North Community High School Analysis of Building ...

North Community High School

Analysis of Building Ventilation Systems

Minneapolis Public Schools

COVID 19 Analysis of Building Ventilation Systems Project Number: 20-472.00 September 24, 2020

COVID 19 Analysis of Building Ventilation Systems KFI Engineers • KFI – 20-472.00 North Community High School Copyright 2020 KFI Engineers

Minneapolis Public Schools 2

Title Page

Building Information Building Owner: Minneapolis Public Schools Building Name: North Community High School 1500 James Avenue North Minneapolis, MN 55411

KFI Project Manager Information

Larry Justin, P.E. Senior Project Manager KFI Engineers 670 County Road B West St. Paul, MN 55113-4527 [email protected] 651-771-0880 - Office 651-771-0878 – Fax

Site Contacts

Curtis Hartog, P.E. Executive Director Capital Planning, Construction & Maintenance Minneapolis Public Schools 1250 West Broadway Avenue Minneapolis, MN 55411 [email protected] 612-668-0275 - Office 612-806-1274 – Fax

mailto:[email protected]

mailto:[email protected]



Table of Contents

Title Page ...........................................................................................................................................2

Table of Contents ...............................................................................................................................3

Glossary of Terms and Abbreviations ..................................................................................................4

Executive Summary ............................................................................................................................6

Disclaimer ........................................................................................................................................ 11

Introduction .................................................................................................................................... 12

ASHRAE Guidance ............................................................................................................................ 13

Building Assessment / Recommendations......................................................................................... 14

HVAC System Filtration and Ventilation .................................................................................................. 14

Building Automation System ................................................................................................................... 49

Nurse and Office Area Air Flow ............................................................................................................... 50

Potential Isolation Area ........................................................................................................................... 51

Appendices ...................................................................................................................................... 52

Appendix A – Matrix of Existing HVAC Systems ...................................................................................... 53

Appendix B – Building System Zone Maps .............................................................................................. 63

Appendix C – Equipment Location Maps ................................................................................................ 66

Appendix D – MERV Filter Ratings ........................................................................................................... 70

Appendix E – Portable HEPA Filtration Units .......................................................................................... 72



Glossary of Terms and Abbreviations

ACH Air Change per Hour

• A measure of air flow in a specified volume of space

AHU Air Handling Unit

• HVAC equipment, typically contains fans, filters, and heating and/or cooling coils

AII room Airborne Infection Isolation room

• Room with mechanical systems designed to reduce the spread of airborne

infection disease to other areas

ASHRAE American Society of Heating, Refrigerating, and Air-conditioning Engineers

• Professional organization that supports industry research and publishes design

best practice guidelines and standards

BAS Building Automation System

• Control system for building HVAC and lighting systems

CAV Constant Air Volume

• Describes the type of control of an AHU- this type of unit varies the supply air

temperature but not the volume of air flow

CFM Cubic Feet per Minute

• Measure of volumetric flow, typically used for air flow

DOAS Dedicated Outdoor Air System

• AHU that supplies 100% conditioned outdoor air (does not mix ventilation air

with recirculated room air)

ERU Energy Recovery Unit

• AHU with a heat exchanger to transfer heat between exhaust air and incoming

outdoor air

HEPA High Efficiency Particulate Air (filter)

• A type of filter that can remove at least 99.97% of particles with a size of 0.3

microns.

HVAC Heating, Ventilation, and Air-conditioning

• Term used to describe building systems and technical expertise of professionals

MERV Minimum Efficiency Reporting Value

• A filter’s ability to capture particles between 0.3 and 10 microns in size

• A higher MERV rating captures a larger percentage of small particles

• See Appendix D for MERV ratings and ratings by particle size

OA Outdoor Airflow

• Ventilation air flow

RTU Roof Top Unit

• An HVAC system located on the roof that contains all heating and cooling

equipment in one packaged unit

SF Square Feet

• Measure of area



TAB Test and Balance

• Measurement and adjustment of building HVAC equipment.

VAV Variable Air Volume

• Describes the type of control of an AHU- this type of unit varies both the supply

air temperature and the volume of air flow to a zone

• Also used to describe the piece of equipment in a zone that includes a damper to

reduce airflow (VAV box)

VRF Variable Refrigerant Flow

• A type of refrigeration system that includes an outdoor condensing unit and

indoor fan units with a cooling coil. Sometimes the indoor unit also includes a

heating coil.



