sustainability efforts at dsk architects

sustainability efforts

HIGH-PERFORMANCE BUILDINGS| SUSTAINABLE DESIGN CENTER FALL 2022

© Copyright by dsk architects, 2022 All Rights Reserved

dsk

architects

SUSTAINABILITY EFFORTS HIGH-PERFORMANCE BUILDINGS| SUSTAINABLE DESIGN CENTER Fall 2022

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ACKNOWLEDGMENTS dsk architects •

926 Natoma Street, Suite 200 San Francisco, CA 94103S

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1539 Sawtelle Blvd, Suite 14 Los Angeles, CA 90025

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6700 Koll Center Parkway, Suite 11 Pleasanton, CA 94566

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663 Hill Street San Luis Obispo, CA 93405

Contact

design@dskarch.com (415) 839 6418

Report Prepared by

H&M Mechanical Group BWF Consulting Engineers KPW Structural Engineers CSW/ST2 Engineering Group, Inc. ANLA Associates, Inc.

Organizations and Groups

Division of the State Architect - DGS.CA.gov, Oakland, CA California Geological Survey, Department of Conservation California Department of Health West Contra Costa Unified School District (WCCUSD)

Payman Sadeghi, PhD, LEED AP BC High-Performance I Sustainable Design Lead

San Francisco Unified School District (SFUSD) San Francisco State University (SFSU)

Collaborative Partners

Thanks to the colleagues for their invaluable inputs specially:

Mark Seiberlich, AIA, NCARB, LEED® AP Amir Kakavand, AIA, MBA, NCARB, LEED® AP Carmen Campos, LEED® GA Jeffery M. Fuller, AIA, NCARB, LEED® AP Brett McCune, RA Randy Dettmer, AIA, NCARB

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Consultants

Flynn Rosenthal, CASp, LEED GA Terry Tran, NCARB, LEED GA Yanyong Boon-Long, AIA, NCARB Negin Babaei Jonathan Hughes, NCARB, LEED GA

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TABLE OF CONTENTS

APPROACH dsk Sustainability Approach

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Project

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People Planet Prosperity

PREFACE

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INTRODUCTION

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CASE STUDY #1 dsk Case Studies

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Project

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People

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Planet

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Prosperity

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Design research

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Climate

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Design Concept

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Evaluation

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CASE STUDY #3

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Indoor Air Quality Study 62 ASHRAE Requirements for IAQ & Thermal Comfort 72

CASE STUDY #2

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Daylighting Evaluation

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RESOURCES

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PREFACE INTRODUCTION

PREFACE FORM FOLLOWS PERFORMANCE Aligned with the American Institute of Architects (AIA) and the 2030 Commitment’s goals in response to the climate crisis, this report details dsk’ sustainability approach and how it is integrated into our design process. Our approach revolves around the notion of the good, and how it can be achieved in a more systematic fashion within the realm of architectural practice.

At its core, architecture seeks the creation of “good”. Yet, due to the subjective nature of this good, it is often contested; a design will be understood differently by the different parties and beneficiaries that engage with it. “Good” architecture must inclusively address all essential issues considered from diverse viewpoints and disciplines. That is, an ingenious, integrated solution derived from the juxtaposition of multidimensional sub-systems to shape architecture into a high-performance whole. This inclusivist viewpoint is also the key to sustainable architecture. An ideal approach, thus, cannot merely address any one of the greater sustainability realms: of environment, economy, or society. Rather, it is an integrated one addressing all of them together to inform the decision-making process of architectural design and built environment. In this perspective, sustainability is not a new concept distinct from architecture; it inclusively expands the realms architects consider in pursuit of good built environments.

After all, to achieve a responsive built environment, design issues must be identified.

Performance requirements, then, are defined based on the established goals coupled with interaction of clients, users, and communities. Finally, architectural concepts are envisioned. That is when evaluation comes to play. Simultaneous evaluations from the early stages of design, with plans to follow and adjust years after it is occupied is the core of a performance-driven solution. In fact, architectural form is not merely following function anymore; “form follows performance.”

Payman Sadeghi Spring 2022

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High-performance systems, wind-catchers in Yazd,Iran, © Philippe Bickon, 2001

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INTRODUCTION

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This booklet has four main sections. The first section clarifies dsk architects’ Sustainability Approach, a concept we refer to as the four Ps - “People, Planet, Prosperity, and Project.” Following our Approach, we present three Case Studies, based on strategies implemented by dsk on recent projects: • • •

Hercules Middle and High School Science Building San Francisco State University Administrative Building San Francisco Unified School District Ventilation Study

For the first case study, we examine how dsk’s exploratory “project, people, planet, and prosperity” approach was applied into the Hercules M/HS project. We review the design research associated with the context and climatic conditions, and the design solutions that these elements suggest. Then, proposed concepts are illustrated. Finally, the proposed concept’s energy and daylighting performance are evaluated.

The second case study shows the daylighting evaluation for a Tenant Improvement (TI) project, exploring ways to rearrange existing interior spaces to address client and occupant needs without changing the exterior enclosures.

The third case study assesses Indoor Air Quality (IAQ) and Thermal Comfort for three prototype San Francisco Unified School District (SFUSD) schools. The existing conditions along with proposed design options are modeled and simulated to develop recommendations for improving IAQ associated with isolation, ventilation rate, purification, and monitoring strategies.

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dsk architects SUSTAINABILITY APPROACH

DSK SUSTAINABILITY APPROACH At dsk, we recognize the significance of an inclusive design approach that sets the highest standard possible for each project. Sustainability is an essential thread which must be woven into this high standard. While LEED®, Architecture 2030, CHPS for Schools, CalGreen, and local agency guidelines are helpful for establishing sustainability performance criteria, our design approach is more holistic. Aligned with the established triple-bottom-line approach towards environment, society, and economy, our all-inclusive philosophy embraces the quartet of People-Planet-Prosperity-Project. Aspiring towards higher performance, our emphasis is on the integration of passive ecological systems with constant evaluation through the architectural delivery process. In this section, we explore the implementation of the four Ps, and the value they bring to the development of our projects.

PLANET

PEOPLE

PROSPERITY

PROJECT

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BUILDING PERFORMANCE FRAMEWORK

Hercules H/MS School Passive System Strategies, © Payman Sadeghi

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PROJECT project specific approach Each project has its own specific opportunities and challenges, characteristics, users, macro and microclimatic conditions, site, context, or program. Our sustainable solutions are project-specific and tailored to address all unique elements that could and should be considered to accomplish a high-performance project: solutions that create a healthier building environment, a better community environment, and provide long term economic benefits to our clients. Through careful interactions with all the project’s beneficiaries - natural settings and habitats included - we pursue an integration-based architectural programming process to explicitly set project goals, performance requirements, and design concepts.

