S02 Final Bid Documents Submission Nov. 2019.pdf

CONSTRUCTION DOCUMENTS

Final Bid Documents Submission

Retro-Commissioning Mechanical Corrections

Contract: 36C24418C0071

Submitted to:

U.S. Department of Veterans Affairs

Lebanon VA Medical Center Attn: Brian Pedersen

1700 South Lincoln Avenue Lebanon, PA 17042

Submitted by:

Alares Engineering 248 Copeland Street Quincy, MA 02169

November 2019

Lebanon VA Medical Center

Achieving swift results

Table of Contents

1.0 Executive Summary

Applicable Codes and Standards

2.0 Building 1, AC-9-1 Replacement

General

Temporary Measures

3.0 Building 22, ERU-1-22 Replacement

General

Temporary Measures

4.0 Building 24, AC-1-24 Replacement

General

Temporary Measures

5.0 Geothermal System Improvements

Temperature Sensor Corrections

5.1.1. General

ERU Control Sequence Corrections

5.2.1. General

WWHP Control Sequence & Valve Corrections

5.3.1. General

5.3.2. Temporary Measures

Cross-Connections on ERU-1S, -2S & 1-P

5.4.1. General

5.4.2. Temporary Measures

Cross-Connection on ERU-1C

5.5.1. General

5.5.2. Temporary Measures

Humidity Sensor Corrections

5.6.1. General

ERU Discharge Air Static Pressure Corrections

5.7.1. General

5.7.2. Temporary Measures

ERU Design Improvement

November 2019 Page 3 of 17 Achieving swift results

5.8.1. General

5.8.2. Temporary Measures

6.0 BAS Improvements

Design Approach

6.1.1. Supply air static pressure setpoint reset:

6.1.2. Discharge air temperature setpoint reset:

6.1.3. VFD scaling issues,

7.0 Pneumatic Control Upgrades

Design Approach

8.0 Mechanical Improvements

Design Approach

9.0 Insulation Repairs

Design Approach

10.0 Sensor Corrections

General

11.0 Chilled Water Improvements

Investigation Results

Appendices Appendix A – 100% Drawings Appendix B – Not Included Appendix C – Catalogue Sheets Appendix D – Comments from 95% Design Submission Appendix E – Specifications Appendix F – Chilled Water Investigation

November 2019 Page 4 of 17 Achieving swift results

1.0 Executive Summary

Alares Engineering (Alares) was retained by the Department of Veterans Affairs (VA) for designing Retro-Commissioning (RCx) Mechanical Corrections at the Lebanon VA Medical Center (LVAMC). Services include site investigation, design development, preliminary drawings, construction drawings, specifications, cost estimates, and construction period services.

The purpose of this Final Bid Documents Submission is to finalize the proposed designs for the RCx mechanical corrections, as outlined under the previous 35%, 65%, and 95% Design Submissions. The design scope includes the following:

1. Air Handling Unit Replacements, including

a. Building 1, AC-9-1 replacement

b. Building 22, ERU-1-22 replacement

c. Building 24, AC-1-24 replacement

2. Geothermal System Improvements, including

a. Temperature Sensor Corrections

b. ERU Control Sequence Corrections

c. Water-to-Water Heat Pump Control Sequence & Valve Corrections

d. Repairs to the Cross-Connections on ERU-1S, -2S & -1P

e. Amendments to Retain the Cross-Connection on ERU-1C

f. Humidity Sensor Corrections

g. ERU Discharge Air Static Pressure Corrections

h. ERU Design Improvements

3. Building Automation System Improvements

4. Pneumatic Control Upgrades

5. Mechanical Improvements

6. Insulation Repairs

7. Sensor Corrections

8. Chilled Water Improvements, including

a. Perform Testing, Adjusting, and Balancing on Secondary Chilled Water Pumps

b. Replace Chilled Water Flow Meters

c. Install new Differential Pressure Sensors

Applicable Codes and Standards The Mechanical / HVAC codes and standards planned to be utilized are the following:

1) Department of Veterans Affairs Design Manuals- HVAC Design Manual – November 1, 2017

2) International Building Code (IBC)

3) International Mechanical Code (IMC)

4) Facilities Guidelines Institute - 2018

5) NFPA 90A, 91, 99, 101

6) ASHRAE 170- 2013, 90.1-2016, 62.1-2016

7) ASHRAE Fundamentals – 2017

(Note: Latest editions, or as required by VAMC Guidelines)

The following sections outline the design approach for each of the noted deficiencies.

