Refrigeration Capacity and Effect of Ageing on the Operation of Cellulose Evaporative Cooling Pads, by Wind Tunnel Analysis

This study investigates the temperature reduction capacity and water consumption of a fan-pad system installed in a greenhouse located in the coastal regions of Almería. The suitability of this system for coastal zones with high environmental humidity during the summer is analyzed. Historical temperature and relative humidity series are studied, obtaining the thermal difference and maximum, medium, and minimum monthly water consumption of the pads based on the operation data of the pads. Despite the high relative humidity of the air in the hottest hours of the day, a decrease of 5.92 ºC in the mean temperature and a water consumption of 13.55 l/h per square meter of an evaporative cooling pad are obtained in the month of August. Additionally, the operation of a cellulose evaporative cooling pad installed for 3 years in a greenhouse is analyzed in a wind tunnel and compared with that of a new pad of the same model. Over time and with low maintenance, the porosity of the pad decreases due to salt incrustation. The salt incrustation makes airflow more difficult in the pad, increasing the pressure drop by 170.04%; however, the air saturation efficiency of the pad increases by 6.6% due to the greater contact time between the air and the waterMinisterio de Economía y Competitividad de España AGL2015-68050-RUnión Europea (FEDER) AGL2015-68050-

Assessment of the cooling potential of an indoor living wall using different substrates in a warm climate

The use of vertical greenery systems in buildings is becoming very popular as they provide several benefits. In this work, the influence of an indoor living wall on the temperature and humidity in a hall inside the School of Agricultural Engineering (University of Seville) was studied. Four different substrates, Geotextile, Epiweb, Xaxim and coconut fibre, were used to grow the plants in order to assess their performance. Several parameters such as temperature, humidity, plant growth or water consumption were monitored and analyzed during a 4-month period. The cooling effect of the living wall was proven, with an average reduction of 4°C over the room temperature though maximum decrements of 6°C have been observed in warmer conditions. Higher air humidity levels were experienced near the living wall, increasing the overall humidity in the room. All the substrates tested were suitable for plant growing and their behaviour was similar. Geotextile showed the best cooling capacity but higher water consumption, coconut fibre presented degradation problems and Epiweb performance was the poorest. Therefore, these systems have been proven to be very useful and interesting for warm indoor environments due to the cooling effect observed in addition to their bio-filtration capacity and the aesthetic component

Energy Efficiency in Greenhouse Evaporative Cooling Techniques: Cooling Boxes versus Cellulose Pads

Evaporative cooling systems using a combination of evaporative pads and extractor fans require greenhouses to be hermetic. The greatest concentration of greenhouses in the world is located in southeast Spain, but these tend not to be hermetic structures and consequently can only rely on fogging systems as evaporative cooling techniques. Evaporative cooling boxes provide an alternative to such systems. Using a low-speed wind tunnel, the present work has compared the performance of this system with four pads of differing geometry and thickness manufactured by two different companies. The results obtained show that the plastic packing in the cooling unit produces a pressure drop of 11.05 Pa at 2 m·s−1, which is between 51.27% and 94.87% lower than that produced by the cellulose pads. This pressure drop was not influenced by increases in the water flow. The evaporative cooling boxes presented greater saturation efficiency at the same flow, namely 82.63%, as opposed to an average figure of 65% for the cellulose pads; and also had a lower specific consumption of water, at around 3.05 L·h−1·m−2·°C−1. Consequently, we conclude that evaporative cooling boxes are a good option for cooling non-hermetic greenhouses such as those most frequently used in the Mediterranean basin

Naturación urbana y jardinería vertical: de las fachadas verdes a los muros vegetales

En las últimas décadas, las urbes están creciendo considerablemente, dedicándose un porcentaje cada vez más elevado a edificaciones. Se prevé que en el periodo entre 2000 y 2030, la población urbana del mundo habrá aumentado un 72%, mientras que la superficie de las zonas edificadas donde viven 100.000 o más personas podría aumentar en un 175%. En este difícil contexto, la aplicación de los principios de sostenibilidad en las áreas urbanas se erige como uno de los mayores retos de las políticas ambientales del siglo XXI. Su éxito dependerá en gran medida del modelo de ciudad a desarrollar, particularmente en lo que se refiere a la relación entre desarrollo urbano y consumo de recursos ambientales

Multidisciplinary Education for New Landscape Engineering Concepts using Problem-Based Collaborative Learning. A Case Study in Spain

Problem-based learning (PBL) is widely regarded as a successful educational method. In Spain, most engineering degrees are still based mainly on old style lecture classes where a great deal of information is given to the students. This work assesses the introduction of a PBL strategy as a complement to traditional engineering education. The instructors’ and students’ attitudes towards its implementation are studied. A new approach has been proposed for the PBL strategy: instead of a single problem, a chain of problems was developed that could be solved in a collaborative environment. Results from the experience showed a high level of student acceptance. Response to the PBL initiative was found to be positive both for instructors and students, though lack of time, difficulties in evaluations and an increase in students’ and teachers’ workloads were the main disadvantages. Compared with traditional engineering curricula, the mixed traditional–PBL model appears to inspire a higher degree of involvement in study activities where on-line learning tools played an important role

Cooperación universitaria para el desarrollo en Makeni (Sierra Leona)