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Emeryville Center Of Community Life (ECCL)

PEOPLE community first approach Architecture has the potential to change people’s lives and improve quality of life by addressing human comfort, social equity, health and well-being, and education. A community of users from diverse socio-economic backgrounds are all beneficiaries of the designed environment. That community should be well represented and involved throughout the design process to ensure their needs and wishes are carefully considered. Human comfort associated with heating, cooling, ventilation and air quality, daylighting, views, water management, noise management, and material selection are imperative to occupant satisfaction and productivity.

Solutions to these challenges can also provide educational opportunities to enhance environmental consciousness.

Emeryville Center Of Community Life (ECCL)

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PLANET passive driven approach Architecture affects natural settings, habitats, resources, energy, water, and waste. At dsk, our goal is to minimize any unproductive impacts of our design on the planet and natural resources. This goal is achieved through application of smart neighborhood and site strategies, contextual passive heating/cooling/ventilation/daylighting systems, appropriate building form and orientation, water management, waste reduction, smart material selection, reuse, and recycling, as well as active technology systems. Our understanding of the Planet as a stakeholder not only impacts our design approach, but also how our firm is operated, with reduced reliance on paper and efforts at energy and waste reduction in all our offices.

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Emeryville Center Of Community Life (ECCL)

PROSPERITY benefit inspired approach Both clients and building occupants benefit from sustainable built environments either directly or indirectly. Energy and water cost saving through passive systems, application of high-performance equipment and fixtures, waste reduction strategies coupled with smart use, reuse, or recycling of resources enable associated beneficiaries to save and instead spend more capital on promoting their quality of life. As a result, sustainable design solutions in this cycle contribute to further sustainable businesses that invite prosperity into the entire community.

Emeryville Center Of Community Life (ECCL)

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EXECUTIVE SUMMARY Case Study #1 Hercules Middle & High School Science Building This case study showcases the implementation of the “Four P’s” approach on the design of a new building, as well as the power of continuous evaluation in the design process.

Hercules Middle and High School share a campus, and the District sought to add a new science building that would share resources while keeping the student pools separated. This case study explores the climate and social context of Hercules, CA and their effect on the building form, energy demands, and occupant comfort. These factors suggest some basic strategies and initial design moves. Digitally modelling this initial design allowed continuous evaluation and refinement of finer design moves to maximize daylighting and natural ventilation options.

Hercules is north of Berkley in the San Francisco Bay area, with a climate moderated by the Bay. A review of climate data shows a site which is moderately cloudy with average temperatures a bit below a typical comfort range and steady, moderate winds predominantly out of the west. Based on the climate data the best passive design strategies include low mass and good air-sealing, operable walls and shaded outdoor spaces, properly designed shading of windows, low pitch roofs, and natural ventilation. The program requirement of keeping middle and high school classes separated, suggested a strong division between the parts of the building, conceived as a bold mid-wall which created numerous opportunities for outdoor shading, integrated ventilation, stack ventilation, and even wind power. This design also creates opportunities for environmental learning by keeping the building dynamically connected to the wind and the movement of the sun, and providing more opportunities for outdoor learning spaces. Natural ventilation supports better indoor air quality and thermal comfort for better teaching and learning experiences.

This initial design was modelled and further explored to refine the design. Modelling daylighting and heat gains prompted dsk to make adjustments to the size of windows and the shape and location of window shading solutions. These changes resulted in more day-lit spaces where electric lighting is not needed. dsk can provide our clients with documentation similar to this case study as part of developing any new project. The study establishes performance baselines for the project, and is an evidencebased way to support and justify high-performance building approaches. A “Four P’s” (Project, People, Planet, Prosperity) assessment coupled with continuous evaluation maximizes the social and environmental potential of every project.

CASE STUDY #1 HERCULES MIDDLE & HIGH SCHOOL SCIENCE BUILDING

DSK ARCHITECTS CASE STUDY #1 HERCULES HIGH SCHOOL & MIDDLE SCHOOL SCIENCE BUILDING PROJECT project specific approach The following list explores how dsk’s “four Ps” analysis is applied to the Hercules project: • Project’s allocated budget limits design decision making and smart material selection (challenge) • A narrow north-south elongated site shape not ideal for design of southfacing forms (challenge) • Project height limitation due to budget that didn’t allow for entire application of north-facing clerestories (challenge) • Decreased operating schedule starting from 8:00 am to 3:30 pm during August to May for daylighting and solar control especially during the hot seasons when school is not fully operated (opportunity) • Students as the primary users of the building support a variety of environmental education opportunities (opportunity) • A smooth site with subtle slope eliminating excavation while promoting walkability (opportunity) • Line of sight and views towards southern and northern natural settings/hills (opportunity) • Available adjacent open and natural spaces for users’ environmental consciousness (opportunity) • Adjacent existing one-story buildings on east, west, and north that not only provide solar control in early mornings and late afternoons, but also not shade the site for heat gain purposes (opportunity) • The necessity of a thick, tall, and separating wall (spine) enables integration of a building system addressing cooling and natural ventilation (opportunity) • The mild climate at Hercules regarding temperature and humidity coupled with ample breezes allows natural ventilation, cooling, and operable windows (opportunity) • Prevailing wind direction is almost perpendicular to the separating wall that enhances cooling and natural ventilation (opportunity)

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Hercules Middle/High School at SD Stage, © dsk architects

Hercules Middle/High School at DD Stage, © dsk architects

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PEOPLE community first approach

• Virtual design workshops/charrettes with students and their parents, staff, and the community starting from early stages in the process to reflect and incorporate all beneficiaries’ ideas (social equity) • Design of ADA compliant on-site spaces and paths that promote an inclusive design approach and walkability (social equity, human health, and well-being) • East-west elongated building form, despite its site shape, to optimize daylighting and solar control/heat gain opportunities (human comfort, health, and well-being) • Open-plan concept layouts to promote daylighting, natural ventilation, and views (human comfort, health, and well-being) • Operable single-hung window selections and ratio for enhancement of fresh air/ cross ventilation critical to indoor air quality and passive cooling via improved air movement (human comfort, health, and well-being) • Clerestory windows that enhance daylighting, glare issues, and visual distraction plus augmented air ventilation opportunities through stack ventilation (human comfort, health, and well-being) • Wind-catcher integration into a tall, thick wall separating middle and high school to boost natural ventilation and cooling prospects via buoyancy effect (human comfort, health, and well-being) • Thermal mass concept by selection of concrete floors that have higher thermal capacities for storing heat gain from the sun during cold seasons (human comfort, health, and well-being) • Shading devices for proposed south-facing and west-facing apertures to avoid overheating issues during hot seasons (human comfort, health, and well-being) • Selection of smart recyclable materials and elimination of chemical-content materials (human health and well-being) • View opportunities towards at least two directions for most of the main spaces (human health and well-being) • Inclusion of surrounding natural settings that create further thermal and visual comfort as well as further interaction with nature (education, human comfort, health, and well-being) • Community garden integrated into the campus for healthy food sources (education, human health, and well-being) • Rainwater collection via roof for irrigation of green areas and environmental consciousness (education) • Adjacent open areas of respite for occupant breaks (human comfort, health, and well-being) • Integration of a wind-turbine into the spine in addition to monitoring system that shows generated energy data for students’ environmental consciousness purposes (education) • Addition of a sundial on the northwest open area coupled with circular open skylights on the canopies for occupants’ environmental consciousness (education)

