Date of Award
Santa Clara : Santa Clara University, 2022.
During summer months there is reliance on air conditioning (A/C), which is energy intensive in nature. The mass use of A/C units during peak hours taxes the energy grid significantly as a demand spike occurs during these peak hours. This demand spike requires an equal response in supply which disproportionately produces greenhouse gas emissions as reserve power plants come online to meet this demand. These reserve power plants, are relatively inefficient, and more expensive to run than base load plants. The Coconut Oil Space Cooler utilizes the latent thermal storage capabilities of phase change materials (PCMs) to provide a temporary alternative cooling solution to A/C during these peak hours. By taking advantage of daily temperature undulations, the Coconut Oil Space Cooler absorbs heat during the day, during peak hours, when the temperature is sufficiently high to melt the phase change material. It absorbs heat from the environment, cooling it in the process. At night when the ambient temperature falls below the melting temperature of the phase change material, the device is operated to solidify the phase change material by releasing the stored heat back into the surroundings. The device is best suited toward a desert climate where day & night temperatures can vary greatly.
As the name states, the device utilizes coconut oil as the phase change material, two separate heat exchangers, a duct fan, pumps, an Arduino microcontroller, solenoid valves, and various hardware to achieve the cooling effect. The device is able to provide, on average, 1 ℃ cooling effect for about 40 minutes of operation. When the Coconut Oil Space Cooler is operated for a single hour, during peak load hours, for a month, it equates to monetary savings of $50; this is for Bay Area utility rates. Many aspects of the product’s design had areas for improvement and optimization: diameter vs length optimizations for the tube-in-tube heat exchanger would optimize heat transfer rate with total thermal storage capacity. Selecting specialized phase change materials for specific temperature conditions would further improve the efficacy of the device. Additionally, adding fins to improve conduction within the tube-in-tube heat exchanger would improve the heat transfer rate.
Covington, Hannah; Fessler, Alexander; and Zhuta, Largim, "Coconut Oil Space Cooler" (2022). Mechanical Engineering Senior Theses. 117.