If you are passing by houses in the US then you might be able to see a solar chimney on the roof. The solar chimney is also known as the thermal chimney and it is used for better ventilation through the windows. Solar chimneys uses air convection by passive solar energy. The chimney consists of a vertical shaft that makes use of solar energy to improve the natural ventilation of the house.
However the solar chimney was in use since centuries in countries of the Middle East, Europe and Rome.
However its design has improved by leaps and bounds in the last few years. The solar chimney is a natural and green way to provide proper ventilation and keep your house cooler. Hence the use of air conditioner decreases and this can save you hundreds of dollars per year.
This is how a solar chimney works. During the day the sun’s rays heats up the chimney and this creates an updraft of air through the chimney. The suction effect created at the base of the chimney cools and ventilates the entire house naturally. In many parts of the world natural ventilation is done through wind power, however on hot and windless days the solar chimney can work wonders.
If you see at the basic elements of a solar chimney then we can begin with the solar collector area. This is the top part of the chimney and the most important points to be considered here are insulation, type of glazing and thermal properties. The factors to be considered in the position of the main ventilation shaft include cross section, height and location. The inlet and the outlet apertures should have excellent aerodynamic properties.
Scientists are now proposing solar power generation for proper ventilation instead of depending only on the solar chimney. You will observe that all solar chimneys are painted black in color and this increases its ability to absorb the sun’s rays. When the air in the chimney becomes heated it rises to the top and pulls the cold air from underground via the heat exchange tubes. The solar chimney is one of the most advanced and viable concepts designed by scientists through research and experimentation.
The solar chimney has to be higher than the roof and it has to be built on a wall facing the sun. Absorption of heat is increased by glazing the surface of the chimney.