Executive Summary

Minneapolis Public Schools (MPS) requested individual facility ventilation studies for all occupied elementary, middle school, and high school buildings. These studies identified improvements to the air handling units (AHUs) and ventilation in the buildings that will allow the building to meet current ASHRAE guidance to limit virus transmission in the ventilation system in the building. Adequate outdoor air flow, or ventilation, can dilute the number of viral particles in the breathing zone of a space. Effective filtration can remove particles from the air. However, viral particles are extremely small. Most filters are not rated to capture particles as small as the virus that causes COVID-19, but some can capture a large fraction of viral-sized particles. While it will not be practical to rely only on filtration, increasing filtration levels will reduce the number of viral particles in the air. This report provides the results for North Community High School. KFI has reviewed existing HVAC plans, Test-and-Balance (TAB) reports, and the building automation system (BAS). KFI has also performed an onsite evaluation for the facility. A request for proposal (RFP) has been submitted for a full HVAC system replacement at North High School. It is anticipated that within five (5) years all units will be replaced. The initial thought of design can be found in the RFP response written by the Pope Architects/KFI Engineers team. North High School has thirty-two (32) air handling units that supply different zones within the building. All mechanical equipment is original to the building except AHU-01/S-41, which was installed in 1996 and S-06/AHU-6, which was installed in 2006. The building was constructed in 1971, and the original mechanical equipment has a projected replacement date of 2001. All units are currently filtered at the MERV 8 level. The filtration levels of each HVAC system are detailed in the Building Assessment section, and the existing final filter MERV levels are provided in Table 1, Table 2, and Table 3. A toilet room connected to the nurse’s area has been identified as a potential isolation area for students or staff who fall ill during the day. This room would require the addition of a dedicated exhaust system, sealing of walls, and rebalancing of S-18. It would require ill persons to enter and exit via the nurse’s office on the first floor.



Through this project, a number of conditions were identified that could be corrected immediately. Table 1 summarizes these immediate corrections. Table 2 summarizes recommendations for future system updates that do not require significant capital improvements. Table 3 identifies recommended improvements that will require a capital program expenditure to complete. These improvements should be part of a larger capital effort for improvement to ventilation systems Districtwide. Table 1: Summary of Immediate Corrections

System Tag Existing

Filtration Level*

Serves Work in Progress

S-01 MERV 8 1st Floor W Lunch /

Dining

• Replace filters with clean MERV 8 filters

• Change schedule to start at 3:30 AM


Kitchen




Classrooms



S-04 MERV 8 1st Floor W Locker

Room



S-05 MERV 8 1st Floor W Locker /

Classrooms



S-06/AHU-06 MERV 8 1st Floor W

Classrooms (North)

• Replace filters with clean MERV 8 filters or

MERV 14 filters depending on measurements

from Table 2


S-07 MERV 8 2nd Floor W

Classrooms (South)



S-08 MERV 8 2nd Floor W Math & Counseling (West)



S-09 MERV 8 2nd Floor W Media

Center & Classrooms




Classrooms & Offices (West)



S-11 MERV 8 2nd Floor W Media

Center & Classrooms




Resources (North)



S-13 MERV 8 1st Floor E Special

Education



S-14 MERV 8 1st Floor E Shops • Replace filters with clean MERV 8 filters




System Tag Existing

Filtration Level*


S-15 MERV 8 1st Floor E Shops /

Classrooms



S-16 MERV 8 1st Floor E Shops • Replace filters with clean MERV 8 filters


S-17 MERV 8 1st Floor E Offices /

Lobby



S-18 MERV 8 1st Floor E Health

Center



S-19 MERV 8 1st Floor E Locker

Rooms



S-20 MERV 8 2nd Floor E Science

Labs (West)



S-21 MERV 8 2nd Floor E Science

Labs (East)



S-22 MERV 8 2nd Floor E Lobby /

South Skyway



S-23 MERV 8 Auditorium • Replace filters with clean MERV 8 filters


S-24 MERV 8 2nd Floor E Lobby /

North Skyway



S-25 MERV 8 Auditorium



• Disable BAS demand control ventilation

S-26 MERV 8 2nd Floor E Art

Classrooms (West)



S-27 MERV 8 2nd Floor E Special Education (East)



S-28 MERV 8 East Wing Gym




S-29 MERV 8 East Wing Gym




S-39 MERV 8 East Wing Music • Replace filters with clean MERV 8 filters




System Tag Existing

Filtration Level*


AHU-1/S-41 MERV 8 Science Addition

• Replace filters with clean MERV 8 filters or

MERV 14 filters depending on measurements

from Table 2


S-40 MERV 8 Boiler Room • Replace filters with clean MERV 8 filters


UV’S MERV 1-4 Auxiliary Gym • Replace filters with clean filters


Table 2: Summary of Recommendations without Significant Capital Expenditures

System Tag Existing

Filtration Level*

Serves Recommendations

S-06/AHU-06 MERV 8 1st Floor W Classrooms

(North)

• Measure actual outdoor airflow.

