Sensitivity analysys and potential evaluation using building thermal mass combined with DSM strategies

CLIMA 2019 Congress. Bucharest, Romania, May 26-29, 2019. S.I Tanabe, H. Zhang, J. Kurnitski, M.C. Gameiro da Silva, I. Nastase, P. Wargocki, G. Cao, L. Mazzarela and C. Inard (Eds.)The objective of the work is to develop an algorithm that automatically manages the activation of the heat pump in response to the most appropriate strategies according to the pricing and operating conditions. It is interesting to see if a balance can be reached between the cost savings, the increase in energy consumed, the thermal comfort of the occupants and the contribution to the reduction of the peak loads. The study shows different results and conclusions, highlighting the important influence of various factors on the results obtained, such as user behavior, constructive quality of the building and electric pricing. Connection with a future renewable production can maximize the economic savings; it is interesting the use of buildings as thermal storage of unused photovoltaic surplus. Finally, the possibility of combining these measures with electrical storage and with the possible arbitration linked to renewable production.Ministry of Economy and Competitiveness (Government of Spain) and European Regional Development's funds (ERDF) project “Zero-Energy Balance Districts Through Algorithms of Adaptive Comfort and Optimal Management of Energy Networks” (BIA2016-77431-C2-2-R)University of Seville (Spain) Plan VI (VPPI-US

Experimental analysis of atmospheric heat sinks as heat dissipators

Artículo premiado ETSI 1er trimestre 2020Overheating, a general problem both in urban spaces and inside buildings, calls for the deployment of passive cooling techniques to reduce energy consumption, protect the environment and institute satisfactory comfort levels. A key factor in such techniques is the capitalisation on the cooling potential of natural heat sinks. The sky, one such sink, has essentially limitless cooling power. In addition, its temperature on fair nights is lower than that of other environmental sinks (ground and air). The sky's promise in that respect prompted this exploration of the potential of nocturnal radiation cooling. A review of the state of the art revealed that in all the radiative dissipators developed and tested to date the dissipation fluid (water) transferred heat indirectly to the heat sink (the sky) by circulating water inside solar collector pipes. The highest values reported for maximum dissipation power were on the order of 100 W/m2. The present study aimed to asses night time dissipation power in a dual system in which water circulated either inside pipes or flowed down the outer surface of the collector. The two modes, one involving in-pipe circulation and the other outer surface downflow, were compared experimentally, for whereas the former has been analysed and assessed by earlier researchers, the latter has not. The empirical findings verified that downflow setups enhanced cooling, delivering up to five-fold the dissipation power obtained with the conventional arrangement.Ministerio de Economía y Competitividad BIA2016-77431-C2-2-RFondos FEDER UIA03-30

Mitigating energy poverty: Potential contributions of combining PV and building thermal mass storage in low-income households

The issue of energy poverty has devastating implications for the society, and it has been aggravated in the past years due to the economic crisis and the increase of energy prices. Among the most affected are those with low incomes and living in inefficient buildings. Unfortunately, the bitter reality is that sometimes this part of the population are facing the next question: Heating, or eating? The declining prices of distributed energy technologies such as photovoltaics provides an opportunity for positive social change. Although their use does not address energy poverty directly, substantial contributions may be made. Measurements of indoor temperatures in a social housing district of southern Spain in 2017 have revealed the unbearable temperatures that the occupants have to endure, both in summer and winter. Using this district as a case study, the present work aims to evaluate the benefits of exploiting its rooftop PV potential to cover part of the electricity consumption of the district (reducing the energy bills), and use the surplus electricity to supply power for the heat pumps in the district. Optimal alternatives regarding maximum PV production, maximum self-sufficiency ratio and minimum investment costs have been found, considering as well different options when sharing the available electricity surplus to improve the thermal comfort of the occupants. As far as the authors know, no previous study has followed an approach aimed at energy poverty alleviation such as the one presented in this work. The results show that using the surplus electricity to heat or cool the whole dwellings would improve the thermal comfort of the occupants in average up to 11% in winter and 26% in summer. If all the PV generation was used or more buildings in the area were employed to install PV modules, improvements up to 33% in winter and 67% in summer could be obtained, reducing at the same time the thermal comfort differences among the dwellings of the district

CartujaQanat: Recovering the street life in a climate changing world. Bioclimatic lattices and confinement of air in exterior conditions

Article number 03205

La red y sus aplicaciones en la enseñanza-aprendizaje del español como lengua extranjera

Producción CientíficaRecoge los contenidos presentados a: Asociación para la Enseñanza del Español como Lengua Extranjera. Congreso Internacional (22º. 2011. Valladolid).Didáctica de la Lengua y Literatur

Socioeconomic Status in Adolescents: A Study of Its Relationship with Overweight and Obesity and Influence on Social Network Configuration

[EN],Socioeconomic status (SES) influences all the determinants of health, conditioning health throughout life. The aim of the present study was to explore the relationship between socioeconomic status and obesity in adolescence through an analysis of the patterns of contact between peers as a function of this parameter. A cross-sectional study was performed, analyzing a sample of 235 students aged 14 to 18 and 11 class networks. Social network analysis was used to analyze structural variables of centrality from a sociocentric perspective. We found that adolescents with a medium-low SES presented a two-fold higher probability of being overweight, but we did not detect any differences in the configuration of their social networks when compared with those of normal-weight adolescents. However, we did find significant differences in the formation of networks according to SES in the overall sample and disaggregated by gender, whereby adolescents with a high SES in general presented a higher capacity to form wider social networks. Elucidating the relationship between SES and overweight and its influence on social network formation can contribute to the design of preventative strategies against overweight and obesity in adolescents, since their social environment can provide them with several resources to combat excess weight.S

