Put a CD on top of hat, reflective side up. At the center of CD drill a hole and put a small black chimney , 1 cm thick, 10 cm tall. Put small holes on sides of hat.

CD reflects sunlight onto chimney heating it up, thus starting passive convection drawing air from within hat

Statistics has shown that 1% of any society in desert areas will be willing to wear this hat.

This idea is an extension of another invention called "solar cooling hat" on HB.
-- VJW, Dec 11 2010

Solar Cooling Hat Solar_20Cooling_20Hat
This idea is an extension of .... [baconbrain, Dec 11 2010]

Solar chimney on Wikipedia http://en.wikipedia.../wiki/Solar_chimney
Black stack makes hot air rise. [baconbrain, Dec 11 2010]

This has unlimitless potential [+]
-- MaxwellBuchanan, Dec 11 2010


//unlimitless

taking that as a complement.
-- VJW, Dec 11 2010


another invention? would you care to link it?
-- po, Dec 11 2010


Soooo.... this is like cooling your house by building a fire in the fireplace. Which does work, sort of.

Statistics show that 13% of people will believe anything, as long as it's prefixed "statistics show." Unfortunately [VJW] got the incantation wrong, so I'm not buying it.
-- mouseposture, Dec 11 2010


This is old hat. It's just convectional widsom.
-- MaxwellBuchanan, Dec 11 2010


This is good. There is some room for improvement, including changing the title, but bun. [+]

"A solar chimney — often referred to as a thermal chimney — is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy. A simple description of a solar chimney is that of a vertical shaft utilizing solar energy to enhance the natural stack ventilation through a building."
-- baconbrain, Dec 11 2010


What CD would be most appropriate? Perhaps not “Fire, I’m on Fire”.
-- pocmloc, Dec 11 2010


CD should not contain any data, especially microsoft windows.

CD serves dual purpose. It completely reflects sunlight from top of hat thus keeping the hat cooler. Reflected sunlight falls on chimney, thereby creating convection. Two birds in one stone!
-- VJW, Dec 12 2010


For night use, a candle could be balenced upon the wearer's head to aid convection.
-- saedi, Dec 12 2010


Indeed! Rather bad for those with lots of hairspray though...
-- saedi, Dec 12 2010



random, halfbakery