Rebalance as needed to maintain a

minimum of 508 cfm of outdoor air

• Measure break horsepower and actual

static pressure to determine if unit can

withstand MERV 14 filtration

S-18 MERV 8 1st Floor E Health Center • Provide standalone HEPA filtration unit

for nurse’s area

AHU-1/S-41 MERV 8 Science Addition

• Measure break horsepower and actual

static pressure to determine if unit can

withstand MERV 14 filtration.

Table 3: Summary of Recommendations Requiring Capital Expenditures

System Tag Existing

Filtration Level*


S-01 MERV 8 1st Floor W Lunch / Dining • Replace unit in its entirety

S-02 MERV 8 1st Floor W Lunch / Kitchen • Replace unit in its entirety


Classrooms • Replace unit in its entirety

S-04 MERV 8 1st Floor W Locker Room • Replace unit in its entirety

S-05 MERV 8 1st Floor W Locker /


S-06/AHU-06 MERV 8 1st Floor W Classrooms

(North)

• Replace supply fan motor depending

on measurements from Table 2

S-07 MERV 8 2nd Floor W Classrooms

(South) • Replace unit in its entirety



System Tag Existing

Filtration Level*


S-08 MERV 8 2nd Floor W Math & Counseling (West)

• Replace unit in its entirety

S-09 MERV 8 2nd Floor W Media Center &


S-10 MERV 8 2nd Floor W Classrooms &

Offices (West) • Replace unit in its entirety

S-11 MERV 8 2nd Floor W Media Center &


S-12 MERV 8 2nd Floor W Resources

(North) • Replace unit in its entirety

S-13 MERV 8 1st Floor E Special Education • Replace unit in its entirety

S-14 MERV 8 1st Floor E Shops • Replace unit in its entirety

S-15 MERV 8 1st Floor E Shops /


S-16 MERV 8 1st Floor E Shops • Replace unit in its entirety

S-17 MERV 8 1st Floor E Offices / Lobby • Replace unit in its entirety

S-18 MERV 8 1st Floor E Health Center

• Replace unit in its entirety

• Convert toilet room into an isolation

area

S-19 MERV 8 1st Floor E Locker Rooms • Replace unit in its entirety

S-20 MERV 8 2nd Floor E Science Labs

(West) • Replace unit in its entirety

S-21 MERV 8 2nd Floor E Science Labs (East) • Replace unit in its entirety

S-22 MERV 8 2nd Floor E Lobby / South

Skyway • Replace unit in its entirety

S-23 MERV 8 Auditorium • Replace unit in its entirety

S-24 MERV 8 2nd Floor E Lobby / North

Skyway • Replace unit in its entirety

S-25 MERV 8 Auditorium • Replace unit in its entirety

S-26 MERV 8 2nd Floor E Art Classrooms

(West) • Replace unit in its entirety

S-27 MERV 8 2nd Floor E Special Education

(East) • Replace unit in its entirety

S-28 MERV 8 East Wing Gym • Replace unit in its entirety

S-29 MERV 8 East Wing Gym • Replace unit in its entirety

S-39 MERV 8 East Wing Music • Replace unit in its entirety

AHU-1/S-41 MERV 8 Science Addition • Replace supply fan motor depending

on measurements from Table 2

S-40 MERV 8 Boiler Room • Replace unit in its entirety

UV’S MERV 1-4 Auxiliary Gym • Replace units in their entirety



Disclaimer

Performance guidelines provided in the report are for informational purposes only and are not to be construed as a design document. Recommendations implemented should be installed in conformance to all local code requirements. Ventilation and filtration recommendations are provided based on ventilation requirements in the Minnesota 2020 Mechanical Code and guidance from ASHRAE on limiting viral transfer. If equipment was installed under an earlier code that equipment is not required to comply with the 2020 code.



