IV.E. - Program Development Study 2.pdf

April 12, 2018 Final Report PDN Number: GS-01P-14-BW-D-0025

EDWARD T. GIGNOUX FEDERAL COURTHOUSE

PORTLAND, MAINE

Prepared For: Prepared By:

General Services Administration Thomas P. O’Neill, Jr., Federal Building 10 Causeway Street, Room 1100 Boston, MA 02222

Edward T. Gignoux Federal Courthouse HVAC Upgrades PDS Report – Follow-on Study

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TABLE OF CONTENTS

TABLE OF CONTENTS

EXECUTIVE SUMMARY

Scope

Primary Purpose

Concerns and Expectations

Implementation Strategy

Critical Delivery Dates

Project Budget

Work Item Summary Table

Third Party Sign-Off Sheet

BUSINESS PLAN

Assets and Goals

Design Alternatives

Report Quality and Cost Control

Planned and Ongoing Projects

Return on Investments

GENERAL BUILDING REQUIREMENTS

Operations/Services

Building Pressurization

PROGRAM GOALS

Sustainable Design

Efficient Operations and Maintenance

BUILDING SYSTEMS

Work Item 10: Replace VAV Boxes

Work Item 11: Install Return Air Ductwork for HVAC-1

Work Item 12: Replace Fan Coil Units

Work Item 13: Heating and Cooling System Modifications

Work Item 14: Improve MAU-1 Ductwork

Demolition and Abatement

Utilities

IMPLEMENTATION PLAN

Government Approvals

Building Operation

Construction Phasing

BUDGET ANALYSIS

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General

Estimated Construction Costs

Professional Services

APPENDICES

Appendix A – Photos

Appendix B – Cost Estimates

Appendix C – Sketches

Appendix D – Calculations

Appendix E – MAU-1 Mold Test Report

Appendix F – Historic Documents

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EXECUTIVE SUMMARY

Scope The Architect-Engineer (A-E) is preparing a follow-on to the Program Development Study (PDS) for HVAC Upgrades at the Edward T. Gignoux Federal Courthouse, Portland, Maine. The original PDS was completed by Colby Company Engineering (CCE) on January 29, 2016 and addressed upgrade options related to mechanical, electrical, and structural systems. This Follow-on study is a supplement to the PDS for HVAC Upgrades completed in 2016. General information on the building history, utilities, and other items not specifically related to this scope of work is not re-created in this report to avoid redundancy.

The Design Program scope items for this follow-on PDS are as follows:

• Evaluate the condition, capacity, and zoning of existing Variable Air Volume (VAV) boxes and Fan Coil Units (FCUs)

• Evaluate the condition, capacity, and zoning of existing Convectors, Fin Tube Radiators (FTRs), Kick-space Heaters, and Unit Heaters (UHs)

• Evaluate the sizes and effectiveness of existing building distribution ductwork and return air paths

• Evaluate the condition and sizing of existing building heating and cooling distribution piping

• Identify impact to the existing fire sprinkler system based on any HVAC upgrade recommendations

For all scope items listed above, recommended construction phasing and sequencing will be described in the Implementation Plan section of this report for all replacements and modifications.

Primary Purpose The PDS phase provides GSA with a sound foundation to pursue the construction funding and design start for this project. During the PDS phase, the project team, customer agency, and stakeholders use the PDS to develop the HVAC Upgrades project in greater detail. The PDS reviews and revalidates (or revises) all previous project assumptions, plans, and budgets. The PDS includes an estimated construction budget and implementation strategy for the project.

Concerns and Expectations Input from stakeholders is being used to understand the tenant agency, local context, stakeholders’ concerns, and opportunities. Installing new mechanical systems in an occupied building of this magnitude will involve phasing, night work, and may influence which equipment is recommended. Ultimately the first choice will be based on the return on investment of the proposed systems and then the complexities of the installation will be considered.

Implementation Strategy The PDS includes implementation strategies for the project. The plan’s purpose is to guide project phasing, construction procurement, and risk management. The Implementation Strategy considers workplace performance goals, impacts to the historic building façade, space requirements, sustainable design, energy usage targets as applicable, updated security for the installed equipment, compliance with historic preservation, environmental laws, and recommended coordination with local plans. Within each Work Item, discussion includes impacts to occupants and public users, work recommended to be performed during off-hours, and protection of spaces. The Implementation Strategy identifies the proposed delivery method and critical implementation issues/procedures.

The following represents a high-level project schedule approach; this includes approximate durations and considers Work Items that should be combined in order to most effectively perform upgrades while minimizing operational

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Refer to the original PDS report dated January 29, 2016 for a description of Work Items #1, 2, and 3.

Work Descriptions and WI Reference Duration Install new BAS front end (WI #3) 4 months Replace, clean and upgrade MAU-1, relocate OA intake, replace FCUs - update controls and replace hot water and chilled water piping as unit replacements are made (WI #3, 12, 13) 12 months Replace AHUs, relocate OA intakes, install RA ductwork, and replace VAV boxes - update controls and replace hot water and chilled water piping as unit replacements are made (WI #1, 2, 3, 10, 11) 24 months

De-commission existing BAS (WI #3) 1 month

Durations noted above do not include construction contract acquisition or project closeout.

