«Urban Problems and sPatial methods VolUme 17, nUmber 1 • 2015 U.S. Department of Housing and Urban Development | Office of Policy Development and ...»
Rogers, Michelle L., James A. Lucht, Alyssa J. Sylvaria, Jessica Cigna, Robert Vanderslice, and Patrick M. Vivier. 2014. “Primary Prevention of Lead Poisoning: Protecting Children From Unsafe Housing,” American Journal of Public Health 104 (8): e119–e124.
U.S. Census Bureau. 2014. 2008–2012 American Community Surveys. http://factfinder.census.
216 Data Shop Industrial Revolution Every home makes compromises among different and often competing goals: comfort, convenience, durability, energy consumption, maintenance, construction costs, appearance, strength, community acceptance, and resale value. Often consumers and developers making the tradeoffs among these goals do so with incomplete information, increasing the risks and slowing the adoption of innovative products and processes.
This slow diffusion negatively affects productivity, quality, performance, and value.
This department of Cityscape presents, in graphic form, a few promising technological improvements to the U.S. housing stock. If you have an idea for a future department feature, please send your diagram or photograph, along with a few well-chosen words, to firstname.lastname@example.org.
Glass-Modified Asphalt Shingles for Mitigation of Urban Heat Island Effect Marwa Hassan Micah Kiletico Louisiana State University Somayeh Asadi Pennsylvania State University Abstract This study aims to use recycled glass cullet (broken or waste glass suitable for remelting) and titanium dioxide powder in asphalt shingles to increase a roof’s solar-reflectance index while maintaining high performance levels. The study also uses cullet-modified asphalt shingles to alleviate the harmful effects of the urban heat island, and it evaluates the reduction in heating and cooling loads when the new class of asphalt shingles is used.
The Status Quo The urban heat island (UHI) phenomenon is becoming increasingly intense as summertime temperatures continue to rise. In the United States, many cities with a population of 1 million or more experience an annual mean air temperature of 1.8 to 5.4 °F (1 to 3 °C) warmer than its surroundings (EPA, 2014). Elevated temperatures during the summertime lead to thermal discomfort, human health issues, and increased consumption of energy for cooling purposes. Development of the Earth’s surface and the use of high-solar-radiation-absorbing materials, including asphalt roof shingles, are causes of UHI effect, especially in areas with a high density of buildings and urban structures. The surface temperatures of a traditional asphalt roof system may reach upwards of 160 °F on a 90 °F day (NRCA, 2013), thus intensifying UHI phenomenon.
Asphalt shingles are true composites made from a variety of materials, including fiberglass or organic felt, asphalt binder, mineral filler, and aggregate granules. By weight, shingles may be made of 80 percent mineral and rock, and, despite being called asphalt shingles, asphalt represents a very small yet important element of the material (Leavell, 2006). In an attempt to continue to use asphalt shingles while mitigating UHI phenomenon, this research project proposes the use of a new type of asphalt shingles that contains recycled cullet coated with light-colored titanium dioxide (TiO2) powder in place of the mineral filler.
Experimental Program Implementing sustainable materials into current manufacturing processes can reduce costs, conserve energy, and lower pollution. For a material to be considered sustainable, it should be cost efficient to the consumer and perform comparably or better than conventional materials. As an approach for mitigating the harmful effects of UHI, the use of cullet in the production of asphalt roof shingles has the potential to become a cool-roof strategy.
The objective of this study is to test the hypothesis that the use of recycled glass increases the solarreflectance index (SRI) without affecting the performance of asphalt roof shingles. To evaluate the feasibility of using recycled glass in this application, the engineering properties of cullet were measured and compared with conventional aggregates used in the production of asphalt roof shingles. Laboratory samples were then prepared and the solar-reflectance properties and strength characteristics of conventional and recycled-glass roof shingles were measured.
Laboratory results showed that the use of recycled glass (see exhibit 1) as a replacement to standard ceramic-coated black roofing granules on the top surface of asphalt shingles resulted in an increased SRI. Further, the addition of white pigment TiO2 powder (anatase ultrafine particles passing mesh #320), which is mixed and applied with the surface granules, improved reflectance values to a level that met the cool-roof threshold. Results also showed acceptable tear strength for the laboratory-manufactured shingles.
Exhibit 1 Recycled Glass Shingle Produced in the Laboratory Photo courtesy of Marwa Hassan Quantification of Energy Benefits A three-dimensional (3-D) transient finite element (FE) model was developed and validated to quantify energy savings provided by the proposed recycling process under various climatic conditions. Simulations were carried out for three cities located in three of the five climate zones in the United States. The U.S. Energy Information Administration (EIA) categorized the climate regions in the United States into five main zones based on the last 30-year average heating degree days (HDD) and cooling degree days (CDD) (EIA, 2011; NOAA, 2012). Exhibit 2 shows the five main climate zones in the United States. For this study, Zones 3, 4, and 5 were simulated. The three cities representing each region were Kansas City, Missouri, for Zone 3; Charlotte, North Carolina, for Zone 4;
and Miami, Florida, for Zone 5.
Exhibit 2 Climate Zones in the United States Source: http://energyiq.lbl.gov/EnergyIQ/tooltips/CBClimateMap.html?width=650&height=700
Exhibit 4 shows the monthly heat flux for a simulated two-floor building’s attic in Charlotte— the first simulation using the proposed shingles and the second simulation using conventional shingles—as well as the monthly cost savings in energy consumption. The expected total energy savings per year is $62.
Exhibit 3 Simulated Heat Flux and Energy Savings for Kansas City, Missouri—Zone 3
–2 –4 –6 –8 0.........
kWh/m2 = kilowatt-hour per square meter.
