LV Rogers High School

Greenhouse and Garden Projects2010/2011

“Green Games” Submission

It all started with students and staff donating to the Greenhouse

Garage Sale

Excavation of boulders

Forms for concrete perimeter

Concrete poured and insulated, sand and gravel floor covering water pipe heating grid

Insulated northwest and northeast walls erected

Framing for glass and for heat vents

Interior paneling almost

finished. Plant benches and water tanks need to be installed.

Some paint touchup to be done when the

weather is warmer.

Stucco, roof and glass completedLayout of garden beds

Gardening is fun!

Irrigation and soil in

place

Waiting for spring!

Beginning to make greenhouse plant benches out of old plexiglas from ice

rink

Planning how to connect our

insulation-stripped hot water tanks for greenhouse heat storage (to

help stabilize day/night

temperature)

Greenhouse Project Details

Since our community and school are focused on “green” initiatives and since a gardening club had just been formed, I thought a greenhouse would be a good project for my grade 9 and 10 technology (design / build) shop classes. The design challenge was to create an efficient, inexpensive greenhouse that used some recycled material and didn’t require auxiliary heat. Although the city of Nelson is located in the southern region of the province, it is in a snowy, mountainous area. Because of this, a greenhouse is expensive to heat in the winter. We chose to design a greenhouse that would allow us to start growing in April until the cold of mid November. Most gardeners in this region plant outside on the long weekend in May; since the school year ends in June, not many vegetables are ready for use by the students unless the plants are started earlier in a greenhouse.

The technology students formed “brainstorming” groups to come up with creative ideas for the greenhouse. They researched the ideas on the internet then sketched possible solutions. We then brought the group solutions together to create our design. Our design solution was to use old patio doors (they have tempered glass for safety and double glazing for insulation). To support the glass we used a reinforced, insulated concrete perimeter foundation. In between the foundation we buried loops of pipe in the sand and gravel floor to stabilize the building temperature. To also stabilize the temperature we placed heat-sensitive gas vent openers at the gable ends of the building. Inside the building we decided to place black hot water tanks (with the insulation removed) to absorb heat especially from the hot afternoon sun. To help retain the heat at night we insulated the north facing wall and ceiling.

Students with some computer drafting experience made the drawings. We took our drawings to the building inspector to get their advice and the building permit. We started the project in April, 2010 by having a garage sale to raise money for building materials. Students and staff generously donated items to the sale. We raised $437.00 on a Saturday morning. Later, a local man also donated $150.00 to our building cause. We also ran advertisements for used patio doors and building supplies. Because patio door glass comes in many sizes, we had to collect two dozen of them to obtain enough sizes that would work! A local glass shop (Kootenay Glass and Mirror) donated three of these used panels and an old insulated glazed door (that we had to make a new frame for and paint up).

Because we were low budget and because we wanted to “tread lightly on the earth”, we excavated a flat spot by hand. Our site is south facing near the unutilized south wall of the school. Our school unfortunately faces south against a mountain that restricts the morning sun. However, the mid morning to late afternoon sun is good. We encountered many challenging large boulders during our excavation; fortunately the grade 9 and 10 boys relished the physical challenge! We assembled the concrete forms out of the materials we would later use as wall studs. With a borrowed mixer, we poured the concrete around our steel rebar. The students placed rigid insulation on the inside of the concrete and then covered exposed insulation with galvanized steel (used furnace ducting).

Once the foundation was finished, we constructed the walls out of mostly recycled building materials (we took apart an unfinished garden shed). We cut and welded some angle iron to support the roof glass (with wooden beams underneath for additional support). Some students constructed light-weight opening gable vents by laminating 1/8” plywood to rigid insulation. The north facing roof was covered with asphalt shingles with a ridge vent and soffit vents to help reduce condensation in the insulated vaulted ceiling. To match the school exterior we covered the outside of the greenhouse walls with stucco; there was a bit of waste on the ground but the students had fun (and it looks good)! The art class is going to paint a “garden themed” mural on it this spring.

By the time it became cold at the end of October, we had the stucco applied, glass installed, door hung, walls insulated, vapour barrier attached, and most of the interior paneling on. We still need to make and install the planting benches; we are going to use old hockey rink puck/fan protection acrylic panels. We also need to connect up our black water tanks and automated watering system. The water tanks will be connected to the school water system. The pressurized water will flow through the tanks into the buried floor pipe loops, then to the irrigation solenoid valves. These valves will be controlled by a lawn sprinkler computer (that we haven’t purchased yet). The ideas is the water in the floor and tanks will heat up during the day, give off heat during the cooler nights, then in the morning the solenoids will open to water the plants. The cold water that replaces the irrigation water will heat up during the afternoon to start the cycle over again. If the building becomes too hot, the gas vent openers will open the gable vents to let the hot air out and promote circulation of fresh air.

The construction of the greenhouse has motivated the gardening club and social justice class to build raised garden beds on the lawn next to the greenhouse. This spring they are also going to plant a variety of trees and plants on the bank above the raised beds. If we are successful with this application we will put the prize money towards finishing the greenhouse and garden projects and also towards our next project….a school solar electricity generating system.

By June the gardening club and special needs students plan to have some vegetables for use by our cafeteria catering and foods classes. The science department also hopes to use the greenhouse for plant growing experiments.

Submitted by Dave Afford

LVR Tech. Ed. teacher