EcoDome: Convention Center to Greenhouse

Hi, I'm Lincoln Clarke, a grade 12 student at Toronto French School.

In this Instructable I'll be presenting an air dome which can be used temporarily as a convention center and then converted into a greenhouse.

For the physical model:

1. 30*30mm fan
2. 12V power supply
3. Wires
4. 4x M3 15mm screws
5. A clear garbage bag
6. Packing tape
7. Super Glue
8. 3D printer (300*300*300mm)
9. 200g grey filament
10. 300g green filament
11. 200g filament of any color

I've always been fascinated by the way air domes can be put up so quickly to provide very large spaces. Air domes are also versatile: They can be used for sports, conventions, as retail space for a trade show, as an emergency shelter/popup hospital and the list goes on.

But air domes can be used as permanent structures and many of their applications are temporary. I was inspired by agricultural air domes as a subsequent use the event hosted in the dome is over.

Although this dome could apply to various events, it would be most symbolic for the dome to host a climate summit and subsequently use it as a greenhouse, going from talk to table and creating a direct impact.

This air dome is designed to be a sustainable and efficient greenhouse that benefits the local community after the climate summit is over.

It would ideally be built in a place that would benefit from a greenhouse. Yellowknife and Whitehorse in Canada would be great locations because of their cold weather conditions and their isolation, which makes food expensive because of high transport costs. These two cities are also large enough to host event they would need a dome for.

It would be easy to convert it from a conference center to a greenhouse since chairs, tables, and modular partitions are easy to remove.

To maximize the efficiency of the greenhouse, plants can be stacked in layers with grow lights on the bottom of each layer to fuel the layer beneath. The top layer benefits from sunlight which can shine through the clear ETFE bubble. Even on the top layer though, grow lights are necessary because of cloud cover and short days during the Northern winter.

The plants are automatically watered with an irrigation system. To improve sustainability, the irrigation system will be partly fed by a rainwater collection gutter around the dome's base.

Whitehorse and Yellowknife both have heavy snowfall during winter. The ETFE bubble needs to be rather curved/spherical and not flat to ensure that snow slides off and doesn't accumulate—like what happened in the photo above! Fortunately, ETFE is naturally slippery, which helps with this, as does the slight heat from the greenhouse which melts the snow and makes it more slippery.

My model will feature a real bubble (made of saran wrap) and a small fan to inflate it.

So, I will design the base of the dome and a little bit of the landscape around it, which I'll glue the bubble to. This piece will be dual color.

I'll also design a mold in the shape of the bubble in order to stretch the saran wrap into the right shape.

I started with the layout of the base and the paths/grass surrounding it (1st image). From there, I designed the gray part as one piece and the green part as another piece, neither of which overlap at all. This allows for them to be merged smoothly for dual color printing. For the origami style doors, I used a multiple lofts between triangles on parallel planes (2nd image). Multiple lofts were necessary because a single loft would blend the geometry into an organic shape rather than creating a geometric, sharper shape, which is the look I was going for. I also used lofts between parallel organic shaped splines to create the bushes (3rd image). To align with the origami style, I then tessellated and reduced the bushes. I mirrored both the bushes and the doors to to create 4 of them.

For the bubble mold, I used the base profile shown in the first image along with the top point of the dome and 2 smoothly curved guide rails.

There are 2 pieces to print (STLs below): The green & gray base and the bubble mold that will be used to shape the inflatable dome.

The base is a dual color print and the gray and green STLs attached need to be merged in the slicer. The bushes do require supports, which I printed in green in case any bits of the supports remain. The hole for the fan also requires supports, and since the fan covers it the color doesn't matter.

The bubble is quite a large volume and lightning infill (as shown above) should be used to reduce filament consumption (It was 180g with lightning versus 800g with grid!). I also made the bottom wall very thin since we don't care about the structural integrity that much: It's only being used once as a mold.

1. Screw in the fan and connect it to 12V power (I just used jumper wires screwed into a barrel jack adapter)
2. Stretch a piece of a clear garbage bag over the bubble mold and then tape the edges down on the bottom side of the base using packing tape.
3. Super glue the bag to the edges of the fan hole and cut a hole for the fan. Optionally, the bubble can also be glued to the doors.

Note: I initially tried using saran wrap for the bubble but it didn't work very well because it stuck to itself and the fan couldn't inflate it.

Plug the fan in and watch as it inflates... Fortunately it's way faster than real air domes!

I've also attached some photos with just the plastic bubble mold instead of the inflatable bubble.

EcoDome is a low cost temporary building that can host a variety of events and then be put to use afterwards as a greenhouse.

It's especially symbolic if it's used for something climate related since it would result in direct action afterwards by producing food in a sustainable way and reducing emissions from food transportation.

I hope you enjoyed!