Introduction

North Community High School is a two-story facility educating over 400 students in grades 9-12. The building was constructed in 1971 with a science addition in 1996. The building is 287,113 sf. AHU-1/S-41 is a Variable Air Volume (VAV) system that provides heating, cooling, and ventilation to the science addition. All other units are a Constant Air Volume (CAV) system that provides heating, cooling, and ventilation to spaces within the building. Two steam boilers and two screw chillers operate to provide heating and cooling for the thirty-two (32) air handling units. Students have not occupied the school building since March of 2020 due to the COVID-19 pandemic. The SARS-CoV-2 virus causes coronavirus disease, or COVID-19. The SARS-CoV-2 virus is new and research into the virus and disease spread is still evolving. So far, we have learned that primary transmission route of the virus is via the air in droplets and aerosols. Recommendations for reducing the spread of COVID-19 focus broadly on: 1) maintaining social distance between people, 2) sanitizing and cleaning surfaces, and 3) reducing the number and circulation of viral particles in the air. HVAC systems can influence this last item. Adequate outdoor airflow, or ventilation, can dilute the number of viral particles in the breathing zone of a space. Effective filtration can remove particles from the air. However, viral particles are extremely small, on the order of 0.12 microns. Filters are typically rated by the size of particles that will be removed, for example, MERV 14 filters are rated to remove 95% or greater of particles down to 3 microns. While it will not be practical to rely only on filtration, increasing filtration levels will reduce the number of viral particles in the air. ASHRAE guidance is available online at: https://www.ashrae.org/technical-resources/reopening-of-schools-and-universities. This report provides the results for North Community High School. KFI has performed the following scope of work:

• Reviewed the existing HVAC building plans and test and balance reports (TAB) to identify

recommended improvements to the systems to meet current ASHRAE guidance for COVID19.

• Performed an on-site assessment of the facility.

• Reviewed the building automation system (BAS) to determine potential control changes to

improve indoor air quality.

https://www.ashrae.org/technical-resources/reopening-of-schools-and-universities



ASHRAE Guidance

The American Society of Heating Refrigerating and Air-Conditioning Engineers (ASHRAE) provides research, standards, and continuing education that typically define best practice in the HVAC industry. ASHRAE has been developing industry standards for best practice in reducing HVAC spread of airborne illnesses for years. ASHRAE has released guidance for schools and universities to prepare for the reopening of school buildings. This advice focuses on three core principles aimed at reducing the spread of COVID19:

1. Increase outdoor air where possible

a. Follow current ventilation standards at a minimum

b. Ventilate at least 2 hours prior to occupancy

c. Disable demand-controlled ventilation during the pandemic

2. Increase filtration levels where possible

a. MERV15 filtration provides similar filtration levels as an N95 mask (95% of particles

entrapped to 3 microns in size)

b. MERV14 filtration is recommended where possible

3. Maintain indoor environments between 40% and 60% relative humidity and temperatures

between 68°F and 78°F where possible

This project focuses on the first two principles above. It seeks to evaluate the ventilation and filtration levels in the existing systems, to evaluate system capacity to increase outdoor air and filtration levels, and to evaluate building control systems to recommend changes. Temperature maintenance for buildings is provided in Board Regulation 3520A. Due to the complexity of establishing and maintaining relative humidity in a space, MPS is not evaluating the relative humidity as part of this study.



Building Assessment / Recommendations

HVAC System Filtration and Ventilation Variable-air-volume (VAV) systems provide heating, cooling, and ventilation to zones within the building. The airflow is able to modulate based on the current space environment. AHU-1/S-41 is the only unit that utilizes a VAV system for the science addition. Constant-air-volume (CAV) systems provide heating, cooling, and ventilation to one specific zone within the building. The airflow is constant, and does not modulate with an increase or decrease in load and is either on or off. These units operate with a supply fan, a heating coil, a cooling coil, and dampers to modulate the amount of return air and outside air. A summary of the systems in the building is provided in Table 4. A matrix was developed for the school systems with airflows, static pressures, filtration, and control details. This matrix is provided in Appendix A. Table 4: System Overview

