UNLV Theses, Dissertations, Professional Papers, and Capstones 5-1-2016 Water Harvesting Methods and the Built Environment: The Role of Architecture in Providing Water Security Adam Joseph Bradshaw University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/thesesdissertations Part of the Architecture Commons Repository Citation Bradshaw, Adam Joseph, "Water Harvesting Methods and the Built Environment: The Role of Architecture in Providing Water Security" (2016). UNLV Theses, Dissertations, Professional Papers, and Capstones. 2646. http://dx.doi.org/10.34917/9112039 This Thesis is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in UNLV Theses, Dissertations, Professional Papers, and Capstones by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. WATER HARVESTING METHODS AND THE BUILT ENVIRONMENT: THE ROLE OF ARCHITECTURE IN PROVIDING WATER SECURITY by Adam J. Bradshaw Bachelor of Science – General Biology University of California, San Diego 2008 A thesis submitted in partial fulfillment of the requirements for the Master of Architecture School of Architecture College of Fine Arts The Graduate College University of Nevada, Las Vegas May 2016 Thesis Approval The Graduate College The University of Nevada, Las Vegas April 15, 2016 This thesis prepared by Adam J. Bradshaw entitled Water Harvesting Methods and the Built Environment: The Role of Architecture in Providing Water Security is approved in partial fulfillment of the requirements for the degree of Master of Architecture School of Architecture Alfredo Fernandez-Gonzalez, M.Arch. Kathryn Hausbeck Korgan, Ph.D. Examination Committee Chair Graduate College Interim Dean Joshua Vermillion, M.Arch. Examination Committee Member Deborah Oakley, M.Arch. Examination Committee Member Jacimaria Batista, Ph.D. Graduate College Faculty Representative ii ABSTRACT Two prototype thermoelectric atmospheric water generator (AWG) devices were constructed and evaluated for their performance in collecting water. The devices consisted of two Peltier thermoelectric cooling (TEC) modules connected to a heat sink and a condensing surface. The TEC/heat sink assembly was anchored to an air-well constructed of extruded polystyrene and 3D-printed frames, and a fan was installed to draw in surrounding air. The condensing surfaces were either copper or aluminum and featured a surface area larger than the cold side of the TEC. The performance of aluminum and copper surfaces were compared by measuring condensate collected after a test period of 5 hours (300 minutes). Relative humidity, ambient temperature and dew-point temperature were recorded at 15 minute intervals. Tests were conducted in Las Vegas, Nevada and Oceanside, CA. Oceanside featured a much higher average relative humidity than Las Vegas (65.3%) and overall, the average condensation collected was higher than condensation collected in Las Vegas, 11.8 mL versus 0.4 mL. Aluminum performed the best, with average condensate of 5.9 mL, suggesting thermal conductivity is not an essential measure of performance. The highest observed condensate collected was 26.9 mL in Oceanside, CA with a 68.4 in2 aluminum surface. T-tests were utilized to compare mean values between datasets to determine significance. Comparisons suggest that in arid environments air inside the air well is significantly colder than ambient temperature (~2°F), however there is no significant difference in humidity. Regression analysis was performed on the data to characterize the relationship between environmental variables. The highest R2 values were associated with relative humidity and the ratio of sensible heat to latent heat. Calculations suggest that large numbers of these devices could generate a large amount of water on-site. The applications to architectural systems are discussed along with the significance in reducing water consumption in buildings. iii TABLE OF CONTENTS Abstract ………………………… iii List of Tables ………………………… v List of Figures ………………………… vi Chapter 1: Introduction ………………………… 1 Chapter 2: Literature Review ………………………… 20 Chapter 3: Methodology ………………………… 51 Chapter 4: Results & Discussion ………………………… 59 Chapter 5: Conclusions ………………………… 83 Bibliography ………………………… 89 Curriculum Vitae ………………………… 111 iv LIST OF TABLES Table 1.1, water consumption in the American West ………………………… 6 Table 1.2, water withdrawals by end use in the American Southwest ………………………… 9 Table 3.1, regional climate data ………………………… 56 Table 4.1, yield for copper condensation surfaces ………………………… 