final project status update: Shading

My original project plan was to construct a scale model of a light-sensing umbrella that could change position to protect a particular location from the sun, no matter what the time of day. This type of technology is particularly necessary in locations like Phoenix, which are extremely dry (unlike more humid locations, temperature in and out of direct sunlight can be vastly different) and flat (the lack of hilly, mountainous terrain means that there is nothing blocking the setting or rising sun).

At the beginning, I did some work getting input from light sensors and using that as output for arduino servos. I’ve done some research on what type of mount would be best (Josh helped me due to his familiarity with telescopes, which use similar tech), but we determined that, for the price and scale we are using, it would be best for me to request a simple “pan and tilt” system, which, while being less smooth in it’s transition, also costs significantly less and is easier to acquire.

Pics: wiring, code

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Pics: some sketches of what finished design would look like using different types of mounts

While using electronics has been a great personal challenge and has allowed me to expand out of my comfort zone, I did feel that the thing I was making was not particularly impressive on the scale of “improving human-heat interactions”.

So, I have tried to design several different examples of how this tech could be used for different outdoor situations.

Pics: For starters, I imagined the simple umbrella sculpture being scaled up. In addition to the possibility of it wacking somebody on the head, there is a significant risk that, when the umbrella is relatively low to the ground, rambunctious youngsters will try to climb onto it, which could cause a serious safety hazard.

Instead, we will be trying to design alternative ways of implementing this technology while reducing risk of lawsuits

Pics: Sketches of how the lighting works in the public areas outside the Memorial Union. Very nice around noon, but the shading falters as the sun lowers in the sky

Pics. One alternative: By having the tarp (or series of solar panels) move with the sun, you get greater energy input and protect the seating-and-working area from become too hot or bright. This would also work well for sport-fields, since the only poles are in the four corners of the structure. Also, since most sports teams practice in the evening (after class, less heat) being able to block the setting sun would be immensely helpful in not blinding athletes as they are try to play sports.

*This system works best in places like Arizona, which are *relatively* closer to the equator, since the angle of the sun will not change as much through different seasons. A more advanced version of this structure could have the two loops that the tarp is connected to actually bend to account for the changing angle of the sun’s ascension.

Pics: Lilypads. This is my personal favorite idea from an aesthetic standpoint, which uses green-blue tarps to protect the area below from the sun. It will both shade the students and given them a sense of a watery-area, without actually having to use water for decoration.

Pics: Personal shade. By using a series of these shaders around tables, it gives students a sense of coolness with additional privacy (at least at sunrise and sunset). Could be used around tables or Greek amphitheater-type seating.

Pics: This is another option that could work for a sports area, as it leave a large area open in the center. A dome composed of a series of geometric shapes, with tarps that can be stretched tightly or loosened over them based on the position of the sun. (because sports people are especially rambunctious, the structure would need to be 12 feet vertical at the bottom, to prevent people climbing on it like a giant jungle gym. This, unfortunately would mean that protection from the setting sun is limited (though an additional tarp could be lowered down the side at that time). On the other hand, some students might enjoy a gigantic jungle gym.

Going forward, I want to create more detailed drawings (and probably at least a few animations) of how these ideas would work. Based on that, it seems that the bulk of my project, while centering on the same concept of shade and moving sun protection, has significantly shifted from a construction focus to a design focus.

Solar Powered Chiller

For the final project I’m planning to build a Solar powered chiller to complement our main theme of “Heat for good”. Chilling canned drinks or other beverages is a common need of many people specially when they are going out for an outing in a hot environment. In this project I propose a cooling mechanism which uses the compressed air as the coolant and plan to build an experimental prototype. If successful this portable device will be able to chill beverages “on-demand” within few minutes and it will take the burden of carrying heavy mobile refrigerators or cooling boxes off while you are enjoying outdoors.

This proposal is largely motivated by Mitchell Joseph’s work on building a self chilling can.

Self-Chilling can
Self-Chilling can

Theoretical background: 

Amontons’ Law of Pressure-Temperature : The pressure of a gas of fixed mass and fixed volume is directly proportional to the gas’s absolute temperature.

Proposed Setup:



  • The Solar powered air-compressor pumps the air to the copper tube and increase the air pressure inside the tube when it is exposed to the sun light.
  • After the inside air pressure reached a desired level, user can place the drink-can inside the coiled copper tube. (See figure)
  • Then user removes the cap allowing the air pressure to decrease drastically resulting a temperature drop. ( See the theory) This results a temperature difference between the drink-can and the air inside the copper tube. Therefore a heat transfer will happen from the canned drink to air through the wall of the copper tube. An insulating material will be used to cover the copper tube from outside environment to eliminate the heat transfer to the outer environment.

Final Project – Possibilities

I want to make a solar cooker that works really well in the summer and hopefully in winter as well. I have tried to use as many “usable trash” components in my project idea but I would also like to use sheets of metal to make the cooker from scratch. I  don’t have access or the skills required to cut and fold metal and this is the biggest limitation.

I have included doodles from my notes to explain the three possible design ideas. THe overarching idea is to use reflection of solar radiation from as many angles possible to heat a metal sheet which heats up, transfers the heat to materials being cooked. I think of it as trapping heat. When the food is almost cooked I would like to cover the cooker to retain moisture in food as well as use energy efficiently.WP_20151027_09_53_03_Pro1WP_20151027_09_54_53_Pro

The simplest design I have uses a large tin can. The sides of the can will be cut along its length and bent outwards to reflect radiation. The upper cover of the can can be cut to size to use as a lid.