Las ciudades medias africanas de menos de 500.000 habitantes representan el principal desafío urbano del momento a nivel mundial. Su desarrollo implicará, en las próximas décadas, un notable incremento de suelo urbano en los países en vías de desarrollo. La falta de recursos, de un marco normativo adecuado, de profesionales en planificación urbana y los déficits de habitabilidad ya existentes en estos entornos, son realidades que evidencian, entre otras, la urgencia de articular un importante esfuerzo colectivo. El planeamiento urbano y territorial convencional no es capaz de responder a estos retos en tiempo y escala. Por una parte, por la velocidad vertiginosa de la progresiva toma de tierra y el incesante crecimiento de la población y, por otra, debido a la dificultad que supone para la población asumir propuestas de planificación con visos de futuro en contextos en los que no existe cultura en planeamiento. Así, entre Madrid (España) y Makeni (Sierra Leona) surge una experiencia en la que la Universidad y la Cooperación al Desarrollo emergen como elementos críticos de fortalecimiento institucional y formativo. La colaboración entre universidades (uspceu-unimak) es el germen de un proceso de reflexión urbana que implica decididamente al Ayuntamiento y a los principales actores locales de la ciudad.Les ciutats mitjanes africanes de menys de 500.000 habitants representen el principal desafiament urbà del moment a nivell mundial. El seu desenvolupament implicarà, en les pròximes dècades, un notable increment de sòl urbà en els països en vies de desenvolupament. La manca de recursos, d’un marc normatiu adequat, de professionals en planificació urbana i els dèficits d’habitabilitat ja existents en aquests entorns, són realitats que evidencien, entre altres, la urgència d’articular un important esforç col·lectiu. El planejament urbà i territorial convencional no és capaç de respondre a aquests reptes en temps i escala. D’una banda, per la velocitat vertiginosa de la progressiva presa de terra i l’incessant creixement de la població i, de l’altra, a causa de la dificultat que suposa per a la població assumir propostes de planificació amb aspectes de futur en contextos en què no hi cultura en planejament. Així, entre Madrid (Espanya) i Makeni (Sierra Leone) sorgeix una experiència en la qual la Universitat i la Cooperació al Desenvolupament emergeixen com a elements crítics d’enfortiment institucional i formatiu. La col·laboració entre universitats (uspeceu-unimak) és el germen d’un procés de reflexió urbana que implica decididament l’Ajuntament i als principals actors locals de la ciutat.Medium-sized african cities, with fewer than 500,000 inhabitants are the main urban challenge of the moment. In the coming decades,urban development will involve a significant increase in urban land in developing countries. The lack of resources, an appropriate regulatory framework, professionals in urban planning and habitability in urban environments of these cities, are realities that show the urgency for to articulate a major collective effort. Conventional urban and regional planning is not able to respond to these challenges in time and scale. On the one hand because of the speed of the progressive increase of illegal settlements and the constant population growth. On the other hand on account of the difficulty for people to take proposals forward planning in contexts where there is no culture in planning. Between Madrid (Spain) and Makeni (Sierra Leone) starts an experience in which the University and Development Cooperation emerge as critical elements of institutional and educational strengthening and training. Collaboration between universities (uspceu-unimak) is the beginning of a process of urban reflection involving the City Council and local stakeholders

Wind tunnel analysis of artificial substrates used in active living walls for indoor environment conditioning in Mediterranean buildings.

In this paper, a low-speed wind tunnel was used for experimental analysis of water volume retained, pressure drop, saturation efficiency and water consumption for three types of synthetic substrates used in active living walls: polyester (PR), polyurethane (PU) and polyamideepolypropylene (PAePP) The substrates were of a similar thickness and were tested for different water and air flows. The water retained increases with higher water flow. The pressure drop increases with the presence of vegetation and when air speed and water flow is higher. Cooling efficiency is enhanced with vegetation and low air speed. Specific consumption of water is greater with vegetation at higher air speeds. (PDF) Wind tunnel analysis of artificial substrates used in active living walls for indoor environment conditioning in Mediterranean buildings. Available from: https://www.researchgate.net/publication/280232473_Wind_tunnel_analysis_of_artificial_substrates_used_in_active_living_walls_for_indoor_environment_conditioning_in_Mediterranean_buildings [accessed Sep 18 2018]

Economía de agua, economía de instalaciones

Water is a scare resource and for this reason it is necessary to use it wisely. This paper puts forward some techniques and strategies which have been developed in different countries, to minimize wasteful water consumption for domestic use. The reason for this is to avoid considerable public expense which is caused by the purifying of unneccessarily polluted water and by equipment and pipes which are too large for their purpose. Also this paper deals with the state of art on techniques saving money on sanitation and treatment of sewage.El agua es un recurso escaso y por lo tanto se considera cada vez más importante optimizar su uso. En este artículo se exponen algunas técnicas y estrategias desarrolladas, en diversos países, para minimizar las pérdidas y el consumo inútil de agua en usos domésticos y evitar los gastos que supone, a la colectividad, la depuración de agua innecesariamente contaminada, así como el sobredimensionamiento de equipos e instalaciones. También se presenta, de un modo general, el estado de la cuestión en cuanto a posibles ahorros económicos en saneamiento (entendido como las instalaciones sanitarias interiores de la vivienda y la red de evacuación exterior) y en depuración de aguas residuales

Vertical Greening Systems and Sustainable Cities

Urban development is causing environmental and social concerns that are compromising human welfare and cities sustainability. New urban greening concepts are appearing in order to mitigate these problems in a sustainable and natural way. Vertical greening systems can be defined as structures which allow vegetation to spread over a building facade or interior wall. These systems are becoming popular though they are still evolving and more knowledge on some of their particular impacts is required. In the last five years, the number of studies published in the scientific literature on this topic, especially involving living walls, has significantly increased. This scientific interest has been corresponded with an increased and parallel attention by the general public. This work offers a broad description of the different systems and a comprehensive review of the particular benefits of these green infrastructures. Knowledge gaps and shortcomings have also been identified and discussed