: To provide the USDA-ARS Plant Science Facility in Raleigh, NC with proper cooling through the removal of the existing faulty chiller and installation of a new, fully functional chiller.

Background: The USDA ARS Plant Science Facility in Raleigh NC is a USDA owned agricultural research facility on land leased from North Carolina State University (NCSU).

The existing Trane (model CGAFC60EAAA1T) chiller was commissioned in 1998. One compressor and expansion valve were replaced in 2007 and two compressors were replaced in 2019. In 2021, a condenser coil began leaking and in 2022, one compressor mechanically seized. The existing chiller is beyond its expected life, no longer under warranty, and is not capable of cooling the building in its current state.

The system was originally installed with pneumatic controls. These controls have since failed and have been abandoned. Efforts are continuous to install DDC controls to reincorporate effective management. The chiller, base pumps, reheat coils, fume hoods, and VAV boxes have no controls currently. DDC controls are installed on each of 5 air handlers and control chilled/hot water valves and blowers as necessary. The existing chiller operates to always maintain a set design loop temperature with no input from external controllers.

Scope of Work:

Furnish all personnel, equipment, tools, materials, supervision, and quality control necessary to perform removal and disposal of the existing chiller, and install a new chiller as defined in this SOW.

Contractor Requirements:

The contractor Shall:

Possess appropriate valid and current HVAC license(s) from NC Board of Examiners of Plumbing, Heating, and Fire Sprinkler Contractors for work being performed and obtain all necessary permits, inspections, and clearances from NC State Construction office and North Carolina State University.

Disconnect and remove, to include rigging and crane, the existing air cooled chiller and all associated components required for the installation of the new chiller system.

Properly remove and dispose of the existing air-cooled chiller from installation grounds.

Drain and properly dispose of all ozone depleting substances in the unit.

Install a new properly sized air-cooled chiller (approx. 60 Ton, Trane CGAM or equal). Approved equals must have scroll compressors and meet the specifications including all scheduled performance. The new chiller must have factory trained and certified support technician and parts available within a 50 mile radius of the installation site. Minimum 1 year warranty on parts to include compressors and use low ozone depleting refrigerant.

Provide and install all necessary electrical components, wiring, and connections.

Provide and install all necessary mechanical piping to allow for proper start-up, loop chemical balance testing, and flow balancing. Supply and return chilled water piping shall include air vents, pressure gauges w/ shutoff valves, thermometers, flow meters, isolation valves, balancing valves, relief valves, strainers (if not provided with chiller), and/or any other devices/materials specified in the chiller manufacturer’s installation instructions. All exposed piping is to be properly insulated and heat traced.

Perform leak test and check for proper operation.

Provide 4 hours of training to USDA representative on use of new air-cooled chiller, water treatment apparatus/methods, and controls.

Provide all operations and maintenance manuals to owner representative prior to close out of contract.

Existing concrete pad is to be re-used if the geometry of the new chiller allows. If not, a new pad should be included in bid price.

Provide, connect, and operate a temporary chiller of sufficient capacity to cool the building’s chilled water loop to design temperatures throughout all phases of construction or until new chiller is operable.

Chiller Specifications

Description

Chiller shall be air cooled with scroll compressors as shown as scheduled on this document. The chiller shall be installed in accordance with this specification and perform at the specified conditions as scheduled.

Operation

Chiller shall be able to start and operate in ambient conditions from 0F – 125F. Wide ambient operation is accomplished with factory installed ant tested protection. If field installed wide ambient solution is used, this shall be purchased and installed at contractor expense.

Chiller shall be capable of operating with a leaving solution temperature range of 40F – 65F without use of glycol.

Chiller shall be capable of starting with 95F entering fluid temperature to the evaporator.

Chiller shall provide evaporator freeze protection and low limit control to avoid low evaporator refrigerant nuisance trips during critical periods of operation. Whenever this control is in effect, the controller shall indicate that the chiller is in adaptive mode; if low ambient/freeze conditions exist longer than 30 seconds, a limit warning alarm shall energize.

Rapid restart after power restoration. Chiller shall be capable of starting in 45 seconds.

Compressors

Compressors shall be fully hermetic scroll type compressors with R410A optimized and dedicated scroll profile.

Provide direct drive motor cooled by suction gas with only three major moving parts and a completely enclosed compression chamber that leads to increased efficiency.

Each compressor shall have internal overload protection.

Each compressor shall include centrifugal oil pump, oil level sight glass and oil charging valve.

Each compressor shall have crankcase heaters installed and properly sized to minimize the amount of liquid refrigerant present in the oil sump during off cycles.

Evaporator

The evaporator shall be a high efficiency, brazed plate to plate type heat exchanger consisting of parallel plates. Braze plates shall be stainless steel with copper braze material.

The water side working pressure shall be rated at 150 psig and tested at 1.5 times the maximum allowable water side working pressure.

