The window seals and structure were designed to be airtight so that air exchange was slow to ensure the experiment and research could be conducted appropriately.
These large diaphragms were called lungs.
Because no window could be opened during the two year time period when the eight crew members lived in the Biosphere, there were huge air conditioners used to control the temperature and to ensure the plants could survive.
For every unit of solar energy that entered the structure, the air conditioners would expend three times as much energy to cool the habitat back down.
This is the inside of the round space like building I posted a few days earlier. These lungs provided all of the air during the two years the crew lived in Biosphere 2.
Check out our travel photos of the fabulous architecture of India at Viva la Voyage!