2.0 Building 1, AC-9-1 Replacement

General It is recommended that AC-9-1 – which serves the penthouse mechanical room of Building 1 – is replaced in kind.

- Install new AHU, AC-9-1 with total capacity of 189.3 MBH and 5,500 CFM to replace the old unit.

- Install new 26x24 supply duct to replace old 24x18 supply duct.

- Install two new supply grilles to match existing grilles.

- Install new isolation valves on chilled water piping serving AC-9-1

- Chilled water supply and return piping needs to be re-routed away from electrical panels

Temporary Measures AC-9-1 shall preferably be replaced during the winter months. However, the Contractor shall assume responsibility for maintaining appropriate space temperatures in the Lift Machine Room, including temporary cooling if necessary.

Occupants will not be disturbed during the AHU replacement. However, the installation of new isolation valves on the CHW lines shall require a temporary, short-term shut-down of AC-5-1. The mechanical contractor shall coordinate this shutdown with the VA to minimize the impact on the operation of Building 1.

3.0 Building 22, ERU-1-22 Replacement

General It is recommended that ERU-1-22 – which serves to provide ventilation and exhaust to numerous areas at all floors of Building 22 – is replaced in kind.

- Install new ERU-1-22 with total capacity of 1,530 CFM SA and 1,950 CFM EA to replace the old unit.

- Implement an operating schedule in the ERU control sequence to save energy.

- Install new occupancy sensors on each floor to energize ERU during off hours.

Temporary Measures Any areas which are to remain operational during the work to replace the ERU shall require temporary ventilation air, such as window-mounted AC units, window-mounted exhaust fans and temporary heating units, where possible.

If practical, the installation of the new ERU might be coordinated with the renovation of the Second Floor. However, this will be at the discretion of the Contractor, and this coordination shall not be relied upon.

4.0 Building 24, AC-1-24 Replacement

It is recommended that AC-1-24 – which serves the Gym of Building 24 – is replaced with a unit which can meet the cooling demand of the space.

- Install new AHU, AC-1-24 with total cooling capacity of 148 MBH and 4,500 CFM with minimum 1,250 CFM of outdoor air to replace the old unit.

- New unit will be located on the ground level of storage room which allows for easier maintenance.

- Install new return fan, RF-1-24 with total flow of 4,000 CFM. New return fan will be at the location of original AHU.

- Install new duct system including metal ducts and ductsox.

- Most of piping are remain unchanged. Steam condensate pipe will be routed along bottom of the wall to get back to pipe chase. Cooling coil condensate will be pumped up to existing condensate pipe.

- Implement a new control sequence so the AHU will operate more efficiently.

Temporary Measures Building 24 HVAC system renovation shall require a temporary shutdown of the Gym due to the nature of work.

5.0 Geothermal System Improvements

The following improvements to the Geothermal System in Buildings 34, 35 and 36 shall be implemented:

1. Temperature Sensor corrections

2. ERU Control Sequence Corrections

3. Water-to-Water Heat Pump Control Sequence and Valve Corrections

4. Cross-Connections on ERU-1S, -2S & 1P

5. Cross-Connection on ERU-1C

6. Humidity Sensor Corrections

7. ERU Discharge Air Static Pressure Corrections

8. ERU Design Improvement

It is recommended that the tasks are carried out in the above sequence. Further, Items 7 and 8 are linked to each other and should therefore be completed simultaneously.

Please refer to the drawings provided in Appendix A of this report for details on the design of each of these items.

Temperature Sensor Corrections

5.1.1. General

All 16 temperature sensors serving the 4 ERUs (i.e. 4 sensors per unit) shall be recalibrated and commissioned to ensure that they are operating correctly.

Any sensors which are identified to be faulty following this process shall be replaced with new equivalent sensors, and re-commissioned.

ERU Control Sequence Corrections

5.2.1. General

The control sequences will be modified such that:

Cooling mode (summer) – supply air discharge temperature setpoint: 55oF / 48oF (DB/WB) Heating mode (winter) – supply air discharge temperature setpoint: 63oF (DB)

WWHP Control Sequence & Valve Corrections

5.3.1. General

All sixteen (16) manual isolation valves in heat pumps primary loops shall be replaced by eight

(8) three-way automatic control valves which are linked to BAS. This shall facilitate the operation of all 4 WWHPs in both heating and cooling mode, as necessary

5.3.2. Temporary Measures

The modification of the control sequences and the modification of valves shall have a minimal impact on the day-to-day operation of Buildings 34, 35 and 36. The mechanical contractor shall coordinate this shut-down with the VA to minimize the impact on the operation of these building.