Critical Delivery Dates Critical delivery dates are included as part of the Implementation Strategy. It identifies key project milestones, stakeholders, funding sources, and uncertainties about or risks to the project’s delivery. It also proposes the project delivery method and assumptions. The dates may include phasing and swing space requirements, potential agency interruptions, utilities coordination, construction phasing, and building turnover plans. It may also describe required stakeholder funding approvals, plus strategies for meeting environmental, historic preservation, and urban development requirements.

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Work Item Summary Table Refer to the previous PDS Report dated January 29, 2016 for Work Items 1 through 9. The following table is a summary of the recommended work items as presented in this report:

Work Item Description

Construction Duration

(excludes pre-construction and project close-out)

Work Item 10: Replace VAV Boxes 12 months

Work Item 11: Install Return Air Ductwork for HVAC-1 6 months

Work Item 12: Replace Fan Coil Units 12 months

Work Item 13: Heating and Cooling System Updates 9 months

Work Item 14: Improve MAU-1 Ductwork 6 months

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Third Party Sign-Off Sheet The purpose of this sheet is for GSA regional program office and principal client agencies to indicate their agreement to the project scope, implementation roles, and funding responsibilities.

Contracting Officer: Michele Valenza

Contracting Specialist: Erin Clark

Project Manager: Waikit Lui

Portfolio Manager (Reg): Bryan Hodgkins

Property Manager: Ann Goodridge

Design and Construction (Reg): Janice Ramsey

HVAC Advocate (Reg): Waikit Lui

Electrical Advocate (Reg): Jeff Schetrompf

Energy Goal Coordination: Brian Wong

Sustainability Program Manager : David Johnson

Regional Historic Preservation Officer: Liz Mees

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BUSINESS PLAN

Assets and Goals The goal of this project is to improve occupant comfort, reduce overall system maintenance, comply with current GSA codes and standards, simplify building operations, reduce building energy consumption for heating, ventilating, and air conditioning (HVAC) systems, and to extend the life of these systems. There are occupant comfort issues in several areas of the building that will not be resolved until modifications to the HVAC distribution systems are completed.

Design Alternatives Refer to the previous PDS Report dated January 29, 2016 for Work Items 1 through 9.

Work Item 10: Replace VAV Boxes Work Item 11: Install Return Air Ductwork for HVAC-1 Work Item 12: Replace Fan Coil Units Work Item 13: Heating and Cooling System Updates Work Item 14: Improve MAU-1 Ductwork

Planned and Ongoing Projects Planned and ongoing projects in the Gignoux courthouse are as follows:

• Second Floor Judges’ Chambers – Install return air and transfer air grilles to improve ventilation distribution.

Project is substantially complete.

• Install UV filters on MAU-1 and Fan Coil Units. Project is substantially complete.

• Vehicle Barrier and Lobby Screening – Extra Field Investigation (EFI) to study security options to be complete by early 2018.

• Courtroom #2 AV Upgrades – Bid documents recently submitted to perform audio-visual upgrades.

Recently completed projects in the courthouse are as follows:

• Basement – Install new restroom exhaust fan.

• Third Floor Judge’s Chambers – Modify existing VAV boxes and install electric reheat coils to address space over-cooling. Also involved installing a standalone BAS to control the VAV boxes.

• Third Floor Visiting Judge’s Chambers – Update finishes and convert for use by an incoming Judge.

The Work Items in the Follow-On PDS Report factor these projects into the analysis as follows:

• Work Item 10 considers long-term upgrades needed to alleviate overcooling issues in the Third Floor Judges’ Chambers.

• Work Item 12 considers that the new fan coil units to be installed will need to be properly pitched and drained to avoid mold issues and the need for UV treatment.

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• Work Item 14 considers the return air and transfer air grilles being installed as part of the Second Floor Judges’ Chambers project.

Return on Investments The Work Items being investigated are primarily intended to improve occupant comfort and extend the life of the building HVAC systems. Improving air and water distribution should yield some energy savings, but the savings are difficult to quantify and are not expected to be substantial.

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GENERAL BUILDING REQUIREMENTS

Operations/Services

Extended Warranties Standard manufacturers’ warranties are recommended for the heating and cooling distribution equipment recommended in this report, including VAV boxes and Fan Coil Units.

Maintenance Services The GSA currently contracts with CMC Mechanical Services (CMC) to provide on-site facilities maintenance. CMC performs most of the preventative maintenance and repairs at the Gignoux Courthouse but does not do major repairs or provide specialty services, such as water treatment.

Alternative Energy Tie-Ins There are no existing alternative mechanical or electrical energy systems in the building. The original PDS investigated solar power and solar hot water heating options, as well as ground-source heat pumps.

