Re: Question?

Michael S. Lorrey (
Thu, 22 Jul 1999 07:55:58 -0400

Ron Kean wrote:
> On Tue, 20 Jul 1999 16:23:51 -0700 "Mark C. Langston" <>
> writes:
> >
> >
> >I believe you also have to take into account the pressure
> >differential
> >between the top and bottom of the building. Unless you want to have
> >the entire top offices sucked into the elevator shafts every time you
> >open a door. :)
> >
> >--
> >Mark C. Langston
> Atmospheric pressure at sea level averages about 14.5 psi, which is about
> one ton per square foot. At an elevation of 1122 feet above sea level,
> it averages about 0.6 psi less than that. But the pressure at any level
> in the building should be just about the same as the pressure outside the
> building at that level, unless the pressure in the building is
> intentionally altered.

If you are building a 20 km tall building it certainly wouldn't do to have the pressure at the top floors equal to the outside atmospheric pressure. And building it airtight to maintain a 3km pressure level would necessitate enough added weight that you'll be reaching diminishing returns at some point.

Mike Lorrey