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== '''Testing Results''' == | == '''Testing Results''' == | ||
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Image:P4120662 2.JPG|Figure 2 | |||
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== '''How to Build''' == | == '''How to Build''' == |
Revision as of 21:42, 22 April 2011
Abstract
Background
Locally Delicious is a group of women collaborating on a new book titled "Lunch Box Envy." Several different Engineering 215 projects are to be included. The school solar dehydrator is one of them.
Team Sodhopper:
Objective and Criteria
Objective
The objective of this project is to make the youth that participate in this project knowledgeable about food dehydration, conservation techniques, and food sustainability.
Critera
Several criteria were weighted and defined shown in the table below.
Criteria | Weight | Description |
---|---|---|
Safety | 10 | This is defined as a structure being stable enough for children, having safe building materials for food quality, and having a completely finished project to protect children against loose material or sharp edges. |
Cost | 9 | Design must cost less than $300. |
Reproducible | 9 | This is defined as the ease of following the directions and constructing the solar dehydrator. |
Durability | 8 | This is defined as having a structure that is able to last two to three years with regular use by adults and children. |
Weather Resistance | 8 | This is defined as the structure’s ability to hold up against all types of weather. |
Ease of Use | 7 | This is defined as a structure that has a design that is easily operated on a child’s level. |
Efficiency | 7 | This is defined as the project's ability to dry food quickly and to dry the food to the operator’s expectations of good quality dehydration. |
Aesthetics | 4 | This is defined as the project with a presentable and school appropriate design. |
Description of Final Project
This project was to design a solar food dehydrator to be replicated by schools.
Sunlight enters the slanted solar collector through the glazing, a polycarbonate sheet, and heats up a metal sheet. The air between the glazing and the solar collector warms, which causes it to become less dense and rise. As this air rises, it is replaced by outside air entering from the bottom of the collector which is then heated as well. The rising air eventually exits the collector and enters an insulated elevated cabinet with an air vent on the top. Since the air inside the cabinet is less dense than the outside air from being heated, it moves vertically within the cabinet and exits the cabinet through the vent. The cabinet contains horizontally oriented frames with nylon mesh in which produce is placed on. This produce dries from the moving hot air it is exposed to.
The solar collector contains a black painted copper sheet which sits on top of insulation within a polycarbonate covered wood box.
Costs
Design Hours
Material Costs
Materials | Use | Quantity | Project Cost ($) | Projected Cost ($) |
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Small Cabinet | Dryer Box | 1 | 6.00 | 30.00 |
Screen | Covering End of Solar Collector | 1 | 1.00 | 4.00 |
Styrofoam Insulation | Insulation of Solar Collector | 4 | 1.52 | 60.00 |
Copper Sheet Metal | Heat Conductor for Solar Collector | 63" X 27" | 40.00 | 40.00 |
Metal Roof | Roofing for Weather Protection | .97 tons | 5.00 | 0.00 |
Reflective Insulation | Insulation for Dryer Box | 5'X 4' | 22.80 | 22.80 |
Polycarbonate | Glazing Material | 10' X 26" | 35.29 | 35.29 |
Screws | For Polycarbonate | 1 box | 6.00 | 6.00 |
Screws, Sealant,Latch, and Polyfoam | General Use | 1 pack | 6.95 | 6.95 |
Sealant | Not used | 1 Tube | 7.75 | 0.00 |
Latch | Locking Cupboard | 1 | 5.00 | 5.00 |
Polyfoam | Sealing Polycarbonate | 1 | 3.00 | 3.00 |
Tacks | Securing Insulation | 1 box | 1.34 | 1.34 |
Caulking | Not used | 1 tube | 5.84 | 0.00 |
Hinges | For Cabinet Doors | 2 packs | 9.88 | 9.88 |
Hinges | Not used | 2 packs | 0.00 | 4.00 |
Piping | Connecting Solar Collector | 1 | 1.00 | 1.00 |
Nylon Mesh | Drying Racks | 3 yards | 6.06 | 6.06 |
All Lumber | Collector Box, Drying Racks, and Base | N/A | 0.00 | 20.00 |
Polyvert Closure | Set Glazing on top of | 1 pack | 3.98 | 3.98 |
Primer | Whole project | 1 can | 8.99 | 8.99 |
Paint | Whole project | 1 can | 31.00 | 31.00 |
Plexi-glass | For roof and base | 6 | 8.88 | 0.00 |
Total | 219.40 | 293.17 |
Maintenance Costs
Testing Results
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Figure 2
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Fig 3: Cabinet before work starts.
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Fig 3a: Justin Thompson measuring for insulation.
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Fig 3b: Shelving and Insulation being installed.
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Fig 3c: Solar Collector with copper sheet, insulation, and polycarbonate.
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Fig 3d: Frame of Solar Collector.
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Fig 3d: Justing Thompson attaching base to Solar Collector.
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Fig 3e: Insulated Solar Collector.
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Fig 3f: Mary Wooldridge cutting nylon mesh for drying racks.
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Fig 3g: Finished Drying Rack.
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Fig 3h: Finished base.
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Fig 3i: Finished Dryer Box.
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Fig 3j: Finished Dryer Box with cabinet doors attached.
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Fig 3k: Finished Dryer Box including Base.