Building Pressurization The GSA has reported concerns about building pressurization and, in particular, that the MAU-1 ventilation airflows greatly exceed exhaust airflows in the building and interfere with proper operation of HVAC-1. Airflows shown on as-built drawings do not indicate that MAU-1 would be over-pressurizing the building or an entire area of a floor in a way that would affect HVAC-1. Appendix C includes pressurization sketches that indicate differential airflow in each room based on as-built drawings.

CCE has not performed measurements to assess actual airflows in the building. However, it is known that the existing air handling systems have balancing issues based on previous GSA measurements and that the HVAC-1 return air is not being properly captured throughout the building. Therefore, it is likely that the building does currently experience pressurization issues based on installed conditions. Without performing measurements, CCE cannot quantify these issues but for all Work Items that address replacement or modifications to air handling systems, we recommend re-balancing of airflows such that the entire building will be balanced once all of the HVAC unit replacements and duct upgrades are performed. Once the systems are re-balanced, the net total positive design airflows at each floor will be low enough to be handled by exfiltration through the building envelope without over-pressurizing the building. A slightly positive building pressure is desirable as it reduces the infiltration rate through the exterior envelope and reduces heating and cooling loads. It also prevents migration of dust, moisture, and other outdoor elements into the building.

PROGRAM GOALS

Sustainable Design This follow-on report to the Gignoux PDS is primarily intended to address the effectiveness of heating and cooling distribution in the building. Improving distribution will have a positive impact on occupant comfort, reduce maintenance, extend the system life, and yield system efficiencies that will save energy. The amount of energy reduction is difficult to quantify and is not expected to be substantial.

Energy Efficiency Load calculations for the work items have been performed for this submission using the Trane TRACE 700 software.

Energy modeling has not been performed as the recommended equipment types are the same as the existing equipment types in the building. CCE recommends that the design phase of this project include more detailed

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computer-based energy modeling in accordance with the GSA’s PBS P-100 Facilities Standards for the Public Buildings Service to confirm that the selected systems are appropriately sized and will meet the GSA’s target energy reduction goal.

There are no known federal, state, local, or utility energy rebates and incentives related to the work items in this report.

Water Conservation This project does not include the replacement of plumbing fixtures or an analysis to reduce water usage inside the building.

Thermal Integrity/Moisture Protection There were historical issues with moisture intrusion into the exterior walls of the building; however, these issues have been corrected as part of past projects performed by others and there are no known issues at this time with thermal integrity and moisture protection.

Efficient Operations and Maintenance All new equipment recommended for installation will reduce operations and maintenance. Work Item 10 will improve occupant comfort and reduce future maintenance by re-sizing and replacing VAV boxes. Work Item 12 will install new fan coil units that do not have any mold contamination, which will improve indoor air quality, and will correct any deficiencies with the existing condensate removal system. Work Item 14 will add access doors to MAU-1 ductwork for cleaning purposes and replace obstructed floor ventilation grilles with ceiling grilles to improve ventilation effectiveness and indoor air quality.

Building Automation Work Item 3 in the previous PDS Report addressed replacement of the existing outdated Building Automation System (BAS) with a new GSA-compliant BAS utilizing BACNet protocol. This will improve operations in the building as the current BAS is over 20 years old, is often unreliable and does not allow for consistent monitoring and control due to its age.

Durability and Maintainability All terminal units evaluated as replacement Work Items will be commercial grade to meet the durability requirements for the HVAC services in the building. The existing VAV boxes and Fan Coil Units are over 20 years old and replacement units are expected to last a nominal 20 years. Existing fin tube radiators and convectors are not recommended for replacement, but their associated control valves and thermostats are recommended for replacement as part of the BAS upgrade in Work Item #3 in the previous PDS report. The fin tube radiators and convectors surveyed as part of this project appear to be in good condition and the maintenance contractor, CMC, does not report any issues with their performance.

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BUILDING SYSTEMS

Work Item 10: Replace VAV Boxes

Scope Summary:

• Replace all VAV boxes and associated controls and branch piping with new.

• Increase HVAC-1 duct sizes as needed to handle new design airflows.

Existing VAV Boxes:

Portions of the basement and all three floors of the building are heated, cooled, and ventilated with VAV boxes controlled by space thermostats. Central air handling unit HVAC-1, located in the basement, delivers supply air to these VAV boxes and return fan RF-1 recirculates mixed room air back to HVAC-1 via a ceiling plenum return system. Both HVAC-1 and RF-1 have exceeded their useful life and are recommended for replacement in the previous PDS as part of Work Item #2. The VAV boxes are over 20 years old, which is the expected service life for this type of unit.

The existing VAV boxes have hydronic reheat coils but these are only enabled during the heating season as the boiler plant is de-energized in the cooling season. This contributes to space overcooling in the summer months in some areas of the building, particularly those that have oversized VAV boxes. Judge Singal’s Chambers have had significant overcooling issues and the VAV boxes that serve this space were recently retrofit with electric duct heaters; however, these heaters have had operational issues and do not meet current GSA energy standards. The VAV boxes serving this Judge’s Chambers are all significantly oversized and decreasing the size of the boxes and associated supply diffusers is expected to provide a long-term solution to reduce overcooling in this space.

