Evaluation of energy savings potential of variable reflective roofing systems for US buildings

Abstract This paper explores the potential energy savings of using dynamic cool roofs (DCRs) with seasonally variable reflective surface for various building prototypes when compared to static cool roofs. The analysis conducted demonstrates that the additional energy savings from DCRs depend largely on the climate, insulation level, and reflectance of the roof, as well as but to a lesser extent on the building thermal mass. This study shows that older buildings, with low insulation levels, in colder climates are the best target for retrofit using DCRs. Specifically, the results show that when a variable reflective costing is applied to low insulation buildings, source energy savings can be achieved and range from 4.33 to 19.44 MJ/m2 (i.e., 1.6–4.9%) for residential units and from 1.17 to 18.00 MJ/m2 (i.e., 0.3–3.9%) for offices. Based on an economic analysis, it is found that the break-even cost for a variable reflectance coating system with a 22-year life span ranges from 0.80 to 4.84 $/m2 for residential buildings, and from 0.86 to 4.92 $/m2 for commercial buildings.

[1]  H. Akbari,et al.  Methods of creating solar-reflective nonwhite surfaces and their application to residential roofing materials , 2005 .

[2]  Moncef Krarti,et al.  Energy performance analysis of variable reflectivity envelope systems for commercial buildings , 2016 .

[3]  H. Akbari,et al.  Estimating the effect of using cool coatings on energy loads and thermal comfort in residential buildings in various climatic conditions , 2007 .

[4]  H. Akbari,et al.  Cooling energy savings potential of reflective roofs for residential and commercial buildings in the United States , 1999 .

[5]  Hamid Reza Hooshangi,et al.  Energy Performance Modeling of Buildings with Directional Reflective Roofs , 2015 .

[6]  Hashem Akbari,et al.  Measured energy savings and demand reduction from a reflective roof membrane on a large retail store in Austin , 2001 .

[7]  Anna Laura Pisello,et al.  On a Cool Coating for Roof Clay Tiles: Development of the Prototype and Thermal-energy Assessment , 2014 .

[8]  Hashem Akbari,et al.  Measured energy savings from the application of reflective roofs in two small non-residential buildings , 2003 .

[9]  Christopher M. Gray,et al.  Application of adaptive albedo roofing coatings in the Southeastern United States , 2015 .

[10]  Leo Rainer,et al.  Monitoring the energy-use effects of cool roofs on California commercial buildings , 2004 .

[11]  H. Akbari,et al.  Calculating energy-saving potentials of heat-island reduction strategies , 2005 .

[12]  Moncef Krarti,et al.  Energy performance analysis of variable thermal resistance envelopes in residential buildings , 2015 .

[13]  R. Moore,et al.  Assessing the impacts of white roofs on building energy loads , 1998 .

[14]  Danny S. Parker,et al.  Demonstration of Cooling Savings of Light Colored Roof Surfacing in Florida Commercial Buildings: Retail Strip Mall , 2002 .

[15]  Ali G. Touchaei,et al.  Modeling and labeling heterogeneous directional reflective roofing materials , 2014 .

[16]  H. Akbari,et al.  Long-term performance of high-albedo roof coatings , 1997 .

[17]  Sarah Bretz,et al.  Preliminary survey of the solar reflectance of cool roofing materials , 1997 .

[18]  Chris Hendrickson,et al.  Life-Cycle Costs of Commercial Roof Systems , 2010 .

[19]  Afroditi Synnefa,et al.  Cool-colored coatings fight the urban heat-island effect , 2007 .

[20]  Ronnen Levinson,et al.  Potential benefits of cool roofs on commercial buildings: conserving energy, saving money, and reducing emission of greenhouse gases and air pollutants , 2010 .

[21]  Hashem Akbari,et al.  Peak power and cooling energy savings of high-albedo roofs , 1997 .

[22]  Ronnen Levinson,et al.  Evolution of Cool-Roof Standards in the US , 2008 .

[23]  S. Konopacki,et al.  Demonstration of Energy Savings of Cool Roofs , 1998 .

[24]  L. Gu,et al.  Measured and simulated performance of reflective roofing systems in residential buildings , 1998 .

[25]  S. Konopacki,et al.  Cooling energy savings potential of light-colored roofs for residential and commercial buildings in 11 US metropolitan areas , 1997 .