2014-04-25 / Front Page

Greenhouse mixes math, science

By Alex Acquisto
Staff Writer


Students from the honors engineering class at Kennebunk High School congregate in front of the off-the-grid hoop house they constructed last year. The engineering course is new this year, said Alan Carp, instructor for the course and STEM coordinator at the high school. Students are growing lettuce, cauliflower, catnip, lavender and chamomile. “We decided this would be an interesting addition for students to integrate math and science in developing a project,” Carp said of his shared idea with Aaron Germana, a math teacher at the high school. 
(Alex Acquisto photo) Students from the honors engineering class at Kennebunk High School congregate in front of the off-the-grid hoop house they constructed last year. The engineering course is new this year, said Alan Carp, instructor for the course and STEM coordinator at the high school. Students are growing lettuce, cauliflower, catnip, lavender and chamomile. “We decided this would be an interesting addition for students to integrate math and science in developing a project,” Carp said of his shared idea with Aaron Germana, a math teacher at the high school. (Alex Acquisto photo) KENNEBUNK — Juniors and seniors in Alan Carp’s honors engineering class at Kennebunk High School have been hard at work since last year constructing and maintaining the first off-the-grid greenhouse on school grounds.

The hoop house, characterized by its length, rounded structural shape and polyethylene material, has two rows of beds lining the interior walls.


Seedlings sprout in the hoop house at Kennebunk High School. Students in honors engineering have cultivated lavender, chamomile, catnip, lettuce and cauliflower in the greenhouse. The two black pipes stretching across the bed are part of an automated sprinkler system devised by students. (Alex Acquisto photo) Seedlings sprout in the hoop house at Kennebunk High School. Students in honors engineering have cultivated lavender, chamomile, catnip, lettuce and cauliflower in the greenhouse. The two black pipes stretching across the bed are part of an automated sprinkler system devised by students. (Alex Acquisto photo) Approximately $3,500 was donated by Sandy and David Perloff of the Perloff Family Foundation to fund the construction of the greenhouse.

“Without that money, we wouldn’t have been able to build it,” Carp said.

The honors engineering class was the brainchild of Carp, who is also the STEM coordinator for the high school, and high school math teacher Aaron Germana.

“He was starting his robotics program and we decided this would be an interesting addition for students to integrate math and science in developing a project,” Carp said.


Students in Alan Carp’s honors engineering class at Kennebunk High School pose in the hoop house many of them constructed last year. From left are Matthew Fortier, Connor Shillington, Noah Cimenian, Shelby Strickland and Ben Broughton. The 12 juniors and seniors have spent the school year researching and maintaining the off-the-grid-greenhouse behind the parking lot at the high school. 
(Alex Acquisto photo) Students in Alan Carp’s honors engineering class at Kennebunk High School pose in the hoop house many of them constructed last year. From left are Matthew Fortier, Connor Shillington, Noah Cimenian, Shelby Strickland and Ben Broughton. The 12 juniors and seniors have spent the school year researching and maintaining the off-the-grid-greenhouse behind the parking lot at the high school. (Alex Acquisto photo) If the weather is warm enough, most class periods are in the greenhouse. Now that the weather is warming consistently, plant growth is detectable.

This particular greenhouse is experimental, said Carp, meaning the focus is more on discerning what growing processes are most efficient rather than what crop the students are yielding.

For example, one row of beds has been watered by hand all year, and the other row has been watered by a solar panel powered sprinkler system. On Thursday, students were working on the final stages of programming a soil moisture sensor to bury in the controlled side’s soil.


Ben Broughton, a junior at Kennebunk High School, programs an Arduino Uno in the greenhouse that he and his classmates constructed. The small hardware will be used as a soil moisture sensor. If the soil is too dry, the Arduino will trigger the battery-powered sprinkler system, also designed by students. The greenhouse is powered exclusively by a solar panel and depletes no other electrical sources, thus it is considered off the grid. 
(Alex Acquisto photo) Ben Broughton, a junior at Kennebunk High School, programs an Arduino Uno in the greenhouse that he and his classmates constructed. The small hardware will be used as a soil moisture sensor. If the soil is too dry, the Arduino will trigger the battery-powered sprinkler system, also designed by students. The greenhouse is powered exclusively by a solar panel and depletes no other electrical sources, thus it is considered off the grid. (Alex Acquisto photo) Once imbedded, it will function exactly as its name suggests: if the soil is too dry the sensor will trigger the automated watering system to water the soil.

Both rows of beds are being used to grow planted lettuce, catnip, chamomile, cauliflower and lavender.