System Tag Age Serves System Type

S-01 1971 1st Floor W Lunch / Dining CAV

S-02 1971 1st Floor W Lunch / Kitchen CAV

S-03 1971 1st Floor W Lunch / Classrooms CAV

S-04 1971 1st Floor W Locker Room CAV

S-05 1971 1st Floor W Locker / Classrooms CAV

S-06/AHU-06 2006 1st Floor W Classrooms (North) CAV

S-07 1971 2nd Floor W Classrooms (South) CAV

S-08 1971 2nd Floor W Math & Counseling (West) CAV

S-09 1971 2nd Floor W Media Center & Classrooms CAV

S-10 1971 2nd Floor W Classrooms & Offices (West) CAV

S-11 1971 2nd Floor W Media Center & Classrooms CAV

S-12 1971 2nd Floor W Resources (North) CAV

S-13 1971 1st Floor E Special Education CAV

S-14 1971 1st Floor E Shops CAV

S-15 1971 1st Floor E Shops / Classrooms CAV

S-16 1971 1st Floor E Shops CAV

S-17 1971 1st Floor E Offices / Lobby CAV

S-18 1971 1st Floor E Health Center CAV

S-19 1971 1st Floor E Locker Rooms CAV

S-20 1971 2nd Floor E Science Labs (West) CAV

S-21 1971 2nd Floor E Science Labs (East) CAV

S-22 1971 2nd Floor E Lobby / South Skyway CAV

S-23 1971 Auditorium CAV

S-24 1971 2nd Floor E Lobby / North Skyway CAV

S-25 1971 Auditorium CAV

S-26 1971 2nd Floor E Art Classrooms (West) CAV

S-27 1971 2nd Floor E Special Education (East) CAV



S-28 1971 East Wing Gym CAV

S-29 1971 East Wing Gym CAV

S-39 1971 East Wing Music CAV

AHU-1/S-41 1996 Science Addition VAV

S-40 1971 Boiler Room CAV

UV’S 1971 Auxiliary Gym CAV



S-01 S-01 serves the lunch room on the first floor of the west wing. It is located in mechanical room 51. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 5. Table 5: System Ventilation and Static Pressure – S-01

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total

SP [in wc] Actual Total

SP [in wc]

S-01 7,667 NR NR 8,009 NR NR

NR = Not Reported Information is not available to determine if this unit meets the outside air requirement of the current code. Heating and cooling coil information is not available to conclude if the unit can withstand an increase in outdoor air ventilation. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. Based on the large increase in static pressure from MERV 8 to MERV 14 filtration, the limited available fan power, and the age of the unit, it will not support an increase in filtration without replacement of the supply fan. We recommend replacing the entire unit and designing around MERV 14 filtration levels. S-01 is shown in Figure 1.

Figure 1: S-01



S-02 S-02 serves the lunch room and kitchen on the first floor of the west wing. It is located in mechanical room 62. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 6. Table 6: System Ventilation and Static Pressure – S-02

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-02 5,492 NR NR 3,649 NR NR

NR = Not Reported Information is not available to determine if this unit meets the outside air requirement of the current code. Heating and cooling coil information is not available to conclude if the unit can withstand an increase in outdoor air ventilation. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. Based on the large increase in static pressure from MERV 8 to MERV 14 filtration, the limited available fan power, and the age of the unit, it will not support an increase in filtration without replacement of the supply fan. We recommend replacing the entire unit and designing around MERV 14 filtration levels. S-02 is shown in Figure 2.

Figure 2: S-02B



S-03 S-03 serves the lunch room and a few classrooms on the first floor of the west wing. It is located in mechanical room 61. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 7. Table 7: System Ventilation and Static Pressure – S-03

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-03 9,497 NR NR 6,695 NR NR

NR=Not Reported Information is not available to determine if this unit meets the outside air requirement of the current code. Heating and cooling coil information is not available to conclude if the unit can withstand an increase in outdoor air ventilation. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. Based on the large increase in static pressure from MERV 8 to MERV 14 filtration, the limited available fan power, and the age of the unit, it will not support an increase in filtration without replacement of the supply fan. We recommend replacing the entire unit and designing around MERV 14 filtration levels. S-03 is shown in Figure 3.

Figure 3: S-03



S-04 S-04 serves the locker room on the first floor of the west wing. It is located in mechanical room 56. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 8. Table 8: System Ventilation and Static Pressure – S-04

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-04 4,905 NR NR 271 NR NR


Figure 4: S-04



S-05 S-05 serves the locker room and a few classrooms on the first floor of the west wing. It is located in mechanical room 63. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 9. Table 9: System Ventilation and Static Pressure – S-05

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-05 9,661 NR NR 2,210 NR NR


Figure 5: S-05



S-06/AHU-06 S-06/AHU-06 serves the locker room and classrooms on the north side of the west wing on the first floor. It is located in mechanical room 71. The unit was installed in 2006, and has a projected replacement year of 2036. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 10. Table 10: System Ventilation and Static Pressure – S-06/AHU-06

System Area

Served [sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-06/AHU-06 7,249 NR 2,000 508 3.4 NR

NR=Not Reported The design outdoor airflow is higher than the code level of outdoor air as calculated with ASHRAE’s default occupancy for each space. Locker rooms have an exhaust requirement than can be met by introducing a large volume of outside air. It is recommended to measure the actual outdoor airflow and maintain a minimum of 508 cfm of outdoor air. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. The break horsepower and actual static pressure information is not available. We recommend measuring the break horsepower and actual static pressure to determine if this unit can withstand an increase in filtration. S-06/AHU-06 is shown in Figure 6.