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PLANET passive driven approach

• Selection of local/native smart materials to decrease related embodied energy (smart material selection, reuse, and recycle) • On/off-campus clean electricity provided by PV panels (active technology systems) • Bicycle facilities on the site (smart site strategies) • Reuse of the existing building materials for the new construction (smart material selection, reuse, and recycle) • Waste management methods during construction phase (smart material selection, reuse, and recycle) • Dedicated recyclable material collection and storage areas for occupants and waste haulers (smart material selection, reuse, and recycle) • Smart, sustainable, and native materials and resources application (waste reduction) • Community garden integrated into the campus for healthy food sources (smart site strategies) • Rainwater collection via roof for irrigation of green areas and environmental consciousness (water management) • Retention pond design on the site for properly managing surface runoffs (water management) • Adjacent open areas of respite for occupant’s break (smart site strategies) • Native and drought-tolerant plants to minimize dependency on maintenance and irrigation (smart site strategies, water management) • Controlled light pollution during night (smart site strategies) • Bioswale and porous paving on site (smart site strategies) • Heat Island reduction via maintaining the surrounding natural setting and use of light-colored roof materials (smart site strategies, smart material selection, reuse, and recycle) • Wind-turbine into the spine to benefit from generated energy of wind as a natural resource (waste reduction and active technology systems) • Operable single-hung window selections for enhancement of fresh air/cross ventilation critical to indoor air quality and passive cooling (contextual passive systems) • Clerestory windows that enhance daylighting, glare issues, and visual distraction plus augmented air ventilation opportunities through stack ventilation (contextual passive systems) • Thermal mass concept by selection of concrete floors that have higher thermal capacities for storing heat gain from sun during cold seasons (contextual passive systems) • Shading devices for proposed south and west-facing windows to avoid overheating issue during hot seasons (contextual passive systems) • Design of ADA compliant on-site spaces and paths to promote walkability and less car usage (waste reduction)

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PROSPERITY benefit inspired approach • Open-plan concept layouts to promote daylighting/natural ventilation/views (energy cost saving) • Bicycle facilities on the site (energy cost saving) • Reuse of existing building materials for new construction (energy cost saving and waste reduction) • Waste management methods during construction phase (waste reduction) • Dedicated recyclable material collection and storage areas for occupants and waste haulers (waste reduction) • Smart, sustainable, and native materials and resources application (energy cost saving and waste reduction) • High-efficiency equipment and fixtures that decrease operational cost (highperformance equipment and fixtures) • Smart, sustainable, and local material and resource applications that support local businesses, therefore, community’s prosperity (waste reduction) • Rainwater collection via roof for irrigation of green areas and environmental consciousness (water cost saving) • Selection of local/native smart materials to decrease related embodied energy (waste reduction) • Selection of smart recyclable materials and elimination of chemical-content materials (smart use, reuse, or recycling)

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Hercules Middle/High School Proposed Landscape, © dsk architects 29

HERCULES M/H SCHOOL DESIGN RESEARCH Hercules, California is a city located about 10 miles north of Berkeley along the coast of San Pablo Bay and the eastern region of the San Francisco Bay Area in western Contra Costa County, California. Hercules is primarily a suburban community dominated by two-story homes and one story commercial buildings. Initially developed in 1881 as a manufacturing center, Hercules has a population of 26,000 with a generally low crime rate.

Hercules is at the intersection of I-80, the principal interstate route between San Francisco and Sacramento, and State Route 4 which provide access to Concord, Walnut Creek, and the Tri-Valley Area. It is situated at 38°01′02″N 122°17′19″W. The West Contra Costa Unified School District and the John Swett Unified School District both serve Hercules. JSUSD serves the area east of Interstate 80 and north of State Route 4, while WCCUSD serves the remainder of the city. Hercules has a diverse population: 45.5% Asian, 22% White, 18.9% Black, and 14.6% Hispanic.

The school site is in a valley next to the Refugio creek, which puts it at a lower level bordered by residential zones. On its north side, the site is surrounded by natural elements such as the creek and trees and is hidden by the hills on the southern side.

In the following pages Hercules climatic condition will be presented.

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Hercules

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Pro Lo pos ca ed tio n

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CLIMATE Similar to much of the northern San Francisco Bay Area and categorized as a Warm-Summer Mediterranean in Köppen climate classification, Hercules generally has long, warm summers below 90 °F and mild, short winters above 32 °F where the annual average temperature ranges from 50 °F to 65 °F. Temperatures in Hercules vary modestly throughout the year, rarely dropping below freezing point or going above 95°F. The hot season persists for three to four months between May to September averaging daily high temperature of around 70°F. The hottest months are August and September averaging a high of around 75°F and low of 55 °F. The cold season endures about three months from December to February averaging low temperature of around 48 °F. The coldest month of the year is December averaging a low of 42° F and high of 57 °F (See the middle graph).

Climate in Hercules © WeatherSpark.com

Precipitation including rain, snow, sleet, or hail is measured when a minimum of 0.01 inches fall to the ground. The most common form of precipitation in Hercules is rain concentrated from November to March about 23 inches on average per year, lower in comparison to the US average of 38 inches. There is a significant seasonal variation in monthly rainfall in Hercules. The month with most rainy days is February, with an average rainfall of 4.0 inches while the month with less rainy days is July, with an average rainfall of 0.0 inch (See the bottom graph).

Considering 2013 California Energy Comfort Model while using Oakland Metropolitan Airport’s climatic condition data, Typical Meteorological Year (TMY3), Climate Consultant 6.0 software generated the following charts associated to temperature, Humidity, Illumination, Radiation, Sky cover, and Wind velocity/ wheel. In addition, the psychrometric chart illustrates the extents to which each strategy impacts human comfort. Lastly, a list of guidelines suggested by the software is provided in order of their importance.

