Since I am growing vanda orchids, I needed an enclosure that was at least 36″ tall. I have seen a vanda coerulea that was 9 feet long. Ideally an enclosure of 5 feet height would work best, but I could not find anything so tall off-the-shelf.
Vandas like air flow to prevent fungus from growing, and they also need carbon dioxide for photo synthesis. Since it is going to be humid inside the enclosure, there may be condensation build up inside during the night and morning when it is cold in California, which will block the view of the orchids. So doors on the front would be useful. Also an unobstructed view of the orchids is probably better for taking close-up photos.
I found a very informative blog by Pumpkin Beth on building an orchidarium. This pointed me in the right direction for an enclosure I could start with. I decided to get the ExoTerra Terrarium Large/X-Tall.
The terrarium comes with vents right below the front doors, and also a mesh wire top. I promptly got rid of mesh top and replaced it with a sheet of polycarbonate so that the humid air inside will not just disappear. I also made an opening in the back of the plastic top for a computer fan. This is for controlling humidity. If you make a paper template of the stop of the terrarium, you can take it to your local sheet plastics store and have them cut the plastic exactly to size (I used TAP Plastics).
I guess now would be a good time to explain what that basket-looking thing resting on top of the orchidarium is. There is going to be water build up on the bottom of the orchidarium. The orchids do not like having their roots sitting in water, so the basket prevents the roots from draping down into the water. Another reason for having the basket is that it can be covered in opaque landscape fabric, which will block any bright light from reaching the stagnant water at the bottom. This will help to prevent algae or fungus buildup (fungus and orchids shouldn’t go together). Again, I took a page from Pumpkin Beth in building a basket out of plastic grids called egg crates.
And I can’t have the orchidarium sitting on the floor! It needs a table to rest on, and that will also house the electronics and water/fertilization buckets. The table must be sturdy enough to support the weight of the glass terrarium, which is really heavy. So I found a table that is built out of a metal frame, but with mango wood panels and top.
I also attached sticky backed heat pads to the bottom of the terrarium so that water collected at the bottom will evaporate. This would be the perfect time to stick them on. I filled up most of the undersurface with two 25W heaters and a larger 24W heater.
This is also a good time to glue Reed switches to the bottom of the doors. These are for determining if the doors are open or closed. When the doors are open, watering is turned off, the fans are disabled, and the heaters are turned off. I cut off the screw mounting tabs with a utility knife.