| The last decade has seen an increase in the efficient use of energy sources such as water, electricity, and natural gas as well as a variety of roofing materials, in the heating and cooling of both residential and commercial infrastructure. Oil costs, coal and natural gas prices remain high and unstable. All of these instabilities and increased costs have resulted in higher heating and cooling costs, and engineers are making an effort to keep them under control by using energy efficient building materials.;The building envelope (that which separates the indoor and outdoor environments of a building) plays a significant role in the rate of building energy consumption. An appropriate architectural design of a building envelope can considerably lower the energy consumption during hot summers and cold winters, resulting in reduced HVAC loads.;Several building components (walls, roofs, fenestration, foundations, thermal insulation, external shading devices, thermal mass, etc.) make up this essential part of a building. However, thermal insulation of a building's rooftop is the most essential part of a building envelope in that it reduces the incoming "heat flux" (defined as the amount of heat transferred per unit area per unit time from or to a surface) (Sadineni et al., 2011). Moreover, more than 60% of heat transfer occurs through the roof regardless of weather, since a roof is often the building surface that receives the largest amount of solar radiation per square annually (Suman, and Srivastava, 2009). Hence, an argument can be made that the emphasis on building energy efficiency has influenced roofing manufacturing more than any other building envelope component.;This research project will address roofing energy performance as the source of nearly 60% of the building heat transfer (Suman, and Srivastava, 2009). We will also rank different roofing materials in terms of their energy performance. Other parts of the building envelope such as walls, foundation, fenestration, etc. and their thermal insulation energy performance value will not be included this study.;Five different UAB campus buildings with the same reinforced concrete structure (RC Structure), each having a different roofing material were selected, surveyed, analyzed, and evaluated in this study. Two primary factors are considered in this evaluation: the energy consumption and utility bills. The data has been provided by the UAB Facilities Management Department and has been monitored from 2007 to 2013 using analysis of variance (ANOVA) and t-test methods.;The energy utilities examined in this study involved electricity, domestic water, and natural gas. They were measured separately in four different seasons over a seven-year time period. The building roofing materials consisted of a green roof, a white (reflective) roof, a river rock roof, a concrete paver roof, and a traditional black roof. Results of the tested roofs from this study indicate that the white roof is the most energy efficient roofing material. |
