There was a technique used or invented by the Romans a long time
ago. A natural form of air conditioning / ventilation was used
roughly as follows:
- A trench 6 to 12 feet deep and 100 to 200 yards long was dug leading
from the "house" in a straight line away from the house.
- Into this trench a large diameter pipe (these days corrugated
drainage pipe 2 or 3 feet diameter) was laid, with holes drilled
into the bottom to drain water that condensed inside the pipe.
The trench was then covered over.
- At the far end a 90 degree elbow was attached and more pipe added
so that it reached above ground and the end covered with some
sort of wire mesh attached to keep out unwanted things such as
rodents, etc., and then another elbow could be added at this end
to shield against rain.
- The house end of the pipe entered the house and was the source
of incoming air.
- The key to making this work is to add a convection chimney.
- The Convection chimney is built such that it's inside opening
is at a high point inside the building.
- On the outside, two intersecting sides of the chimney; are painted
flat black, and the resulting V formed by the two connecting sides
face south. In other words, the V needs to face the mid point
between where the sun rises and sets.
- The two other sides must be transparent, Plexiglas or some equivalent.
Also, the higher/larger the chimney, the better.
How it works: the sun heats up the chimney causing the air inside
to rise, thus drawing air through the cool pipe. The pipe cools
the air drawn from the outside to the temperature of the earth
at the depth at which it is buried (which is virtually constant
year around at this depth). By the way, an interesting note: Even
in cold climates where the ground is frozen, the incoming air
is only 32F when the air outside may be much colder, we need only
heat the air by 38F to bring it to 70F; as opposed to heating
outside air of say -15F to 70F we would have to heat the incoming
air by 85F - quite a difference in the amount of heating energy
we would have to supply by some other means.
Of course, without the sun to warm the chimney (or some other
source) the system isn't worth fooling with.