Battle in his article “The Air We Breathe” from Big & Green starts the reading off discussing the importance of air and it as a “unifying substance for mankind.”  He notes that “every molecule of air we breathe has a 99% chance of having been breathed before,” yet, Battle argues, “we have not yet developed a sense of responsibility for air as a finite resource.” Battle makes his argument saying that we fail to recognize our responsibility for maintaining air quality and cleaning the air we pollute.

Battle then goes on to discuss cities as complex systems of input and output.   “Cities, like other assemblies of organisms, have a definable metabolism, consisting of flow of resources and products through the urban system for the benefit of urban populations” says Herbert Giradet in Creating Sustainable Cities.  Cities are responsible for a vast amount of waste, about 70 % of which is typically returned, untreated, to the biosphere and Battle argues that we are now in a situation in which the outputs from humans as a whole far exceed the capabilities of our planet’s natural treatment systems.  Because of this, Battle compares cities to the human body (much like Moe does in his text).  Battle argues that “cities should act as kidneys by cleaning everything that passes through them and generating clean energy.”  I agree completely with this argument.  Cities as a whole can make a great effort to clean up waste.  For example, NYC has made a valiant effort with the High-Line (as discussed before).  This is just a small step but can greatly affect the ventilation throughout the city and generate cleaner air.

Battle then narrows down from the city to the building, as a smaller step towards cleaner air. He argues that we have become too dependent on air condition and have lost the use of natural resources such as water, light and air.  These resources can be extremely useful and can help create a cleaner environment if we use them more and use them effectively.  For example, as Moe discussed more water walls.  Or even just opening up windows or creating more windows.  Buildings need to react with the environment more.

In class we were discussing the importance of insulation in energy consumption.  Battle discusses this idea further and introduces the term ‘double skin.’

Double Skin Facade Design Detail

Double skin is a ventilation device that makes use of solar energy. According to research by Battle McCarthy in association with Franklin Andrews on behalf of the UK Department of Environment, Transport, and Regions, has shown that double skin buildings can reduce energy consumption and running costs by 65%, and can cut carbon dioxide emissions by 50% in the cold temperate climatic prevalent in the UK.  “In the winter the cavity acts as a thermal buffer zone between inside and outside which reduces space heating requirements because conduction and infiltration gains are reduced. During mid-seasons the skins can be opened allowing natural ventilation. During the summer the skin is sealed and blinds within the cavity allow for solar control and exhaust air is extracted through the cavity to remove heat gains.”   I think these facades should be utilized more.  Some criticism of the system  is that the cavity results in a decrease in usable floor space and the construction of a second skin may also present a significant increase in materials and design costs.  (Joseph W. Lstibure  However, the cost of electric bill and the cost on the globe far exceed these costs.  Thinking sustainably means acting now and progressively seeing results.  They will not come easy or fast, but if we act now, the will come.

Battle uses the Commerzbank Headquarters in Frankfurt by Foster and Partners as an excellent example of a double skin façade.

Window and heating/cooling ventillation strategies used in the typical office, Copyright Foster + Partners

Battle makes great arguments that really makes you think about the resources that we have and introduces case studies with advanced systems that make use of these resources.  I think this is the kind of architecture we should be paying attention to in order to clean the air in our environments.

Reading: The Air We Breathe by Guy Battle from Big & Green

For more information on double skin facades/building envelopes here are some great articles: