Fig 1: The Solar Swing


Abstract

The Solar Swing is a project from Humboldt State University's Engineering 215 class. The Solar Swing is a solar oven designed to be implemented in elementary schools across the United States to give children confidence while they learn about solar technology and practice cooking skills.

Background

Locally Delicious is a group of ladies from Humboldt County, California who promote the local foods movement and strive to move away from industrial agriculture. They have helped to fund many local projects such as Food for People, which selects six local farmers to grow specific food for food banks, the Mobile Processing Unit for the Poultry Cooperative, and the Potawot Garden in Arcata.

The group gets their name from their first book, which aims to provide recipes and resources for residents of the north coast. They are currently working on their second book- Lunchbox Envy. The book is targeted towards parents, older children and their mentors. The goal is to create healthy lunches that kids will want to eat and includes projects that kids can do by themselves, with adults or at their school.

Locally Delicious contracted our team to design and implement a solar oven in Trinidad School to be used as an example for a do-it-yourself project to be included in Lunchbox Envy.

Project Definition

This project is a solar oven that can be replicated at elementary schools across the United States by adults with the possible help of the students. It must meet the client's criteria.

Project Criteria

The Project Criteria was created by the group and discussed with the client. The Criteria was then weighted in order to determine the strengths and weaknesses of the Alternative Solutions.

Table 1: Project Criteria, Descriptions and Weights.

Criteria Description Weight
Cost Each team member contributes up to $75 and the client contributes up to $100, so the final cost cannot exceed $400. 7
Portability The oven must be easily moved around the Trinidad School campus. 8
Food Safety The oven must meet California Retail Food Code. 4
Oven Safety The oven must meet the school’s insurance policy. 10
Durability The oven must last for three to five years. 9
Effectiveness -teaching The oven must meet the Common Core Content Standards for English and Mathematics selected by the California Academic Content Standards Commission (http://www.scoe.net/castandards/). 6
Efficiency The oven must thoroughly cook the food prepared by the Junior Chefs within their designated meeting times. 9
Storability The oven must fit into the space designated by the Junior Chefs at the Trinidad School. 8
Ease of Use The oven must be operable by the Junior Chefs grades fourth through sixth. 7

Cost

Design Hours

The following chart includes how much time was spent in each section of the design process.

Reupload this with a more descriptive name and not in 3D. This caption could include the total hours.

Building and Materials Costs

Table 2 includes the current retail value of the materials used as well as the cost that our team was able to produce it at.

Table 2:Material Costs

Quantity Material Source Our Cost($) Retail Cost ($)
1 Mylar Roll Ace Hardware 18.52 18.52
1 Thermometer Ace Hardware 8.00 8.00
1 Doubled Paned Window Arcata Recycling Center Donated 112.00
5 Thick Wood 35x23 Arcata Recycling Center Donated Unknown
8 Thin Wood 35x23 Arcata Recycling Center Donated Unknown
Totals $26.52 $26.52

Maintenance Costs

The solar oven should be durable for three to five years. Table 3 shows current retail values of possible replacement items.

Table 3:Maintenance costs

Task Time (min/year)
Repair panels 3
Replace Thermometer 1 Ace Hardware 8.00 8.00
Total Cost $26.52

Final Design

The Slanted Box is a box-shaped oven that has one wall that is taller than the rest, creating a top face that is slanted downwards. It has four fold-out panels on hinges that hold the panels onto the box, allowing them to swing inwards and outwards. One pane of tempered glass makes up the top, slanted face of the oven. The door is on the top of the oven and opens into the box with the use of hinges. There are a swinging tray inside of the oven so that the oven can be propped up while in use.

This solution excels in several client criteria. The oven can be made compact by folding its panels inwards, so it is easily stored. Although not quite as much sunlight is allowed in, the amount of heat retained outweighs the heat kept out. The fact that the top face is slanted allows more direct beams of sunlight to enter, which are more powerful than reflected beams. The oven is effective as a teaching tool by demonstrating alternative technologies, reflectivity, basic concepts of heat, and geometry of the sun. Drawbacks of this design include the fact that it most likely must be moved by a dolly. Materials in the solar oven include wood for the box and the reflector mount, Mylar for the reflective material and the inside sides, window glass for the top.

[figure of design]

Building and Implementation Instructions

This is where we tell you how to build the oven.

Results

Testing of the solar oven solution is in progress and the results are not yet available. The oven has been able to get bred to rise but the temperature value was not recorded.

Discussion

The solar oven built for a school fits the criteria required for this project. The results of our testing are still unavailable but as soon as we get it in updates will be made.

Next Step

With the solar oven complete our next step will be to take it to Trinidad School and have the Junior Chefs use it and give us feed back so we may make any minor alterations they might have.

References

These are our references.

2011 Team

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