Cross-Connections on ERU-1S, -2S & 1-P

5.4.1. General

Three (3) ERUs (ERU-1S, -2S and -1P) have been fitted with cross-connection flexible ducts and must be removed. Openings for outdoor air intake and exhaust air ducts shall be patched and sealed.

5.4.2. Temporary Measures

The repair work will require temporary shutdowns of each of the 3 ERUs. However, the repairs will be carried out sequentially and on a single ERU at any one time, to minimize impact on the relevant buildings.

Cross-Connection on ERU-1C

5.5.1. General

ERU-1C is fitted with cross-connections flexible duct shall be modified. Flexible duct shall be replaced by a hard duct. Exhaust air from several rooms (toilets, locker rooms, HAC rooms) will be modified so that they will exhaust directly to outside.

- Install new exhaust fan with capacity of 775 CFM

- Ductwork shall be modified so exhaust air from several rooms (toilets, locker rooms, HAC rooms) will directed to outside thru new exhaust fan.

5.5.2. Temporary Measures

In order to proceed with this work, ERU-1C will need to be shut down on a temporary basis.

However, in order to minimize any down-time, a phasing strategy will be developed as follows: -

The contractor shall install ductwork distribution, new exhaust fan and other ancillary equipment as practical without any shutdown.

The contractor shall notify the VA of an impending shutdown to finalize the works – this notification shall include details on the initial shut-down date, the anticipated duration of the shutdown, and the temporary measures which will be provided (e.g. portable window-mounted AC units). This shutdown shall primarily allow the contractor to complete connections between existing and new systems. The contractor shall be directed to minimize the duration of the shutdown.

Humidity Sensor Corrections

5.6.1. General

Seventy (70) new humidity/temperature sensors will be provided in the rooms within Buildings 34, 35, and 36 which are served by chilled beams. A control sequence will be implemented which will ensure that the chilled water supply temperature is at least 2 degrees greater than the dew point temperature.

ERU Discharge Air Static Pressure Corrections

5.7.1. General

The supply fans in all 4 ERUs shall be replaced, to achieve a discharge static pressure of at least 1.3” water gauge at the discharge side of ERU.

Modular plenum fans will meet the airflow, spatial and static pressure requirements of the ERUs and the buildings.

5.7.2. Temporary Measures

The installation of new supply air fans shall require a temporary shutdown of each ERU. These tasks shall be completed in conjunction with all other items which will require ERU shutdowns in order to minimize the number and duration of ERU shutdowns.

ERU Design Improvement

5.8.1. General

The Basis of Design for this work shall include the following modifications.

Install new supplemental DX coils within the ERUs, in place of the existing hot gas reheat coils. The hot gas reheat coils shall be positioned outside of the ERU, along the supply air duct. This shall allow the cooling coils to share a condensate drain and will also ensure that the cooling and heating sequences are carefully coordinated to maintain appropriate supply air temperature and humidity content.

The new supply fans must achieve a discharge static pressure of at least 1.3”. The table below lists the total static pressure drop that must be overcome by the fans to achieve this requirement. This figure includes the pressure drop from the existing coils and the new supplementary coils.

Table 1: ERU Supply Fan Selection Data

SUPPLY

FAN

ORIGINAL DESIGN DATA IN

REALITY NEW DESIGNED DATA

AIRFLOW TOTAL

SP

EXTERNAL

SP

EXTERNAL

SP

SUPPLEMENTARY

COIL SP AIRFLOW TOTAL

SP

ERU-1S 1,773 2.22 1.30 0.35 0.5 1,773 3.67

ERU-2S 1,828 2.26 1.30 0.78 0.5 1,828 3.28

ERU-1C 4,188 2.16 1.30 0.09 0.5 4,188 3.87

ERU-1P 2,588 3.32 1.30 0.41 0.5 2,588 4.71

The existing concrete walkaround outside Building 35 shall be extended to facilitate the placement of the new DX condensing unit. The contractor shall submit shop drawings to demonstrate that the new sidewalk will match the existing installation.

