The Three Levels of Cool Roof Benefits
March 22, 2011
Today's tip is about how cool roofs can have three different levels of benefits. The Department of Energy, in conjunction with several well-known cool roof experts, is working on a document titled the Cool Roofs Roadmap that delineates these three levels, and offers research and analysis for each.
First, cool roofs can benefit individual building owners with savings on air conditioning costs. Building owners are probably well familiar with this benefit, as it has been the major focus of most cool roof marketing for a long time. The amount of energy that can be saved depends on a number of factors, including amount of insulation, roof assembly, location of facility and type of facility.
Secondly, cool roofs and other reflective surfaces can help mitigate the urban heat island effect. This is a benefit that accrues to the entire community, simply because if the temperature is reduced a few degrees on hot summer days, everyone uses less air conditioning energy. Several studies are underway to quantify the exact amount of energy that can be saved if a particular percentage of surfaces in a city change to reflective. Currently, the Department of Energy is working with the White Roofs Alliance to recruit 100 cities to take part in a study that will quantify the benefits of cool roofs.
Finally, similar to how cool roofs can help mitigate the urban heat island effect, cool roofs can also help slow global warming. By reducing the global surface temperature only a few fractions of a degree by using cooler surfaces, the offset in terms of carbon emissions and the resulting warming they cause would be tremendous. A researcher at Lawrence Berkeley National Lab concluded that raising the worldwide albedo - or reflectance - by 0.0003 would have the equivalent of offsetting 44 billion metric tons of carbon dioxide.