Cool roofs

Methodology to analyze the impact of shade trees, cool roofs, and cool pavements on energy use and air quality (smog). 

Cool surfaces (cool roofs and cool pavements) and urban trees can reduce urban air temperature and hence can reduce cooling-energy use and smog. A... 

In motivating consumers and contractors to use cool roof technology, some energy companies have started to offer monetary incentives. In some zones of California, the Pacific Gas And Electric Company and Southern California Edison are offering rebates for cool roofs [24, 25]. Other rebate programs exist in Idaho,... 

Texas, and Florida. [2 3] One significant advantage to these programs is that the Cool Roof specifications mentioned above are guidelines for new construction (Table 24.2). The rebates provide incentive for converting existing low reflectance roofs to the higher standard. 

Data adapted from Sadineni et al. [21] and Cool Roofing Material Database [22], LBNL... 

Lawrence Berkeley National Laboratory. Cool roofing materials database, http //energy.lbl. gov/coolroof/... 

The roof, in the form of a dome, is either comprised of refractory brick held in place by a water-cooled steel roof ring, or it may be composed of water-cooled panels. Sometimes water-cooled rings or glands are placed on the roof around the electrodes to maintain the refractory. On high power furnaces refractory is used around the electrodes to minimize the possibiUty of electrical short circuits. 

When primary fume capture is performed by the enclosure, furnace off-gas combustion efficiency is lower than experienced by furnace direct evacuation control. The off-gas, rich in carbon monoxide (CO), rises from furnace roof openings and partially burns and cools with enclosure air. Significant levels of CO have resulted in the enclosures and exhaust ducting from this type of combination. These levels are not explosive but present a potential hazard to personnel working in the enclosure or in downstream fume cleaning equipment. 

Easy maintenance access must be provided. Removable roof panels for access to furnace subassemblies are desirable. Water-cooled equipment, electrode, and roof movement mechanisms, etc. all require overhead access for proper maintenance. 

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