Predicting the Impact of Climate Change on Thermal Comfort in A Building Category: The Case of Linear-type Social Housing Stock in Southern Spain

The Climate Change scenario projected by the IPCC for the year 2050 predicts noticeable increases in temperature. In severe summer climates, such as the Mediterranean area, this would have very negative e ects on thermal comfort in the existing housing stock, given the current high percentage of dwellings which are obsolete in energy terms and house a population at serious risk of energy poverty. The main aim of this paper is to generate a predictive model in order to assess the impact of this future climate scenario on thermal comfort conditions in an entire building category. To do so, calibrated models representing linear-type social multi-family buildings, dating from the post-war period and located in southern Spain, will be simulated extensively using transient energy analyses performed by EnergyPlus. In addition, a sensitivity analysis will be performed to identify the most influential parameters on thermal discomfort. The main results predict a generalized deterioration in indoor thermal comfort conditions due to global warming, increasing the average percentage of discomfort hours during the summer by more than 35%. This characterization of the future thermal behaviour of the residential stock in southern Spain could be a trustworthy tool for decision-making in energy retrofitting projects which are so badly needed. To do so, further work is required on some limitations of this model so that di erent user profiles and typologies can be represented in detail and an economic assessment can be included

Summer Overheating in a New Multi-storey Building in Berlin: Numerical Study for Improving the Indoor Microclimate

Abstract The topic of indoor overheating in a modern and well-insulated building is investigated. A real case study is proposed, where, even if the summer ambient conditions are not extreme, thermal discomfort has been verified during the first years of operations. The office building, built recently in Berlin, fulfils the German requirements in matter of energy performance of buildings and heat protection in summertime. Active system for the space cooling are not installed. In the frame of the new international approach to the cost-optimality, by adopting the adaptive comfort criteria for naturally-ventilated buildings, strategies for improving the indoor conditions during the cooling season are here investigated, by analysing various typologies and management strategies for solar shadings

villas on islands cost effective energy refurbishment in mediterranean coastline houses

Abstract This paper aims to underline the variability of constructions in Mediterranean regions, where different climates, architectural techniques and kinds of building uses determine different optimal energy refurbishments of residential buildings placed on the coastline. More in detail, by considering two different construction technologies (i.e., a lightweight house in reinforced concrete and a massive tuff-made villa), two different climates (Greek coast, climate of Athens and Italian coast, climate of Naples), two cost-optimal energy retrofits are presented. The optimized energy retrofit, performed by coupling transient energy simulations and genetic algorithm for generating improved models, have taken into account all levers of energy efficiency, and thus optimization of building envelope (thermal insulation, reflectance, windows and solar screens), active energy systems (daylight control, HVAC systems for the regulation of indoor conditions) and renewable energy sources at the building scale (namely, solar photovoltaic)

Prescriptive- and Performance-based Approaches of the Present and Previous German DIN 4108-2. Hourly Energy Simulation for Comparing the Effectiveness of the Methods

Abstract The study proposes a comparison between the thermal performances of a real building, built according to the German standard DIN 4108-2:2003, and a refurbished one (in a theoretical investigation), aimed at satisfying the more restrictive requirements of the new version (i.e., 2013) of the same standard. The analysed building, completed during the 2012, is located in Berlin. The building has good performances in terms of energy demand for heating. Diversely, during the first years of operations, some overheating problems have been verified in summer. Because of sustainability motivations, cooling devices are not installed. An energy-oriented retrofit is here proposed, aimed at verifying if the fulfillment of the new version of the DIN 4108-2:2013 will produce better microclimatic conditions in summer. The results show the necessity of an accurate approach to the topic of summer thermal protection

Thermal Dynamic Insulation: Numerical Modeling in a Transient Regime and Application to Alternative Aviary Houses

Abstract The paper proposes a numerical model for investigating the energy performance of thermal dynamic insulation in transient conditions. This technology consists of porous building components that are permeable to airflow, ensuring high levels of energy performance and IAQ. The model is implemented in MATLAB environment and allows an accurate evaluation of heat transfer through porous media, with the final purpose of quantifying the energy benefits deriving from dynamic insulation. Beyond its presentation, the model is used to investigate the implementation of a dynamically-insulated ceiling to an alternative aviary house for laying-hens, located in Des Moines, Iowa (U.S.). The proposed system produces thermal, energy and economical savings in both cold and warm seasons

