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ME425/525: Advanced Topics in Building Science
Indoor environmental quality for sustainable buildings: Lecture 1
Dr. Elliott T. Gall, Ph.D.
Introductions
• Today’s objectivesoCourse introduction
─ Logistics/syllabus
oIntroduce myself
oIntroduce yourselves
oIntroduction to IEQ aspects of building science─ IEQ: Indoor Environmental Quality
─ Assumed since you’re in an “advanced topics”, you’ve had other building science courses
─ If not, no prior knowledge of building science courses is assumed
The built environment
• Why should we care about buildings?
We spend 90% of our time in buildings
We inhale ∼45,000 L of indoor air each day
Building consume 41% of U.S. energy
Investments in building stockBuildings represent a tremendous investment:
Are we satisfied?• A large survey of offices (34,000 responses, 215 buildings):3,4
80% occupant satisfaction with air quality: 26% of buildings
~40% of primary energy production1 ~21 h/day spent indoors2
Vehicle 5%
Outdoors8%
Indoors87%
Buildings41%
Industry33%
Transportation27%
References: 1 U.S. Department of Energy and IEA http://www.iea.org/aboutus/faqs/energyefficiency/ 2 Klepeis et al 2001, 3Huizenga et al. 2006, Proc. Of Healthy Buildings 2006; 4 Schiavon and Altomonte, Build. and Env. 2014
Buildings are where we are productive
“Each doubling ventilation rate (in the range of 3-30 L/s/person) improves office task performance by an average 1.7%”1,
IEQ impacts productivity:
Outweighs energy costs:
Increasing ventilation rate in US offices to 10 L/s/person would yield $5.6 billion in productivity gain, $0.02 billion in energy cost2
References: 1 Wargocki et al. 2000, Indoor Air. 2 Fisk et al. 2011, Indoor Air
Buildings are where we are…
“1 in 8 of total global deaths result from air pollution exposure”1
“Indoor air pollution is among the top 5 environmental risks to public health”2
Particulate matter
Ozone Carbon monoxide
Bioaerosols Radon
Air pollution with indoor and outdoor exposures, e.g.
Other air pollution exposures are largely unique to buildings, e.g.
… and so buildings are where exposures occur
Energy-exposure nexus
Energy Exposure
• electricityusage
• building weatherization
• indoor/outdoor sources
• pollutant fate and transport
• time-activity• ventilation• building materials
Built environment
Key challenge: Enable sustainable urban buildings in the 21st century
- emphasis on constraints posed by IEQ and exposure- In the GBRL here at PSU:
Mass and energy balances
Buildings are a “nexus” of energy and exposure:
Personal exposure,
biomarker studies Lab tests and field validation
So what are we going to do about it?
• Study it in this class…o Apply scientific principles to the study of buildings
o Link measurements and models
o Develop parameterizations to enable meaningful linkages between measurements and models
o Actually measure stuff─ Project 1: In class project with the BUILT Lab:
“CO2 in indoor environments: From sensing to application”
o Learn from those before us─ Project 2: Literature review (undergrad)
─ Project 2: Literature review + model (grad)
About this class
ME425/525: Advanced Topics in Building Science
Spring 2017 Topic: Indoor environmental quality for sustainable buildings
• Will have a custom course number/name in subsequent years
4 credit hours
Meeting times: 14:00-15:50 Monday and Wednesday
Meeting Location: Ondine 54
Course reference numbers: 64674 (graduate), 64673 (undergraduate)
Course website: https://www.pdx.edu/green-building/ieq-2017
This website and your email will be the predominant
means of communications for this course! Check both regularly!
About me
• B.S.E., Environmental Engineeringo University of Florida, 2006
• M.S.E., Environmental and Water Resources Eng.o The University of Texas at Austin, 2009o Thesis topic: Primary and secondary emissions of
VOCs from green building materials
• Ph.D., Civil Engineeringo The University of Texas at Austin, 2013o Dissertation: Transport and reaction of ozone in
porous materials
• Post-doctoral research in Singapore
About you?
• Background (major, year)
• Interest in the course
• Building science/IAQ experience?