Work Item 10:

Replacement of all VAV boxes, controls, and associated branch piping, including shutoff valves and balancing valves, is recommended. The existing VAV boxes have reached the end of their useful life and have outdated controllers. These units are expected to contribute to significant maintenance issues in the future if they are not replaced. Additionally, replacement of VAV boxes is recommended to alleviate issues with overheating and overcooling in some areas of the building.

Appendix D includes Trane TRACE 700 heating and cooling load outputs for all rooms in the building served by a VAV box. Detailed heating and cooling load calculations are to be performed during the design phase of this project. These calculated loads have been compared to the installed unit capacities, as determined using as-built drawings from 1993, when the VAVs were installed. A spreadsheet comparing the calculated vs. installed unit sizes is included in Appendix D.

These load calculations are preliminary and should not be used for final equipment sizing. Units that are oversized, undersized, and appropriately sized per the TRACE model are indicated in this spreadsheet. The results of this spreadsheet are transferred onto Cooling Capacity sketches in Appendix C. These sketches indicate whether the existing VAV boxes are believed to be appropriately sized for the spaces they serve.

The sizes of HVAC-1 supply air ductwork were also evaluated based on the calculated cooling airflows. Sketches indicating where ductwork is undersized and would require replacement are included in Appendix C.

This project does not include comprehensive surveying of all VAV boxes in the building as part of the PDS scope. During the design phase of the project, the design engineer should validate the VAV box installed locations and provide a design that clearly addresses the sizes and locations of all VAV boxes prior to construction.

The power supply to the VAV boxes is 24 volts and these electrical connections can be handled by the controls contractor rather than an electrical contractor. There is no known scope in this work item that would require an electrician.

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Architecture:

To accommodate the installation of the VAV boxes and associated ductwork, it will be necessary to provide access to the space above the existing suspended ceiling. This will require acoustical ceiling tiles to be removed, salvaged and reinstalled to accommodate the space needed to complete the installation. In areas where the existing 2x2 ceiling tiles and grid system obstruct access to existing VAV boxes or ductwork, the grid in addition to the ceiling tiles, will need to be removed, salvaged, and reinstalled. The design firm will need to conduct a materials assessment to determine the specific materials required to match existing as any materials that are damaged during this work are to be replaced to match that of the existing.

Due to the location of the VAVs and the undersized ductwork that will require replacement, the Contractor and the GSA will need to coordinate and develop a schedule that accommodate the building’s occupants and public users. Some of this work may need occur during the weekends or evening hours. If swing space is available, it would be ideal to evacuate an area of the building (2-3 VAV zones) for a period of one to two weeks to perform all necessary upgrades in that space and avoid night and weekend work. Special attention will be required to protect all existing room finishes, furniture, and equipment. Relocation of existing conduit and utilities above the ceiling may be required and this will need to be investigated further during the Type B design phase.

This is a Historic Facility and the existing materials within the areas proposed for this work item are both historic and non-historic in nature. The preservation levels for historic materials within this facility are stated as Zone 1 (area to be restored), Zone 2 (area to be preserved) and Zone 3 (area to be rehabilitated). It is a requirement to respect and minimize the disturbance of any historic features to complete this work scope. It is anticipated that the scope of work for Work Item #10 will affect preservation Zone 3 within each of the floor levels. A diagram of each floor level showing the relationship of proposed mechanical work and its relationship to historic preservation zones can be seen in Appendix C and the Historic Documents in Appendix F. The finishes within the areas of Work Item #10 consist of 2x2 ACT and areas of gypsum board ceilings. The walls are primarily painted gypsum wall board. Given the nature of the finishes that are anticipated to be disturbed within the proposed work scope, coordination and consultation with GSA’s Regional Historic Preservation Officer (RHPO) will be required.

Fire Protection:

There will be minimal sprinkler impact as the VAV boxes and associated supply diffusers and grilles are intended to be replaced in-kind. Where some modifications are necessary due to slightly increased duct sizes or where access to the boxes for removal is limited, some sprinkler re-configuration could be required and should be further investigated during the Type B design phase. Preliminary sketches indicating areas that could require sprinkler replacements and that show expected control valve locations are included in Appendix C.

If the existing sprinkler system requires re-configuration, the sprinkler contractor will need to drain portions of the sprinkler system using existing floor control valves. Interim Life Safety Measures will be required and the contractor will need to coordinate with the GSA and Portland Fire Department prior to the sprinkler outages. A fire watch may be required if a sprinkler outage will last more than one day.

Work Item 11: Install Return Air Ductwork for HVAC-1

Scope Summary:

• Install new return air ductwork for HVAC-1 to meet P-100 requirements for a plenum return system.