Figure 6: S-06/AHU-06



S-07 S-07 serves the classrooms on the south side of the west wing on the second floor. It is located in mechanical room 56. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 11. Table 11: System Ventilation and Static Pressure – S-07

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-07 9,169 NR NR 3,985 NR NR


Figure 7: S-07



S-08 S-08 serves the math classrooms and counseling on the west side of the west wing on the second floor. It is located in mechanical room 57. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 12. Table 12: System Ventilation and Static Pressure – S-08

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-08 8,250 NR NR 2,993 NR NR


Figure 8: S-08



S-09 S-09 serves the media center and classrooms on the east side of the west wing on the second floor. It is located in mechanical room 66. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 13. Table 13: System Ventilation and Static Pressure – S-09

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-09 10,369 NR NR 3,925 NR NR


Figure 9: S-09



S-10 S-10 serves the classrooms on the west side of the west wing on the second floor. It is located in mechanical room 76. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 14. Table 14: System Ventilation and Static Pressure – S-10

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-10 7,890 NR NR 2,120 NR NR


Figure 10: S-10



S-11 S-11 serves the media center and classrooms on the east side of the west wing on the second floor. It is located in mechanical room 67. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 15. Table 15: System Ventilation and Static Pressure – S-11

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-11 9,652 NR NR 3,498 NR NR


Figure 11: S-11



S-12 S-12 serves the classrooms on the north side of the west wing on the second floor. It is located in mechanical room 77. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 16. Table 16: System Ventilation and Static Pressure – S-12

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-12 9,072 NR NR 3,857 NR NR


Figure 12: S-12



S-13 S-13 serves the special education classrooms on the first floor of the east wing. It is located in mechanical room 11. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 17. Table 17: System Ventilation and Static Pressure – S-13

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-13 4,125 NR NR 2,235 NR NR


Figure 13: S-13



S-14 S-14 serves the shops on the first floor of the east wing. It is located in mechanical room 11. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 18. Table 18: System Ventilation and Static Pressure – S-14

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-14 3,487 NR NR 1,656 NR NR


Figure 14: S-14



S-15 S-15 serves the shop offices and classrooms on the first floor of the east wing. It is located in mechanical room 21. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 19. Table 19: System Ventilation and Static Pressure – S-15

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-15 7,501 NR NR 1,799 NR NR

NR=Not Reported Information is not available to determine if this unit meets the outside air requirement of the current code. zHeating and cooling coil information is not available to conclude if the unit can withstand an increase in outdoor air ventilation. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. Based on the large increase in static pressure from MERV 8 to MERV 14 filtration, the limited available fan power, and the age of the unit, it will not support an increase in filtration without replacement of the supply fan. We recommend replacing the entire unit and designing around MERV 14 filtration levels. S-15 is shown in Figure 15.

Figure 15: S-15



S-16 S-16 serves the shops on the first floor of the east wing. It is located in mechanical room 22. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 20. Table 20: System Ventilation and Static Pressure – S-16

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-16 3,488 NR NR 1,533 NR NR


Figure 16: S-16



S-17 S-17 serves the main office and lobby on the first floor of the east wing. It is located in mechanical room 23. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 21. Table 21: System Ventilation and Static Pressure – S-17

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-17 6,189 NR NR 545 NR NR


Figure 17: S-17



S-18 S-18 serves the health center on the first floor of the east wing. It is located in mechanical room 24. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 22. Table 22: System Ventilation and Static Pressure – S-18

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-18 4,092 NR NR 1,272 NR NR


Figure 18: S-18



S-19 S-19 serves the locker rooms on the first floor of the east wing. It is located in mechanical room 31. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 23. Table 23: System Ventilation and Static Pressure – S-19

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-19 8,988 NR NR 205 NR NR


Figure 19: S-19



S-20 S-20 serves the science classrooms on the second floor of the east wing. It is located in mechanical room 16. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 24. Table 24: System Ventilation and Static Pressure – S-20

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-20 8,312 NR NR 3,410 NR NR


Figure 20: S-20



S-21 S-21 serves the science classrooms on the second floor of the east wing. It is located in mechanical room 16. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 25. Table 25: System Ventilation and Static Pressure – S-21

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-21 6,569 NR NR 2,982 NR NR


Figure 21: S-21



S-22 S-22 serves the lobby and south skyway of the second floor that connects the east and west wings. It is located in mechanical room 26. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 26. Table 26: System Ventilation and Static Pressure – S-22

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-22 4,835 NR NR 361 NR NR


Figure 22: S-22



S-23 S-23 serves the auditorium in the east wing. It is located in mechanical room 27. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 27. Table 27: System Ventilation and Static Pressure – S-23

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-23 5,448 NR NR 6,100 NR NR


Figure 23: S-23



S-24 S-24 serves the lobby and north skyway of the second floor that connects the east and west wings. It is located in mechanical room 28. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 28. Table 28: System Ventilation and Static Pressure – S-24

