Leemhut met termieten airco
Op De Kleine Aarde willen we vragen aan de groep oudere kinderen of ze zin hebben om een unieke leemhut te maken, met airco zoals termieten dat gebruiken om de temperatuur constant te houden. Eventueel kunnen we hetzelfde principe later ook gebruiken om paddenstoelen te kweken voor onze voedselvoorziening op het ecodorp. Daar gebruiken de termieten dit systeem namelijk ook voor!
Bovenin zit een zwarte schoorsteen die door de zon opgewarmd wordt. De lucht erin stijgt op en daardoor wordt de lucht eronder aangezogen. Deze loopt door buisjes in de muur naar een grote buis die onder de muur van de leemhut doorloopt. Deze buis haalt lucht uit een buis die onder de grond doorloopt (waardoor de lucht gekoeld is) en een paar meter verder omhoog komt.
The Eastgate building, Harare, Zimbabwe: The Eastgate, also called "The Anthill", is modeled on the self-cooling mounds of Macrotermes michaelseni termites. These termites maintain the temperature inside their nest to within one degree of 31°C, day and night. The mounds accomplish this even when the external temperature varies between 3°C and 42°C. Eastgate uses only 10 percent of the energy of a conventional building its size, saved 3.5 million in air conditioning costs in the first five years, and rents space for 20% lower than a newer building next door.
Tropical Hospital Las Gaviotas in the Vichada: This hospital uses the same principles demonstrated in Harare and Sundsvall with the added benefit that the air rising from the tunnels contains a mere 17% humidity, thanks to the condensing effect of aluminum rods installed in the underground tunnels.
Biomimicry’s Cool Alternative: Eastgate Centre in Zimbabwe
The Eastgate Centre in Harare, Zimbabwe, typifies the best of green architecture and ecologically sensitive adaptation. The country’s largest office and shopping complex is an architectural marvel in its use of biomimicry principles. The mid-rise building, designed by architect Mick Pearce in conjunction with engineers at Arup Associates, has no conventional air-conditioning or heating, yet stays regulated year round with dramatically less energy consumption using design methods inspired by indigenous Zimbabwean masonry and the self-cooling mounds of African termites!
Read more: Green Building in Zimbabwe Modeled After Termite Mounds | Inhabitat - Green Design Will Save the World
Termites in Zimbabwe build gigantic mounds inside of which they farm a fungus that is their primary food source. The fungus must be kept at exactly 87 degrees F, while the temperatures outside range from 35 degrees F at night to 104 degrees F during the day. The termites achieve this remarkable feat by constantly opening and closing a series of heating and cooling vents throughout the mound over the course of the day. With a system of carefully adjusted convection currents, air is sucked in at the lower part of the mound, down into enclosures with muddy walls, and up through a channel to the peak of the termite mound. The industrious termites constantly dig new vents and plug up old ones in order to regulate the temperature.
The Eastgate Centre, largely made of concrete, has a ventilation system which operates in a similar way. Outside air that is drawn in is either warmed or cooled by the building mass depending on which is hotter, the building concrete or the air. It is then vented into the building’s floors and offices before exiting via chimneys at the top. The complex also consists of two buildings side by side that are separated by an open space that is covered by glass and open to the local breezes.
Air is continuously drawn from this open space by fans on the first floor. It is then pushed up vertical supply sections of ducts that are located in the central spine of each of the two buildings. The fresh air replaces stale air that rises and exits through exhaust ports in the ceilings of each floor. Ultimately it enters the exhaust section of the vertical ducts before it is flushed out of the building through chimneys.
The Eastgate Centre uses less than 10% of the energy of a conventional building its size. These efficiencies translate directly to the bottom line: Eastgate’s owners have saved $3.5 million alone because of an air-conditioning system that did not have to be implemented. Outside of being eco-efficient and better for the environment, these savings also trickle down to the tenants whose rents are 20 percent lower than those of occupants in the surrounding buildings.
Who would have guessed that the replication of designs created by termites would not only provide for a sound climate control solution but also be the most cost-effective way for humans to function in an otherwise challenging context?
Read more: Green Building in Zimbabwe Modeled After Termite Mounds | Inhabitat - Green Design Will Save the World