• Patch all existing return air transfer openings in walls and chases that are intended to be fire or smoke barriers.

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• Install two new central AHUs (HVAC-5 and HVAC-6) to condition the north, south, and east portions of the third floor and remove all HVAC-1 ductwork in these areas.

• Remove Rotunda smoke control fan from third floor mechanical room and install new rooftop smoke control fan to facilitate installation of HVAC-6.

Existing HVAC-1 Return Air Paths:

HVAC-1 is a central air handling unit located in the Basement. It delivers supply air to VAV boxes located on all floors of the building, as described in Work Item #10. The supply air consists of recirculated (return) air from the conditioned spaces as well as outdoor air for ventilation. The return air is handled by a separate, dedicated fan, RF-1, located adjacent to HVAC-1. The intent of the return air system is to remove some air from each room served by a VAV box to encourage mixing of the supply air inside the room and prevent over-pressurization of the space.

The most effective method to remove air from each room is to have a fully ducted system, which connects every return air grille directly to the return fan using a continuous section of ductwork. HVAC-1 was designed to be a plenum return air system, which uses the building’s ceiling plenum to transport air from each room back to the return fan. Current GSA PBS P-100 standards require every plenum return grille to be within 50 feet of a return air duct. This helps ensure more even distribution of return air throughout the building. Currently the only return air ductwork for RF-1 in the Gignoux Courthouse exists in the basement. The basement return air ductwork connects to the North Chase, which runs vertically and serves all floors of the building. The North Chase is used as the primary chase for return air, in conjunction with the ceiling plenums on all four floors. There are rooms in the building intended to be served by RF-1 that are several hundred feet away from the basement return ducts. Considering that most of the rooms in the Courthouse have full-height walls creating enclosed, contained ceiling plenums, and the lack of transfer ducts/grilles in full-height building walls, CCE believes that the likelihood that return air is migrating back to RF-1 is very low.

While surveying an area above the ceiling in the 1st floor Marshals’ Area, CCE noted two large holes through a fire rated stairwell, as shown in Appendix F. These holes appear to be used to help transfer return air from the south ceiling plenum in the Marshals’ area to the North Chase. These openings should be patched and all penetrations should be re-routed and firestopped in order to provide a continuous fire barrier per code. There are other similar openings in stairwells and chases throughout the building. The designer of record will need to survey and document all openings and specify repairs during Type B services.

The third floor Electrical Room does not have full-height walls that go all the way to the roof deck, as shown in Appendix F. This room is currently used as a plenum for return air to HVAC-1, which is not permitted by code. As part of this Work Item, the walls of the electrical room should be sealed, patched, and firestopped to provide a 1-hour fire barrier.

Work Item 11:

This work item involves patching all fire-rated chases, stairwells, and the third floor Electrical Room and providing new return air ductwork to more effectively transport air from the ceiling plenum to RF-1. The return air ductwork would be installed to within 50 feet of every return air grille, where field conditions permit. Disturbance of finishes in Zone 1 historical zones should be minimized to the extent possible. This additional ductwork will require replacement of RF-1 to accommodate the increase in static pressure. Replacement of RF-1 is addressed in the previous report under WI #2.

There is not sufficient cross-sectional area to route a new return air duct riser continuously through an existing chase, especially in light of future proposed outdoor air duct risers in Work Item #1 (see previous PDS report). The south chase does have some available cross-sectional area on the second floor, but the third floor north and south chases are both inaccessible due to existing shallow interstitial ceiling space and congestion with existing MEP systems.

Sketches in Appendix C indicate proposed routing of new return air ducts for HVAC-1 on all floors of the building. This routing is based on as-built drawings and preliminary field investigations. Further field work will be needed in the Type B design phase to validate the sizes and locations indicated, as well as all incidental work needed to accomplish the duct installation. CCE could not identify a feasible method to handle all of the HVAC-1 return air for the third floor. Judge

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Woodcock’s chambers is adjacent to an existing abandoned chase, which can be utilized for a new return air duct. Other areas of the third floor, however, do not have access to any existing chases due to congested ceiling plenums and low ceiling plenum heights in historically sensitive areas of the building. CCE recommends installing two new air handling units (HVAC-5 and HVAC-6) in existing third floor mechanical rooms, as shown in Appendix C drawing MSK-113. These units would handle heating, cooling, and ventilation for the two portions of the west side of the third floor. It is recommended to remove all existing HVAC-1 supply ductwork in these areas and to provide new supply air and return air ductwork for the new HVAC units. This will lead to a decrease in the size of HVAC-1 and RF-1 when they are replaced in the future. Replacement of HVAC-1 and RF-1 are addressed in the previous PDS report under Work Item #1. During Type B services, the design team will need to perform detailed calculations for re-sizing HVAC-1 and RF-1 to match the new loads.

