Thermal Chimney & Solar Chimney Design — FarmPal
A thermal chimney is a solar-heated vertical shaft that drives natural ventilation by creating strong updraft. Paint the chimney exterior dark (solar absorptance >0.9) or glaze one side facing the sun. As air inside heats to 120-160°F, it rises rapidly, pulling cooler replacement air through the building from shaded intake vents. Design rules: minimum 10 ft tall for useful draw; cross-section area = total intake vent area; locate on the hottest wall (typically west). A well-designed solar chimney moves 500-2000 CFM equivalent to a large exhaust fan using zero electricity. Combine with earth tubes for dramatic effect: earth-cooled air enters at floor level, solar chimney exhausts hot air at ceiling. Post-2020 computational fluid dynamics studies show optimized solar chimneys reduce cooling loads 40-60% in hot-arid climates.
A thermal chimney is a solar-heated vertical shaft that drives natural ventilation by creating strong updraft. Paint the chimney exterior dark (solar absorptance >0.9) or glaze one side facing the sun. As air inside heats to 120-160°F, it rises rapidly, pulling cooler replacement air through the building from shaded intake vents. Design rules: minimum 10 ft tall for useful draw; cross-section area = total intake vent area; locate on the hottest wall (typically west). A well-designed solar chimney moves 500-2000 CFM equivalent to a large exhaust fan using zero electricity. Combine with earth tubes for dramatic effect: earth-cooled air enters at floor level, solar chimney exhausts hot air at ceiling. Post-2020 computational fluid dynamics studies show optimized solar chimneys reduce cooling loads 40-60% in hot-arid climates.