SmartSA Vendor Summit Sustainability City of San Antonios Under 1 - - PowerPoint PPT Presentation
SmartSA Vendor Summit Sustainability City of San Antonios Under 1 Roof program PERFORMANCE ASSESSMENT OF HIGHSOLAR REFLECTANCE ROOFS IN SAN ANTONIO HAZEM RASHEDALI, PH.D. Associate Professor, The University of Texas at San Antonio
PERFORMANCE ASSESSMENT OF HIGH‐SOLAR REFLECTANCE ROOFS IN SAN ANTONIO
HAZEM RASHED‐ALI, PH.D.
Associate Professor, The University of Texas at San Antonio President, Architectural Research Centers Consortium
City of San Antonio’s Under 1 Roof program
– Assess impact of high solar-reflectance roofs on attic temperatures in different seasons. – Assess impact of high solar-reflectance roofs of home electricity use intensity.
analysis of 30 homes. An additional 30 homes are currently being monitored.
– Monitoring, analyzing and comparing average home attic temperatures pre- and post- roof installation. – Analyzing home electricity use (billing) information to assess the impact of the cool roof installation on electricity use. Utility data were normalized for weather. – Surveying home-owners to identify any external factors that may have affected electricity use.
5 10 15 20 25 30 35 40 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM 12:00 AM
Temperature Difference (°F)
5 10 15 20 25 30 35 40 1:00 AM 3:00 AM 5:00 AM 7:00 AM 9:00 AM 11:00 AM 1:00 PM 3:00 PM 5:00 PM 7:00 PM 9:00 PM 11:00 PM
Temperature Difference (°F)
Average Summer Temperature Difference between Attic & Outdoor – Pre‐Installation Average Summer Temperature Difference between Attic & Outdoor – Post‐Installation
5 10 15 20 25 30 35 40 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM 12:00 AM
Temperature Difference (°F) Temperature Difference Pre‐ Installation Temperature Difference Post‐ Installation
Summer Temperature Difference Pre‐ and Post‐Installation
5 10 15 20 25 30 35 40 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM 12:00 AM
Temperature Difference (°F)
5 10 15 20 25 30 35 40
1:00 AM 3:00 AM 5:00 AM 7:00 AM 9:00 AM 11:00 AM 1:00 PM 3:00 PM 5:00 PM 7:00 PM 9:00 PM 11:00 PM
Temperature Difference (°F)
Average Winter Temperature Difference between Attic & Outdoor – Pre‐Installation Average Winter Temperature Difference between Attic & Outdoor – Post‐Installation
5 10 15 20 25 30 35 40
1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM 12:00 AM
Temperature Difference (°F) Temperature Difference Pre‐Installation Temperature Difference Post‐Installation
Winter Temperature Difference Pre‐ and Post‐Installation
Pre‐and Post‐installation EUI for Phase I Homes 36.3 37.9 39.9 35.0 36.7 34.4 35.1 34.9 34.6 35.3
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 All homes All homes except excuded Homes w/Central AC Homes wo/ Central AC Homes wo/ Central AC except excluded Post‐Installation WN EUI (kBtu/ft2.yr) Pre‐Installation WN EUI (kBtu/ft2.yr)
Percentage of Reduction in EUI for Phase I Homes ‐5.1% ‐7.3% ‐12.5% ‐1.1% ‐3.9% ‐20.0% ‐18.0% ‐16.0% ‐14.0% ‐12.0% ‐10.0% ‐8.0% ‐6.0% ‐4.0% ‐2.0% 0.0%
All homes All homes except excuded Homes w/Central AC Homes wo/ Central AC Homes wo/ Central AC except excluded
Hazem Rashed‐Ali, Ph.D.
Associate Professor, The University of Texas at San Antonio President, Architectural Research Centers Consortium hazem.rashedali@utsa.edu