654-20-132 Refrigeration Replacement Design Report.pdf

Basis Of Design Report

Refrigerant System Design

Reno Nevada VA Medical Center

Submitted to:

U.S. DEPARTMENT OF VETERAN AFFAIRS

Attn: Steven A. Elliott, PE, CHFM

Reno VA Hospital

975 Kirman Ave, Reno, NV 89502

Submitted by:

Alares LLC

248 Copeland Street

Quincy, MA 02169

November 2020

Refrigerant System

Reno VA Medical Center

November 2020 ii

Table of Contents

Section Page

1.0 Executive Summary

2.0 Existing conditions

3.0 Design Approach

3.1.1 Design Considerations

3.1.2 Design

3.1.3 Design Approach

4.0 Electrical Design Approach

APPENDICES

APPENDIX A – Construction Drawings

APPENDIX B – Specifications

APPENDIX C – Cost Estimate

APPENDIX D- Equipment Selection

November 2020 1

1 .0 EX EC U TIV E S U MMA RY

This 100% Basis of Design contains all design requirements and intent for the design of a new refrigeration system that serves multiple walk-in fridges and freezers at The Reno VA Medical

Center (Reno VAMC).

The current refrigeration system is beyond its useful life and is leaking in several areas. This report documents the complete design approach of the refrigerant system replacement project.

2 .0 EX IS TIN G C O N D ITIO N S

2 . 1 . 1 E q u i p m e n t

The existing refrigeration system consists of:

- Evaporators in each walk-in refrigerator and freezer (8 total).

- Hussmann Protocol condensing unit located in the basement.

- Bohn condensing unit located in the basement.

- Copelamatic condensing unit located in the basement.

- Condensing water pump skid located in the storage room of the basement.

- Recold cooling tower located on grade outside the building.

- Water treatment system located in the small room below cooling tower.

The equipment and the spaces they serve are listed below in Table 1:

- Table 1: Equipment List

Room Number Room type Served by

130A Medium temperature Hussmann

130B Medium temperature Hussmann

C7-C1343 Medium temperature Hussmann

C7A-C1344 Low temperature Hussmann

C8-C1345 Low temperature Hussmann

C9-C1342 Medium temperature Hussmann

C2339 Medium temperature Bohn

Traulsen Low temperature Copelamatic

- All evaporators were installed together with their respective condensing units. All units appear to be in fair condition. However, it is recommended to replace the evaporators when replacing the condensing units and refrigerant piping.

November 2020 2

- All condensing units are water-cooled type and past their useful life. Replacement is recommended.

- Cooling tower is past its useful life and in poor condition. Replacement is recommended.

- Water treatment system is in poor condition. Replacement is recommended.

- Condensing pumps are in working condition.

As-built drawings are included in APPENDIX A – Construction Drawings.

2 . 1 . 2 R e f r i g e r a n t P i p i n g S y s t e m

The Hussmann condensing unit is connected to common supply and return refrigerant headers.

From these headers, branches extend to all spaces served by this unit. The existing headers appear to be in fair condition. However, all the branches are in poor condition. Insulation is missing on most of the piping branches. Piping currently runs through the crawl spaces, making it difficult to resolve the pipe and insulation deficiencies.

The Bohn condensing unit only serves room C2339. The existing refrigerant piping seems to be in fair condition.

The Copelamatic condensing unit only serves the Traulsen walk-in freezer. The refrigerant piping seems to be in fair condition.

2 . 1 . 3 S y s t e m P e r f o r m a n c e

According to feedback from the VA engineering and maintenance staff, there are several issues with the system. The system frequently requires service to maintain operation. The VA desires to replace the entire system.

November 2020 3

3 .0 D ES IG N A P PR O A C H

3 . 1 . 1 D e s i g n C o n s i d e r a t i o n s

The goal of the project is to design a cooling system that complies with current VA Design

Guidelines and meets cooling requirement for all the existing walk-in refrigerators and freezers.

- New refrigeration system shall be provided with redundancy configuration.

- New refrigeration system shall utilize modern technology.

- New refrigeration system shall operate with ambient temperature range from 12°F to 96° as required from the VA design manual.

- Construction of the new system will avoid interrupting the current system.

- Design will satisfy all codes and regulations.

- All penetrations from demolition will be sealed, fire stopped and painted to match existing area.

3 . 1 . 2 D e s i g n

- Install eight (8) new air-cooled condensing units on the high roof.

- Pipe supports at roof as required PPLO with channel from PHP systems or equivalent.

- Condensing units shall require bird protection.

- Condensers shall be equipped with current sensors to verify system operation.

- Condensing units will have oversized receivers and oil separators to account for long pipe runs.

- Condensing units will be placed on an elevated platform.

- Four (4) new refrigerant linesets will drop along the east walls down to the low roof. Two linesets will penetrate the low roof to get down to level 2. Two linesets will offset above low roof to northeast corner of the building and penetrate the low roof to get down to level 2.

- Four (4) new refrigerant linesets will drop along the west walls down to first floors to serve spaces on first floors.

- Install seven (7) new frost-free evaporators in each room. The Traulsen freezer will not require a new evaporator.