New VAV boxes for these areas are covered under Work Item 10. Central AHUs tied to VAV boxes would be less expensive and require less maintenance (fewer fans and filters) than converting these areas to utilize fan coil units (FCUs) with 100% dedicated outside air systems (DOAS). However, prior to the 35% Type B design submission, the design team should verify the feasibility to install the larger supply and return ducts required for a central AHU system in these two areas of the building. If the duct routing is found to be infeasible, four-pipe fan coil units and DOAS units would be recommended. If fan coil units are installed, it may be feasible to utilize existing power supplies to VAV box electric heating coils in Judge Singal’s chambers.

The existing exhaust systems on the third floor, as designed, have sufficient airflow to relieve the ventilation air from HVAC-1 and future HVAC-5 and HVAC-6 and avoid over-pressurization. However, the exhaust systems on all floors should be re-balanced as part of this work item to ensure that actual flow rates match design flows.

The Implementation Plan portion of this report includes a section on Construction Phasing that describes some of this coordination.

Electrical:

Due to anticipated work scope of stairwell wall patching on the first floor, some electrical cabling that transverses these wall openings will require attention. It is expected that an Electrical Contractor would trace out all cabling and identify abandoned cable for removal and source/load of all active cabling. Once this process is complete, existing cabling must be sleeved through any wall patches and fire stopped to allow a uniform finish and restore the required 2-hour fire barrier at the stairwell. Power and signal/communication cabling will be routed separately in accordance with National Electrical Code requirements.

Feeders for the two (2) new third floor air handling units will be provided from Panel PB3, located in the third floor Electrical Room. It is assumed that each AHU will receive 208-volt, 3-phase feeders, requiring new panelboard breakers and associated starters and disconnects.

Note that equipment feeders will be subject to P-100 electrical distribution requirements at the start of a particular design project. Ensure all work is compliant with the current P-100 edition at the time of design.

Architecture:

To accommodate the installation of this mechanical work, walls and floors will need to be penetrated to accept the return air duct runs and riser. The first and second floor slabs will be penetrated by the vertical return air riser and interior walls will be penetrated by the horizontal duct work. Structural design will be completed in the Type B design phase to develop details for any structural penetrations in walls and slabs. The modifications to the duct runs associated with the vertical chase in the North-East corner of the facility will leave large non-fire rated openings within the vertical chase. The chase walls will require a continuous fire rated wall assembly from deck to deck to provide a continuous fire stop. This will require infill to match existing and potential fire-stopping materials as the modification of the mechanical runs will leave large non-fire rated openings within the vertical chase.

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All fire and smoke ratings of the existing assemblies are to be maintained. The designer of record will specify fire-stopping at all penetrations to maintain existing ratings as required by codes. The designer of record will be required to assess all fire and smoke requirements to ensure that the life safety of this facility is being met as the Courts have raised concern that there are additional areas of deficiency within the fire rated assemblies that are to be addressed.

In addition to the wall and floor penetrations, the installation will require openings to be made through the existing ceiling plane. This will require acoustical ceiling tiles to be removed, salvaged and reinstalled to accommodate the space needed to complete the installation. In areas where the 2x2 ceiling tiles and grid system cause confined areas, the grid in addition to the ceiling tiles, will need to be removed, salvaged and reinstalled to allow for additional access for larger installation items. This will be a similar case for the areas of hard ceilings as the drywall ceiling board will need to be cut to accommodate the installation work and then patch in like material, primed and painted for a uniform finish. It should be noted that in some areas such as the third-floor office space containing Judges Chambers, to the North of the floor layout, there are many custom ceilings with gypsum board surrounds and raised ACT ceiling areas with accent trim and recessed lighting. In addition, there are skylight/dormers that contain round port-hole windows within painted gypsum surrounds. In the North-East corridor adjacent to Courtroom #2, the ceilings are painted gypsum and transition to painted gypsum with metal mesh backer within the secure corridor spaces. This is the similar case for the corridor, running North to South at the East portion of the First Floor. The ceiling is gypsum with a metal mesh backer and therefore will require care both in removal scope and installation scope. The designer of record shall take care in conducting a materials assessment to determine specific materials and compositions to match into the existing, both in assemblies and aesthetic. Any materials that are damaged during this work are to be replaced to match that of the existing for a uniform finish.

As the ceilings to be removed are located in many rooms, specific scheduling will be required between Contractor and GSA. Some of this work may be required to be accomplished during the weekends or evening hours. Special attention will be required to protect all surrounding room finishes, and also, room furnishings; covering or removal of furniture will be required.

This is a Historic Facility and the existing materials within the areas proposed for this work item are both historic and non-historic in nature. The preservation levels for historic materials within this facility are stated as Zone 1 (area to be restored), Zone 2 (area to be preserved) and Zone 3 (area to be rehabilitated). It is a requirement to respect and minimize the disturbance of any historic features to complete this work scope. It is anticipated that the scope of work for Work Item #11 will affect preservation Zones 1, 2 and 3. A diagram of each floor level showing the relationship of proposed mechanical work and its relationship to historic preservation zones can be seen in Appendix C and the Historic Documents in Appendix F. Given the nature of the finishes that will be disturbed within the proposed work scope, this will require coordination and consultation with GSA’s RHPO.

