Uplifting architecture

[Loren Booda]

A building with air capacity of 100,000 m3 is heated to 20oC on a winter day of -10oC. During a summer day of 40oC it is cooled to 25oC. Assuming the building is airtight and rigid, and with standard pressure outside, what is its difference in weight between these two days?

[russ_watters]

Do a google search for "psychometric chart." You need to know humidity though.