Harness the Sun’s Natural Heating Ability with a Solar Chimney

A solar chimney is a technology that can be used to enhance the ventilation of a residential or commercial structure and uses the same principle at play in a fireplace. Heat naturally rises—like air from a fire will rise through a chimney—creating draft and taking the smoke with it. This suction is the reason why there is no smoke in a dwelling when a fire is burning in the fireplace.

In the case of a solar chimney, the sun’s natural heat warms the air in the chimney, causing it to rise and create a draft that moves the hot air out of the structure. This heating process causes the cooler air from below to be pulled into the chimney for heating while the hot air is released from the top. The act of pulling in cooler air creates air movement, which provides ventilation in the structure.

solar chimney diagram

One of the most important things to consider when preparing for a solar chimney is placement. The solar chimney must be placed on the roof of a structure in an area that is naturally hit by the sun’s rays. The best scenario is to place the chimney in an area that gets hit when the sun is strongest in the afternoon. It is also important to consider the thermal characteristics of the solar chimney and design it with materials that absorb the most heat. This generally includes a black frame, tinted glass, and insulated glazing. Also remember that the size of the solar chimney is another important consideration—the larger the chimney is, the more effective it will be.

Harley School solar chimney

Another important factor is determining how to funnel the cool air to the base of the chimney so the suction effect can be achieved and ventilation can occur. Typically, one of two different methods is utilized for this process.

The first option uses windows on the lowest level of the building to capture cooler air and funnel it through the dwelling to the base of the chimney. This set-up requires no underground work and is best for structures that are maybe limited on ground area around the structure. The second method utilizes a pipe buried underground; the air in the pipe cools underground and is eventually drawn through the building to the chimney’s base where, through suction, the air passes into the solar chimney where it is heated and released.

Solar Innovations, Inc. can offer solar chimneys with operable or fixed vent options for the function. Both fixed and operable vents have a place in solar chimney applications, but if you’re not sure what is best for you, consult your Solar Innovations, Inc. sales representative.

Harley School solar chimney
Solar Chimney render