The joint influence of albedo and insulation on roof performance: An observational study
We focus on understanding the temperature and heat flux fields in building roofs, and how they are modulated by the interacting influences of albedo and insulation at annual, seasonal and diurnal scales. High precision heat flux plates and thermocouples were installed over multiple rooftops of varying insulation thickness and albedo in the Northeastern United States to monitor the temperature and the heat flux into and out of the roof structures for a whole year. This analysis shows that while membrane reflectivity (albedo) plays a dominant role in reducing the heat conducted inward through the roof structures during the warmer months, insulation thickness becomes the main roof attribute in preventing heat loss from the buildings during colder months. On a diurnal scale, the thermal state of the white roof structures fluctuated little compared to black roof structures; membrane temperature over white roofs ranged between 10 °C and 45 °C during summer months compared to black membranes that ranged between 10 °C and 80 °C. Insulation thickness, apart from reducing the heat conducted through the roof structure, also delayed the transfer of heat, owing to the thermal inertia of the insulation layer. Furthermore, this has important implications for determining the peak heatingmore »
- City College of New York, NY (United States); Princeton Univ., NJ (United States)
- Tsinghua Univ., Beijing (China). Hydraulic Engineering Dept.
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Princeton Univ., NJ (United States). Civil and Environmental Engineering Dept.
- Publication Date:
- OSTI Identifier:
- Report Number(s):
Journal ID: ISSN 0378-7788; PII: S0378778815001450
- Grant/Contract Number:
- Accepted Manuscript
- Journal Name:
- Energy and Buildings
- Additional Journal Information:
- Journal Volume: 93; Journal Issue: C; Related Information: This work was supported by the U.S. Department of Energy through Pennsylvania State University's Energy Efficiency Building Hub under grant No. DE-EE0004261 and by the Helen Shipley Hunt Fund through Princeton University.; Journal ID: ISSN 0378-7788
- Research Org:
- Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
- Sponsoring Org:
- Country of Publication:
- United States
- 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION Cool roof; Roof albedo; Roof heat flux; Roof insulation
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