CCAT Cold Box
The idea of a cold box is to create a naturally controlled environment that provides short-term housing for fresh fruits and vegetables. The cold box works best if constructed on the northernmost wall of the home or building, this is due to our location in the Northern Hemisphere. It is designed to take in cool air from the outdoors through a vent, allow the air to rise up through the shelves of food, and exit through a top vent. The air that circulates up and through not only is a method of cooling the fruits and vegetables but also removes any of the odors resulting from the ripening process. Insulated walls inside the box maintain it at a cool temperature. This is a simple project that provides an energy efficient solution to a refrigerator as well as offer proper housing for fruits and vegetables which may reduce waste.
 Description of Opportunity
The cold box that I design and build will be for the Campus Center for Appropriate Technology (CCAT) house at Humboldt State University. In 2004 they did in fact have a cold box, and even though they haven't for the past few years, the cut out and vents are still in tact. After their house was relocated in 2007 due to the new Behavioral Social Sciences building being built on the CCAT site , they unfortunately lost much of the appropriate technologies that were implemented. It is up to me to give them a cold box once again while striving to make it even more efficient and beautiful.
- Locality of Materials: (Localism) offers the idea of limited productions for the purpose of saving the environment and scarce resources.
- Thermal Effectiveness: Thermal mass acts as a thermal battery. Thermal mass is not a substitute for insulation. Thermal mass stores and re-radiates heat. Insulation stops heat flowing into or out of the building. A high thermal mass material is not generally a good thermal insulator.
- Mold and Rot Resistance: Alternative techniques used to prevent hyphae from growing.
- Sustainability: The ability to maintain a certain process or state.
- Cost: The value of money spent to complete this project. The less the cost the better.
- Aesthetics: A critical reflection on art, culture and nature. My goal is to modernize the look of a standard kitchen cupboard.
- Social Justice: A world which affords individuals and groups fair treatment and an impartial share of the benefits of society.
- Environmental Justice: Environmental justice proponents generally view the environment as encompassing "where we live, work, and play" (sometimes "pray" and "learn" are also included) and seek to redress inequitable distributions of environmental burdens (pollution, industrial facilities, crime, etc.) and equitably distribute access to environmental goods such as nutritious food, clean air & water, parks, recreation, health care, education, transportation, safe jobs, etc.
- Demonstrativeness: serving to demonstrate; explanatory or illustrative.
The criteria I have chosen to use for this project are to facilitate the most appropriate cold box that I can in this location as well as to create a design that can be used by CCAT as a demonstration to others.
Most definitions are from Wikipedia.
|Qty||Materials Needed||Source||Cost||Total Cost|
|7.25 square ft.||16 Gauge Galvanized Sheet Metal||Donated||$0.00||$0.00|
|17.6 square ft.||Granite||Donated||$0.00||$0.00|
|1 Box||1/8" Rivets||Hardware Store||$2.79||$2.79|
|2||Wall Fasteners||Hardware Store||$12.00||$24.00|
|3 lbs.||Woolen Insulation||Donated||$0.00||$0.00|
|1||Exhaust Pipe||Hardware Sore||$5.00||$5.00|
|2||Cabinet Door Hinges||Hardware Store||$3.00||$6.00|
|1||Mesh from Window Screen||Junk Yard||$5.00||$5.00|
|32||Steel Screws (Bulk)||Hardware Store||$0.07||$2.24|
 Proposed Time Line
|2/26/09||Finish Research & Development|
|3/6/09||Junk Yard Rummaging for Materials/ Donations|
|3/10/09||Purchase Final Materials|
|5/5/09||Finalize Findings and Complete Appropedia Page/ Upload Photo's|
 A Change of Plans
With direction taken from one awesome interview I just recently had, my cold box plans are now being re-worked. From the information I was hearing, I realized this project could be drastically enhanced simply by using better materials. Rather than wood as the structure lined with insulation, I will use metal for the exterior to act as a reflector from the other sources of heat within the kitchen. Granite or marble will be the shelving as well as the internal walls. Yes this sounds expensive. I will do my best to locate these materials and see if any can be donated for this project.
The reason for making the changes within the plans are attributed to the understanding that this cold box will be more effective and efficient if I can harness the thermal mass properties found in natural stone, the stone will absorb the cool and keep it in. Due to the slower process of conduction the temperature will have less fluctuation and provide a more stable environment for the dairy, produce, and other goods. I will keep a gap between the internal box and the external surfaces. In this gap I will fill with local, hand-carded wool. This is to prevent the cool within the granite from transferring to the metal exterior. This will add to the efficiency and prolong the life of fruits and vegetables.
- Design internal dimensions of box; plan for separate compartments within these dimensions. My internal dimensions are 42"Hx16"Wx16"D. Attach bottom to side panels with 1/8" rivets.
- Measure and cut out sides, top and bottom pieces of metal (I made all cuts either 1/2" or 3/4" longer, this allows to roll over the sharp edge to create a softer look while making it safer use). The tool I used for this with an electric hand sheer.
- Cut shelf braces to 16"x20" and bend lengthwise 90 degrees. I filed the edges to remove any sharp burrs. I cut these strips with a hand sheer, her name is Beverly. Attach these braces to side panels at correct height of where you want your shelves to be. Use steel screws, 4 per brace.
- Cut out granite or marble shelves to dimension. I used a power saw with a diamond tip blade. (This was like cutting warm butter, just make sure to keep the blade wet with water to avoid a burnout).
- Once I complete the internal box, I will attach it to the wall where the cutout is. From there I will be able to see where I need to make a hole for my exhaust pipe.
- To make this internal portion of my cold box appropriate for anyone to make, I chose to use no welds. Not everyone will have access to an oxy-acetylene set up. Besides, the rivets and steel screws are strong enough.
- I have designed this so the external box will "float" around the internal box. This will give me the space to insulate with my hand-carded wool.
 Literature Review
Passive Cooling (Solar Heat Technologies). London: The Mit Press, 1989.
- Whereas this book focuses on passive cooling for homes and buildings, the science and simple engineering behind it I found relative to my project. Chapter 2 on Ventilative Cooling and Chapter 6 on Passive Cooling Systems provided me with better insight and purpose.
Olkowski, Helga, Sim Van Der Ryn, and Bill Olkowski. The Integral Urban House: Self Reliant Living in the City. Dallas: New Catalyst Books, 2008.
- The Integral Urban House has been the only piece of literature I have found that addresses a cold closet. However, with only one page attributed to it, this book does show schematics and the construction procedure for one style of passive cooling.
- This Technical Manual is Australia's guide to environmentally sustainable homes.
- Alternative Moth Balls. 5 Natural ways to keep moths out of your wool.
- Problems with killing Moth Larvae.
- Properties of thermal mass.
- Using carded wool as insulation.
- How to hand card wool