Average Hourly Temperature in Hercules © WeatherSpark.com

Average Monthly Rainfall in Hercules © WeatherSpark.com

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TEMPERATURE annual range Temperature control within occupants’ comfort zone is one of the main considerations in designing buildings. Depending on the macro and microclimatic conditions of a given context, various passive strategies could be applied to achieve thermal comfort.

Understanding temperature fluctuation throughout the course of the year is the first step in this realm. “In Hercules, the summers are long, warm, arid, and mostly clear and the winters are short, cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 41°F to 79°F and is rarely below 33°F or above 89°F. The hottest month of the year in Hercules is August, with an average high of 78°F and low of 55°F. The cool season has an average daily high temperature below 60°F. The coldest month of the year in Hercules is January, with an average low of 42°F and high of 56°F.” © WeatherSpark.com

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SKY cover range When it comes to daylighting opportunities associated with visual comfort, sky cover range and illumination received from the sun play integral roles. The cloudiness of the sky has direct correlation with the level of foot candle in interior spaces of buildings. “In Hercules, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year. The clearer part of the year in Hercules begins around May 19 and lasts for 5.1 months, ending around October 23. The clearest month of the year in Hercules is July, during which on average the sky is clear, mostly clear, or partly cloudy 91% of the time. The cloudier part of the year begins around October 23 and lasts for 6.9 months, ending around May 19. The cloudiest month of the year in Hercules is January, during which on average the sky is overcast or mostly cloudy 55% of the time.” © WeatherSpark.com

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ILLUMINATION annual range As discussed in the previous section, illumination range and daylighting are interrelated. The graph below illustrates the level of footcandles throughout the year. Generally, around 30 footcandles are sufficient for typical interior spaces. “The length of the day in Hercules varies significantly over the course of the year. In 2023, the shortest day is December 21, with 9 hours, 31 minutes of daylight; the longest day is June 21, with 14 hours, 48 minutes of daylight.” © WeatherSpark.com

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RADIATION annual range Being the main contributor to heat gains in buildings, solar radiation has the most impact on building energy balance during the daytime. This section illustrates the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation. The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year. The brighter period of the year lasts for 3.5 months, from May 7 to August 25, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest month of the year in Hercules is June, with an average of 8.3 kWh.The darker period of the year lasts for 3.5 months, from November 4 to February 18, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest month of the year in Hercules is December, with an average of 2.2 kWh.” © WeatherSpark.com

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HUMIDITY Annual Relative Analyzing the environment’s typical humidity range during the design of buildings helps to address both human comfort and condensation issues. High levels of moisture in the air can make occupants uncomfortable. This moisture withing building components, specifically building envelopes, could potentially impact the performance of buildings. The humidity comfort level should be based “on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change less, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Hercules, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.” © WeatherSpark.com

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WIND velocity Indoor Air Quality (IAQ) is dependent on the level of fresh air introduced into rooms or spaces. Therefore, wind characteristics such as velocity, frequency, direction, or temperature will be critical if natural ventilation, as a passive strategy, is considered. “This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages. The average hourly wind speed in Hercules experiences mild seasonal variation over the course of the year. The windier part of the year lasts for 5.6 months, from March 18 to September 5, with average wind speeds of more than 7.9 miles per hour. The windiest month of the year in Hercules is June, with an average hourly wind speed of 9.1 miles per hour. The calmer time of year lasts for 6.4 months, from September 5 to March 18. The calmest month of the year in Hercules is October, with an average hourly wind speed of 6.8 miles per hour.” © WeatherSpark.com

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WIND Prevailing wind in fall One of the main characteristics of the wind, velocity, was comprehensively discussed in the previous section. Other stated aspects should be studied as well for proposing practical natural ventilation solutions. As a rule of thumb, a wind speed of 5 mph is potentially sufficient for considering natural ventilation. The following graphs show various wind characteristics in Hercules in each season of fall, winter, spring, and summer respectively:

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WIND Prevailing wind in winter “The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.The average hourly wind speed in Hercules experiences mild seasonal variation over the course of the year. The windier part of the year lasts for 5.6 months, from March 18 to September 5, with average wind speeds of more than 7.9 miles per hour.” © WeatherSpark.com

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WIND Prevailing wind in spring “The windiest month of the year in Hercules is June, with an average hourly wind speed of 9.1 miles per hour. The calmer time of year lasts for 6.4 months, from September 5 to March 18. The calmest month of the year in Hercules is October, with an average hourly wind speed of 6.8 miles per hour.” © WeatherSpark.com

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WIND Prevailing wind in summer “The predominant average hourly wind direction in Hercules varies throughout the year. The wind is most often from the west for 9.2 months, from February 10 to November 16, with a peak percentage of 95% on July 31. The wind is most often from the north for 2.8 months, from November 16 to February 10, with a peak percentage of 39% on January 1.” © WeatherSpark.com

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PSYCHOMETRIC CHART passive strategies This psychrometric chart below helps to understand the relationships between various parameters of the humidity and supply air. This is more critical when passive strategies are to be applied to a building. The following graph indicates the number of hours that are comfortable without implementing any heating, cooling, humidification, dehumidification, or ventilation strategies. It also illustrates how each specific strategy can increase the number of comfortable hours.

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DESIGN GUIDELINES best strategies As the Climate Consultant Software puts it, “the Design Guidelines screen shows a list of suggestions, specific to this particular climate and selected set of Design Strategies, to guide the design of buildings such as homes, shops, classrooms, and small offices. Architects call these envelope dominated because they do not have large internal thermal loads and thus the design of the building’s envelope will have a great deal of impact on the thermal comfort of the occupants. The Guidelines at the top of this list apply most strongly in your climate, while those toward the bottom might be weaker.”

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DESIGN CONCEPT

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DESIGN CONCEPT Considering both the mild macro and microclimatic condition of the campus in Hercules, dsk proposed an east-west elongated building form. It is fully protected from the sun during hot seasons while delicately exposed during cold seasons. By taking advantage of the building’s south-facing form and its open-plan concept, main lab spaces allow for daylighting and natural ventilation with maximized views of the surrounding green areas. Accordingly, the supporting spaces such as preparation rooms, restrooms, and service areas are shifted toward the center where daylighting and view opportunities are less available. Implementation of a proper window to floor area ratio coupled with operable and clerestory windows enable natural ventilation, visual and thermal comfort, and daylighting. To maximize passive cooling and ventilation options for a healthier indoor quality, the tall, thick wall separating middle and high school is converted into a wind-catcher that supports air movement and stack ventilation. The combination of these high-performance strategies is expected to lower the building’s energy utilization, which is linked to an optimized operational cost, profitable for clients, community, and environment.