Fire Protection:

Routing new return air duct main through an existing sprinklered building is anticipated to require sprinkler piping modification and sprinkler head relocation. The exact locations and sections of sprinkler piping will need to be field verified during the Type B design phase. Preliminary sketches indicating areas that could require sprinkler replacements and that show expected control valve locations are included in Appendix C.

If the existing sprinkler system requires re-configuration, the sprinkler contractor will need to drain portions of the sprinkler system using existing floor control valves. Interim Life Safety Measures will be required and the contractor will need to coordinate with the GSA and Portland Fire Department prior to the sprinkler outages. A fire watch may be

PDS Report – Follow-on Study Page 16 Final Report

Work Item 12: Replace Fan Coil Units

• Replace all fan coil units and associated controls and branch piping with new.

• Install two new fan coil units in the basement to condition offices and a break room.

Existing Fan Coil Units:

Portions of the building that require cooling and are not served by VAV boxes or air handling units are heated and cooled with fan coil units (FCUs). Most of the fan coil units on the first and second floors are floor-mounted while the majority in the basement are ceiling suspended. The fan coil units have heating and cooling coils and are fed by separate hot water and chilled water piping. The majority of the fan coil units are over 20 years old, exceeding the expected service life threshold.

The fan coil units do not provide ventilation air; outdoor air is conditioned by a basement Make-Up Air Unit (MAU-1) and directly ducted to each space. The FCUs have had known mold contamination issues in the past and were removed and cleaned as part of previous project.

Following are specific locations within the building that require fan coil unit modifications:

• A storage room (Room 014) was converted into two offices. The offices do not have a cooling unit and experience overheating.

• A break room for the Marshals (Room 010) in the basement also does not have a cooling unit.

• A former conference room on the first floor was converted to a Women’s room and there is an existing fan coil unit that is no longer needed.

• There is no ventilation air in the first-floor corridor and rotunda, which does not meet code.

Work Item 12:

CCE recommends the replacement of all fan coil units in the building and re-sizing to meet actual heating and cooling loads. Detailed heating and cooling load calculations are to be performed during the design phase of this project. All FCU controls and pipe branches, including shutoff and balancing valves, should also be replaced.

Appendix D has a spreadsheet that compares the existing FCU capacities to calculated capacities using TRACE 700. These load calculations are preliminary and should not be used for final equipment sizing. Installed locations of all FCUs would need to be verified during the design phase and the heating and cooling loads would need to be determined in design with more detailed load analysis than what has been performed for this PDS report.

Sketches in Appendix C indicate areas where replacement of hot water and chilled water piping is recommended based on pipe sizing calculations and/or pipe condition. Refer to Work Item #13 for more information. Some additional FCU system modifications are recommended for the building:

• A new four-pipe fan coil unit with heating and cooling coils should be installed to serve the basement offices (Rooms 014).

• A new fan coil unit is also recommended for the Marshals break room (010).

• The Women’s Room floor-mounted fan coil unit (Room 031) should be removed.

• The Women’s Room is an interior space and can be adequately heated and cooled by existing make-up air from the adjacent corridor.

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PROPERTY OF THE UNITED STATES GOVERNMENT FOR OFFICIAL USE ONLY

Electrical: HVAC unit replacement would essentially result in a one-for-one unit change-out. Therefore, it is anticipated that existing electrical feeders could be re-used. No significant impact to the electrical system would be necessary.

Approximately 85 fan coil units would be replaced in-kind, resulting in electrical disconnect/reconnect of existing power supplies. Two (2) new fan coil units are scheduled to be installed in the Basement. These units would require dedicated power feeders and local disconnecting means from a local panelboard. One (1) fan coil unit would be removed on the First Floor, with its power supply being removed in its entirety back to the source panel.

Architecture:

To accommodate the installation of this mechanical work there will be a minimal amount of cutting and penetrations to allow the piping and routing to each floor mounted fan coil unit (FCU) to be replaced. Once the units are removed and the replacements installed, the walls and floors will then require patching, painting and sealing to provide finished surfaces to match that of the existing. All penetrations will be sealed to maintain the existing fire and smoke rating of the assemblies penetrated. It is anticipated that each of the existing wooden cabinets that house the fan coil units will remain in place and that there will be no alterations to the cabinets themselves. The replacement work is to take place in a careful manner as to avoid any rework to the existing cabinetry.

• The existing first floor Women’s Room (031) houses a floor mounted FCU. The unit will be removed and the existing floor and wall finishes will be restored to match the existing.

• In addition to the floor mounted FCU work, Room 014 will receive a new FCU above the ceiling. This will require acoustical ceiling tiles to be removed, salvaged and reinstalled to accommodate the space needed to complete the installation.