62 Table 4.2, yield for aluminum condensation surfaces ………………………… 63 Table 4.3, ANOVA table for aluminum surfaces ………………………… 69 Table 4.4, ANOVA table for copper surfaces ………………………… 70 Table 4.5, t-test results for mean air temperature differences ………………………… 73 Table 4.6, t-test results for Las Vegas temperature data ………………………… 74 Table 4.7, t-test results for Oceanside temperature data ………………………… 75 Table 4.8, t-test comparing condensate yield between aluminum and ………………………… 76 copper surfaces Table 4.9, t-test for mean relative humidity differences in Las Vegas ………………………… 77 Table 4.10, t-test for mean relative humidity differences in Oceanside ………………………… 78 v LIST OF FIGURES Figure 1.1, Keeling Curve ………………………… 2 Figure 1.2, Drought data for the Southwestern United States ………………………… 4 Figure 1.3, usable water in the world, by source ………………………… 7 Figure 1.4, groundwater use in the Southwestern United States ………………………… 8 Figure 1.5, World Economic Forum global threat matrix ………………………… 10 Figure 2.1, Stepwell in Rajasthan, India ………………………… 23 Figure 2.2, the Peltier effect in thermoelectric cooling (TEC) ………………………… 43 Figure 3.1, schematic cross-section of the test apparatus and assembly ………………………… 52 Figure 3.2, image of the fully constructed prototype ………………………… 53 Figure 3.3, photographs showing the various experimental surfaces ………………………… 54 Figure 4.1, temperature measurements 1 ………………………… 59 Figure 4.2, temperature measurements 2 ………………………… 60 Figure 4.3, psychrometric chart ………………………… 61 Figure 4.4, condensate collected versus wet-bulb temperature ………………………… 64 Figure 4.5, condensate collected versus condenser surface area ………………………… 65 Figure 4.6, condensate collected versus relative humidity ………………………… 66 Figure 4.7, comparison of latent heat to condensate yield ………………………… 67 Figure 4.8, condensate collected vs. ratio of sensible to latent heat ………………………… 67 Figure 5.1, schematic drawing illustrating of thermoelectric AWG ………………………… 86 Figure 5.2, schematic section of AWG and roof structure ………………………… 87 vi o1 | INTRODUCTION “Water is the driving force of all nature.” -Leonardo Da Vinci Climate change is the impetus behind the greatest problems that our civilization faces today. As the effects of climate change become increasingly tangible, one of its largest symptoms, drought, is intensifying in specific regions of the world. D’Odorico et al. specifically identify desertification as the major problem lending momentum to climate change, expressing it as a “change in soil properties, vegetation or climate, which results in a persistent loss of ecosystem services that are fundamental to sustaining life.” (D'Odorico et al. 2013, 326-344) If the current destabilization of our vast and varied ecosystems continues, the ecosystem services upon which civilization depends may become threatened. Overall, the consequences are severe, including limited agricultural yield, increased wildfire risks and extreme weather conditions and most importantly, exacerbated scarcity of freshwater sources. (MacDonald and Turner 2010, 21256-21262) As groundwater mining increases and reservoirs, such as Lake Mead in Nevada, drop to dangerously low levels, the water crisis is rapidly approaching an event horizon from which there may be no viable path to recovery within the near future. Careful revision of existing water policy and infrastructure is essential, but issues of baseline consumption also need to be addressed. For the purposes of this research project, the American Southwest serves as the locus of interest, in that it is one of the regions hardest hit by worsening desertification in the face of climate change. Climate change is threatening the stability of our communities and standard of living. The findings of the IPCC have corroborated the artificial culpability in exacerbating the global greenhouse effect, and the effects are just now beginning to manifest. In many ways, climate change has become the Gordian Knot of our era, representing a series of worsening environmental problems that are dramatically outpacing our ability to ameliorate them through either legislation or action. The inertia involving sociopolitical, economic and behavioral patterns in regard to these concerns is immense and there has yet to be a consensus on the 1 approach to resolving these environmental problems. All the while the consequences are becoming more severe. Rising carbon dioxide levels have been observed since 1958, when the construction of the Keeling Curve