Biomimicry Global Design Challenge Winners
Idea: Retrofit large buildings in hot coastal urban areas with triple layer exterior insulation to reflect and dissipate heat.
Biological Inspiration: Camel nostrils, cactus corrugations, capillary action in wheat plants, termite mound convection cooling shafts, and the reflective hairs of the Saharan silver ant.
Environmental Benefit: Reduce urban heat island effect, minimize runoff, and use graywater for passive cooling – all using minimal materials, without internal renovations or demolishing existing infrastructure to build out a whole new site.
A team of students in Long Beach California designed triple layer exterior insulation panels to reduce the urban heat island effect and the use of air conditioning. The panels attach to the walls of existing buildings and moderate building temperature with convection and graywater, using passive cooling effects to reduce the overall cooling load and minimize surface heat collected by the buildings.
The exterior is shiny white to reflect heat like the Saharan Ant, while the surface pattern takes cues from a cactus with deeply corrugated skin to dissipate heat and cast shade on the more vulnerable tissues between ridges. The shapes also mimic turbinates, specialized nasal cavities in camels with thin convoluted walls and small passages to minimize loss of moisture as they exhale. The internal layer is a mat that draws water up through capillary action, as seen in plants like wheat. The panels are installed with their bases in a trough fed by waste graywater from the building. Engineered channels between panel layers modeled on the burrows of cathedral termites encourage naturally rising warm air to pass in through the exterior holes. As hot air rises it is cooled by the moisture in the mat. Together the layers reflect and dissipate heat and passively power the intake of cooler ground level air through convection and evaporation.
I’m impressed by the practicality of this solution because it has no moving parts, requires no modifications to the support structure or interiors of buildings, and is powered only by naturally occurring forces.