The controlled side is watered by two tubes that stretch from one end of the greenhouse to the other. The problem is that the current system does not distribute water evenly. During last Thursday’s class, students brainstormed solutions.


Alan Carp, STEM coordinator at Kennebunk High School and teacher of the honors engineering class, walks behind his students through their hoop house. Kyle Bronti in brown, Jacob Connors and Liz Cable, along with nine other students, have designed the mechanics of the experimental hoop house, which includes an automated watering system as well as a water heating system, both powered by a solar panel. 
(Alex Acquisto photo) Alan Carp, STEM coordinator at Kennebunk High School and teacher of the honors engineering class, walks behind his students through their hoop house. Kyle Bronti in brown, Jacob Connors and Liz Cable, along with nine other students, have designed the mechanics of the experimental hoop house, which includes an automated watering system as well as a water heating system, both powered by a solar panel. (Alex Acquisto photo) “If you hang them higher, they will impede growth less,” said Matthew Fortier, a senior. “What if you cross the hoses?”

Junior Connor Shillington suggested covering the beds partially with holepunched taut plastic so that water would trickle evenly out each hole.

Another student proposed the idea of essentially a vibrating robot who would water one bed at a time. Noah Cimenian, also a junior, suggested uprooting the growth and burying the hoses so that water could seep into the soil.

As the students brainstormed, Carp stood by listening but refrained from intervening.

“It’s hard sometimes as a teacher not intervening and, instead, watching them make mistakes,” Carp said.

The greenhouse is powered by a large solar panel. It powers a battery, which aids the sprinkler system and heats water that runs through pebbles underneath the beds to keep the plants warm in the winter and at night.

Attached to either side of the greenhouse’s exterior are two rain gutters that drain water into three barrels.

During a decent-sized rainstorm, the six barrels will fill about halfway, Carp said. The gutter system was also devised by students.

The informality that spurs spontaneous group discussion and decision making, along with the hands-on curriculum, are an integral aspect of the curriculum in honors engineering.

Aside from off-campus vocational classes students have the option of enrolling in, virtually no class at the high school allows for out-of-the-classroom learning in this capacity, Carp said.

“One thing we’re also trying to do is push diversity in the upper level classes,” Carp said. “Some are vocational students, some are AP, and they all bring different levels of input.”

As high school students age, and their sights for a specific diploma narrows (i.e. honors, or a level of STEM certification), classrooms become more homogenous – honors students take classes with other honors students, and so on.

An objective of the honors engineering class, as Carp and other teachers were mapping STEM curriculum last year, is to open its doors for an amalgamation of students at varying levels.

The honors engineering class has 12 students this year, a few of whom attend vocational classes at the Biddeford Regional Center for Technology.

“Everyone works really well together. They’ve each found their niche: Ben is excellent with software,” Carp said while motioning to Ben Broughton who was tinkering with an Arduino Uno. “And others are very good with construction.”

A cluster of students were working together to cut a square window at the opposite end of the greenhouse – another project in the works.

As the soil moisture sensor will trigger the sprinkler system if it’s too dry, students are preparing a temperature sensor to test the heat level inside the greenhouse.

If the heat becomes too high, the goal is that the window, by programming another Arduino robot, will peel open on its own.

Much of the greenhouse material is recycled: the six rain barrels were at one time used by an Asian restaurant to store soy sauce, and the screen window students began installing on Thursday was pulled from a dumpster behind the school.

It sounds like the work of trained professionals, but most of the students only became familiar with what it takes to maintain a greenhouse this year. Liz Cable, a senior, said aside from growing some plants leisurely at home, she had virtually no experience with how a greenhouse operated.

“It took a lot of research and a lot of trial and error,” Cable said.

The course offers the most hands-on curriculum of any class Cable has taken at the high school, she said.

“I enjoy it very much. I’m glad I got to take it before I left.”

Cable will pursue civil and environmental engineering next year in Orono at the University of Maine.

“This is a one-year class, but a lot are coming back next year,” Carp said of the remaining juniors.

At least 22 students are enrolled for the course next year, as it has gained a lot of popularity around the high school.

“It’s because they heard about all the amazing stuff we do,” Cimenian said.

Next year Carp plans to construct a second hoop house with a focus on production.

As the period came to an end, Carp asked the students to tidy the area.

“What do you say we spend some time cleaning up?” Carp asked the students. “This is our greenhouse and we like it messy,” Shillington said facetiously. “I made the mistake of telling them once that they own it,” Carp said with a smile.

Carp’s students were enthusiastic and very proud of their work, as was evident when he asked if any students would be willing to come by and check on the greenhouse over spring break.

Most of them volunteered excitedly. “I’ll be here every day at 10 a.m.,” said Cimenian.

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