As part of the construction process, the Contractor shall arrange for a factory-certified maintenance technician to evaluate and, if necessary, service the heat pumps which serve each ERU.

5.8.2. Temporary Measures

The installation of new cooling coils shall require a temporary shutdown of each ERU. These tasks shall be completed in conjunction with all other items which will require ERU shutdowns (see Sections 5.4, 5.5 and 5.7 of this report) in order to minimize the number and duration of ERU shutdowns.

The installation of the new DX condensing units (including the concrete pad and protective fencing) shall have minimal impact on the day-to-day operation of the buildings.

6.0 BAS Improvements

Design Approach The approach is to correct programming in the BAS to provide better efficiency. Set point resets will be implemented for both discharge air temperature and supply air static pressure.

6.1.1. Supply air static pressure setpoint reset:

When two (adj.) or more VAV dampers are more than 90% (adj.) open, the supply fan static pressure setpoint shall be reset upward. This will continue until no more VAV dampers are 90% (adj.) open or the static pressure setpoint has reset upward to the system maximum setting (maximum setpoint to be determined and documented by Test and Balance contractor).

When all but one (adj.) VAV dampers are less than 80% (adj.) open, the supply fan static pressure setpoint shall be reset downward, until at least two (adj.) dampers are more than 80% open or the static pressure setpoint has reset to the system minimum setting (minimum setpoint to be determined and documented by Test and Balance contractor).

The units for which the static pressure resets will be implemented is listed below:

AC-8-1, AC-7-1, AC-14-1

AC-1-17, AC-2-17, AC-3-17, AC-4-17, RTU-1-17

6.1.2. Discharge air temperature setpoint reset:

The controller shall monitor the discharge air temperature and shall reset the discharge air temperature setpoint based on outside air conditions and satisfying all zone cooling requirements.

o The initial setpoint shall be 56°F (adj.)

o The DAT setpoint shall incrementally reset between a high and low offset range as described below. As zone cooling demand increases, a minimum of 3 cooling requests (adj.), the setpoint shall incrementally reset down to a minimum of the low offset. With no cooling requests, the setpoint shall incrementally reset up to a maximum high offset.

Cooling requests shall typically be determined at the terminal unit zone level

Increment shall be 0.2°F/minute (adj.)

o When outside air temperature is above 70°F (adj.), the DAT setpoint shall range from high offset of +2°F (adj.) to a low offset of -3°F (adj.).

o When outside air dry-bulb temperature is between 70 and 60°F (adj.) and dewpoint is below 56°F (adj.), proportionally vary low offset to 0°F (adj.) and maintain those offsets when the outside air temperature is 60°F (adj.) and below.

The units for which the discharge air temperature resets will be implemented is listed below:

AC-4-1

AC-4-17, RTU-1-17

6.1.3. VFD scaling issues, The control programming will need to be adjusted to align the BAS and field values for the VFD.

Similarly, the drive settings for several VFDs will need to be corrected or recalibrated to align BAS and field values, and to ensure the drive remains operable with changes in value. A lack of proper calibration can result in VFD hunting as controlling setpoints (downstream static pressure, airflow, etc.) become unstable. The corrective action plan is to require a factory representative to work alongside a controls contractor to reprogram the VFDs. The fan drives included can be seen in the table below:

Table 2: VFD Scaling and Feedback Issues – VFD Make/Model

Bldg. Unit ID Make Model 1 AC-5-1 SF-05 Square D E-Flex

17 AC-1-17 SF-01 York AYK550 17 AC-2-17 SF-02 York AYK550 17 AC-3-17 SF-03 York AYK550 17 AC-4-17 SF-04 York N/A 17 RF-04 York N/A 17 RTU-1-17 SF-01 Trane TR200

19 AC-1-19 SF-01 SEMCO EPD-13

RF-01 SEMCO EPD-13

19 AC-2-19 SF-02 York N/A RF-02 York N/A

Table 3: Fan Interlock Issue

Bldg. Equipment Issue Description

17 AC-3-17

The exhaust fan is not interlocked with the supply fan. When unit was tripped off the exhaust fan kept running when the supply fan was off. The exhaust air damper also remained

OPEN.

The exhaust fan did not shut down upon the freeze-stat trip, but it did shut down when commanded to do so via the service switch at the local control panel. Further investigation of this issue showed there to be a programming error for the exhaust fan. The corrective action plan is to rectify the programming error to ensure the exhaust fan shuts down upon a hardwired safety trip.

