Michael Lu's Blog

Keeping with the reinterpretations of iconic forms, I am curious as to whether the chimney form can be repurposed as a passive cooling system. Two systems I am exploring: the ‘passive down-draft cooltower’ and the ‘solar chimney’ are presented below as passive cooling options to circulate air within each home without the use of fossil fuel driven HVAC systems.

A passive down-draft cool tower allows water to evaporate at the top of a tower, either by using evaporative cooling pads or by spraying water. Evaporation cools the incoming air, causing a downdraft of cool air that will bring down the temperature inside the building. Airflow can be increased by using a solar chimney on the opposite side of the building to help in venting hot air to the outside. This concept has been used for the Visitor Center of Zion National Park.

A solar chimney — often referred to as a thermal chimney — is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy. A simple description of a solar chimney is that of a vertical shaft utilizing solar energy to enhance the natural stack ventilation through a building.