The Filtration Dilemma

Few things are as fundamental to human well-being as the air we breathe. This issue of EBN features air filtration, a complex and important topic. Lurking behind the filtration technologies and life-cycle cost analyses, however, is an ethical and social minefield.

In an all-too-human paradox, building occupants respond to promises of highly filtered air almost as enthusiastically as we embrace operable windows, which are not very effective at filtering out anything smaller than a basketball. The choice between operable windows and filtered air is one aspect of a philosophical debate about the relationship of buildings with their surroundings. Operable windows are popular because they give occupants some control over their indoor space, but even more because they allow a direct connection to the air, the sky, and the world outside. One manifestation of green design, especially in forgiving climates, is to make the building skin permeable and adjustable, so that light and air from outdoors can enhance the occupants’ world.

At the other extreme is the more classic engineering solution of making the building shell a fortress against ambient conditions, and using technology to manufacture light and introduce controlled and conditioned outdoor air. Some engineers even make a case for purifying and recirculating air to minimize the need for air from outdoors. While the fortress approach is unappealing to the romantic nature-lover in me, I can’t argue with the fact that the so-called fresh air around many of our buildings is so polluted that the people inside are healthier if they don’t breathe it directly.

This is where the social dilemma comes in: While people who live and work in high-end modern offices and apartment buildings can benefit from expensive and energy-intensive filtered air, others don’t have that luxury. People who live and work on city streets, or in buildings without state-of-the-art climate controls, are stuck breathing the very air that others find unacceptable. To make matters worse, air filtration indirectly contributes to the poor ambient conditions through emissions from generating the energy that the filters use. There is something distasteful about a society in which the haves and have-nots are separated not merely by their wardrobes and their cars but by the very air that they breathe.

History teaches us that as long as the rich and powerful are isolated from a problem, there will be much less pressure to solve it for everyone. For example, the air pollution in most cities would be greatly enhanced if all the diesel-powered buses and trucks switched to a cleaner-burning fuel like biodiesel or natural gas. In some cases, the difference might be enough to encourage office workers to open their windows instead of filtering their air. But if those who live in the suburbs and work in the city’s class-A office space feel safe in their filtered-air bubbles, will they still have the political will to invest in cleaner air for all?

If you have to filter the air to provide a healthy space for the occupants of your next building, by all means, do what it takes. But don’t let that stop you from doing all you can to bring about a day when those filters aren’t necessary.

– Nadav Malin