- Evaporators will have electric heaters to prevent ice accumulation.

- Isolation valves will be added to evaporator piping for maintenance.

- Drain line heaters are required for freezers.

- All devices will be BACnet compatible.

- All devices will need to be able to remotely transmit data to the Johnson Control System.

- All piping will be concealed by a pipe chase. The pipe chase will be a Unistrut framed enclosure assembled from cantilever components at the ends of the horizontal pipe support channels that will support the sheet metal cover.

- All piping that penetrates the roof will have a dedicated pipe housing for protection.

- Pipe hangers will need to be seismically braced if the hanger rods are over 12” from the deck.

- Seismic bracing will not be required for hanger rods less than 12” from the deck.

- The entire existing system will be removed entirely after new systems are operational.

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- Fall arrest tie offs will be included on framing or roof.

3 . 1 . 3 D e s i g n A p p r o a c h

Construction shall be carried out in the following phases:

Phase 1: Install new condensing units, power, and refrigerant line sets

The existing system will not need to be shut down during this phase.

- Fabricate and Install roof platforms and procure eight condensing units on the roof.

- Install refrigerant line sets and run lines to spaces served on the first and second floor

(C7, C7A, C8 and C9 on the first floor) (130A, 130B, Traulsen and C2339 on the second floor)

- Install electrical subpanel on platform and connect to existing panel DB7 in penthouse.

- Run power and control lines to spaces served on the first and second floor together with refrigerant line sets.

Phase 2: Install new equipment for 130A & 130B

- Mount the evaporators in 130A and 130B

- Install electrical subpanel PB8RB.2

- Connect refrigerant lines and power to evaporators

- Charge the systems with refrigerant to manufactures standards

- Verify operation of units.

- Once unit operation in each room has been verified and commissioned, remove existing evaporators, refrigerant lines and electrical connections in their entirety. Patch all wall penetrations

Phase 3: Install new equipment for C2339 and Traulsen

- Install new equipment

- Once unit operation has been verified and commissioned, remove existing evaporator, refrigerant lines and electrical connections in their entirety

- Patch all wall penetrations to applicable standards

Phase 4: Install new equipment for C9

- Install new equipment for C9

- Once unit operation has been verified and commissioned, remove existing evaporators, November 2020 5

- Replace food back into C9

Phase 5: Install new equipment for C7

- Install new equipment for C7

- Once unit operation has been verified and commissioned, remove existing evaporators, Phase 6: Install new equipment for C7A

- Install new equipment for C7A

- Once unit operation has been verified and commissioned, remove existing evaporators, refrigerant lines and electrical connections in their entirety

- Patch all wall penetrations to applicable standards

Phase 7: Install new equipment for C8

- Install new equipment for C8

- Connect refrigerant lines and power to evaporator

- Once unit verification has been verified and commissioned, remove existing evaporators, Phase 8: Remove all old equipment

Demo all old equipment in basement:

- Refrigerant/ condensing water lines

- Cooling tower

- Condensing water pump skid

- BOHN compressor serving C2339

- Copeland Copelametic unit serving Traulsen freezer

- Compressors serving: 130A/B, C7, C7A, C8 and C9

- All line sets

- Fire seal all openings

- Patch and paint

Concept design drawings are included in APPENDIX A – Construction Drawings

November 2020 6

4 . 0 ELEC TR IC A L D ES IG N A P PR O A C H

Upon the completion of new work and successful operation of new compressor and evaporator units, the existing equipment mentioned in section 2.1.1 will be disconnected. All conduit and wire associated with this equipment will be removed and the circuit breakers in their respective panelboards will remain in place as spares for future use.

Changing from 3 condensing units in the basement to 8 condensing units on the roof makes reusing the existing circuits in the basement impractical. To effectively reduce shutdown times and reduce long conduit runs, a new panelboard will be installed on the roof near the compressors. This will be a Nema 3R, 200 amp MCB, 120/208 volt panelboard rated for outdoor conditions with additional space left over for future roof loads. This new panelboard will be fed from the distribution panelboard “DB7” which is located inside the penthouse. This will require installation of a new 200 amp breaker in panelboard “DB7”. All 8 condensing units are 208V/3Phase loads and will be fed from the new panelboard. Nema 3R rated local lockable disconnect switches will be installed at each condenser within line of sight. Receptacles will be provided on the roof for future service and maintenance of eight (8) condensing units.

New evaporators for the walk- in refrigerators and freezers listed in “Table 1: Equipment List” of section 2.1.1 on levels one and two have either 208 volt single phase or 120 volt single phase loads.

Two new panelboard load centers will be installed to provide power to the evaporators. Both load

100A panelboard load centers will be fed from the new 200A panelboard on the roof. The conduits between the 200A panelboard and these two load centers will follow the refrigerant lines into the building. . Providing a new panelboard load center on floors 1 and 2 to power the new evaporators will allow the existing evaporator units to run during installation of new equipment, and will reduce shutdown time of refrigerators/freezers when making connections to the new refrigerant lines. One smaller 40A load center with one 2-pole breaker will be installed on the second floor as the disconnecting means for the C-2339 evaporator.