Free Air Conditioning with a Solar Chimney

Solar Chimney | Free Air Conditioning

Free air conditioning sounds like a deal you can’t pass up. Actually, it requires some up-front costs to install. But after that, there is no cost to run it.

I’m talking about a solar chimney. This is a system that can effectively cool your house, especially if you live in a dry climate.

A solar chimney utilizes the physics of warm air rising. The “chimney” is a vertical shaft that rises above the roof, similar to a fireplace chimney. The sunny side of the shaft is glass. The inside of the shaft is painted a dark color. When the sun pours into the shaft, it hits the dark interior surfaces and warms the air in the shaft. The warm air then rises and is allowed to vent out near the top of the chimney through operable vents.

The rising air creates a “convective current.” As the warm air rises, other air must move in to replace it. The rising air literally sucks in the replacement air. At the bottom of the shaft is another vent that allows the air in the house to become that replacement air. The house air enters the shaft and replaces the rising air that is venting out the top of the shaft. The house air then must be replaced. This could happen by opening windows around the house. An internal breeze is created and the house cools naturally without electricity usage.

On very hot days, the outside air may be too hot to create a sufficient cooling effect. To make this system even more effective, and to truly provide free air conditioning, an underground piping system can be installed to conduct outside air into the house as the replacement air for the exhausted house air. With the windows kept closed, air is drawn in through the only available opening, the underground piping system. The intake for this air is located on the cooler, shady side of the house. The air travels through underground pipes and is cooled by the earth. Because of the earth’s cooling effect, when the air enters the house, it is cooler than the outdoor air.

This kind of system creates a convective flow of air. That’s what the action of rising hot air and falling cool air is called. The air flows without any mechanical fan and the air is cooled without any air conditioning compressor. A solar chimney is all natural and uses no electricity. Your house is air conditioned for free!

Bill Hirsch

Bill Hirsch

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