Thursday, June 17, 2010

Rooftop Pods: Seeds For Solution Part II

While the concept of a rooftop garden (which I recently blogged about) may have been intriguing to you, we have discovered some new technology via EcoGeek that is even more exciting. An alternative concept has been developed by Natalie Jeremijenko, an aerospace engineer and environmental health professor at New York University. Her rooftop pod designs minimize the potential weight added to the building roof with rooftop gardens, transferring the load onto load bearing walls. The steel stilts on her structure distribute the structure’s weight to the building’s load-bearing walls. And the farms weigh less because they grown in hydroponic, soil free trays.
Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, or coconut husk.
The curved shape of the structure optimizes sun exposure and doesn’t require moving parts or grow lights, unlike many greenhouse designs. To attain a streamlined shape which fares well on windy rooftops, Jeremijenko’s design incorporates a skin of Ethylene tetrafluoroethylene (ETFE) stretched over curved ribs of steel. EFTE is a tough, translucent polymer, which is used to cover stadiums and other big spaces.
Most interestingly, the greenhouse is linked to the building below, sharing energy, air, and water. The plants absorb carbon dioxide and increase the oxygen content in air, and some species can filter other harmful gases, such as formaldehyde as well. Besides the air, the farms would also recycle and purify gray water, which is wastewater from sinks, bathtubs and drinking fountains.
The average cost of this technology is not yet available but to find out more on this emerging invention, check out:http://www.popularmechanics.com/technology/engineering/infrastructure/future-urban-rooftop-agriculture.