One major obstacle this technology will face-- even in regions where ambient air temperatures are appropriate-- is control. The bimetal strip can only act base

One major obstacle this technology will face-- even in regions where ambient air temperatures are appropriate-- is control. The bimetal strip can only act based on its local temperatures. By contrast, the amount of heating or cooling a building needs generally is set by the distributed conditions throughout the building. For example, many commercial buildings require cooling in the core throughout the year-- without regard for the insolation or the air temperature at the envelope. So this technology will not, in many cases, eliminate the need for mechanical assist. Another aspect of the control problem is the wishes of occupants in the perimeter spaces. As described, the incident sunlight, or the interior temperature, are meant to control the porosity of the material. Thus occupants get no say in the amount of sunlight they get, or the amount of air passing through the wall. Competing technologies allow much more control. For example, "smart glass" can regulate the amount of light entering a space, either in response to occupants, or to a building-level controller. Passive inlet vents can maintain a desired airflow rate, in the face of changes in wind pressure and indoor-outdoor temperature differences (controlling to airflow, rather than to local temperature, is desired for air quality reasons).