Institut Politècnic d’Innovació i Recerca en Sostenibilitat (INSPIRES)
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INSPIRES és un centre de recerca de la Universitat de Lleida. Conforma un grup multidisciplinari que posa especial atenció a la recerca al voltant de la millor gestió energètica, l’eficiència, la usabilitat, la seguretat, la computació d’altes prestacions i la resolució i optimització de problemes, entre altres temes. Tot amb nexes comuns, girant al voltant de l’àmbit de la sostenibilitat i la tecnologia. Suposa una unió d’esforços dels diferents centres de recerca que de manera separada tractaven diferents línies i àrees, ara aquests esforços es comparteixen generant sinèrgies.[Més informació].
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Browsing Institut Politècnic d’Innovació i Recerca en Sostenibilitat (INSPIRES) by Author "Álvarez, Servando"
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- ItemOpen AccessEnergy Efficiency Indicators for Assessing Construction Systems Storing Renewable Energy: Application to Phase Change Material-Bearing Façades(MDPI, 2015) Tenorio, José Antonio; Sánchez-Ramos, José; Ruiz Pardo, Álvaro; Álvarez, Servando; Cabeza, Luisa F.Assessing the performance or energy efficiency of a single construction element by itself is often a futile exercise. That is not the case, however, when an element is designed, among others, to improve building energy performance by harnessing renewable energy in a process that requires a source of external energy. Harnessing renewable energy is acquiring growing interest in Mediterranean climates as a strategy for reducing the energy consumed by buildings. When such reduction is oriented to lowering demand, the strategy consists in reducing the building’s energy needs with the use of construction elements able to passively absorb, dissipate, or accumulate energy. When reduction is pursued through M&E services, renewable energy enhances building performance. The efficiency of construction systems that use renewable energy but require a supplementary power supply to operate can be assessed by likening these systems to regenerative heat exchangers built into the building. The indicators needed for this purpose are particularly useful for designers, for they can be used to compare the efficiency or performance to deliver an optimal design for each building. This article proposes a series of indicators developed to that end and describes their application to façades bearing phase change materials (PCMs).
- ItemOpen AccessExperimental study of a ventilated facade with PCM during winter period(Elsevier, 2013) Gracia Cuesta, Alvaro de; Navarro Farré, Lidia; Castell, Albert; Ruiz-Pardo, Álvaro; Álvarez, Servando; Cabeza, Luisa F.The aim of this article is to test experimentally the thermal performance of a ventilated double skin facade (DSF) with phase change material (PCM) in its air channel, during the heating season in the Mediterranean climate. Two identical house-like cubicles located in Puigverd de Lleida (Spain) were monitored during winter 2012, and in one of them, a ventilated facade with PCM was located in the south wall. This ventilated facade can operate under mechanical or natural ventilation mode and its thermal control depends on the weather conditions and the energetic demand of the building. Hence, three different tests were performed: free floating, controlled temperature and demand profile conditions. The experimental results conclude that the use of the ventilated facade with PCM improves significantly the thermal behaviour of the whole building (working as a heat supplier in free floating tests and reducing significantly the electrical consumption of the HVAC systems). However, these improvements might be increased if thermal control is used. Moreover, the measured electrical energy consumption of the heat pumps and fans indicates that the use of mechanical ventilation in this system is not justified; unless a fast heating supply is needed.
- ItemOpen AccessPCM incorporation in a concrete core slab as a thermal storage and supply system: proof of concept(Elsevier, 2015) Navarro Farré, Lidia; Gracia Cuesta, Alvaro de; Castell, Albert; Álvarez, Servando; Cabeza, Luisa F.Phase change materials (PCM) have been widely implemented in buildings envelope as passive system as well as in storage tanks for active systems. A new promising technology has been designed to act as a hybrid system between the passive and active ones. The main idea is using the internal slab as a thermal energy storage system to cover partially the energetic demand both during heating and cooling periods. This innovative constructive system consists of a prefabricated concrete slab with PCM macroencapsulated in small tubes and inserted in its hollows. A direct cross-flow heat exchange occurs between the air pumped into the slab and the PCM for conditioning purposes. A prototype has been implemented in a two storey house-like cubicle and has been tested under real conditions, where the slab becomes a thermal storage and supply component. The objective is to study the thermal performance of the slab and its components, in a theoretical analysis, as well as the suitability of the system in a Mediterranean continental climate. The concept was proved experimentally and compared to the theoretical results to demonstrate the potential of the technology. However, experimental results remarked the importance of a further investigation under real operating conditions.
- ItemOpen AccessSolar absorption in a ventilated facade with PCM. Experimental results(Elsevier, 2012) Gracia Cuesta, Alvaro de; Navarro Farré, Lidia; Castell, Albert; Ruiz-Pardo, Álvaro; Álvarez, Servando; Cabeza, Luisa F.The paper investigates experimentally the thermal performance of a ventilated double skin facade (DSF) with phase change material (PCM) in its air channel, during the heating season in the Mediterranean climate. Two identical house-like cubicles located in Puigverd de Lleida (Spain) were monitored during winter 2012, and in one of them, a ventilated facade with PCM was located in the south wall. The ventilated facade can operate under mechanical or natural ventilation mode and its thermal control depends on the weather conditions and the energetic demand of the building. The experimental results conclude that even though the use of the ventilated facade with PCM improves significantly the thermal behaviour of the whole building (working as a heat supplier in free floating tests, and reducing significantly the electrical consumption of the HVAC systems), these improvements might be increased if a thermal control is used.
- ItemRestrictedThermal analysis of a ventilated facade with PCM for cooling applications(Elsevier, 2013) Gracia Cuesta, Alvaro de; Navarro Farré, Lidia; Castell, Albert; Ruiz-Pardo, Álvaro; Álvarez, Servando; Cabeza, Luisa F.A new type of ventilated facade (VF) with macro-encapsulated phase change material (PCM) in its air cavity is presented in this paper. The thermal performance of this special building envelope is experimentally tested to analyze its potential in reducing the cooling demand during the summer season in the Continental Mediterranean climate. Two identical house-like cubicles located in Puigverd de Lleida (Spain) were monitored during summer 2012, and in one of them, a ventilated facade with PCM was located in the south wall. Six automatized gates were installed at the different openings of the channel in order to control the operational mode of the facade. This versatility allows the system to be used as a cold storage unit, as an overheating protection system or as a night free cooling application. The experimental results point out the night free cooling effect as the most promising operational sequence to reduce the cooling load of the cubicle. On the other hand, the thermal resistance of the outer skin of the facade must be increased; otherwise the cold storage system cannot be used efficiently.
- ItemOpen AccessThermal energy storage implementation using phase change materials for solar cooling and refrigeration applications(Elsevier, 2012) Oró Prim, Eduard; Gil, Antoni; Miró, Laia; Peiró Bell-lloch, Gerard; Álvarez, Servando; Cabeza, Luisa F.The final goal of this study is to implement and to test a thermal energy storage (TES) system using different phase change materials (PCM) for solar cooling and refrigeration applications. A high temperature pilot plant able to test different types of TES systems and materials was designed and built at the University of Lleida (Spain). This pilot plant is composed mainly by three parts: heating system, cooling system, and different storage tanks. The pilot plant uses synthetic thermal oil as heat transfer fluid (HTF) and has a working temperature range from 100 ºC to 400 ºC. Two different PCM were selected after a deep study of the requirements of a real solar cooling plant and the available materials in the market, finally d-mannitol with phase change temperature of 167 ºC and hydroquinone which has a melting temperature of 172.2 ºC were used.