• Anything else you may want to share
Course information
• Spring 2017 topic: Indoor environmental quality and sustainable built environments. oMaterial balance principles applied to fate and
transport of pollutants in urban and indoor environments;
oapproaches for quantifying and characterizing sources, transport, transformation, and control of indoor air pollutants;
oenergy conservation and indoor air pollution; quantifying human exposures to air pollutants;
ohands-on project will include introduction to microcontroller based sensor design and fabrication.
Learning objectives
• See syllabus for detailed learning objectivesoThree priorities:
1) Understand history, context of indoor air pollution:
Earliest known IAQ problem?NIST Net-Zero
Demonstration house
What are typical indoor air pollutants? What are their sources? Why are they important? Where are we exposed to indoor air pollutants? What/who (personal, regional, governmental, trade organizations, etc.) affect indoor air quality?
Building models, Building science
Indoor pollutantOutdoor
pollutantPλ
EmissionsLosses
λ
C.V.
How do we move from observations/hypotheses about an environment?
To a set of descriptive equations that informs us about the dynamics of pollutants in the space?
• Buildings are increasingly connected and “smart”o Importance of embedded systems, microcontrollerso How will this change building operation?
oHands on project (in-class), developed w/ PSU BUILT Lab
The future of building science
Course materials
• There is no textbook for this courseo Syllabus for assigned & suggested readings
o Required readings will be posted
o In-class notes will be important!
• Textbooks (suggested) are on course page: o My two go-tos: BSL (bird, stewart, lightfoot) &
Seinfeld and Pandis
• Attendanceo Not mandatory (i.e., graded), but expected
─ Lecture slides will be posted online, notes will not
Course projects
• In-class projecto 2-3 weeks of the course (we’ll see…)o Week 5: build CO2 monitor
─ Arduino platform─ Breadboard circuit, basic programming, calibration─ Know a bit about circuits, how CO2 sensors work, why they are
relevant to built environments
oWeek 6: With either sensor you build, or off the shelf─ Building science measurements:
i. Air exchange rate (decay vs. steady-state)ii. Disease transmission (fraction of re-breathed air)iii. Personal exposure to CO2
o ~ a week later – synthesize findings, present─ Create database, subsequent classes will build on it
Term projects
• Undergraduateso This project is flexible, and can relate to your other
classes, projects, or interests, but must relate to building science and IAQ
o Literature review (teams of 2)
oUse this as a chance to “double-up”!
• Graduateso Use this as a chance to extend your research into an
area you are interested in
o Literature review + model dev. (solo)
oUse this as a chance to do your research…
Other goals….
• Literature review! o A fourth goal of this class
o One of the most important things you can do
o Can save a lot of time…
o Can be the spark for new ideas
• This will be major focus of your term project
• Outcome is similar to a conference papero Present your findings succinctly, but you should have
reviewed and possibly cited between 20-50+ papers on your topic.
Prerequisites
• No required prerequisiteso Familiarity or willingness to learn:
─ Continuity equation principlesi. And ODEs/PDEs that result from them for buildings
ii. This class will be mostly (maybe all) first order ODEs
─ Fluid mechanic principlesi. Ideas and theory, possibly applied
─ Chemistryi. Applied, we will go through this
Grading
• Graded components of courseo Homeworks
─ 5 assignments
o In-class project─ 2 of your 5 assignments─ Presentation and report
o Term project ─ Undergraduate: 2500 word literature review on topic of
your choosing (teams of 2)─ Graduate: 3500 word literature review and develop and
apply model on topic of your choosing (individual)─ Presentation (grad 17 min, undergrad 12 min)
o Final exam: 24 hour take home final
Basis of grading
Questions?
• Questions so far? o My office hours are Thursdays, 10-11 AM
o Otherwise, e-mail is best way to get in touch
Introduction to indoor enviornments
• Why should we study indoor environments?o Buildings are a complex microcosm
In a physical sense: • Buildings “operations” are akin to an organismSkin -> Building façadeHVAC system -> respiratory systemEnergy use -> metabolismClutter -> fatEtc.
