In the last 20 years, high solar reflectivity roof membranes has been a focal point of energy saving efforts in building design. In design standards and building codes prescriptive aged and or initial roof membrane solar reflectivity are prescribed. Currently, practitioners and researchers alike only have aged solar reflectivity values provided by the roof membrane manufacturer to use in building HVAC design and energy use modeling. These aged roof membrane reflectivity values are not based on in-service roofs but utilize a prescribed aging process. Studies and field experience have shown that this prescribed aging process does not accurately predict real world solar reflectivity values for roofs.
To explore this fundamental issue, the Midwest Roofing Contractors Association and National Roofing Contractors Association undertook a field study solar reflectivity for single ply roof membranes in 2015. Representative roofs were located and measured in three different climates in the United States. The data has shown that the prescribed aging process for low-slope roof membranes in the CRRC-S100 standard does not accurately predict in-service aged low-slope roof membrane solar reflectance. Based on this study, the researchers have proposed reductions of -0.10 and -0.15 in the fractional aged solar reflectivity values currently reported for design and model purposes.
Citation: 2017 Winter Conference, Las Vegas, NV, Conference Papers
Product Details
- Published:
- 2017
- Number of Pages:
- 8
- Units of Measure:
- Dual
- File Size:
- 1 file , 680 KB
- Product Code(s):
- D-LV-17-C048