The next design is a bit quirky and uses the frame of a broken umbrella. I intend to place metal sheets or other reflective surfaces along the inner surface of the umbrella. The doodle explains the design better. When finished it will look like flower. This setup is only the arrangement of the reflective surface. The actual cooking can be done in a stainless steel plate with a border of at least an inch. This plate needs to be placed inside the reflective surface setup.


The third design possibility is the one that I shared in class the other day. For this a food grade metal sheet needs to be bent to form an angle between 45 and 60 degrees. Since I intend to cook food  in it there needs to a panel system built around the sides of the v. When food is half cooked the cooker can be sealed from both sides and the top. I will definitely need to use tools and acquire basic fluency with metal work. WP_20151027_09_53_15_Pro

Final Project – Solar Refrigerator

How to: Solar Refrigerator

The hotter it gets, the more important it is for cool food to stay cold!

There are 2 types of solar refrigerators –
the high tech expensive kind
(use a solar panel to power a normal-functioning refrigerator
the also technical but less expensive kind
(uses a coolant heated up by the sun to draw heat out of the refrigerator)
This will be an attempt to create one of the second kind

most common cooling materials: lithium bromide or ammonia

* ammonia is poisonous, so must handle with caution

single-effect devices coefficient of performance: 0.6-0.7
(60 to 70 Btus of cooling for every Btus of input heat)
Btus – British thermal units

some pipe
a bucket of water
some calcium chloride (absorbent)
ammonia or lithium bromide (as refrigerant)
sheet of shiny metal (solar collector)
something with good insulation to work as refrigerator


Solar ammonia absorption ice maker – good pictures, diagrams, & descriptions

Their description of materials and pricing:
Quan Material Cost
4 Sheets galvanized metal, 26 ga. $100
1 3″ Black Iron Pipe, 21′ length $75
120 Sq. Ft. Mirror Plastic @$0.50/sq. ft. $60
2 1/4″ Stainless Steel Valves $50
Evaporator/Tank (4″ pipe) $40
Freezer Box (free if scavenged) $40
1 Sheet 3/4″ plywood $20
6 2x4s, 10 ft long $20
Miscellaneous 1/4″ plumbing $20
2 3″ caps $15
1 1/4″ Black Iron Pipe, 21′ length $15
4 78″ long 1.5″ angle iron supports $15
Other hardware $15
15 Lbs. Ammonia @ $1/lb $15
10 Lbs. Calcium Chloride @ $1/lb $10
Total $510



paper on how to build a solar ammonia absorption refrigerator
senior design project

Click to access 1113.pdf


How to make a solar-powered refrigerator- solar design wiki


absorption refrigerator solar prototype from Chile

Final Project Ideas

Usable Trash Repurposing old toys and toy components
Beer bottle hydroponics system

Beer bottle + LED bulb

Instant papier mache
Light saber
Discarded yo-yo used in skirt to light up with a spin
Block printing system
Reflective surfaces art
DIY wagon
Find new purpose for a tooth brush motor
Christmas trees that are not trees
DIY loom
Rainbow maker
Holiday décor
Repurpose plastic bags
Soda can heating system
DIY Bio Vermicomposting kit
DNA extraction kit
Bacterial culture kit
Ginger ale
Fruit ripening system
Art Art machines
Graded thermochromics
LED toys to blinking capes and costumes
Laptop bag with Wi-Fi detector
Seat that lights up when you sit on it
Glow stick creations
Culture Recreate traditional baby carrying systems
Find out, through interviews, what happens to old toys, gadgets, and “stuff”
Interview artists-makers-scientists about their transitions across the interface

In the spirit of sustainability preliminary notes were taken on a restaurant menu.

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Final project pitch and proposal

In this assignment you will finalize your project idea. This is a 2-part assignment: you will post your project proposal to the blog, and you will pitch your idea in class.

Project pitch (5 minutes in class)
You will have five minutes to pitch your idea to the class. You can use any format you want (slides, skit, poster, video, etc.). Your goal is to convince the class that your project is a good idea. Since you only have 5 minutes, you have to succinctly explain the vision, problem or opportunity your project fulfills (or how your project fits within our class theme of heat); who might use your project; where it might be used; and why it’s a good idea.

Project proposal
In addition to the pitch, write a more detailed project proposal for the class blog. At the very least, include the following:

  • motivation (similar to the pitch, describe what problem, research question, or opportunity your project addresses)
  • related work (do a quick search to see if other projects have tried to address a similar topic; find 2-3 similar projects)
  • your idea (what you plan to build, who will use it, where it will be used, and why it’s different from existing work)
  • implementation (how you plan to implement your idea)
  • parts list (a tentative list of components you might use for this project)

Post your project proposal on the class blog under the “project proposal” category.

The proposal posted on the blog is worth 4 points and counts towards your final project grade
1 point for describing your project  motivation
1 point for describing related work
1 point for describing your project idea
1 point for adding your parts to this list and descriving implementation details in your proposal

The in-class pitch is worth 2 points and counts towards your final project grade
2 points for clearly presenting your idea in class