I am excited to finally complete the Northwestern pre-college course. I have learned so much through its thoughtful lessons and interactive activities, making me become in love with engineering. My final capstone project over improving outdoor workers safety in the extreme heat is written below. Hope you enjoy!

Construction workers, farmers, and other outdoor laborers oftentimes work in extreme heat for extended periods of time, leading to dehydration, fatigue, and other heat issues. As a result, these workers require a lightweight device, which can cool their body as they work, in order to ensure safety for these individuals and maintain the quality of their work. The primary users of this device are outdoor workers who perform their daily duties in hot temperatures.  On the other hand, the stakeholders for this problem would be the engineers, public health officials, and the employers of the workers. Four user needs for the device is that it must be wearable, lightweight, last the whole work day, and effectively cool them when the weather is extreme.  Users and stakeholders require the solution to adequately cool workers body temperatures for long durations of time, without being distracting or difficult in a way that makes their work less effective. In order to meet my user needs, my cooling device must be able to be worn without causing any discomfort or exhaustion and most importantly have an effective energy source that allows my user to  cold air spraying on them for the duration of the work day, One key environmental challenge for my device is that in outdoor environments there is a lot of dust or small particles that can potentially find its way in the fans of the cooling device. If this were to occur then the device’s effectiveness would go down drastically and not be able to perform the task that the user needs. Therefore,  I must come up with a solution that minimizes particles from entering the fan zone by potentially adding a physical  barrier or filters to minimize the suction of small particles.

One possible solution to solve the issue of prevalent heat related problems is a small battery powered neck fan that goes around the user and circulates air in the user’s face. Another solution is a breathable mesh clothing set that responds very well in heat and blocks harmful UV rays, while maximizing airflow. A third solution to the problem could be an ice pack vest, which can be used by putting in frozen ice packs into compartments of the vest, in order to cool the user down. The last solution I have thought of to solve this issue is a lightweight cooling vest with small battery powered fans all pointed in different directions, in order to maximize airflow throughout the body.  The two categories I selected for my user, due to importance, are effectiveness in cooling and long-term wearability.  In the matrix I made, only two solutions came close to addressing those needs.  Ultimately, I ended up selecting the battery powered vest over the neck fan, since it covers a greater surface area of the body, thus aiding more in the prevention of heat related problems.  In addition to this, its similar design to a vest makes it highly wearable over shirts or instead of them, while being less prone to discomforts.

My structural sketch that I drew is a basic lightweight vest made of mesh, which is a breathable piece of material that allows for air flow. This product is designed to be worn instead of typical shirts with a thin layer of mesh on the outside and inside of the device. The fans would be in between the two meshes, blowing cold air all over your body. In my design I have my fans rotating, thus maximizing the air flow all over your body rather than solely the chest. The battery packs would be in the back of the vest and are crucial to starting the whole system up.  Batteries last long periods of time, so changing them will not have to happen that frequently and not act as a nuisance along the way. In addition to this, the vest will have an off/on button and a power button to determine the needed fan speed for the user. Lastly, this vest is made in different sizes to allow for a greater multitude of users to use the product. 

A functional flowchart to use this product starts with the user receiving the vest in their respective size (S-XXL). After receiving the vest, the user would put it on and hit the on button to jumpstart the system. Automatically, the small fans will begin to circulate air at the default settings, picking up speed as time goes on, until it reaches the max for that setting.  At this moment, the fans will begin to rotate and distribute air through the vest to different parts of the body. If temperatures increase then the user can up the fan speed and if they were to decrease the user can slow it down. The mesh fabric will allow for body heat and warm air to exit, while the fans will help push cold air inside toward the user.

After showing my parents my flowchart and sketch, I had received feedback on my product. One piece of feedback I had got was that the on button and fan settings should be on the front of the vest, in order to allow for easier user access. This suggestion, I totally agree with and I made the tweaks to my model right away. The next piece of feedback I had received was that my idea to put mesh layers between the fans in the front and back was very smart, because it would limit the amount of particles coming inside and be more comfortable for the user.

TESTING PLAN

1. Can the vest be worn for a long duration of time without causing any issues of uncomfortability?
2. Can the vest adequately protect the interior fans from being clogged with dust, grass, and other small particles. 
3. How often does the user have to change out the battery?

To test the questions above I would have to create a works-like prototype and a looks-like prototype. My looks-like prototype would use mesh and model batteries and fans, in order to test the comfort of the product as well as where the user would like to place the on/off button and fan speed switch. Overall, this prototype would help me determine how to make the vest as comfortable as I possibly can for the user over long periods of time or if the current model is good as is. My works-like prototype would use a very  small model of the battery and fan system covered with the mesh layers, in order to see how well the prototype prevents small particles like dust from clogging the airways. Additionally, this model would help determine how many hours the system can operate for before needing new batteries. Based on my questions and testing plans, I would make improvements to the vests depending on the prototype testing. For example, if too much dust is getting into the airways I would add protective fan covers or use smaller mesh openings to prevent debris from entering, while allowing just enough air for cooling. Another change I could make if my battery life is too low would just be to make the fans more energy efficient or use a higher powered battery system for my device. Lastly, if my vest is too uncomfortable I could adjust the placement of the fans and buttons higher to the user’s chest and design them to be less bulky, so it doesn’t impact the user with weight at all and improves the accessibility of the buttons. All in all, I believe this model effectively addresses the issue of heat for the user and aids in the cooling of their body temperature greatly. However, engineering designs are not perfect and always require lots of refining before achieving a successful outcome.