With funding from the U. S. Department of Energy and the City of Miami, the Museum has launched a Green Roof Demonstration Project at its current facility. The project will explore different types of green roof designs to learn more about which design could work best in South Florida’s subtropical climate, providing valuable information for the green roof components planned for MiaSci’s new building downtown at Museum Park. In particular, the Museum is interested in learning which design could potentially help retain the most storm water, and which could help keep temperatures coolest, above the roof and inside the building.

Working with landscape architects Rana Creek, who recently completed the green roof on the new California Academy of Sciences, the Museum has designed an experiment to test different combinations of soil depth, plantings and irrigation. One of the units has a white metal roof, to provide a comparison (see diagram below).

Temperature sensors hooked up to all five roof samples are collecting ongoing data to help determine which combination of soil depth, irrigation, and plantings helps keeps the interior of each unit the coolest at different times of year, and how these compare to the high-reflectivity roof. The chart below provides an example of the type of temperature data the Museum is collecting from the green roof exhibit.

This chart shows that for this particular unit, the green roof kept temperatures under the roof well below the outdoor temperature during the hot afternoon. The roof also lessened the large temperature variations that occurred outdoors, helping to keep indoor temperatures constant. A brief rain around noon dropped the outdoor temperature nearly 20°F in just over an hour, but less than an hour later, the temperature had risen back by over 25°F!

The Green Roof Demonstration will also begin collecting data on the amount of storm water retained by each of the planted units, to help answer questions about which green roof design performs best during Miami’s frequent heavy rain events. All of these data will be available online in the near future, linked to the Museum’s web page and the MiaSci blog site, allowing visitors, students, teachers and other interested professionals to view the experiment in real time.