7.0 Pneumatic Control Upgrades

This project scope includes replacing existing pneumatic valves with new DDC controlled valves which will be tied into the existing BAS.

AC-3-18 and AC-4-18 in Building 18 are roof-mounted York air handling units. Both units are utilizing pneumatic actuators for the following components:

Outside Air Damper Exhaust Air Damper Return Air Damper Face & Bypass Damper Steam Heating Valve Chilled Water Valve

The location of the pneumatic valves and actuators are shown in Appendix A.

8.0 Mechanical Improvements

Various mechanical improvements were recommended to repair an outside air damper linkage, to replace an energy recovery wheel, and to convert staged electric heat to SCR controlled modulated heat for four VAV terminal units.

This project scope includes the following improvements.

Table 4: Mechanical Improvements

Bldg Equipment & Location Improvements

1 AC-2-1 Repair the outside air damper linkage AC-3-1 Replace energy recovery wheel

136 Electric Heating

Convert the staged electric heat to SCR controlled modulated heat for the following terminal units: VAV-02 (Room 111), VAV-04 (Room 104), VAV- 05 (Room 106), and VAV-06 (Room 109).

Refer to Appendix A - Drawings for equipment sizes of the VAV reheats.

9.0 Insulation Repairs

This project scope includes the following repairs.

Table 5: Insulation Repairs

Building Equipment and Location Repairs

AC-1-1

6th Floor

Room 618

The preheat, reheat, and humidifier pipes are missing insulation.

Preheat: 3’ long, 2" diameter, 190 deg F Reheat: 2’ long, 2” diameter, 220 deg F

3 Strainer Jackets, 1 Valve Jacket Humidifier:

6’ long, 2" diameter, 220 deg F 2.5’ long, 1" diameter, 210 deg F 3’ long, 1.5" diameter, 210 deg F Return air duct:

32” by 30” duct missing 15’ of insulation Outside air duct:

30” by 76” duct missing 5’ of insulation

AC-4-1

6th Floor

Room 618

The low pressure steam lines are missing insulation.

2.5’ long, 1" diameter, 230 deg F 1.5’ long, 1/2" diameter, 200 deg F 1.5’ long, 1/4" diameter, 180 deg F Supply air duct:

35” by 30” (to 20” by 30”) duct missing 40” of insulation 20” by 30” duct missing 106” of insulation

AC-6-1

5th Floor

Room 541

The medium pressure preheat steam lines are missing insulation.

3’ long, 1/2" diameter, 180 deg F

AC-14-1

Ground Floor

The medium pressure steam lines are missing insulation.

7’ long, 1/2" diameter, 210 deg F (30psi)

1 Strainer Jacket, 2 Valve Jackets

AC-2-18

Attic

The condensate return piping is uninsulated.

2’ long, 2" diameter, 110 deg F

AC-3-18

1st Floor

The steam preheat line is uninsulated.

3’ long, 1" diameter, 150 deg F

102 RTU-1-102 The preheat steam line is missing insulation.

5’ long, 2" diameter, 200 deg F

34 Hot Water Piping Approx. 6” of insulation required on 2” copper pipe

36 Hot Water Piping Approx. 6” of insulation required on 2” copper pipe

See Appendix A - Drawings for details and locations of insulation repairs.

10.0 Sensor Corrections

This project shall replace inoperable sensors to improve BAS monitoring and issue diagnosis, and equipment safety.

Listed in the table below are the sensors which will be replaced as part of this project.

Table 6: Sensor Corrections

Bldg. Equipment Sensor Range Description Product Number

AC-3-1 High Static Safety Switch

1” to 12”

WC

SPST/Manual Reset

SW 141-

AC-14-1

Discharge Air Humidity Sensor

0 – 100% RH Duct Sensor QFM3101

Mixed Air Temperature

Sensor

20°F to 120°F

Averaging Sensor, 4-20 mA 535-490-36

Bldg Sensor Range Description Product Number

1 SCHW Return Temperature 30 ˚F to 250 ˚F Immersion Well 536-767-40 19 SCHW Return Temperature 30 ˚F to 250 ˚F Immersion Well 536-767-25

See Appendix A – Drawings for detailed locations of sensors

11.0 Chilled Water Improvements

Investigation Results Alares developed a chilled water model of the campus using the HVAC Solution – Professional software. The model results and recommendation are included in Appendix F.