• In areas where the 2x2 ceiling tiles and grid system cause confined areas, the grid in addition to the ceiling tiles, will need to be removed, salvaged and reinstalled to allow for additional access for larger installation items

This is a Historic Facility and the existing materials within the areas proposed for this work item are both historic and non-historic in nature. The preservation levels for historic materials within this facility are stated as Zone 1 (area to be restored), Zone 2 (area to be preserved) and Zone 3 (area to be rehabilitated). It is a requirement to respect and minimize the disturbance of any historic features to complete this work scope. It is anticipated that the scope of work for Work Item #12 will affect preservation Zones 1, 2 and 3. A diagram of each floor level showing the relationship of proposed mechanical work and its relationship to historic preservation zones can be seen in Appendix C and the Historic Documents in Appendix F. Given the nature of the finishes that will be disturbed within the proposed work scope, this will require coordination and consultation with GSA’s RHPO.

Fire Protection:

There will be minimal sprinkler impact, as the fan coil units and associated supply diffusers and grilles are intended to be replaced in-kind. Where some modifications are necessary or where access to the units for removal is limited, some sprinkler re-work could be required. The exact locations and sections of sprinkler pipe will need to be field verified during the Type B design phase. Preliminary sketches indicating areas that could require sprinkler replacements and that show expected control valve locations are included in Appendix C.

If the existing sprinkler system requires re-configuration, the sprinkler contractor will need to drain portions of the sprinkler system using existing floor control valves. Interim Life Safety Measures will be required and the contractor will need to coordinate with the GSA and Portland Fire Department prior to the sprinkler outages. A fire watch may be

PDS Report – Follow-on Study Page 18 Final Report

Work Item 13: Heating and Cooling System Modifications

• Replace all building chilled water and hot water piping with new and re-size pipes for design water flows.

Existing Heating System:

This building has a gas-fired hot water boiler plant located in the basement and air-cooled chillers on the roof. The chilled water plant was installed in 2016. Upgrades to the boilers and hot water pumps were addressed in Work Item #7 in the previous PDS report. Hot water is distributed to air handling units, VAV box reheat coils, fan coil units, unit heaters, convectors, and fin tube radiators. The existing unit heaters are in acceptable condition and since they are in unoccupied mechanical spaces, CCE recommends that they be replaced as needed, as they exceed their useful life. The existing convectors and fin tube radiators are located mostly in occupied areas of the building and appear to be in good condition. The radiators and convectors do not have any moving parts that require maintenance and have no reported leaks.

The chilled water pipe mains are steel and the branches to terminal units are copper. CMC & Maintenance reports that there are no significant chilled water leaks, but various sections of chilled water piping in the basement (HVAC unit mechanical room, MAU-1 mechanical room, and mechanical room adjacent to chilled water pump room) shows evidence of significant exterior corrosion under insulation for the steel piping and uninsulated pipe hangers have also experienced corrosion. The copper chilled water pipe branches appeared to be in good condition. Photos are included in Appendix A. CMC reports that the portions of hot water piping that use Victaulic fittings leak when the seasons change and the boilers turn on or off. Additionally, the hot water supply temperature has been elevated beyond what the building requires in order to prevent leakage at these fittings. CCE did not observe significant exterior pipe corrosion while spot-checking hot water pipes in multiple basement mechanical rooms.

Work Item 13:

All steel chilled water piping and associated valves, insulation, and hangers should be replaced due to evidence of corrosion and anticipated future maintenance issues. Sketches that indicate where CCE believes this piping is located are included in Appendix C. All Victaulic fittings in hot water piping should be replaced with welded fittings per the P-100 in order to mitigate leakage issues during seasonal changeover. It appears that hot water piping 2-inches and larger have Victaulic fittings.

When VAV boxes and fan coil units are replaced as part of Work Items #10 and #12, the chilled water and hot water branches will be replaced and the piping systems should be re-balanced in their entirety to ensure that flows are being distributed as designed. Due to the need to replace the steel CHW mains as well as the terminal unit branches, there would be minimal sections of existing CHW pipe remaining once those removals are made and CCE believes that it would be easier for a contractor to remove and replace all building chilled water piping (except the piping in the basement chilled water pump room, which was installed in 2016) with new rather than retaining limited sections of copper branch piping. Similarly, since the hot water piping runs parallel to the chilled water piping and the 2” and larger hot water piping has leakage issues, it is recommended to replace all building hot water piping at the same time. The chilled water piping was recently flushed as part of the chiller upgrade project but the hot water piping likely has not been cleaned or flushed in recent history. Flushing is recommended prior to re-balancing the chilled and hot water system.

When a new fan coil unit is installed in the Room 014 Office, the convector, hot water control valve, and thermostat in that room will no longer be needed and all can be removed. The Room 013 Open Office will also not require a convector as it is served by two fan coil units that are capable of handling the entire heating load.

PDS Report – Follow-on Study Page 19 Final Report

PROPERTY OF THE UNITED STATES GOVERNMENT FOR OFFICIAL USE ONLY

All terminal unit chilled water and/or hot water shutoff valves and balancing valves should be replaced as the associated units…