This chart compares the temperatures below vehicles on different Porous Paving Types. Only Grasspave2 and Gravelpave2 measured below the ambient outside temperature - They are the "Best in Class." Click to view larger graph. Test was conducted by Sasaki Design Firm.

What is Urban Heat Island Effect (UHI)?
The UHI occurs when urban or developed land is hotter than surrounding rural and undeveloped land. Sunlight energy is absorbed by rooftops, pavements, structures, and other surfaces and then converted and released as heat energy into the air. Since the spacing of man-made structures is much more dense in urban areas, more heat is released causing the outside temperature in a city to be sometimes 6-8 degrees (F) hotter than rural areas.

Invisible Structures' Product Line can help mitigate the effects of Urban Heat Island (UHI).
Cool pavements, more trees, green roofs, and unique development options make ISI's product line a perfect choice to help fight UHI in you site plans. Grasspave2 and Gravelpave2 address many components of Urban Heat Island mitigation including: thermal conductivity, heat storage capacity, density, albedo (see chart to right), and emissivity. Grasspave2 has the added component of "air-conditioning effect."

• Cool Pavements - Grasspave2 and Gravelpave2 are some of the coolest pavements available. See the Sasaki Chart
• More Trees, Vegetation and Green Space - Grasspave2, Gravelpave2, Slopetame2 and Rainstore3 can help achieve these goals.
• Green Roofs – Draincore2 is a great solution for green roof drainage. Click here for more green roof information.

Gravel surfaces can substantially cool down faster at night time than adjacent dense pavements as seen through this thermographic image. – images reprinted with permission from The National Center of Excellence on SMART Innovations for Urban Climate and Energy (www.asuSMART.org), Arizona State University. "Thermography and visible light photographs show gravel and grass surfaces can be cooler than dense paved surfaces" – images reprinted with permission from The National Center of Excellence on SMART Innovations for Urban Climate and Energy (www.asuSMART.org), Arizona State University.