December 19, 2013
By Mike Killeen
Stephanie Pinkalla compares constructing the Full Circle Greenhouse at the College of Saint Benedict to riding a rollercoaster - lots of ups, coupled with a few low moments when it seemed unlikely the project would ever get done.
But on Dec. 12, the ride ended and the greenhouse - located just north of the Maintenance/Transportation Building on the southern edge of the CSB campus - opened.
When running at full capacity, the passive solar greenhouse will grow spinach, carrots, radishes, lettuce, sprouts and possibly kale. The produce will be sold to McGlynn's, for use at the sports-themed eatery at CSB.
"We've been on this constant rollercoaster - hurrying up and getting something done, and then having to wait, or finding out that we had to change something," said Pinkalla, a senior political science major from Eagan, Minn., who led the student volunteer effort to build the greenhouse with technical help from CSB grounds and maintenance workers.
"The victory is sweet, now that we're at the end. All of the setbacks and the hurdles that we encountered have really made it very special that we've gotten to this point. We can say that the greenhouse is done. That's not something that I'm used to saying. It's always been in progress," Pinkalla said.
"Less determined students would have given up," said Judy Purman, CSB director of sustainability who is the project's adviser. "Their tenacity is to be commended. Despite the obstacles, they persevered and in the process, learned the practicalities involved in turning a concept into a reality."
Getting the greenhouse built was no small task. Three different locations were proposed to the CSB Master Planning Committee beginning in the fall of 2011. Initially, the students had hoped to build more in the center of campus to make it more visible. It wasn't until Jan. 31 that a current location was approved.
Construction began in May, but almost immediately was hit by a major glitch. The foundation was laid almost 90 degrees on the wrong angle.
"The angle that the greenhouse faces is really important because we want to maximize the sun. We need (the greenhouse) to be at a particular angle where we're getting the longest amount of time with the winter sun," Pinkalla said.
Fortunately, Honer Excavating - which dug and donated the foundation - came back and redid the foundation on the right angle.
Pinkalla said that 27 students from CSB and SJU have been "significantly involved" in the process over the past three years. They are led by four students managing the project: Pinkalla, SJU senior Connor Klausing, CSB sophomore Megan Lundquist and SJU sophomore Tyler Thompson.
In addition, a number of professionals helped in the construction of the greenhouse, including George Hemmesch, a carpenter with the CSB maintenance department; Chris Brake, grounds director at CSB; Larry Christen, facilities director at CSB; and Brad Sinn, executive director of facilities at CSB.
The Full Circle Greenhouse is similar to the greenhouse constructed and opened earlier this year at SJU in that it uses passive solar energy in the greenhouse, which measures 16 feet wide by 22 feet long.
"Passive solar is exactly that - passive," Pinkalla said. "When the sun hits those Plexiglas panels that we have on the greenhouse, the paneling diffuses the sunlight, which actually makes it more productive for the plants. It ends up giving them more light than they would get if there was just a regular window.
"The way the sunlight hits the panels, it enables the heat that's coming from the sun to be contained in that space, and it doesn't escape through like a regular window. Heat is also circulated through a ground heating system that we have. We have a corrugated pipe that will go along the panels at the top of the greenhouse, and the air inside that is warmed and recycled through a pump with a blower down into the ground under the soil, where there are coils that will heat plants from the ground up as well.
"We're using the passive solar system not only to generate the ambient temperature, but also to physically warm the plants from the ground up."
The system makes it perfect for planting during the academic year - from roughly the end of September through late April or early May. That will allow three "great" harvests, as well as continuous weekly harvests. The greenhouse is too hot to grow produce in the summer, and that time is used for sterilization.
Now that the greenhouse is up and running, the group hopes to add an educational component to it as well. Pinkalla hopes students from various academic areas at CSB and SJU, as well as elementary students from the nearby area, will "see what a greenhouse looks like and get their hands in the dirt," she said.
"We have everything in place. Now, it's just a matter of waiting for the seeds and the plants to grow," Pinkalla said.