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In line with the integrated passive strategies, protected outdoor spaces are envisioned in the south, southeast, and northwest corners of the building to promote natural ventilation and fresh air, cooling, views, and area of respite. These open spaces not only function as community spaces but enhance students’ environmental consciousness via illustration of the sun position through circular openings on the canopies and a sundial. In addition, two wind-turbines with monitoring systems are integrated with the design, generating energy and data and encouraging learning and social interaction among users. Evaluation of design concepts is supported by energy modeling, which informs and validates our design decisions. Energy modeling was utilized on this project, guiding us to optimiz window sizes, and allowed us to explore the impact of different energy saving options.

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DAYLIGHTING EVALUATION

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DAYLIGHTING EVALUATION Daylighting was one of the main performance criteria on this project, with direct effect on occupants ‘comfort and productivity’.

The graphs below illustrate the foot candle levels in different spaces. With adjustments to window size and height, we were able to increase these from 5-10 at SD stage (design option 1) to 10-20 at CD stage (design option 3) to potentially reaching all learning spaces with 30 foot candles (a good target for classroom work) in the design option 4.

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ENERGY EVALUATION After analyzing the proposed design options in SD stage, the following integrated strategies were examined from energy and during the daylighting standpoints: • Optimize both location and area of windows • Add clerestory windows on south (with overhang) and north façade for further solar gain and daylighting • Enhance canopy depths and locations for increasing solar gain in winter and decreasing it in summer • Convert the spine into a building system component through integration of natural ventilation (both cross and stack ventilation akin to the concept of wind-catchers in traditional Persian architecture)

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ENERGY EVALUATION The Energy Utilization Intensity (EUI) of the school at DD stage was projected via simulation of the existing condition. That is, both the location and area of the windows along with canopy depths were optimized. Based on the assumption that the building is conditioned mechanically, EUI at DD stage was estimated at around 56.1 kBtu/ft2/yr. Since various passive strategies for daylighting, cooling, solar control, and natural ventilation were integrated into the building, there could potentially be a drastic decrease in the level of EUI provided that the building is conditioned naturally. Accordingly, the EUI could be reduced to 6.96 kBtu/ft2/yr, which is an 87.5% energy savings.

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CASE STUDY #2 SFSU ADMIN. BUILDING DAYLIGHTING EVALUATION

DAYLIGHTING EVALUATION For this Tenant Improvement (TI) project, the client wished to provide natural light to all spaces and control glare without changes to the exterior enclosure. The entire second floor was rearranged to address the client and occupant needs. The physical program demanded 24 private advising rooms from a doulbe-loaded “L” block plan, making it challenging to simultaneously address all aspects of building performance such as visual, acoustical, and thermal comfort. Two options were proposed. Option 1, was more budget friendly, and added a sidelight window and two clerestories between advising rooms so that interior rooms could share some of the daylighting from the perimeter. Seen in the diagrams below, extracted from Insight software, rooms adjacent to the corridors were improved, but did not quite reach the 30 footcandle lighting target.

Option 1’s 3D Model with Sidelight & Clerestory Windows

Option 1’s Daylighting Level: Sidelight & Clerestory Windows 58

DAYLIGHTING EVALUATION To more consistently improve the thermal and visual impact of daylighting, dsk explored a second option. This option included full height storefront windows along the hall side, and the walls between advising rooms - replacing much of the solid paritions with controlled glazing. External vertical shading devices were positioned on every other mullion to avoid glare and excessive heat gain on east and west facades. This option allowed a daylighting level of at least 50 footcandles for every advising room. These results are comparable to the theoretical “base run” design, which explored the lighting effects of fully de-partitioning the space. The study offered the client options for improving their space, and an evidence based “best condition” to inform their design goals.

Base Run Daylighting Level: No Interior Wall (Just Bldg. Shell)

Option 2’s Daylighting Level: Full Height Interior Storefronts 59

EXECUTIVE SUMMARY Case Study #3 SFUSD Indoor Air Quality Study SFUSD is one of dsk’s biggest clients. They expressed interest improving indoor air quality (IAQ) District-wide. The District has hundreds of school sites and a full IAQ study requires a digital model of the building. dsk and the District took a more schematic approach, modelling 3 schools which represented very common building typologies for the District.

Indoor Air Quality is improved by reducing sources of pollution and increasing the number of air changes per hour in a classroom. These efforts can be at odds, as increasing outside air during wildfire season or in high pollution conditions dramatically worsens IAQ. dsk explored 4 overall strategies, and used the data developed in the digital models to support specific strategies for design and site operation that dramatically improve indoor air quality for students and staff. The data identified some excellent synergies, like improvements to thermal comfort associated with increased air changes. It also revealed some counter-intuitive findings, such as high air velocities producing incomplete air changes in classrooms. The report identified 4 general categories of strategies: • Isolation – Shutting off natural ventilation sources during wildfires, reducing use of materials which off-gas volatile organic compounds (VOCs), providing deck-to-deck wall partitions to limit spread of pollutants.

• Increased Ventilation – Setting air change per hour (ACH) targets at 3 or higher, implementing building design strategies that encourage cross-ventilation and stack ventilation, coordinating active mechanical ventilation with passive strategies.

• Purification Providing – MERV 15 or higher filtration for active mechanical systems, portable air cleaners, and dedicated outdoor air systems to process air for the whole site.

• Monitoring – Tracking CO, CO2, and particulate levels to adjust ventilation strategies as needed.

Specific implementation depended on the form of the building and its orientation to the prevailing winds. The case studies generated both general and building-specific strategies, as well as a wealth of data to support decision-making by the District.

CASE STUDY #3 SFUSD INDOOR AIR QUALITY(IAQ) STUDY

INDOOR AIR QUALITY STUDY PROBLEM STATEMENT

The third case study assesses the Indoor Air Quality and Thermal Comfort of three prototype San Francisco Unified School District (SFUSD) schools. The existing condition, along with proposed design options, then, were all modeled and simulated. Accordingly, recommendations for improving IAQ associated with isolation, ventilation rate, purification, and monitoring strategies were indicated.

Indoor Air Quality (IAQ) is essential to providing a healthy environment for building occupants. IAQ is even more critical at schools. Studies have shown that children learn and perform better in schools with clean air and comfortable classrooms. Yet, there are many schools in which the minimum required standards are not met, resulting in contaminant levels that are higher than recommended. Recent wildfires, as well as COVID concerns, have only served to amplify the issue. This demands careful consideration of the air quality in our schools. This Ventilation Study, focused on three prototype San Francisco Unified School District (SFUSD) schools, endeavors to enhance the IAQ and Thermal Comfort of San Francisco’s Schools.

OVERALL FINDINGS

The following items are mainly outcomes supported by the natural ventilation evaluation of the prototype schools made possible by application of performance-driven software such as Autodesk CFD (table 1): • Considering ASHRAE, the required Air Change per Hour (ACH) for a typical classroom (50′L x 20′W x 12′H) of 25 students is determined to be 2.22. CHPS, however, recommends 30% higher than ASHRAE’s, which will be translated to an ACH of 2.88, around 3.