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-24 4,879 NR NR 371 NR NR


Figure 24: S-24



S-25 S-25 serves the auditorium in the east wing. It is located in mechanical room 29. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 29. Table 29: System Ventilation and Static Pressure – S-25

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-25 5,448 NR NR 6,100 NR NR


Figure 25: S-25



S-26 S-26 serves the art classrooms on the west side of the east wing on the second floor. It is located in mechanical room 36. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 30. Table 30: System Ventilation and Static Pressure – S-26

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-26 8,986 NR NR 3,706 NR NR


Figure 26: S-26



S-27 S-27 serves the special education classrooms on the east side of the east wing on the second floor. It is located in mechanical room 36. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 31. Table 31: System Ventilation and Static Pressure – S-27

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-27 9,229 NR NR 3,778 NR NR


Figure 27: S-27



S-28 S-28 serves the main gym in the east wing. It is located in mechanical room 46. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 32. Table 32: System Ventilation and Static Pressure – S-28

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-28 8,145 NR NR 3,375 NR NR


Figure 28: S-28



S-29 S-29 serves the main gym in the east wing. It is located in mechanical room 47. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 33. Table 33: System Ventilation and Static Pressure – S-29

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-29 8,145 NR NR 3,375 NR NR


Figure 29: S-29



S-39 S-39 serves the music rooms on the first and second floor of the east wing. It is located in mechanical room 283. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a CAV system. Ventilation air flows and static pressures are summarized in Table 34. Table 34: System Ventilation and Static Pressure – S-39

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-39 7,875 NR NR 3,032 NR NR


Figure 30: S-39



AHU-1/S-41 AHU-1/S-41 serves the science addition on the south side of the west wing. It is located in mechanical room 173. The unit is original to the addition (installed in 1996), and has a projected replacement year of 2026. It is a VAV system. Ventilation air flows and static pressures are summarized in Table 35. Table 35: System Ventilation and Static Pressure – AHU-1/S-41

System Area

Served [sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

AHU-1/S-41 12,938 NR NR 5,176 NR NR

NR=Not Reported Information is not available to determine if this unit meets the outside air requirement of the current code. Heating and cooling coil information is not available to conclude if the unit can withstand an increase in outdoor air ventilation. This unit has MERV 8 filters. MERV 14 filtration is recommended where possible per ASHRAE. The break horsepower and actual static pressure information is not available. We recommend measuring the break horsepower and actual static pressure to determine if this unit can withstand an increase in filtration. AHU-1/S-41 is shown in Figure 31.

Figure 31: AHU-1/S-141



S-40 S-40 serves the boiler room and mechanical room 247. The unit is original to the building (installed in 1971), and has a projected replacement year of 2001. It is a combustion air unit. Ventilation air flows and static pressures are summarized in Table 36. Table 36: System Ventilation and Static Pressure – S-40

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

S-40 2,387 NR NR 0 0.85 NR

NR=Not Reported This unit is used to ventilate the boiler/mechanical room only. There is no requirement of outdoor airflow for mechanical rooms per ASHRAE. Since the unit serves unoccupied spaces, we recommend maintaining current operation. It is recommended to replace the unit, due to age, when funding is available. S-40 is shown in Figure 32.

Figure 32: S-40



Unit Ventilators The auxiliary gym is served by nine (9) unit ventilators that are ceiling mounted. The units are original to the building (installed in 1971) and have a projected replacement year of 1996. Ventilation air flows and static pressures are summarized in Table 37. Table 37: System Ventilation and Static Pressure – Unit Ventilators

System Area Served

[sf] Actual OA

[cfm] Design OA

[cfm] Code OA

[cfm] Design Total


SP [in wc]

UV’s 7,035 9,446 total 11,250 total 7,035 0.17 each NR

The design and actual outdoor airflows are higher than the code level of outdoor air as calculated with ASHRAE’s default occupancy for each space. It is recommended to maintain the current ventilation of an outdoor airflow of 9,446 cfm. Unit ventilators typically have small fans that do not have the power to support higher filtration levels than they were designed for. In 1971, these units were most likely designed for MERV ratings of MERV1 to MERV4. We recommend replacing these units to provide higher filtration levels. The ceiling mounted unit ventilators are shown in Figure 33.

