Geodesic dome greenhouse: advantages and disadvantages
Merits
The Geodesic Dome is a very strong structure due to the use of triangles in the design. It is rigid and stable and transmits stress evenly throughout the structure. They are extremely strong for their weight and pack the largest volume of space for the smallest surface area.
They can withstand storms and extreme winds, and have been tested in extreme weather conditions around the world. Two cases are the Remote Early Warning Line Domes in Canada, and during 1975 a dome was built at the South Pole, the Amundsen-Scott South Pole Station (1975-2003), where resistance to snow loads and wind is very important. The Dome was 50 meters (164 ft) wide and 16 meters (52 ft) high, with 14 × 24 m (46 × 79 ft) steel arches, modular buildings, fuel and equipment depots. Separate buildings within the dome housed instruments for monitoring the upper and lower atmosphere and for numerous complex projects.
The “Pillow Dome” was invented by James Tennant Baldwin, the American industrial designer. This transparent, insulated aluminum and Teflon structure is used at the Eden Project in Cornwall, England. This is a steel frame with an inflated skin of hexagonal cells stretched over it. The hexagons are sealed at the edges and form a thermal blanket, insulating the buildings. Two huge closed domes are linked together and, with several smaller domes, provide habitats for plant species from around the world. The first dome has a tropical feel, and the second a Mediterranean feel. A computer controlled environmental control system regulates the temperature and humidity in each dome
drawbacks
Geodesic domes have many drawbacks, especially when used to provide housing. Construction has a large number of intersecting surfaces, compared to conventional structures, and all of them must be waterproof.
Surface coating is a problem because of the continuous series of flat areas, each joined on several sides, and falling to form the surface of a large curve. Access for repair and maintenance is difficult as nothing is flat, there are no ridges, and depending on the materials, it may require even more than normal care to prevent damage. The need to let light through and the lack of suitable flexible materials is also a problem. Flexing of structures due to normal atmospheric heating and cooling again puts much more stress on the waterproof seals.
The curvature of the sides makes the interior space a bit more difficult to use. The most effective roofing method is tile or tile. This creates problems near the top of the dome as the angle flattens out; it’s hard to keep the water out. One method is to provide a one piece “cap”, or provide a steeper pointed top, to cover this area. Some domes have been built with plastic sheets arranged to overlap and spew water.
Lloyd Kahn (a pioneer of Green Building and Green Architecture) was influenced by Buckminster Fuller, and during 1968 he began building geodesic domes. He became coordinator of the construction of 17 domes at Pacific High School and in the Santa Cruz Mountains. Experimental geodesic domes were fabricated from plywood, aluminum, sprayed foam, and vinyl. The children built their own domes and lived in them.
Having lived in a dome for a year, Kahn decided that domes didn’t work well: he calls them “intelligent but not wise.”
He lists the problems –
The dome shape makes various elements difficult to accommodate: chimneys, floor vents, fire escapes.
The conventional rectangular shape of the materials leads to great waste when cutting the triangular sections that are commonly used.
Windows can be 10 to 15 times more expensive.
Labor costs are high for wiring.
The interior shape makes the internal walls more difficult to build.
There may be issues with privacy, odors, noise nuisance, furniture fit, and lack of clearance along the walls on upper levels.
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