Passive Solar Greenhouse

A serious issue facing small scale biodiesel production is the wastewater produced in the washing process. In order to solve this problem, we are developing a wastewater treatment system that will utilize natural and biological filtration mechanisms to bioo-remediate the wastewater our facility produces. In order to ensure that this system and its biological components can function year round, we have built a passive solar greenhouse to moderate the cold winter conditions that we experience in Boone, NC.

This element of the Collaborative Biodiesel Project adds an interesting interdisciplinary twist to the facility.

The first step in our implementation of the wastewater treatment design was the construction of our greenhouse. The university physical plant folks were happy to bring their backhow back out, and helped us dig out our foundation. Then, we carefully placed and levelled concrete forms to support the posts of the greenhouse.

Next, we ordered concrete again, and had lots of help filling the forms. A birds eye view from the top of the processor building shows Paul celebrating the achievement at the end of the day. 

In preparation for installing the wastewater treatment system, we buried a series of pipes to carry water between the greenhouse and the processor building. We insulated the channel because we will also be pumping hot water from our solar system into the greenhouse to heat our oil storage, and keep the whole building warm. We also connected all the drain lines from the processor building to the greenhouse; all of the water from our sink and floor drain will be treated there was well.

Finally, before filling in the footers, graucho buried 2" of foam insulation two feet deep all around the perimeter of the building to prevent heat loss through the foundation. Our ever-ready team of volunteers then helped us spread gravel around to form the floor of the greenhouse.