This $200 Black Shaft Air Conditions Your Home For Free Forever -- Why Is It Banned in the U.S.?
• https://www.youtube.com, OffGrid SecretsYou don't need a massive AC compressor to cool a house. A thermal chimney is a tall, black-painted hollow shaft built onto the sunny side of a house. As the sun beats on it, the air inside gets scorching hot and naturally rises out the top vent.
