Sean McGuire, Green Building Network Coordinator, welcomed attendees to the meeting and attendees introduced themselves. Sean then reviewed some of the items listed in previous GBN announcements and alerts.

Urban Heat Island Effect, Local Government Approaches, and Baltimore’s “Cool Roofs” Program – Eva Wong, EPA, and David Brosch, Baltimore’s Weatherization Program

Eva Wong began the evening with a quick overview of her presentation; namely, a brief explanation of the Urban Heat Island Effect, some of the key approaches to counter the UHIE, the benefits of these technologies, what communities are doing, and lastly what EPA is doing. Eva reviewed what the UHIE is: the increased temperatures in urban and suburban areas compared to more rural and natural areas. The increased temperatures translate into higher levels of air pollutants, smog, and energy consumption, there are also impacts on human health and the local environment.

Eva showed the percentages of average land cover in urban areas, with pavement being 40% with temperature readings of more than 140-degrees and roofs being 22% with temps being 170-degrees. Conversely, vegetation is only 26%, but emits temperatures of only 60-100 degrees through shading and evapotranspiration.

Eva then went through some of the approaches and technologies to abate UHIE, starting with living roofs and urban reforestation. Through urban vegetation, studies show 25-60% energy savings, ambient air temperature reduction, air pollution removal, and stormwater management. Another approach to abate UHE is cool roofing. When considering cool roofing, check to ensure it is Energy Star labeled and approved by the Cool Roof Rating Council, as well as investigating your climate, heating penalty, and roof-surface building/volume ratio. Just like living roofs, cool roofing translates into considerable energy savings, reduced air pollution and emissions, and increased durability.

Cool pavements are another approach. While there is no standard for cool paving, there are options available. Asphalt has a 5-20% reflectance, while concrete has a 25-40%. An option is porous or permeable surfaces. Currently, cost factors, product availability, climate conditions, and application considerations can, but not always, be limiting to using cool pavements. But its benefits include a reduction in surface temperature. Also, studies suggest that cooler pavements last longer and reflective surfaces reduce the need for night lighting.

Eva then reviewed some of the programs and policies throughout the country implementing UHE reduction approaches, and concluded with several EPA programs and policies, including Urban Heat Island Pilot Project and others. For more information, go to website at www.epa.gov/heatisland, or go to the following sites for additional resources.

EPA’s Global Warming Website: www.epa.gov/globalwarming
The Energy Star Website: www.energystar.gov
The Cool Roof Rating Council: www.coolroof.org
Lawrence Berkeley National Laboratory's Heat Island Group: http://eetd.lbl.gov/heatisland
International Council for Local Environmental Initiatives (ICLEI): www.hotcities.org