Week 8: Getting Everything Together

     This week is where we bring everything together and prepare for the final presentation. After eight weeks of research and critical thinking, we have a working design that will remove cooking smoke from the cooking huts of the Bo Klua people. The medical clinic survey conducted by Dr. Moseson back in 2009 found an average of 34 cases of pulmonary problems. We hope that our design will help to bring down this number and improve the quality of life in the Bo Klua region.

Figure 1: Model of house and the turbine

Week 7: First Draft of Final Report

     This week we worked on the first draft of the final report. The report was written a week before the deadline. Each member was assigned tasks based on past contribution. Based off the feedback from the Teaching Assistants on the past week's design proposal, we applied those criticism towards this report. Final revisions for the report were made to pairwise matrix such as adjusting the units to fit the needs better. The specification table was fixed to only deal with the our groups main focus which is the fan ventilation system. Also, improvements were made to the concept tree. While submitting the report, there were formatting issues and problems with condensing the report to ten pages.

Figure 1: Concept Tree

      We also began conducting research on the physics behind our project. 

  This video link explains air pressure in the atmosphere

     Finally, we reevaluated our priorities to give ourselves enough time to complete any future task such as the final report and presentation.  

Week 6: Design Drawings and Ventilation System Materials

      Our goal for this week is to create detailed drawings of the ventilation system the group agreed on. From the placement of the fan and dome to the method of attaching the vent to the roof, the team drew multiple designs of the system (Figure 2) . The method of attaching the vent system had to be taken into consideration because the homes of the villagers are not typically made out of concrete but instead is constructed using thatch and/or wood. Designing a heavy or bulky ventilation system would mean instability with the roof and the structure of the homes. 

Figure 1: Thatch roof

       The group is aware of the design constraints of the system and it needing to a flexible system so that it can be easily manipulated for any home's roof. The team decided on having the vent system made out of metal. Preferring its durability and ability to witstand the elements, aluminum was the top choice.

Figure 2: Concept Drawings

Week 5: Initial Concept Production

     Our goal for this week is to create multiple designs for the fan ventilation system out of household materials and/or Creo PTC. Each group member is responsible for creating a new design by week 6. We do not plan on creating full metal prototypes of the fan or the exhaust pipe but instead plan on using paper and everyday office supplies to construct a dome and fan that will give the same results. An anemometer will be used during the testing process of the exhaust fan to see how much wind it will take to spin the dome and to also measure how effective is it in reducing the amount of smoke inside the house.


Figure 1: The wind mechanics of a wind exhaust fan

 

  This video link explains in detail how a wind powered exhaust fan works

     The above video explains how roof ventilators work and how effective it is in reducing the temperature in a house during hot summer days and reducing the smoke produced by wood fired stoves. Wind causes the fan to spin and create a vacuum inside the dome of the fan. This sucks up the smoke from inside the house and takes it outside the house. Our goal for the coming weeks is to make an efficient, and affordable prototype that will clearly show how the fan will help the villagers.

Week 4: Pairwise Decision Matrix

     After going back and revising our stakeholders, needs, specification and concept chart, our next step in the project was to complete the pairwise decision matrix. The pairwise decision matrix will give us a better understanding of which concept to go forward with for the project. Rather than relying on human feelings or opinions, we employed the quantitative analysis process to determine the working concept. On the first page of the excel sheet, we listed all the needs of each stakeholder and weighed them against each other as seen in figure 1. Each need was individually considered against every other need and judged to be less important, equally important or more important than the other. The purpose of this step is to find out which needs are more important and which are negligible.
    

Figure 1: Shows the pairwise weights

Next, the four concepts that we previously chose were judged individually in regards to each specification. A five star rating system was employed in this process with 5 being the best and 1 being the worst. The purpose of this step is to see which of the four concept is better suited to fit the needs that were weighed in the previous step. Figure 2 shows our concept ratings.

Figure 2:  Shows the concept ratings

Finally, the excel sheet tabulated the inputted data and calculated which concept is the most ideal for the needs and values given to each need. Figure 3 shows that the wind-powered ventilation concept was chosen by the matrix based again on quantitative factors.