The refrigerant side working pressure shall be rated at 460 psig and tested at 1.1 times the maximum allowable refrigerant side working pressure.

The evaporator shall be insulated with a minimum of 0.75 inch (K= 0.28) UV rated insulation.

Evaporator heaters shall be factory installed and shall protect chiller down to -20F. Contractor shall wire separate power to energize heat tape and protect evaporator while chiller is disconnected from main power.

Provide water drain connection, vent, fittings, factory installed leaving water temperature controls, and low temperature cutout sensors.

Proof of flow device shall be provided by the equipment manufacturer, mechanically installed and electrically wired at the factory of origin.

Fans

Low sound fans shall be dynamically balanced and direct driven.

All condenser fan TEAO motors shall have permanently lubricated ball bearings and external overload protection.

Condenser

The condenser coils shall consist of copper tubes mechanically bonded into plate type aluminum fins.

The condenser coils shall have an integral sub-cooling circuit and shall be designed for at least 650 psig working pressure, leak tested at 650psig.

Chiller Construction

Frame, panels, and access doors shall be constructed of galvanized steel.

Panels, base rails, and control panels shall be finished with a baked on powder coat paint.

Mount starters and terminal blocks in a UL 1995 rated weatherproof panel provided with full opening access doors. If a circuit breaker is used, it shall be a lockable, through the door type with an operating handle and clearly visible from the outside of the chiller indicating if the power is on or off.

The coating or paint system shall withstand 500 hours in a salt-spray fog test in accordance with

ASTM B117.

Chiller Mounted Starter

The starter shall be across-the-line configuration, factory mounted and fully prewired to the compressor motors and control panel.

Units shall have single point power connection.

Control power transformers shall be factory installed and wired.

Control panel shall be dead front construction for enhanced service technician safety.

Unit wiring shall be run in liquid tight conduit.

Power line connection shall be standard with a terminal block.

Refrigerant Circuit

Chiller shall have 2 refrigerant circuits, each with two manifolded compressors.

Each refrigerant circuit shall include:

o Liquid line shutoff valve o Discharge service valve o Filter o Liquid line sight glass o Electronic expansion valve sized for maximum operating pressure o Charging Valve

Full operating charge of R410A and oil.

Controls

Controls shall be factory mounted to the control panel door.

Operator interface shall have an LCD touch screen display.

The display shall include a menu driven interface with touch screen navigation to organized sub-system reports for compressors, evaporators, motor information, and diagnostics.

The interface shall provide password protection of all setpoints.

The chilled water temperature control shall be microprocessor based and show water and refrigerant temperatures, refrigerant pressure, and diagnostics. The control shall be supplied with the chiller by the manufacturer.

The front of the chiller control panel shall display the following without codes, tables, or gauges:

o Run time o Number of starts o Current operating mode o Chilled water setpoint and setpoint source o Electrical current limit setpoint and setpoint source o Entering and leaving evaporator water temperatures o Saturated evaporator and condenser refrigerant temperatures o Oil pressure o Phase reversal/imbalance/single phasing and over/under voltage protection o Low chilled water temperature protection o High and low refrigerant pressure protection o Load limit thermostat to limit compressor loading on high return water temperature o Condenser fan sequencing to automatically cycle fans in response to load, expansion valve pressure, condenser pressure, and differential pressure.

o Display diagnostics o Compressor status, RLA percentage, anti-short cycle timer, and automatic compressor lead-lag.

On chiller, mount weatherproof control panel, containing starters, power and control wiring, factory wired with terminal block power connection. Provide primary and secondary fused control power transformer.

The chiller controller shall utilize a microprocessor that will automatically take action to prevent chiller shutdown due to abnormal conditions associated with evaporator refrigerant temperature, high condensing pressure, and motor current overload.

Provide the following safety controls with indicating lights or diagnostic readouts:

o Low chilled water protection o High refrigerant pressure.

o Loss of chilled water flow.

o Contact for remote emergency shutdown.

o Motor current overload.

o Phase reversal/unbalance/single phasing.

o Over/under voltage.

o Failure of water temperature sensor used by controller.

o Compressor status (on or off).

Provide the following operating controls:

o A variable method to control capacity to maintain leaving chilled water temperature based on PI algorithms. Five minute solid state anti-recycle timer to prevent compressor from short cycling. Compressor minimum stop-to-start time limit shall be 2 minutes. If a greater than 5 minute start-to-start, or greater than 2 minute stop-to-start timer is included, hot gas bypass shall be provided to insure accurate chilled water temperature control in light load applications.

o Chilled water pump output relay that closes when the chiller is given a signal to start.

o Load limit thermostat to limit compressor loading on high return water temperature to prevent nuisance trip outs.

o High ambient unloader pressure controller that unloads compressors to keep head pressure under control and help prevent high pressure nuisance trip outs on days when outside ambient is above design.

o Compressor current sensing unloader chiller that unloads compressors to help prevent current overload nuisance trip outs.

o Low ambient lockout control with adjustable setpoint.

o Condenser fan sequencing which adjusts the speed of all fans automatically in response to ambient, condensing pressure and expansion valve pressure differential thereby optimizing chiller efficiency.

