Roofing & Heat Island Effect

Sophia Gordon has a bright white roof made of Sarnafil. Unlike a conventional dark roofing material, it reflects much of the solar radiation, reducing the Heat Island Effect and helping to keep the building cool in the summer.

Heat Island Effect
(The following text was taken from: http://www.epa.gov/heatisland/)
The term "heat island" refers to urban air and surface temperatures that are higher than nearby rural areas. Many U.S. cities and suburbs have air temperatures up to 10°F (5.6°C) warmer than the surrounding natural land cover.

The heat island sketch pictured here shows a city's heat island profile. It demonstrates how urban temperatures are typically lower at the urban-rural border than in dense downtown areas. The graphic also show how parks, open land, and bodies of water can create cooler areas.

While they are distinct phenomena, summertime heat islands may contribute to global warming by increasing demand for air conditioning, which results in additional power plant emissions of heat-trapping greenhouse gases. Strategies to reduce heat islands, therefore, can also reduce the emissions that contribute to global warming.

Urban Heat Island Pilot Project Research Initiatives: HIRI conducted studies to determine the impacts of heat island reduction measures on meteorology and air quality in northeastern cities. These northeastern cities are part of the Northeastern Ozone Transport Region, which includes northeastern states with long-standing ground-level ozone problems.

Interactions between meteorology, pollutants, ground-level ozone formation, and transport are complex, and initial results from the Urban Heat Island Pilot Project Research Initiatives indicate that heat island reduction strategies may have mixed effects on ozone in these cities.

In U.S. cities with populations over 100,000, peak utility loads increase 1.5-2.0% for every 1°F (0.6°C) increase in summertime temperature. Steadily increasing downtown temperatures over the last several decades mean that 3-8% of community-wide demand for electricity is used to compensate for the heat island effect. Installing cool roofs and cool pavements, and planting shade trees and vegetation are sensible steps that communities can take to decrease urban air temperatures and summertime energy use.

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