copyright harvard graduate school of 9/16/2020 design

copyright Harvard Graduate School of Design

9/16/2020

Holly Samuelson, Pamela Cabrera, Sara Tepfer 1

Dr. Holly Samuelson Associate Professor | Registered ArchitectHarvard Graduate School of Design

Pamela Cabrera PardoAssociateTranssolar KlimaEngineering

Sara TepferDoctoral StudentHarvard Graduate School of Design

Joint Center for Housing Studies of Harvard UniversitySeptember 15, 2020

COULD CLIMATE CHANGE INCREASE THE RISK OF MOLD IN HOUSING?

image: www.familyhandyman.com/project/how‐to‐remove‐mold



Sara TepferDoctoral StudentHarvard Graduate School of Design


COULD CLIMATE CHANGE INCREASE THE RISK OF MOLD IN HOUSING?



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OUTLINE

Background

Proof of concept

Expanding the Scope

Next Steps

BACKGROUND


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Damp homes adverse respiratory effects [1-3]

World Health Organization: mold in homes correlated to increased risk of allergies, asthma, respiratory problems, and immunological reactions [4]

Lawrence Berkeley National Laboratory: building dampness increases health risk effects by 50% [5]

HEALTH IMPACTS OF DAMPNESS AND MOLD IN BUILDINGS

[1] Microorganisms in the Built Environment. Microbiome 3(1): 78.[2] Heseltine, E., Rosen, J., (2009). WHO Guidelines for Indoor Air Quality: Dampness and Mould. Copenhagen: World Health Organization.[3] Dales, R., Zwanenburg, H., Burnett, R., Franklin, C., (1991). Respiratory Health Effects of Home Dampness and Molds Among Canadian Children. AmericanJournal of Epidemiology, 134: p. 196-203.[4] E. Heseltine, J. Rosen, J. (Eds.), WHO guidelines for indoor air quality: dampness and mould. WHO Regional Office Europe(2009).[5] D. Mudarri, W. J. Fisk, Public health and economic impact of dampness and mold. Indoor Air 17 (3), 226–235 (2007).doi:10.1111 /j.1600-0668.2007.00474.x


World Health Organization, Braubach, M., Jacobs, D., & Ormandy, D. “Environmental burden of disease associated with inadequate housing”,2011

EBD = Environmental Burden of DiseaseDALYs = Disability Adjusted Life Years


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Annual health costs of asthma attributable to dampness and mold in buildings in U.S. = $3.5 billion (in 2007 dollars)

High-profile closings of courts, schools and other public facilities in recent years due to mold

D. Mudarri, W. J. Fisk, Public health and economic impact of dampness and mold. Indoor Air 17 (3), 226–235 (2007).doi:10.1111 /j.1600-0668.2007.00474.x

Typical mold fungi found in moisture damaged wood are (described by VTT research):

Alternaria alternate

Aspergillus species

Aureobasidium pullullans

Cladosporium cladosporioides

Chaetomium globosum

Paecilomyces variotii

Penicillium speciesTrichoderma viride

Common allergens in humans, causing hay fever or hypersensitivity reactions that sometimes lead to asthma

Only harmful for people with weakened immune systems

Chronic human exposure to A. pullulans via humidifiers or air conditioners can lead to hypersensitivity pneumonitis (extrinsic allergic alveolitis) or "humidifier lung". This condition is characterized acutely by dyspnea, cough, fever, chest infiltrates, and acute inflammatory reaction

important in seasonal allergic disease

causes health effects such as skin and nail infections.

associated with a number of infective diseases of humans and animals. It is also an important indoor environmental contaminant. It is also known from decaying wood and creosote-treated wood utility poles.

Only a health hazard when consumed

Spores are extremely toxic. release spores that include dangerous substances called mycotoxins. When they become airborne, you can inhale them.

Source: Hannu Viitanen. Mold and bluestain on wooden surface

MOLD FOUND ON BUILDING MATERIALS


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EXTERIOR WALL SECTIONS: BASED ON CLIMATE ZONE

Cabrera, P. Samuelson, H. Kurth, M. “Simulating Mold Risks under Future Climate Conditions.” Proceedings of Building Simulation 2019, Rome.

“Uncovering Mold Risks in Existing Residential Walls in a Changing Climate,” Cabrera, P., Samuelson, H., Building and Environment, under review

WHAT HAPPENS TO EXISTING WALLS WHEN CLIMATES CHANGE?


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EXTERIOR WALL SECTIONS



EXTERIOR WALL SECTION: SEASONAL PERFORMANCE




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BACKGROUND: ASHRAE CLIMATE ZONE MAP FOR U.S.