Provide user interface on the front of the panel. If display is on the inside of the panel, then a control display access door shall be provided to allow access to the display without removal of panels. Provide user interface with a minimum of the following features:

o Leaving chilled water setpoint adjustment from LCD input o Entering and leaving chilled water temperature output o Pressure output of condenser o Pressure output of evaporator o Ambient temperature output o Voltage output o Current limit setpoint adjustment from LCD input.

The chiller control panel shall provide leaving chilled water temperature reset based upon return water temperature.

The chiller control panel shall provide an alarm relay output that shall energize whenever a fault requiring manual reset is detected by the panel.

SOUND

Acoustics: Manufacturer must provide both sound power and sound pressure data in decibels.

Sound pressure data per AHRI 370 must be provided at full load.

If manufacturer cannot meet the noise levels, sound attenuation devices and/or barrier walls must be installed to meet this performance level.

ACCESSORIES

Chiller shall have full architectural louvers panels.

Chiller shall ship with elastomeric isolators

INSTALLATION

Install in accordance with manufacturer's requirements.

Level the chiller using the base rail as a reference. The chiller must be level within 1/2" in over the entire length and width. Use shims as necessary to level the chiller.

SERVICE AND START-UP

Provide all labor and materials to perform startup. Startup shall be performed by a factory-trained technician from the original equipment manufacturer (OEM). Technician shall confirm that equipment has been correctly installed and passes specification checklist prior to equipment becoming operational and covered under OEM warranty. This shall be done in strict accordance with manufacturer's specifications and requirements. Third-party service agencies are not permitted.

A start-up log shall be furnished by the factory approved start-up technician to document the chiller's start-up date and shall be signed by the owner or his authorized representative prior to commissioning the chillers.

Chiller manufacturers shall maintain service capabilities no more than 50 miles from the jobsite.

Provide local service agent with direct access to factory support on equipment.

Site Visit: Vendors are encouraged to visit the site and be escorted by a government representative to confirm locations, dimensions, and conditions of the project before a bid is submitted. The site visit shall be for the purpose of observing firsthand any conditions relevant to the completion of this project. No consideration will be given to claims based on lack of knowledge of existing conditions, except where Contract Documents make definite provisions for adjustment in cost or extension due to existing conditions not readily foreseeable.

Utilization of Bio-Based Products: The contractor shall utilize products and material based from bio-based materials as applicable, (e.g. bio-based greases; bio-based hydraulic fluids, bio-based absorbents), to the maximum extent possible without jeopardizing the intended end use of detracting from the overall quality delivered to the end user. All supplies and materials shall be of a type and quality that conform to the applicable Federal Specifications and Standards. All supplies and materials to be used in the performance of work described herein are subject to the approval of the Contracting Officer Representative (COR). Products can be found at: www.biopreferred.gov

Safety: The contractor will submit a Site Safety Specific Plan/Accident Prevention Plan in industry recognizable format to the Contracting Officer within 14 days of contract award. Contractor shall furnish a Site-Specific Safety Plan (SSSP) and the Government shall review the SSSP prior to the start any construction activities. SSSP shall be in typically accepted industry format.

Material / Submittals:

The material for the entire work shall include but are not limited to those detailed above necessary to successfully complete the project and deliver a functioning system as required. Submittals on all material, including shop drawings and specifications, used on this project shall be submitted to the EPM and Contracting Specialist as noted in this document. Electronic submittals are acceptable otherwise three written submittals are required.

Damage to Property:

Any damage to the Government buildings, utilities, etc. caused as the result of the contractor’s activities shall be repaired or replaced to the satisfaction of the Government.

Inspection and Acceptance:

A government representative shall inspect and approve the work performed on this project. The Contractor shall schedule inspection a minimum of 10 days in advance, in writing, to the Contracting Officer.

Project Schedule:

The completion of this project shall not exceed 183 days from date of contract award. A request for time extension must be submitted to the Contracting Specialist in writing. Each request must include specific and detailed reasons in support of the schedule alteration.

Work Hours:

Contractor work hours shall be Monday through Friday, eight (8) A.M. to five (5) P.M. with the exception of Government holidays. Any changes to work schedule shall be submitted to Contacting Officer for written approval prior to schedule change.

Picture 1 - Existing Chiller Data Plate

Picture 2 - Design Chiller Schedule

Picture 3 - Existing Chiller, Overhead View, Facing West

Picture 4 - Existing Chiller and Service Disconnect, Facing Northwest

Picture 5 - Existing Chiller, facing Northeast

Picture 6 - Existing Chiller, Facing Southeast

Picture 7 - Existing Chiller, Facing Southwest

Picture 8 - Existing Chiller, Control Interface

Picture 9 - Existing Chiller Disconnect