Evaluation of the behavior of an innovative thermally activated building system (TABS) with PCM for an efficient design

The global energy crisis has caused a double effect. On the one hand, users are increasingly aware of the energy cost they face. On the other hand, public administrations have become aware of the importance of limiting energy consumption in buildings as a way to combat climate change and reduce the energy dependence with the climate. This situation supposes a great opportunity for innovative constructive solutions with an energetic behaviour that surpasses the traditional approach of reduction of the transmittance. In this work, studies are presented to obtain potential of a new solution thermally activated with two innovations with respect to those existing in the market: its activation is done by hot / cold water produced by renewable systems; and its concrete structural element in addition to having coupled the heat exchanger presents an innovative mortar doped with PCM microencapsulated phase change material.Ministry of Economy and Competitiveness (Government of Spain) and European Regional Development's funds (ERDF) project “Zero-Energy Balance Districts Through Algorithms of Adaptive Comfort and Optimal Management of Energy Networks” (BIA2016-77431-C2-2-R)University of Seville (Spain) Plan VI (VPPI-US

Evaporative Mist Cooling as Heat Dissipation Technique: Experimental Assessment and Modelling

The severity of extreme weather conditions brought on by climate change are conditioning quality of life, economic development, and well-being in today’s cities. Conventional measures have been shown to be insu cient for tackling climate change and must be supplemented with ecofriendly approaches. Hence, the scientific community’s endeavor to develop natural cooling techniques that lower energy consumption while delivering satisfactory comfort levels. For its simplicity and low cost, evaporative cooling has gained in popularity in recent years. The substantial cooling power to be drawn from evaporative mist cooling, makes it an attractive alternative to conventional systems. Research conducted to date on the technique has focused on producing cold air, whilst cooling the water involved has been neither assessed nor experimentally validated. No readily applicable simplified model for the system able to use operating parameters as input variables has been defined either. The present study consequently aimed to experimentally assess the cooling power of the evaporation of sprayed water and experimentally validate a simplified model to assess and design such systems. The findings confirmed the cooling power of the technique, with declines in water temperature of up to 6 C, and with it the promise a orded by this natural air conditioning method. Finally, simplified model developed allows to evaluate this technique like a conventional system for producing fresh water.Urban Innovation Actions by the CartujaQanat UIA03-30

Fresnel solar cooling plant for buildings: Optimal operation of an absorption chiller through inverse modelling

Increasing comfort conditions in buildings imply higher energy demands. However, these needs can be mitigated by solar cooling solutions. These systems, such as absorption chillers, are complex and require stable operation, with strict control to maximise the solar fraction and minimise gas consumption. This is incompatible with the variability of renewable resources, so they are often coupled with auxiliary gas systems. Although gas-free operation is possible if these systems are optimally controlled, they would require special supervision. This paper aims to develop an experimental validation of an inverse model to manage an absorption chiller coupled with a solar cooling plant. To know its real behaviour, long-term experiments have been performed using this plant, which consists of a linear Fresnel solar collector and an auxiliary natural gas boiler. The inverse model is used as a predictive control tool to decide the auxiliary boiler commands of the absorption chiller to optimise its operation: maximum cooling production by minimising gas consumption and maximising solar contribution. It has been identified with data from two weeks and validated with data from one summer month. Results show that the model estimates, on a time base of fewer than 30 min, are acceptable with errors of less than 5%. In addition, the maximum error of the estimated seasonal COP and the renewable fraction are less than 6% per day. Therefore, the results prove the usefulness of the proposal as a predictive control for optimal operation. Furthermore, it could be used as a baseline for preventive maintenance. If the proposed model is used for optimal management of the absorption chiller, the thermal efficiency of the plant increases significantly, doubling the solar contribution. As a result, the gas consumption of the solar cooling plant is halved and the total cost of air conditioning the building decreases by 16%.Comisión Europea A_B.4.3_02

Adaptative Cover to Achieve Thermal Comfort in Open Spaces of Buildings: Experimental Assessment and Modelling

The global need for healthy and safe open spaces faces continuous temperature rise due to the heat island phenomenon and climate change. This problem requires new strategies for improving the habitability of open spaces (indoor and outdoor conditions in buildings). These techniques include reducing solar radiation, reducing the temperature of surrounding surfaces, and reducing the air temperature. The radiant solutions are essential for outdoor comfort, both in summer and in winter. They are easy to integrate into open spaces. This study explores a new concept of radiant solutions adapted for outdoor spaces. The solution was evaluated in a test cell to obtain its thermal behaviour in different operation conditions. Solutions were optimised for operating in a cooling regimen since it has been identified that the demands for comfort in open spaces in hot climates during the most severe summer months are more pronounced. Experimental results have allowed getting an inverse model to analyse the thermal behaviour of the solution. The inverse model achieved high precision in its estimations. Also, it facilitated knowing the radiant and convective effects. Only the radiant heat flux is relevant in open spaces with a low level of air confinement. Finally, the discussion describes the application of the proposed model. The model allows the replicability of the solution—creating new designs (integration) or evaluating into different operating conditions of the system. This discussion demonstrates the high level of knowledge acquired in the characterisation of the solution studied.e European Commission / European Regional Development Funds (ERDF) UIA03-301-CartujaQanat of Urban Innovative Action (UIA