I came across the article recently, and if you’re an architect, environmental designer, and/or termite enthusiast you might find it just as fascinating as I did. Apparently, it’s been a topic and biomimetic precedent that has been under investigation for some time. New tools and monitoring techniques have shed some new light recently, however. A more detailed journal article has been published by Hunter Kinga, Samuel Ockob, and L. Mahadevana under the title “Termite mounds harness diurnal temperature oscillations for ventilation” and can be accessed through Penn Franklin.
Worth a read…
Here is a more detailed abstract from that journal:
Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diur-nal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combina-tion of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ven-tilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations.
This project grew out of an investigation into lighthouses as a historical building typology and the reasons for their failure. As portion of the focus of our final project in Building Pathology, what was discovered was that more often than not historic lighthouses today fail due to a lack of maintenance. At their heyday, lighthouses were manned 24 hours a day and maintained 24 hours a day: making sure pooled water on sashes was wiped up, ensuring broken windows were repaired, and ensuring weather-tightness of the structure in general. When the modern era replaced this antiquated system of navigation, this maintenance was indefinitely deferred, which ultimately leads to their failure in some way or the other.
I posed the question about redefining the lighthouse typology by embracing modern methods and techniques to optimize form to account for this unfortunate yet inherent idiosyncratic design feature.
Briefly, the premise was to remove the previously necessary maintenance input into the typology and rely purely on form to provide the navigational guidance toward prominent shipping lanes by redirecting the sun’s rays at critical moments during the day and year. So, instead of a lighthouse what is created is a reflective obelisk. By analyzing the predominant shipping lanes in the area and weather data for the year the form could be optimized by: rotation, twist, height, concavity/convexity, and translation of the top relative to the bottom of the tower.
I was able to then assign which surfaces were to be reflective or not. The process was repeated in three different locations world-wide: Cape May, NJ USA; Hel Peninsula, Poland; and Isola del Giglio, Italy.
The full report can be viewed here in detail, which goes on to describe the full methodology including genetic algorithm methods used as well as the results in finer detail. It should also be mentioned that this project is not an end-all-be-all ‘solution,’ rather an example of how it is possible to dovetail new technologies and methods with age-old questions. If anything, it is a project that at the end poses yet more questions.