Sometimes the best way to cool an area is by releasing the hot air. These projects use the ambient air temperature to operate to allow hot air to escape. Once cooled, the system returns to it non-porous state.
Thicker versions of thermobimetal curl at higher temperatures and have more inherent strength. In these cases, the thick sheet metal is heated to 250-300˚F during the assembly process to curl into configuration. When cooled, it forms a lightweight, pre-tensioned surface.