Exhibit 4 Simulated Heat Flux and Energy Savings for Charlotte, North Carolina—Zone 4
–2 –4 –6.........
kWh/m2 = kilowatt-hour per square meter.
kWh/m2 = kilowatt-hour per square meter.
Exhibit 5 shows the monthly heat flux for a simulated two-floor building’s attic in Miami—the first simulation using the proposed shingles and the second simulation using conventional shingles—as well as the monthly cost savings in energy consumption. The expected total energy savings per year is approximately $93.
As demonstrated by the FE results, more energy savings are attained in warmer climates. This technology is very well suited for use in Miami and locations with similar hot weather in the United States.
Authors Marwa Hassan is the Performance Contractors Distinguished Associate Professor in the Department of Construction Management at Louisiana State University.
Micah Kiletico is a graduate research assistant at Louisiana State University.
Somayeh Asadi is an assistant professor in the Department of Architectural Engineering at Pennsylvania State University.
References Energy Information Administration (EIA). 2011. Annual Energy Outlook. DOE/EIA–0383. Washington, DC: U.S. Energy Information Administration.
Environmental Protection Agency (EPA). 2014. “State and Local Climate and Energy Program, Heat Island Effect.” http://www.epa.gov/hiri/index.htm.
Leavell, Daniel N. 2006. “Roofing Materials.” In Industrial Minerals and Rocks, 7th ed., edited by
Jessica Elzea Kogel, Nikhil C. Trivedi, James M. Barker, and Stanley T. Krukowsk. Littleton, CO:
Metallurgy and Exploration Society for Mining: 1173–1178.
National Oceanic and Atmospheric Administration (NOAA). 2012. “National Climatic Data Center.” http://www.ncdc.noaa.gov/.
National Roofing Contractors Association (NRCA). 2013. “Roof System Types.” http://www.nrca.
Additional Reading National Renewable Energy Laboratory. 2014. “1991–2005 Update: Typical Meteorological Year 3.” http://rredc.nrel.gov/solar/old_data/nsrdb/1991-2005/tmy3/.
222 Industrial Revolution Foreign Exchange Foreign Exchange, a department of Cityscape, reports on what the U.S. Department of Housing and Urban Development’s Office for International and Philanthropic Innovation has learned about new departures in housing and development policy in cities and suburbs throughout the world that might have value if applied in U.S. communities. If you have a recent research report or article of fewer than 2,000 words to share in a forthcoming issue of Cityscape, please send a one-paragraph abstract to lawrence.j.handerhan@ hud.gov.
Measuring U.S. Sustainable Development Eugenie L. Birch University of Pennsylvania
In recent decades, such global institutions as the United Nations (U.N.) have promoted sustainable development, loosely defined as improving the human condition without compromising the ability of future generations to meet their needs. In its advocacy, the U.N.
has called for the crafting of measures to benchmark current conditions and mark progress toward the overall goal. As national and subnational governments have undertaken these activities, they have also been involved in developing a wide range of monitoring tools, especially defining indicators reflective of their distinctive programs in this arena.
The work of the Partnership for Sustainable Communities (PSC), an alliance between the U.S. Department of Housing and Urban Development, the U.S. Department of Transportation, and the U.S. Environmental Protection Agency, founded in 2009, provides an example of this phenomenon. Working with researchers from the University of Pennsylvania Institute for Urban Research and funded by the Ford Foundation, the PSC has launched the Sustainable Communities Indicator Catalog described in this article.
Cityscape 223 Cityscape: A Journal of Policy Development and Research • Volume 17, Number 1 • 2015 U.S. Department of Housing and Urban Development • Office of Policy Development and Research Birch Introduction Public and private decisionmakers in the 21st century are fashioning sustainable development policies and programs in response to a variety of global concerns that include climate change, resource depletion, economic downturns, high levels of poverty, wasteful settlement and urbanization patterns, and a scarcity of adequate, affordable housing and basic services. They assume that human settlement activity has lasting effects on the well-being of individuals and society and understand that sustainable development is an ongoing process, not a “fixed state of harmony” (Hardi and Zdan, 1997: 9). In their choices of policies and programs, decisionmakers adhere to the so-called Brundtland Commission’s interpretation of sustainable development to improve the human condition to meet current needs without compromising the ability of future generations to meet their needs, an idea refined at the Rio Earth Summit in 1992 and further developed at the Rio +20 Conference in 2012. The Future We Want, the outcome document of the 2012 meeting, defined sustainable development as working for poverty eradication, changing unsustainable patterns of consumption and production, and promoting inclusive and equitable economic growth (U.N., 2012).
Notably, The Future We Need called for the formulation of sustainable development goals, targets, and indictors to be applied to all nations (U.N., 2012). This declaration would call for broadening and extending an earlier setup, the soon-to-expire Millennium Development Goals that applied to only the developing countries. Thereafter, the United Nations (U.N.) initiated a 3-year deliberative process to develop a post-2015 development framework of sustainable development goals, targets, and indicators to be presented for U.N. General Assembly approval in September 2015. By the early spring of 2015, U.N. member states had made much progress toward agreeing, in principle, to 17 goals with associated targets and were deeply involved in determining indicators that the U.N. Statistical Commission agreed to deliver by March 2016.
General Background on Sustainable Development Over the years, much work has been done to strengthen the research, policy, practice, and subsequent evaluation of sustainable development. Many believe that progress has been sluggish, however, and attribute the slow adoption of the paradigm to political resistance, limited financial resources, and such technical issues as the absence of scientifically valid and credible indicator systems (Evans and Steven, 2011; UNCTAD, 2011).