Figure 33: Unit Ventilators in Auxiliary Gym



Building Automation System The building automation system was reviewed for temperature and humidity levels and to review system schedules and control. Details are included in Appendix A. Typical unit schematic in the BAS is shown in Figure 34. Before the building is occupied, we recommend changing the system operation schedules to have the supply fans for all units start 2 hours before occupancy (3:30 AM). A few units (S-25, S-28, and S-29) have demand control with CO2 setpoints. We recommend disabling demand control ventilation and introduce max OA. We recommend that the exhaust fans run on a 24-hour schedule to improve air quality and increase ventilation rates. Maximizing the economizer mode would help with ventilation when outside temperatures are 71°F or below. We recommend disabling the economizer sequence once outside air temperatures reach 71°F on all units. The graphics in the BAS display the outside air temperature (OAT) in two locations. These values should match, and it is recommended to change the point mapped for the outdoor air on S-01, S-02, S-03, S-05, S-07 and S-11. See the red outline in Figure 34 for the location of the two OAT measurements.

Figure 34: Typical AHU BAS Schematic – S-11



Nurse and Office Area Air Flow Summaries of the airflows in the nurse and main office are provided in the tables below. Outdoor airflow information is not available to determine the percentage of outside air the units serving the nurse and front office units are supplying to the space. Air from the nurse’s office is mixed with the general S-18 return air. The nurse’s area (green) and main office (red) is located on the first floor as seen in Figure 35. A stand-alone HEPA filtration unit at a capacity of 12ACH located in the nurse’s office would limit the viral particles that are returned to S-17. Table 38: Nurse’s Office Air Flow

Health area HVAC System

Supply Air Flow to

Nurse’s Room (cfm)

Area of Nurse’s Room

(sf)

Ceiling Height of Nurse’s Room (ft)

Current ACH Percent OA

S-17 250 345 9.0 4.8 NA

NA = Not Available Table 39: Main Office Air Flow

Office area HVAC System

Supply Air Flow (cfm)

Area of Main Office (sf)

Ceiling Height (ft)

Current ACH Percent OA

S-18 700 590 9.0 7.9 NA

NA = Not Available

Figure 35: First Floor - Main Office Area (Red), Nurse’s Area (Green), and Potential Isolation Room (Blue)



Potential Isolation Area An area has been identified that could be renovated to serve as an isolation room for students who fall ill during the day. This area would need to be designed around ASHRAE Standard 170-2017 Ventilation of Health Care Facilities for Airborne Infection Isolation (AII) Rooms. The airborne infection isolation room would need to be maintained with a negative pressure relationship to adjoining rooms with a minimum of 12 ACH of outdoor air and a minimum 12 ACH of total supply air. All room air will need to be exhausted. If the 12 ACH of supply air is not possible, a HEPA filtered recirculating unit could be provided to increase equivalent ACH requirements. When the room is not used for isolation conditions, the room would need to remain with a negative pressure relationship and the minimum supply air rate could be reduced to 6 ACH. The toilet room off of the nurse’s office (room 314) could be renovated to serve as an isolation area. It is located on the first floor and is accessible through the nurse’s area. This area is highlighted in blue and pictured in Figure 35. Airflow in this space is summarized in Table 40. If this area were to be converted to an airborne infection isolation room it would need to have a new dedicated exhaust system at approximately 15 ACH (70 CFM). Since the potential isolation room is a toilet room currently, a path to the roof for the exhaust duct is already in place. Provide new supply air VAV with reheat at 12 ACH (55 CFM). S-18 would need to be re-balanced to accommodate the new supply air. The new exhaust fan and addition of a room pressure controller will maintain the required pressure relationship. In addition to the mechanical modifications, the door and walls would need to be sealed air tight and an addition of a window between the isolation room and the nurse’s office is recommended. Table 40: Airflow of Potential Isolation Areas

Room or Area HVAC Syste

m

Supply Air Flow

(cfm)

Floor Area (sf)

Ceiling Height

(ft)

Current Total ACH

Current ACH of

OA

Required ACH

Required ACH of

OA

Toilet Room S-18 0 30 9.0 0 0 12.0 2.0

The anticipated capital construction costs would be approximately $100,000 - $125,000.



Appendices



Appendix A – Matrix of Existing HVAC Systems



Appendix B – Building System Zone Maps

cuhar001

Text Box

Redacted for Building Security Purposes



Appendix C – Equipment Location Maps Created and provided by MPS staff

cuhar001

Text Box

Redacted for Building Security Purposes



Appendix D – MERV Filter Ratings



https://www.nafahq.org/understanding-merv-nafa-users-guide-to-ansi-ashrae-52-2/

https://www.nafahq.org/understanding-merv-nafa-users-guide-to-ansi-ashrae-52-2/



Appendix E – Portable HEPA Filtration Units AJ Manufacturing, retails at $4,500 requiring approximately 1hour of assembly.

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