Let's build a rain forest atrium in Downtown Birmingham, AL. It's a cool idea whose time has come. "The Magic City Rain Forest" is an organic laboratory for new and effective medicines derived from tropical rain forests. UAB Biomedical Research could have a tropical rainforest greenhouse for rare herbs and tropical plants adjacent to compus.
The Birmingham Botanical Garden has outgrown it's greenhouse and thousands of visitors enjoy it's exotic environment. Birminghams-Magic-City-Rainforest could be a mecca for international botanists, garden lovers and anyone desiring a stroll through a rare and exotic world.
The Magic City Rainforest could have subterranean parking.
The first major factor is how do we build a building that will duplicate the tropics but do it in Birmingham, Alabama? Birmingham is in the heart of Dixie where the weather isn't terribly cold. The winter temperatures can easily drop well below freezing for weeks at a time so the building has to keep the plants warm and humid but also give them all the light they need to develop, grow and reproduce. The major problem is to build such a building on a tight budget.
There are many companies who build "sun rooms", and that type of structure may work. The cost of having one built could exceed $2 million US dollars. We could build Birminghams-Magic-City-Rainforest for about 40% that cost using professional labor for the structure. We could build it within budget by using a great deal of volunteer labor. The value of the adult plants to be installed could easily equal the original cost of the structure.
Using a really good thermal material that will do the job, not break the bank, and will last a very long time while withstanding hail storms.
GE Lexan Thermoclear™ is one highly recommended thermal material. There are a lot of materials out there including Lexan corrugated material. but the multi-walled Thermoclear™ is one of the best values. Experience has proven it works great double walled and around 1/4 inch thick. It works quite well but the triple wall version may be a better long term solution. Heating expense each month in the middle of winter to heat a 600 square foot atrium to a minimum of 55 degrees could pay for the difference in wall thickness in five years. During the day, so long as the sun is shining, the GE Lexan Thermoclear™ will create enough heat energy from sunlight to keep the atrium comfortable. But when the sun falls we have to rely on some type of artificial heat to do the job.
General Electric's Lexan Thermoclear™ will help hold the heat in during the night but one of its best properties is its ability to create heat from light during the day. With the rising price of natural gas and other fuels, especially electricity, the thicker material can save a bundle on overall heating costs. When it gets in the 20's, and lower, the thicker material will save even more every month! The double wall may work just fine but at least consider spending the extra on the thicker, more protective, and more efficient material. Lexan Thermoclear™ and information about its uses are on the General Electric website and they give names and phone numbers of dealers who sell it.
Lexan Thermoclear™ comes in either 4 x 8 foot or 4 x 12 foot sheets and is easily installed. An atrium of pressure treated cedar 2 x 6's atop a concrete foundation set 18 inches (46cm) into the ground could work. For maximum support there is one large 6 x 8 inch pressure treated cedar timber in the center of the room with another 6 x8 cedar cross beam running from the east to west wall to tie the entire building together. The the center support beam is sunk in two feet or concrete.
For a more beautiful structure there are companies including General Electric that make metal frames that allow the Lexan Thermoclear™ to be simply inserted into slots within those structures. With Lexan Thermoclear™ you can even make the walls curve slightly.
Lexan Thermoclear™ is sealed with clear Silicone sealant. Once the Lexan is attached thin strips of cedar were applied to the seams to seal them further and make the exterior of the building look more professional. The tiny gaps between sheets MUST be sealed with silicone sealant. If you leave the seams unsealed the Thermoclear™ will loose efficiency and mold will form between the doubled layers of the exterior walls.
Birminghams-Magic-City-Rainforest could be 4 stories tall at the highest point with a 2 story outer wall height. Many plants have already outgrown their home at the Birmingam Botanical Garden.
A metal grid framework is recommended to contain a highly tropical environment. The interior moisture and humidity will remain high year round.