Focal point of social issues:e.g., gentrification, public housing,
Expression of ideals:e.g., high profile architecture
The importance of buildings
• Building contribute to: o Asset value: 10s of trillions of dollars
• Time activity patterns: o In the developed world:
─ 90% of our time indoors
─ 68% of our time in a residence
─ 32% of time in a bedroom
• Buildings are where exposure occurs:o We bring materials, devices indoors that create emissions
o We create emissions (human bioeffluents)
o Indoor and outdoor air are connected (buildings breathe)
Built environment drive exposures
• Concentrations of most pollutants higher indoors than out, especially VOCs, pesticides
Ott and Roberts, 1988, Sci American
Counterintuitive?
• Psychologically, we consider building “protective”o We place important materials, artifacts indoorso We’re told to go indoors during air pollution eventso Control over the space
• No regulations for indoor air o OSHA standards for workplace, smoking banso Outdoor regulations typically look at “releases”
Indoor exposure to outdoor pollution
Meta-study of indoor-outdoor ratios of particles
Indoor spaces may not be protective• Even for pollutants we consider to be “outdoor problems”
• Jump ahead! What is the difference between a gaseous pollutant and a particle pollutant?
Chen and Zhao, 2011, Atm Env.
Each bar is taken from another study!
But what does it all mean…
Differences in ozone mortality across cities (each number in the plot is a different city in the US), are partially explained by differences in outdoor-indoor transport and indoor pollutant dynamics!
Chen et al. 2012, EHP
Exposures are impactful
Singapore, 2013 credit: telegraph.co.uk
PM exposure (3.1 million deaths):respiratory infection/other infection
respiratory disease
cardiovascular disease
cancer
Dominici et al 2006, JAMA
US E.P.A.
Lim et al. 2012, The Lancet
Turner et al 2011, Am. J. Resp. & Crit. Care Med.
Schwartz 1993, Env. Research
Global DALYs in 2010 from:Each color a different disease outcome
Most colorful, hmm……
Ozone exposures
Lim et al. 2012, The Lancet
Global DALYs in 2010 from:
Santiago, Chile, 2011
• Ozone exposure (0.2 million deaths):- reduces breathing capacity
- causes inflammation
- decreases irritant removal
• 0.87% ↑ in mortality w/10 ppb ↑ in O3Bell et al 2005, Epidemiology
Cumulative health impacts from IAP
Recall that…
“Each doubling ventilation rate (in the range of 3-30 L/s/person) improves office task performance by an average 1.7%”1,
IEQ impacts productivity:
Outweighs energy costs:
Increasing ventilation rate in US offices to 10 L/s/person would yield $5.6 billion in productivity gain, $0.02 billion in energy cost2
References: 1 Wargocki et al. 2000, Indoor Air. 2 Fisk et al. 2011, Indoor Air
History of IAQ
• So why is this problem so difficult?
• We’ve known about air quality for a long timeo But not really understood it…
─ Ventilation in early dwellings
─ Hippocrates: “miasma” as a carrier of disease from decaying organic matter (from marshes, wetlands)
─ Frist century BC - 15th century: Air quality to be remedied by careful city planning, don’t site near marshes (again with the marshes?)
Climate change and building sci
On Tangier Island, Virginia, in the southern Chesapeake Bay, residents are facing the inundation of a place some local families have called home since the 1600s.
https://www.pri.org/stories/2016-07-12/rising-seas-are-washing-away-two-us-towns-how-theyre-responding-matter-faith
Nazaroff, 2013
Industrial revolution
• Increasingly urbanized societies brought problems with air quality into focus:
By Source (WP:NFCC#4), Fair use, https://en.wikipedia.org/w/index.php?curid=42189020
Fumifugium, or, The inconveniencie of the aer and smoak of London…
tis the sea-coal smokeThat always London does environ,Which does our lungs and spirits choke,Our hanging spoil, and rust our iron.Let none at Fumifuge be scoffingWho heard at Church our Sunday's coughing.