• Implementation of natural ventilation and relevant passive strategies for San Francisco’s macro climatic conditions have the potential to reach an ACH of 10 to 28, which is up to 10 times more than recommendations.

• In most SFUSD schools, operable windows located on the building envelopes open to a maximum of 45º resulting in approximately half of the window areas being used for air supply in naturally ventilated schools. The ACH could be almost doubled by fully opening the operable windows as opposed to the maximum of 45º.

• The role of corridors in schools can be analogous to that of “Aorta” in the human body. The studied prototypes demonstrated that for schools with double-loaded corridors or single-loaded corridors facing prevailing wind, the amount, velocity, and quality of airflow in corridors play a significant role in ACH rates, and thus IAQ of classrooms. Therefore, it is critical to evaluate and optimize design solutions that positively affect these factors using performance-driven tools.

• Simulations of the school classrooms illustrated that thermal comfort and ACH are interconnected, and that, if properly designed, classroom temperatures could range within the commonly comfortable temperature of the ambient.

Hence, it is highly expected that a classroom with poor IAQ has overheating issues and vice versa.

• In colder seasons, the classroom temperatures would be close to the ambient air if the level of ACH is higher than the minimum recommendations.

This would require complementary strategies such as warmer garments or higher heating set-points to meet the occupant’s thermal comfort.

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OVERALL FINDINGS • Teachers, principals, and school directors’ literacy on natural ventilation and passive strategies is key to ensure of the proposed solutions practicality. When and which windows/openings are to be opened, for instance, is critical to maximize cross and stack ventilation opportunities.

• Passive systems and natural ventilation are proven to be effective in SF. A hybrid system approach, however, would be more appropriate considering passive strategies are not recommended during wildfire seasons.

• Increased number of vertical openings such as windows, doors, louvers, or dampers linked to high-quality ambient air may enhance cross ventilation and IAQ of certain spaces. Yet, this strategy might impact other spaces performance highlighting the significance of performance assessment of all design solutions.

• Integrated horizontal openings such as skylights or outlets on roofs of corridors and staircases have potential to improve IAQ as well predominantly through stack ventilation opportunities. Similarly, these solutions should be evaluated in conjunction with other factors such as building context, form, height, orientation, windows.

• Converted staircases into vertical shafts are proven to be an effective solution for combined stack and cross ventilation, which could possibly result in higher ACH, and thus IAQ. • Certain volatile results associated with the three school prototypes underscore the importance of various design options’ evaluation to reach high-performance solutions for each unique school conditions.

• Increasing classroom heights will increase classroom volumes resulting in lower demand for ACH, in cases where fresh air availability is limited due to lower wind velocity, obstacles, or building adjacencies.

• Prediction of airflow direction and velocity will be more challenging for buildings that are situated close to each other or include a variety of orientations.

• Informed material selections associated with Volatile Organic Components (VOC) and Low-Emitting Materials is an essential step towards IAQ. • Use of Portable Air Cleaners (PACs), in conjunction with active mechanical systems, is strongly advised in wildfire-prone regions, when passive ventilation options --such as windows, are not advisable. Yet, it should be noted that PACs will not increase ACH and only filters the air.

• The combined application of Heat Recovery Ventilators, with high-performance filters and portable air cleaners/scrubbers dedicated for each classroom, is a cost-effective solution in the case of wildfires and/or viral and bacterial existence within the inside air.

• Monitoring and tracking the acceptable levels of Carbon monoxide (CO), Carbon dioxide (CO2), PM2.5, and other air pollutants, especially in wildfire cases, will help to validate a higher IAQ.

(Table 1) Existing and proposed ACHs and costs of the three school prototypes compared to minimum requirements and recommendations

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RECOMMENDED SOLUTIONS The following are our recommendations for improving IAQ associated with isolation, ventilation rate, purification, and monitoring strategies explored in this study (diagram 1 and 2). Accordingly, a decision tree outlines the steps under which a given intervention should be implemented, in two phases (diagram 3 and 4):

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1.

•

Isolation Recommendations: Prevent natural ventilation in case of wildfires since wildfire smoke can easily enter the building without any control or filtering system through openings and windows.

•

Restrict initial contamination by careful selection of appropriate materials and equipment. Then, isolate inevitable pollution sources.

•

Avoid off-gassing caused by pollutants and chemical sources via using deck-todeck partitions with dedicated mechanical exhaust to the outdoors at a rate of at least 0.50 cfm/ft2 and adequate make up air.

2.

•

Ventilation Rate Recommendations: Set minimum airflow of 130% of the value determined in accordance with the ASHRAE 62.1 ventilation rates, as suggested by CHPS. As discussed, this will be translated to an ACH of 3 for a typical classroom.

•

Aim to even double ACH rates defined by CHPS, around 6, either naturally or by mechanical means, as the most effective solution for reducing air contaminants in this mild climate and in the absence of wildfires.

•

Integrate passive system strategies such as cross, stack, and combined ventilation to efficiently enhance ACH.

•

Place openings and windows on the opposite walls at the farthest wall corners while windows are not exactly facing each other. For further effective air circulation, place the inlets at lower and outlets at higher heights.

•

Integrate active systems like mechanical equipment since hybrid systems are more reliable solutions in situations where passive systems cannot be an option.

3- Purification Recommendations: •

Provide filtration methods with a Minimum Efficiency Reporting Value (MERV) of 15 or higher, as suggested by numerous guidelines for restricting air contaminants.

•

Use portable air cleaners (PACs), which can function in conjunction with active mechanical systems when windows need to be closed.

•

Include Dedicated Outdoor Air System (DOAS) with the ability to efficiently process and manage ventilation down to the individual room level.

4- Monitoring Recommendations: •

Utilize Demand Controlled Ventilation by including carbon dioxide sensors that control the carbon dioxide’s level to be less than 600 ppm.

•

Monitor and maintain PM2.5 levels and Carbon monoxide (CO) in smoky conditions to be at levels of 1 ppm since higher levels of CO can cause fatigue, headaches, dizziness, and nausea.

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INDOOR AIR QUALITY STUDY

(Diagram 1) IAQ hierarchy recommendations with indication of their effectiveness adapted from ‘Schools for Health: Risk Reduction Strategies for Reopening Schools,” Jones et al., 2020.

