SmartSA Vendor Summit Sustainability City of San Antonios Under 1 - PowerPoint PPT Presentation

SmartSA Vendor Summit Sustainability

City of San Antonio’s Under 1 Roof program 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

PROJECT OBJECTIVES • Project has two major objectives: – 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.

PROJECT METHODOLOGY Phase I includes the monitoring and performance • analysis of 30 homes. An additional 30 homes are currently being monitored. The study included three major parts: • 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.

Outdoor – Pre‐Installation Average Summer Temperature Difference between Attic & ATTIC TEMPERATURE – SUMMER Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 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 Outdoor – Post‐Installation Average Summer Temperature Difference between Attic & Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 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

ATTIC TEMPERATURE – SUMMER Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 1:00 AM Summer Temperature Difference Pre‐ and Post‐Installation 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 Temperature Difference Post‐ Installation 2:00 PM Temperature Difference Pre‐ Installation 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

Outdoor – Pre‐Installation Average Winter Temperature Difference between Attic & ATTIC TEMPERATURE – WINTER Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 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 Outdoor – Post‐Installation Average Winter Temperature Difference between Attic & Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 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

Winter Temperature Difference Pre‐ and Post‐Installation ATTIC TEMPERATURE – WINTER Temperature Difference (°F) -10 10 15 20 25 30 35 40 -5 0 5 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 Temperature Difference Pre‐Installation Temperature Difference Post‐Installation 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

ELECTRICITY USE INTENSITY 35.3 Homes wo/ Central AC except excluded 36.7 34.6 Homes wo/ Central AC 35.0 34.9 Homes w/Central AC 39.9 35.1 All homes except excuded 37.9 34.4 All homes 36.3 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 Post‐Installation WN EUI (kBtu/ft2.yr) Pre‐Installation WN EUI (kBtu/ft2.yr) Pre‐and Post‐installation EUI for Phase I Homes

ELECTRICITY USE INTENSITY Homes wo/ Central AC except excluded ‐3.9% Homes wo/ Central AC ‐1.1% Homes w/Central AC ‐12.5% All homes except excuded ‐7.3% All homes ‐5.1% ‐20.0% ‐18.0% ‐16.0% ‐14.0% ‐12.0% ‐10.0% ‐8.0% ‐6.0% ‐4.0% ‐2.0% 0.0% Percentage of Reduction in EUI for Phase I Homes

THNK YOU Hazem Rashed‐Ali, Ph.D. Associate Professor, The University of Texas at San Antonio President, Architectural Research Centers Consortium hazem.rashedali@utsa.edu