ASHRAE 2010

BACKGROUND: ASHRAE CLIMATE ZONE MAP FOR U.S. & FUTURE PREDICTIONS

Stackhouse Jr, P.W., Chandler, W.S., Hoell, J.M., Westberg, D. and Zhang, T., 2015. An Assessment of Actual and Potential Building Climate Zone Change and Variability From the Last 30 Years Through 2100 Using NASA's MERRA and CMIP5 Simulations.

TODAY YEARS: 2071-2100


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Stackhouse Jr, P.W., Chandler, W.S., Hoell, J.M., Westberg, D. and Zhang, T., 2015. An Assessment of Actual and Potential Building Climate Zone Change and Variability From the Last 30 Years Through 2100 Using NASA's MERRA and CMIP5 Simulations.

OUR RESEARCH: UNCOVERING MOLD RISK IN FUTURE CLIMATES



Tepfer, S. and Samuelson, H. Hygrothermal and mold modeling of building envelopes under future climate conditions. Proceedings of the Passive Low-Energy

Architecture Conference. September 1-3, 2020. A Coruna, Spain.

Samuelson, H. Keenan, J., Cabrera, S., Carmody, K., Estreall Guillen, E. Kurth, M. and Linkov, I. “Investing in Resilience Retrofits of Buildings to Address Moisture Challenges in a Changing Climate”, work in progress

Simulating mold growth within wall cavities incurrent and future climates

Considering climate stress (temperature andhumidity) only, not shocks (floods, leaks, etc.)

Conservative assumptions about rain

Not currently part of climate resilienceconsiderations


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PROOF OF CONCEPT

2. Future Weather Data –

Typical Weather• We use EnergyPlus (.epw) files of Typical Meteorological Year data (TMY3) from the U.S. Department of Energy

Future WeatherWe ‘morph’ hourly future data for the year 2080 using:• CCWorldWeatherGen V1.9 tool• The IPCC Third Assessment Report A2 model, produced by the Hadley Centre Coupled Model GCM, version 3

(HadCM3). (based on the work by Belcher et al.)• Shortcomings: rain data, among others.

CCWorldWeatherGen Version 1.9 Morphing Computation by Sustainable Energy Research Group – University of Southampton

Source: Tim Bralower Source: IPCC TAR

Tem

pera

ture

Cha

nge

°C

2

2080

“Uncovering Mold Risks in Existing Residential Walls in a Changing Climate,” Cabrera P., Samuelson H., Building and Environment, pending review 2020


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2. Future Weather Data – Morphed Future Weather Results

Dry Bulb Temperature

Change in Dry Bulb Temperature Change in Dew Point Temp.

Future

Typical Present

2


17 · exp 0.68ln 13.9ln 0.14 0.33 66.2

Index Growth Rate

0 No growth

1Small amounts of mold detected only with a

microscope, initial stages of local growth

2Several local mold-growth colonies on the surface

detected with microscopy

3Visual findings of mold on surface <10% coverage,

or <50% coverage of mold (microscope)

4Visual findings of mold on surface, 10%–50%

coverage, or >50% coverage of mold (microscope)

5Plenty of growth detected visually, >50% visual

coverage

6Very heavy and tight growth detected visually

(coverage 100%)

4. Mold Growth Model - VTT Mold-Growth Model (Valtion Teknillinen Tutkimuskeskus) by the Technical Research Centre of Finland

The calculation is computed hourly, and it simulates both mold growth and decay.

4



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4. Results

EXPANDING THE SCOPE


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KEY QUESTIONS

Which exterior façade constructions are most vulnerable to mold issues in future climate conditions?

At what point in the 21st century will this become an issue?

Can we begin to quantify the magnitude of this issue?

MOST POPULOUS CITIES IN CLIMATE ZONES 4A AND 5A

Philadelphia (4A)

New York (4A)

Chicago (5A)

Columbus (5A)

Boston (5A)

Indianapolis (5A)Washington DC (4A)

Detroit (5A)

Nashville (4A)Louisville (4A)

Omaha (5A)

Kansas City (4A)

Raleigh (4A)

Baltimore (4A)


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NEXT STEPS

Develop a better understanding of the human health impacts of mold in wall assemblies.

Refine typical air exchange rates within the wall cavity that are used for hygrothermal modeling.

Develop method for morphing rain data to future climate conditions.

Develop “typical moisture year” weather file for hygrothermal modeling.

NEXT STEPS: WHAT DO WE DO ABOUT THIS?

Update building codes to avoid new construction that it’s maladaptive to future climate.

Fund more research to continue this work and provide clear roadmaps for retrofit.

Our upcoming paper reveals possible retrofit measures.

Samuelson, H. Keenan, J., Cabrera, S., Carmody, K., Estreall Guillen, E. Kurth, M. and Linkov, I. “Investing in Resilience Retrofits of Buildings to Address Moisture Challenges in a Changing Climate”, work in progress


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Sara TepferDoctoral CandidateHarvard Graduate School of Design


THANK YOU


copyright harvard graduate school of 9/16/2020 design

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