Energy Performance of Cool-colors and Roofing Coatings in Reducing the Free Solar Gains during the Heating Season: Results of an In-Field Investigation☆

Abstract Today, it is not well-known the impact of cool roofs during heating season in balanced climates. Proposed study tries to quantify the increase of energy demands of buildings characterized by high-reflective and high-emissive coatings of roof, by means of experiments and numerical simulations. Three coatings are investigated with different solar absorptance and thermal emittance. The experiments have been carried out at the living lab of the University of Sannio, a full-scale test-room, provided with a large flexibility in terms of variability of the thermal envelope and air-conditioning system. Moreover, numerical evaluations of heating and annual energy consumptions are presented

energy refurbishment of a university building in cold italian backcountry part 1 audit and calibration of the numerical model

Abstract The study provides a methodological approach for designing energy refurbishment measures of buildings, enabling to understand the uncertainty of using numerical modelling and the real impacts due of adopting some energy efficiency technologies. The case study is a University building of the centre of Italy, and the reference scenario has been supported by various in-situ surveys, investigations and evaluations of the indoor comfort. Collected data, together with a comparison with energy bills, has allowed a proper calibration of a numerical model simulated by means EnergyPlus. All this phase is described in this paper, while a second part will discuss the energy retrofit and the building energy optimization

nzeb target for existing buildings case study of historical educational building in mediterranean climate

Abstract A key element of the Energy Performance of Building Directive 2010/31/EU is the introduction of nearly zero energy building (NZEB) standard for new constructions. However, considering the very low rate of new built volume, the major change for achieve the sustainable grow of the European economy, appears to be the renovation of existing building stock. But, is it possible to reach very low or nearly zero energy standard during refurbishment design? Proposed paper tries to answer this question, evaluating if the refurbishment of historic architectures to very low energy need is possible and economically feasible. With reference to a case study, this paper investigates the cost-optimal energy refurbishment of a Renaissance-style palace, located in the center of Naples, South Italy. The adopted methodology consists of various steps. Firstly, a model of the building has been accurately built and calibrated. Then, it has been used to evaluate possible interventions concerning both the envelope and the energy systems. The best solutions, chosen according to the European methodology of cost-optimality, have been combined in a last simulation. The results show that great energy savings as well as economic and environmental improvements are possible, although heritage buildings present a less flexibility in the proposal of energy efficiency measures

energy refurbishment of a university building in cold italian backcountry part 2 sensitivity studies and optimization

Abstract The first part of this study provided a discussion about the methodological approach for designing energy refurbishment measures of buildings. The case study is a building owned by University of Molise, in Campobasso, a cold Italian city. The reference scenario is a numerical model built after deep investigations, and thus surveys, questionnaires, documents and experimental measurements on the real building. Then, a calibrated energy model was presented. In this second part, starting from the calibrated model, some energy retrofit measures have been implemented. The obtained results allow to discuss two key points for researches in matter of energy refurbishment of buildings: a) the importance of using validated models to simulate the present performance; b) the environmental benefits and the economic implications of a deep energy refurbishment

Multidisciplinary Approach to Structural/Energy Diagnosis of Historical Buildings: A Case Study

Abstract A synergic approach for the investigations of the historical building performances - with reference to both the structural behavior and the energy performances for the space heating and cooling - is presented. The historical masonry building "Palazzo Bosco Lucarelli", located in Benevento, has been chosen as case study. The structural and energy analyses are carried out in parallel, especially during the identification of the building characteristics through tests and surveys in-situ. For the structural analysis - beyond examinations on materials - some dynamic tests have been used for better assessing a numerical Finite Element model necessary for the verification of the structure safety. Moreover, being necessary a structural refurbishment, also an energy retrofit could be realized. A rigorous evaluation procedure - aimed to guarantee the necessary reliability of numerical predictions - is performed in order to verify the technical and economical convenience of various energy retrofit solutions