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INDOOR AIR QUALITY STUDY

(Diagram 2) IAQ hierarchy with specific recommendations and indication of their effectiveness

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INDOOR AIR QUALITY STUDY

(Diagram 3) SFUSD Schools Indoor Air Quality (IAQ) Four Main Tasks

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INDOOR AIR QUALITY STUDY

(Diagram 3) SFUSD Schools Indoor Air Quality (IAQ) Four Main Tasks (Continued)

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INDOOR AIR QUALITY STUDY

(Diagram 4) SFUSD Schools Indoor Air Quality (IAQ) Screening 70

INDOOR AIR QUALITY STUDY

(Diagram 4) SFUSD Schools Indoor Air Quality (IAQ) Screening (Continued) 71

ASHRAE REQUIREMENTS FOR IAQ AND THERMAL COMFORT The acceptable rate of IAQ is defined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, ASHRAE, Standard 62.1- 2007 as the “air in which there are no known contaminants at harmful concentrations as determined by cognizant authorities and with which a substantial majority (80% or more) of the people exposed do not express dissatisfaction.” One of the contributions to IAQ is the amount of clean airflow in a space. At this stage of the study, a pertinent question is: how much fresh air is required for an acceptable IAQ? To answer this question, it is essential to investigate the function of a building (building type), its volume (building height and square footage), and the number of its occupants.

Accordingly, ASHRAE specifies the minimum level of ventilation for various spaces.

Air flow is, often, expressed by hourly ‘air change rate’ (ach), which is the airflow rate into a room, zone, or building divided by its volume. Therefore, Air Exchange rate of I is calculated as: I= Q/V Where: Q = volumetric flow rate of air into space in m³/s in SI (cfm in imperial) V = interior volume of space in m³ SI (ft³ in imperial) air exchange rate of 1 ACH in SI, thus, can be recognized as: I= (3600 Q)/V In the Imperial system, I= (60 Q)/V While both volumetric and mass flows are used for the airflow rate, mass flow is more common. It is widely used in ventilation and air flow calculation techniques. Typical units for volumetric flow are m3/s, l/s, kg/s, and cfm, for the mass flow.

According to TABLE 6.2.2.1 Minimum Ventilation Rates in Breathing Zone (Figure 16), education facilities and specifically classrooms and daycares require 10 cfm/ person as well as 0.18 cfm/ft² (this could be 0.12 cfm/ft² for typical classrooms). It also

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recommends 25 people/1000 ft². For a typical classroom (40′L x 25′W x 10′ H) of 25 students, the minimum ventilation will be calculated as: 25′ W 40′ L

12′ H

a. Area = 40′L x 25′W = 1000 ft2 b. Required Cubic Feet Per Minute (cfm) for area = 1000 ft2 x 0.12 cfm/ft² = 120 cfm c. Required Cubic Feet Per Minute (cfm) for people = 25 x 10 cfm/person = 250 cfm Therefore, the total required airflow (cfm) for a typical class will be: (b) + (c) = 120 + 250 = 370 cfm (1) Also, d. Interior volume of the classroom in ft³ is 50′L x 20′W x 10′W = 10000 ft3 Considering the minimum ASHRAE requirement of 370 cfm for this hypothetical typical classroom of 10000 ft3, air change rate of I is calculated as: I= (60 Q)/V I = ACH = 60 x 370 cfm / 10000 ft = 2.22 per/hour (ASHRAE recommendation) 3

ASHRAE Standard 55-2017, Thermal Environmental Conditions for Human Occupancy, notes that for thermal comfort purposes, temperatures could range from approximately 67°F to 82°F. It should be noted that these numbers are minimum requirements for airflow and temperature range related to human comfort; The Collaborative for High Performance Schools (CHPS) recommends 130% of the value determined in accordance with the ASHRAE. Therefore, I = ACH = 2.22 per/hour X 130% = 2.88 per/hour (CHPS recommendation)

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INDOOR AIR QUALITY STUDY The minimum required ACH of 2.22 per/hour was assessed for typical classrooms in the previous section. The ACH of the existing classrooms will be calculated using both macroclimatic conditions extracted from Climate Consultant software, and the airflow velocity obtained from Autodesk CFD software. These analyses are illustrated in the following graphs. The proposed solutions, were then integrated into the simulated model to aim for improvement in IAQ in the classrooms. Finally, a new ACH was determined and compared with the ASHRAE/CHPS recommendations as well as the existing condition.

The simplified model of school B’s EXISTING condition demonstrating various building components assumptions in Autodesk CFD

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INDOOR AIR QUALITY STUDY The Autodesk Revit software was used for the modeling of school B. A reliable software in the building industry, Revit is coupled with other performance-driven software tools, specifically Computational Fluid Dynamics(CFD), to evaluate this school’s ventilation and thermal comfort capacities. A more holistic and simplified approach to BIM was undertaken to optimize ACH and temperature of classrooms. This method eliminates probable conflicts or gaps between components assessed in CFD before the simulation is run, which is shown in the graph below.

Airflow velocity and its performance in school C simulated by Autodesk CFD software

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INDOOR AIR QUALITY STUDY Thisz Iso Surface graph below displays both airflow behavior and its temperature in various spaces in the plan view of the existing condition. The diagram shows the temperature of indoor air for an airflow velocity of 8 ft/m in which all spaces are within comfort zone except staircases. The buoyancy effect reflected in staircases can be used for exhausting air. At this level of velocity, the entire classrooms are fully circulated. The diagram also shows how the air starts flowing from the west facade, which faces the prevailing wind, into the corridors. The air then moves towards the staircase and classrooms.

This “Iso Surface” graph displaying both airflow behavior and its temperature in school B’s EXISTING condition at 8 ft/m (air fully circulated)

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INDOOR AIR QUALITY STUDY The Iso Surface below graph displays both airflow behavior and its temperature in various spaces in the plan view of the proposed condition. The diagram shows the temperature of indoor air for an airflow of 40 ft/m in which all spaces are within comfort zone except staircases. At this velocity, the air in all classrooms is fully circulated. This indicates that proposed strategies which increase the airflow velocity from 8 to 40 ft/m still create fully circulated spaces, and results in a higher level of air changes per hour (ACH).

This “Iso Surface” graph displaying both airflow behavior and its temperature in school B’s PROPOSED condition at 40 ft/m (air fully circulated)

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INDOOR AIR QUALITY STUDY The diagram below shows the temperature of the proposed condition’s indoor air for airflow of 80 ft/m. The diagram demonstrates that 80ft/m is actually too fast: at this level of airflow, higher velocity air currents create eddies and dead spaces and the entire classroom is NOT circulated. This graph begins to clarify the impact of airflow velocity at different levels. This graph also supports an airflow target of 40 ft/m for a typical classroom.

This “Iso Surface” graph displaying both airflow behavior and its temperature in plan view for school B’s PROPOSED condition at 80 ft/m

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INDOOR AIR QUALITY STUDY The diagram below shows the temperature of the proposed condition’s indoor air for airflow of 60 ft/m. At this level of airflow, the classrooms are still NOT fully circulated. However, the diagram shows improved air flow between corridors, staircase, and classrooms.

