Low Cost Green Roofs for Cooling

ABSTRACT: Green roofs have many benefits over conventional roofs, they reduce storm water runoff, the heat island effect in cities, and energy requirements for cooling; all of this while sequestering some CO2 from the atmosphere. But because of their expense, the building industry has yet to fully embrace their large scale implementation. Over the course of three summers several green roofs have been built and tested at the Lyle Center for Regenerative Studies in Cal Poly Pomona University to determine their cooling potential combined with night ventilation. Results indicate that the test cell with the uninsulated green roof consistently performs better than the test cell with the insulated green roof and the conventional white insulated roof. This indicates that in mild climates with warm summers, green roofs can be thermally coupled with the interior of the space to improve the performance of night cooling systems, reducing energy consumption and greenhouse gas emissions