Portable Sunshade [Duke University]

Figure 1. Portable Sunshade

Henry Hwang, John Lee, Tamara Louie, Nicholas Ong

ABSTRACT

The nature facilities available at the Goodwill Industries of Eastern North Carolina (GIENC) are used to produce gardening products and to provide people with disabilities with pleasant gardening experiences. During the summer months, staff members and people with disabilities work at these outdoor nature facilities under direct sunlight. The goal of this project was to provide a portable sunshade device to GIENC. The device consists of a sixty square foot UV-resistant shade attached to a frame of galvanized steel, mounted on four wheeled poles for mobility. When the device is deployed, the users can work in a shaded area and enjoy a respite from the sun’s light.

VIDEO

BACKGROUND

The GIENC manages a nature program for adults with physical and/or mental disabilities, where the participants care for the GIENC’s outdoor gardens, and tend to edible and ornamental crops. However, working in hot and humid conditions is difficult during the summer, especially for extended periods. Related health risks such as hyperthermia and UV-related skin disorders may also affect those who work in hot conditions without adequate protection. Therefore, it is important that workers have means of protection against the sun. The workers will be able to enjoy a more pleasant gardening experience with a portable sunshade.

PROBLEM STATEMENT

The goal of this project is to provide a sturdy portable sunshade for people with disabilities, so that they may enjoy a pleasant gardening experience even in the sun’s presence.

DEVELOPMENT AND DESIGN

During the initial client meeting, we asked the Nature Center Coordinator a list of questions to clarify needs. We also examined the gardening facility to decide which design would be most appropriate for the specific use in the GIENC facility. The client wanted a portable, sturdy, and safe sunshade. The client also expressed concern about the safety of the sunshade during inclement weather conditions such as strong wind and rain. After talking with the client, we first considered attaching a sunshade to the sides of raised gardening beds with clamps. However, GIENC did not allow any modification of gardening beds. After more client meetings and group discussions, we decided to build a sunshade canopy with lockable wheels to maximize the shading area and mobility. This preliminary design was developed into the final product.

Since no commercial sunshade canopies satisfied our need of mobility, we attached lockable wheels to a commercial canopy. We purchased and attached pneumatic 8-inch lockable wheels using a wheel base (Figure 2). The pneumatic wheel is attached to the bottom of a 6-inch diameter aluminum disk, and a 1-3/8 inch canopy footpad is attached to the top of the disk.  The vertical poles of the canopy slide into the footpad and are secured using round eyescrews; there is a pre-drilled hole in both the footpad and the height pole, and when lined up, they allow the round eyescrew to be threaded through both components to attach the two together.

Figure 2. Wheel base

The canopy is 6 feet 7 inches tall, 9 feet 7 inches long, and 5 feet 11 inches wide, with a flat roof. This size provides adequate shade for 5-10 people, and is tall enough for people to stand under comfortably. It is made from 1-3/8 inch galvanized steel poles.  These poles are connected using linear connectors (Figure 3a) and 3-way 90° connectors (Figure 3b).  We attach the connectors and poles using eyescrews and predrilled holes in each pole and connector. Once the holes in the pole and connector are lined up, a rounded eyescrew (linear connector) or a pointed eyescrew (3-way 90° connector) is threaded through both components.

Figure 3a. Linear connector

Figure 3b. 3-way 90° connectors

The selected canopy fulfills all of the criteria: it is 6 feet by 10 feet, covers the full area of the canopy space, and provides up to 73% shade; it is made of UV protected material to prevent degradation; and it has a mesh surface, to allow water and air to pass through (Figure 4). The bungee cords are used to attach the shade to the canopy frame at the shade’s metal grommets, spaced 18 inches apart on the border (Figure 4).

Figure 4. Bungee cord-mesh tarp connection

After testing the device, we determined that it needed stability and more rigidity. Thus, we added aluminum supports at each corner, connecting the vertical pole to one of the horizontal poles. These aluminum supports are 1 foot 8 inches long, with a pre-drilled hole at each end.  The pre-drilled holes in the poles are aligned with the holes in the supports, and we connect the two using 2 inch bolts and nylon-insert nuts (Figure 5).  This design component added a significant amount of rigidity and stability to the device. Next, the portable sunshade was powder-coated to prevent corrosions.

Figure 5. Triangular support system

Lastly, we observed that some kind of grip or handle upon the height poles would make the device easier to move around, as well as minimize the client touching hot metal surfaces.  Thus, we attached a waterproof, weather-resistant, rubber grip to each height pole.  This grip is 4 feet off of the ground, spans 4 inches in length, and completely surrounds the circumference of the pole (Figure 6).

Figure 6. Rubber handle

DISCUSSION AND CONCLUSIONS

The Portable Sunshade has several major advantages that make it more suitable than currently existing sunshade-like devices for use by workers. It is large enough to provide shade for more than five people. It is lightweight enough to be moved by two people but heavy enough to withstand both inclement weather and rough handling. It can be left outside for long periods of time with no ill effects, and can be easily disassembled for long-term storage.

One drawback of the Portable Sunshade is its large size. While the Portable Sunshade is necessarily large due to client need, the size limits the portability of the product as its legs can get stuck behind the edge of a gardening bed. In order to minimize this problem, it is recommended that users get used to moving around the Portable Sunshade before use. Another drawback of the Portable Sunshade is the fixed angle of the shade. Since the mesh tarp is fixed at the top of the device, workers will have to move the Portable Sunshade when the sun angle is low for better shading. Although the option of having angled shade was discussed, the idea was not implemented since the client indicated that the device will be primarily used during summer afternoons, when the sun angle is high.

To make the Portable Sunshade a more competitive commercial item, its construction and assembly process need to be simplified. The process of drilling/tapping holes in the steel frame and aligning holes could be simplified to reduce the construction time.

SUMMARY OF IMPACT

The portable sunshade allows our clients to enjoy gardening under the shade during summer. Since our clients had difficulties with summer sun and heat while participating in the nature program, they will be able to enjoy gardening experience with the portable sunshade. The supervisor says, “The portable sunshade creates a space for shade while our groups of adults with disabilities are working in the raised planters and other places on the farm, tolerating more time outside and providing UV protection for a large number of people. It is also a mobile device that makes it handy to move about easily with just a couple of people.”

FINAL BUDGET

Table 1. Development cost of the portable sunshade

Table 1 above shows the development cost of the portable sunshade.

Table 2. Replacement cost of the portable sunshade

Table 2 above shows the replacement cost of the portable sunshade. It should be noticed that only the cost of caster was omitted from the development cost due to the design change.

ACKNOWLEDGEMENTS

This project is supported by the National Science Foundation under Grant No. CBET-0967221. We would like to thank our professor, Dr. Laurence Bohs, for his insights and constructive feedback on our device design, our Teaching Assistant, Veronica Rotemberg, for her assistance throughout the course, Steve Earp for his aid in machining, Top Coat Inc. in Raleigh for providing free powder-coating services for our device, and our client for her enthusiasm and unwavering support throughout our project.