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Sanctuary solar food dehydrator
The four members of Team BALM are Environmental Resources Engineering Majors at Humboldt State University in ENGR 215, Introduction to Design.
The problem analysis defines the specifications required from the Sanctuary, as well as considerations necessary to identify pertinent information related to the location, the client and solar food dehydrators.
The alternative solutions to the Sanctuary’s need for a solar food dehydrator. The brainstorming included in this section is the process team BALM used to find different alternatives to pursue. The decision process outlines which of the designs proposed is chosen for the Sanctuary’s solar food dehydrator.
The solution is outlined below in the description of solution section, supported by a computer-generated design and plan of action.
Team BALM built a Solar Food Dehydrator for the Sanctuary, a non-profit organization located in Arcata California.
Team BALM are engineering students at Humboldt State University in Introduction to Design Course. Team BALM includes Lynn Brown, Brayden Leach, Andrew Rushing and Marissa Woolsey. The client for the project is the Sanctuary.
The Sanctuary is a non-Profit corporation located in Arcata, California. The mission of the Sanctuary is to inspire creative growth through arts. The Sanctuary provides art facilities for the Arcata Community and the general public. The art facilities include a general shop, a garden, a library, a kitchen, and workshop spaces for textiles, ceramics, jewelry, music, printmaking and bike repair. The sanctuary is focused on restoration, recycling and repurposing materials as well as inspiring waste-diversion and prevention.
Waste-diversion and prevention is modeled in different ways at the Sanctuary. One way the Sanctuary diverts waste is the compost system located on the property. The system reduces the amount of food waste sent to landfills and provides nutrients used in the garden. Another way the Sanctuary diverts waste is through an agreement with local farms. Food with imperfections or unable to be sold is donated to the Sanctuary by the local farms. The food donated is usually thrown away by the farms but this opportunity reduces the waste in the community while feeding the community. The food donations come in large quantities at one time. The produce is available for all who visit the Sanctuary. The food is used in the kitchen at the sanctuary. When there is not enough demand for the donations before they go bad, the Sanctuary creates alternative ways to preserve the food. The means of food preservation occurs through canning and dehydrating at the Sanctuary.
The Sanctuary utilizes food dehydrators to preserve excess food. The two current dehydrators on site, run on electricity and both are stored in the indoor workshop space. One of the current food dehydrators is large and produces a lot of noise when in use. Due to the size and weight of the food dehydrator it is not easily transported by the Sanctuary Staff.
Problem Statement and Criteria
The Sanctuary is in need of an alternative solution for dehydrating food. The current food dehydrator uses too much energy. The space in the Sanctuary workshops are dynamic as well as limited, the two dehydrators onsite both use a significant amount of this space.
The objective of this project is to find and create a food dehydration system that reflects upon the Sanctuary’s mission on waste-diversion and recycling. The food dehydration must use solar energy, and be portable.
Criteria and Constraints
After sitting down with the client, these were the main criteria weighted on a 1-10 scale
|Safety||10||The unit needs to be able to be operated without causing harm to users. It should have weight distributed in such a way that makes it difficult to knock over. The resulting food must be safe to eat after dehydration.|
|Durability||10||Must withstand environment for two years with semiannual maintenance|
|Recycled Materials||9||In order to save on costs and uphold standards of Client, using recycled parts is a must. It must be constructed from appropriate materials|
|Insect Proofing||9||Must deter insects from entering the food compartment.|
|Effectiveness||9||The unit must function as designed and dehydrate food in a reasonable amount of time|
|Adaptability||8||The dehydrator must be able to change whether it packing it up and taking it to a new location or storing it easily in the off season when dehydration cannot occur.|
|Portability||8||The design must be conducive to movement about the Sanctuary's given outdoor space.|
|Ease of Use||7||Must be able to be operated with less than a fifteen-minute training for an adult|
|Aesthetics||7||Exceed the look of Bayside Food Dehydrator, must look like it belongs to the Sanctuary|
|Cost||7||Must use the least amount of money possible.|
|Replicability||6||People need to be able to look at the design and be able to recreate it.|
Description of Final Project
The Solar Food Dehydrator made for the Sanctuary is a trapezoidal food box with a detachable solar collector on a stand. The dimensions for the food box are, base 19”x 21.5”, top 19” x 24” the height is 27”. The side panels are identical to one another. The front of the box is a framed piece of polycarbonate attached on the angled end of side panels. The 4”x19” space below the frame is for the detachable solar collector. Figure 5-1 AutoCAD of Final Design is the computer- generated model of the project. The racking space available for dehydrating is an area of 41 𝑓𝑡!.
This document outlines the team's work towards our final product. It also includes research that has been put into the construction of the solar dehydrator and the decision making process.
This video was made to show the different components of the solar dehydrator, as well as disassembling the heat collector from the food box.