London, 1661, letter to King Charles II, One of the first known works documenting air pollution issues
More recently
1940s Chattanogga, TN, USA• Visibility <0.5 km; • Women’s nylon leggings disintegrated due to
interaction with SO2 and acidic aerosols(Griffin, Principles of Air Quality Mgmt)
1800s-1960s London, England• 1800’s Londoners accepted smog as part of life• 1952 smog event left 4,000 people dead(Griffin, Principles of Air Quality Mgmt)
2010s Beijing, New Delhi• “Airpocalypse” of 2013; 1 mg/m3 PM2.5 (Harbin)• 6 of 7 million deaths associated with air
pollution in 2012 were in SE Asia/Pacific (WHO, 2014)
Population and economic growth continues to be “extractive”
Building science and climate change
https://plus.google.com/photos/+GoogleEarth/albums/5875822979804092129
https://earthengine.google.com/timelapse/
We’re changing the face of our planet, and it is in no small part due, indirectly or directly) to how we design, construct, and operate our building stock:
Building energy use
To achieve purpose, a high performance building must: • Materials, energy → safe, comfortable, healthy indoor environment
non-fossil sources
fossil sources
projected* *assumes electricity from renewable/non-renewable equal to 2016
40% of yearly CO2 emissions
Challenges in built environments
A sustainable building solves a constrained, multi-objective problem Goals:- enhance well-being with good indoor environmental quality- improve health by mitigating air pollution exposuresConstraints:- minimal or no additional energy input- a changing outdoor climate
Mass and energy balances, at micro and macro scales
Lab and field tests of pollutant fate and
transport
Personal exposure studies, measurement of breath biomarkers
Key GBRL capabilities:
Modern indoor environments
In the developed world:
Modern indoor environments
• In the developing world: o Biomass burning
─ Crop residues─ Dung─ Wood
o Inefficient, often not ventilated─ Large PM, PAH exposure
o 4% of global mortality (largest environmental contributor)
─ 2 million deaths/year
o 2/3 of lung cancer victims in dev. world do not smoke!
Types of air pollutants, sources
• Hundreds to thousands of possible sourcesSome important ones: oOutdoor air
─ Ozone action daysoBuilding materials
─ Organic compounds with high vapor pressure (VOCs) oCleaning products/air fresheners
─ Organic, highly reactive compoundsoReactive gases
─ Ozone, hydroxyl radical, nitrate radicaloCombustion
─ CO poisoning from poorly vented gas furnacesoRadon
─ Soil vapor intrusiono Other synthetic chemicals
─ SVOCs, e.g., plasticizers in building materials, consumer products
Cooling and ventilation
• More airtight buildings• Less flushing of indoor
air pollutants• More time for
interactions• Greater importance of
indoor sources• Including
weatherization materials (sealants, insulation)
Huge market for “green”
• But is it healthy?o Industry far outpaces
our ability to test/understand
implications of new materials
• Lots of misinformation: ozone generators
A “soup” of IAPs
When in doubt…
write a mass-balance!
“Fate and transport”
• Indoor air is the media • Contains a “matrix” of pollutants
o Inorganic gases─ CO, CO2, O3, SO2, NO2, etc.
o Organic gases─ VOCs (Volatile Organic Compounds)
i. Hundreds to thousands of interestii. Formaldehyde is well-known
oReactive gases─ Ozone, OH, NO3
oParticulate matter ─ solid or liquid particles suspended in air
• Others we will spend less time on (SVOCs, Radioactive gases, Microbiological)
These are gases! Follow ideal gas law!
Solids and liquids, not gases!
Indoor vs. outdoor environments
• Indoor air and outdoor air are closely relatedo indoor air becomes outdoor air, vice versa
o air-exchange
• Similar physics and chemistryolight, rain, temp, shorter residence times, S/V ratio
Bringing it all together
Understanding pollutant dynamics allows us to quantitatively understand exposures
Time-concentration
model of exposure,
exposures are then
mapped to health,
productivity effects
l
j
m
i
iiinkjjokk tCtCEx1 1
,,
Exposure [=] µg m-3 h
1. Outdoor air quality data
Outdoor pollutant concentration,
where k is PM2.5 or PM10,
[=] µg m-3
2. Time-activity budget
Time spent in
microenvironment i or j
[=] h
3. Indoor concentrations
Indoor pollutant concentration,
(from indoor proportion of outdoor
pollution)
[=] µg m-3Data collection challenges are enormous: 1. Quality of data dictates model capability 2. Assess exposure, identify specific data needs
Bringing it all together
• Next classoProperties of air, units, conversions
oMore on exposure models
oThink about topics for your project