This “Iso Surface” graph displaying both airflow behavior and its temperature in school B’s PROPOSED condition at 60 ft/m (not fully circulated)

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INDOOR AIR QUALITY STUDY This enlightening graph below shows the tendency of hot air to collect at the top of stairwells, suggesting a strategy of converting the staircases into vertical exhaust shafts, allowing hot air to escape the stairwells through proposed skylights. The temperature graph demonstrates the school’s various building components and their associated temperatures ranging from 70ºF to over 100ºF. The higher temperature of the staircase roofs illustrates the buoyancy effect and validates the locations proposed to be opened to exhaust indoor air. This strategy increases the ventilation rate while maintaining thermal comfort in classrooms, as illustrated in the next pages.

This temperature graph illustrating the temperature profiles of various spaces in school B’s PROPOSED condition by CFD software

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INDOOR AIR QUALITY STUDY This graph below illustrates the typical airflow velocity of the proposed design, which is used to calculate for calculation of air changes per hour (ACH) for classrooms. As shown, all classrooms meet an airflow velocity of minimum 40 ft/m while majority of the spaces have around 60 ft/m of airflow velocity. Therefore, the ACH will be calculated based on the lower available air velocity of 40 ft/m.

This Iso Surface graph in section view displaying the temperature of indoor air in school B’s PROPOSED condition by CFD software

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INDOOR AIR QUALITY STUDY The simplified model below displays assigned materials, operable versus fixed windows, 20 rectangular prisms representative of students, plenum spaces above ceilings, and various assumptions made in Autodesk CFD software.

This simplified model of school C’s EXISTING condition demonstrating various building components assumptions in Autodesk CFD

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INDOOR AIR QUALITY STUDY The temperature graph below demonstrates various building components and their associated temperatures ranging from 70ºF to over 100ºF. The higher temperature towards roofs illustrates the buoyancy effect as well as the hot surfaces that have potential to be opened for exhausting indoor air. This strategy could increase the ventilation rate while maintaining thermal comfort in classrooms, which could be overheated due to weather conditions or internal loads of occupants and lighting/electrical systems.

This temperature mesh model illustrating the temperature of various spaces in school C’s EXISTING condition simulated by CFD

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INDOOR AIR QUALITY STUDY The diagram below shows the temperature of indoor air for airflow of 320 ft/m. At this level of airflow, most of the classrooms facing the prevailing winds are circulated while the other classrooms on leeward said are not. The next graphs illustrate the reason that airflow of 60 ft/m was considered as the typical airflow in typical classrooms and airflow of 20 ft/m for the newly added modular classrooms.

This “Iso Surface” graph exhibiting both airflow performance and its temperature in various spaces of school C’s PROPOSED condition

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INDOOR AIR QUALITY STUDY The graph below with airflow vectors in the plan view displaying the temperature of indoor air at airflow level of 60 ft/m. At this level, the entire classrooms (except the modular classrooms) are beyond being fully circulated while vector directions are towards the doors where a 2” gap and transom area are assumed for the connection between classrooms and corridors.

Here is the Iso surface graph in the plan view at 60 ft/m indicating that all PROPOSED condition’s classrooms are fully circulated, except the modulars

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INDOOR AIR QUALITY STUDY Below is the graph with airflow vectors in the perspective view displaying the temperature of indoor air at airflow level of 60 ft/m. At this level, the entire classrooms (except the modular classrooms) are beyond being fully circulated while vector directions are towards the doors where a 2” gap and transom area are assumed for the connection between classrooms and corridors.

Iso surface graph in the 3D view at 60 ft/m where all PROPOSED condition’s classrooms are fully circulated, except the modulars

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INDOOR AIR QUALITY STUDY Below is the graph with airflow vectors in the perspective view displaying the temperature of indoor air at airflow level of 20 ft/m. At this level, the entire classrooms are beyond being fully circulated. The warmer temperature of around 80-85ºF above the ceilings supports the buoyancy effect in which the warmer air will always moves towards upper levels. The hot surfaces have the potential to be opened for exhausting indoor air. This strategy could increase the ventilation rate while maintaining thermal comfort in classrooms, which could be overheated due to weather conditions or internal loads of occupants and lighting/electrical systems.

Iso surface graph in the 3D view at 20 ft/m showing how all PROPOSED condition’s classrooms, even the modulars, are fully circulated

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RESOURCES

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Journal of Exposure Science & Environmental Epidemiology, 18(5), 503-511.

Chan, W. R., Parthasarathy, S., Fisk, W. J., & McKone, T. E. (2016). Estimated effect of ventilation and filtration on chronic health risks in US offices, schools, and retail stores.

Indoor Air, 26(2), 331-343.

Cottrell, M. (2014). Guide to the LEED Green Associate V4 Exam. John Wiley & Sons.

Fisk, W. J., & Chan, W. R. (2017). Health benefits and costs of filtration interventions that reduce indoor exposure to PM 2.5 during wildfires. Indoor Air, 27(1), 191-204.

Jones et al., 2020. Schools for Health: Risk Reduction Strategies for Reopening Schools.

Harvard Healthy Buildings Program. https://schools.forhealth.org.

Harvard Healthy Buildings Program. https://schools.forhealth.org.

Mendell, M. J., Eliseeva, E. A., Davies, M. M., Spears, M., Lobscheid, A., Fisk, W. J., & Apte, M. G. (2013). Association of classroom ventilation with reduced illness absence: A prospective study in C alifornia elementary schools. Indoor air, 23(6), 515-528.

Mott, J. A., Meyer, P., Mannino, D., Redd, S. C., Smith, E. M., Gotway-Crawford, C., & Chase, E. (2002). Wildland forest fire smoke: health effects and intervention evaluation, Hoopa, California, 1999. Western Journal of Medicine, 176(3), 157.

Office of Environmental Health Hazard Assessment of California EPA. Guidance for schools during wildfire smoke events. OEHHA. 2019. https://oehha.ca.gov/media/ downloads/air/fact-sheet/wildfiresmokeguideschoolsada.pdf. Accessed 8 Jul 2020.

Sun, Wind, and Light, by G.Z. Brown and Mark DeKay, published by Wiley Wargocki, P., & Wyon, D. P. (2007). The effects of moderately raised classroom temperatures and classroom ventilation rate on the performance of schoolwork by children (RP-1257). Hvac&R Research, 13(2), 193-220.

Washington State Department of Health. Summary guidance: wildfire smoke. https://www.doh.wa.gov/Portals/1/Documents/4300/334-431WIldfireSmokeSCHOOLSummary.pdf. Accessed 24 Mar 2020.

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