Steve and Wanda Mouzon are the scary-smart and very entertaining principals of Miami Beach’s Mouzon Design, producer of town-building tools and services. Their house plans have been featured repeatedly as Home of the Month in Southern Living, Coastal Living, and Cottage Living. Steve blogs on Original Green and is well known for his rants on how people stayed warm and cool before thermostats, including with breeze chimneys.
Breeze chimneys are designed to turn into the wind, like a weathervane, so that the open end is always leeward. Air moving past an opening tends to pull gases or liquids out of that opening – a phenomenon known as the Venturi effect. Breeze chimneys make use of the Venturi effect to help air circulate through a house. The thermal chimney effect, which can be summarized as hot air rises when given the opportunity, pulling other air in behind it from the room below, contributes to the breeze chimney’s effectiveness.
Pulling in air almost as warm as the air exhausted by a breeze chimney wouldn’t do much good, so you need to find a window around the house or shop where the air is coolest, according to Steve Mouzon. The best place would be under a grove of trees or big shrubs. Not only do the leaves shade the area around the window, but they also cool the air even further by giving off water vapor. It can easily be 10-15 degrees cooler under a shady grove or in a thicket.
In any case, it’s the act of opening a window that starts the breeze chimney’s operation because without replacement air pulling into the house, the chimney can’t pull air out. Think of it as an attic fan that doesn’t require any electricity.
“I haven’t yet built a breeze chimney, so I’m sure it would require a bit of tinkering, but that’s the general idea of how it should work,” said Mouzon.