 Figure 2: Result of the matrix

We are still in the broad conceptual phase of designing; nonetheless, figure 4 shows the basic idea of the system. In the simplest terms, wind will be used to push out smoke from inside the house to the outside. There are quite a bit of ways we can go from here, but that is left for later weeks. We really like this idea because it uses wind: a renewable form of energy. Add in the the fact that Bo Klua Village is situated in a mountainous, therefore windy region and we have a good recipe for success.

Figure 4: The basic idea of the win-powered ventilation system

     The design proposal was also worked on during week 4 and into week 5. The work was evenly distributed among the group members. Each member did his part well; however, we ran into some issues because of time constraints. We will allow ourselves more time to work on the final report in response this issue.

Week 3: Taking a Step Back

    The group's goal for this week is to narrow down from the 12 design concepts to 4 working ideas. Also the Design Matrix and Classification tree was looked at. After talking with the professor, we realized that our original classification tree was too specific and that we needed to broaden our scopes with the project. By doing so, we were able to focus on more aspects of the project than originally intended.

Working Design Ideas

1) A wood stove with a solar powered ventilation system. While using the traditional, three-stone stove that is used by the natives, the solar powered fan will use the energy from the sun in order to power the fan that will remove all smoke from the fire. If there is not a presence of sun in order to power the ventilation system, a backup battery will be installed. A few pros regarding this system is the use of solar energy and sticking with native tradition of cooking. Cons include the effectiveness of the ventilation fan and and the lack of sun in the native area.

Figure 1: Solar powered fan will push the smoke out of the house

2) A Rocket stove will be a hand-made newly designed stove made out of a cheap but effective metal. The rocket stove's effectiveness will depend on the material used to power the heat generated. Depending on the material used, the amount of smoke produced will be greatly reduced thus improving the health of the natives cooking. A major con regarding this concept is finding a cheap and useful material to fuel the stove.

Figure 2: A traditional rocket stove

3) A wood stove with a wind powered smoke ventilation system. This is one of our top designs as the traditional wood stove will be accepted by the natives and the act of installing a ventilation system will greatly improve the health conditions of the natives and reduce the risk of smoke related illness. As for the wind-powered ventilation system, since the natives live high in the mountains, a constant stream of wind powering the machine will be key in keeping the relative cost down. In the few cases there is no wind, an additional backup battery will be installed for rare occasions. One con regarding this concept is the size of the ventilation system that will be installed.

Figure 3: A wind powered air vent will push all the smoke out of the house

A solar powered electric stove is another great concept idea as smoke will be completely eliminated. While the idea of the design is great in theory, it does have quite a few drawbacks. First, creating the solar panel will be a hard task as the material does not come cheaply. Also, including the times there is no sun present, the amount of energy generated from the sun may not be enough in order to completely cook the food. Additionally, the natives will be hard-pressed to accept this new idea and would have to adapt to this new cooking style. While the benefits are great regarding this concept, the flaws may outweigh the positive aspects.

Figure 4: A solar powered stove will completely eliminate all smoke from wood burning.

Week 2 - Starting the Design Process

     The focus of this week was to modify and improve the stakeholders needs and specification sheet, to discuss the 12 design proposals of the stove, and splitting and assigning sub groups to complete tasks.

The 12 Design Proposals
    
     A rocket stove is currently the group's stove of choice but there are components within the stove that could still be changed and optimized for the Bo Kluea villagers.

Figure 1: Traditional Rocket Stove Operation

     The materials that the stove was to be made out of was also considered. The criteria for the materials were, that it needed to be a domestic product, easy to build and repair by the villagers, and affordable for both the manufactures and villagers. Clay, different metal alloys, and bricks were considered for the outer shell of the stove. The cost of the stove cannot exceed $10.00 (฿322 Thai Baht) ideally. It needs to be easily affordable by the villagers and if a component gets damaged, the repair needs to be cheap and easy. The stove needs to fit all these requirements while still having sufficient heat output and decrease the smoke output per cubic inches.

Figure 2: Working Specification Sheet