This is a labeled picture of the final dehydrator design
This is the vision of the design made using the AutoCAD program
How to Use
This is a step by step on how to use the dehydrator
- Step 1:Cut desired fruits and vegetables into half inch pieces
- Step 2: Get the unit set up so that you are maximizing the sunlight that hits the collector
- Step 3: Open rear door and pull out a tray
- Step 4: Place fruit and vegetables on the tray
- Step 5: Close Door and check every 2 hours until items are dehydrated
This chart shows the amount team BALM spent on materials used for the project, and the total amount spent.
|Quantity||Material||Source||Cost ($)||Total ($)|
|2||4'x8' -Pine Plywood||The Hardware Store||22.00||44.00|
|1||Corrugated Polycarbonate Plastic - 4' x 4', Transparent||The Hardware Store||33.47||33.47|
|150||Screws (Various Sizes)||The Hardware Store||16.00||16.00|
|1||Black Spray Paint||The Paint Store||8.50||8.50|
|1||Double Pane||The Hardware Store||54.00||54.00|
|1||Silicone Tube||The Hardware Store||8.00||8.00|
|1||Roll of Mesh Screen||The Hardware Store||21.00||21.00|
|1||Roll of Weatherproof .25”x17’||The Hardware Store||5.00||5.00|
As of 12/8/16 there hasn't been any testing on the food dehydrator. A food dehydrating box and heat collector was constructed that is stable and safe. What is still left for the dehydrator is painting the outside and creating trays. The plan for testing the unit is set for 12/10/16. A thermometer has been placed in the dehydrator box that will allow users to monitor the temperature within. The solar food dehydrator will be used during the spring and summer seasons. The results will be added once testing is done.
How to Build
Food Drying Box
This section explains how to build the food drying box
- Step 1- Buy necessary materials from your local hardware store
- Step 2- The dimensions for the food box are, base 19”x 21.5”, top 19” x 24” the height is 27”. The side panels are identical to one another. Refer to AutoCAD for Design.
- Step 3- Cut top piece, bottom piece, and door in order to match the side panels. Make sure the door is 22" in width and 25" long. Cut all these out of 1/2" plywood
- Step 4- Cut 1"x1" pieces of wood and attach the to frame the side panels
- Step 5- Screw all the pieces together using the sides as the main guide
- Step 6- Attach door using hinges
- Step 7- Build frame for polycarbonate out of 1"x1"s, place polycarbonate in frame, and attach frame to front of the unit
- Step 8- Cut 1"x1"s and attach them to the inside of the unit 1 inch apart of each other to act as the rails for the trays
- Step 9- Cut holes in the door 2 inches in diameter for exit air
- Step 10- Attach third hinge on opposite side of the door hinges to act as a tight door lock. Make sure hinge has a removable pin
This section explains how to build the heat collector
- Step 1-Buy necessary materials from a local hardware store
- Step 2- Cut 1/2 inch plywood to 22"x30"
- Step 3- Paint the plywood black using food safe paint
- Step 4- Cut corrugated plastic to the same dimensions
- Step 5- Cut 2 2x4s to 30 inches
- Step 6- Attach 2x4s to the long sides of the plywood using wood screws
- Step 7- Attach corrugated plastic to 2x4s using wood screws and silicone
- Step 8- Fold metal screening and slide it under the corrugated plastic
- Step 1- Simply use a stool that is somewhere between 1.5' and 3'
This is a basic Maintenance guide for the solar food dehydrator. The maintenance schedule is broken down into daily, weekly, and yearly tasks.
This is when to maintain what.
- Make sure unit is being hit by sun while dehydration is attempted
- Clean Trays
- Clean inside bottom of unit
- Inspect tray integrity
- Check seals to insure their integrity
- Check locks and latches functionality
These are instructions on how to maintain the unit
|Make sure the unit is being hit by the sun||When checking the foods progress every two hours, also make sure the sun is still hitting the unit. Rotate and move unit as necessary||5 minutes|
|Cleaning the trays||Pull out each tray fully and use a wet towel to clean any leftover food on the tray.||30 minutes|
|Cleaning the inside bottom of the unit||Pull out the bottom 4 trays of the unit so the bottom of the unit is more accessible. Use a wet Towel and wipe out any leftover food scraps that may have fallen to the bottom of the unit. Then replace the trays that were removed.||15 minutes|
|Inspecting tray integrity||Pull out all the trays and inspect each one individually. Ask yourself these questions: Is the inner tray maintaining its structure? Is the outer tray also maintaining its structure? Are there any holes in the tray?||1 hour|
|Checking seals on unit||Open door and make sure the weatherstripping is still intact. Check the silicon that frames the front polycarbonate frame. Check the various holes that were filled with silicon and make sure its intact. Check the heat collector and make sure the polycarbonate is still tight to the 2x4s.||30 minutes|
|Check lock and latch functionality||Make sure the three hinges on the door are all functioning properly. Make sure that the latches that attach the heat collector to the food drying box are still easy to operate and are holding the weight of the unit.||20 minutes|
This is a guide for troubleshooting various issues with the unit
|Heat Collector won't latch to Food Drying Box||Make sure the Heat Collector is fully pushed into the Food Drying Box. If the problem persists, trying latching one side and then latching the other.|
|The unit isn't maintaining heat or getting to the desired temperature||Make sure the door is shut tightly and the Heat Collector is fully attached to the Food Storage Box.|
|Bugs are getting to the food||Check and make sure all the bug safe screening is in good shape and doesn't have any holes or broken spots. There is screening on the exit holes on the door, on the air intake at the base of the Heat Collector, and in the space above the Heat Collector and below the Food Drying Box.|
Discussion and Next Steps
The total amount of hours that team BALM spent on making the dehydrator came out to be 366.5. Team BALM has recommendations in building this dehydrator that will be of use in replication of the design. The recommendations that are of high priority for future construction are the following. First, when gathering materials inspect plywood for warping, the materials must be level; this makes lining up components such as the door and the solar heat collector a lot easier. Another recommendation is having the tray sizes set up before construction; in doing so it will make the construction smoother. Lastly, make a full diagram before starting construction. This would have made the process smoother. By doing so if a size change or anything of that nature occurs, it can easily keep the desired dimensions and recalculate sizes.
The solar dehydrator trays and painting is a future step that will be done by The Sanctuary.
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