• Energy Research

This work evaluates the potential for the reduction of energy demand in residential buildings by acting on the exterior envelope, both in newly constructed buildings and in the retrofitting of existing stock. It focuses on analysing social housing buildings in Mediterranean areas and on quantifying the scope of that reduction in the application of different envelope design strategies, with the purpose of prioritizing their application based on their energy efficiency. The analyses and quantifications were made by means of the generation of energy models with the TRNSYS tool for simple or combined solutions, identifying possible potentials for reduction of the energy demand from 20% to 25%, basically by acting on the windows. The case study was a newly built social housing building of a closed block type located in Seville (Spain). Its constructive techniques and the insulation level of its envelope are standardized for current buildings widespread across Mediterranean Europe.

Hospital buildings present a significant savings potential in order to meet the objectives of H2020. The improvement of healthcare built environments contributes to improving the health of patients. In this respect, passive measurements must be prioritized, especially in relation to the weakest element of the building thermal enclosure: the window opening. Shading devices allow solar radiation and indoor temperature to be controlled, as well as improving visual comfort, mostly in buildings with a Mediterranean climate. This factor is of great importance when considering the increase in outdoor temperatures expected due to climate change. Unlike other studies in which predictive models are implemented, this paper examines a methodology based on the simultaneous monitoring of ambient variables, in real use and operative conditions, for two hospital rooms located in southern Spain. The aim of this research is to provide a comparative assessment of ambient conditions in a standard room with an egg-crate device and in a non-shaded one. The use of an egg-crate device allows a better yearly performance, improving natural illuminance levels, reducing incident solar radiation on the window, and decreasing artificial lighting consumption. However, its efficiency is greatly conditioned by the user patterns in relation to ambient systems, as the blind aperture level and the activation of the lighting system are directly controlled by users.

Este trabajo forma parte del proyecto de investigación Efficacia: Reducción del consumo energético y del impacto ambiental en la construcción de viviendas protegidas en Andalucía. Dicho proyecto tiene como objeto de estudio el edificio de viviendas protegidas de Cros-Pirotecnia, emplazado en el Barrio “Pirotecnia” del Distrito Sur de la ciudad de Sevilla. Uno de los objetivos de este trabajo es conocer la demanda y consumo energético, en tiempo real, de este conjunto de viviendas en régimen de alquiler. Para tener en cuenta la influencia de sus habitantes, los resultados obtenidos mediante la instalación de monitorización se ha complementado con una serie de encuestas sobre los hábitos de consumos de sus inquilinos. En este artículo se describe la metodología empleada para la monitorización y se presentan los principales resultados obtenidos, una vez transcurridos doce meses desde el comienzo del período de medida. Asimismo, se ofrecen los resultados más significativos de las encuestas realizadas a los inquilinos.

One of the main retrofitting strategies in warm climates is the reduction of the effects of solar radiation. Cooling loads, and in turn, cooling consumption, can be reduced through the implementation of reflective materials such as solar control films. However, these devices may also negatively affect daylight illuminance conditions and the electric consumption of artificial lighting systems. In a hospital building, it is crucial to meet daylighting requirements as well as indoor illuminance levels and visibility from the inside, as these have a significant impact on health outcomes. The aim of this paper is to evaluate the influence on natural illuminance conditions of a solar control film installed on the windows of a public hospital building in a Mediterranean climate. To this end, a hospital room, with and without solar film, was monitored for a whole year. A descriptive statistical analysis was conducted on the use of artificial lighting, illuminance levels and rolling shutter aperture levels, as well as an analysis of natural illuminance and electric consumption of the artificial lighting system. The addition of a solar control film to the external surface of the window, in combination with the user-controlled rolling shutter aperture levels, has reduced the electric consumption of the artificial lighting system by 12.2%. Likewise, the solar control film has increased the percentage of annual hours with natural illuminance levels by 100–300 lux.

This paper presents the validation of two daylight dynamic predictive metrics, obtained through simulation with DaySim 3.2 tool: Daylight Autonomy (DA) and Continuous Daylight Autonomy (DAC). To that effect, a validation protocol is developed, in which the annual results of the predictive simulation model are compared to the illuminance values measured during a whole year into an existing test cell, located in Seville (Spain), which is used as a reference. After trials it was found that, for three illuminance thresholds of 100, 250 and 500 lux, the mean difference of daylight autonomy between measurements and dynamic simulations is lower of 2% with a standard deviation of 6.8%, and the mean difference for continuous daylight autonomy is 1.0% with a standard deviation of 4.9%. It is concluded that the use of these two metrics by calculation with DaySim tool is adequate for small-sized rooms with one window, located in the Mediterranean area. The exposed methodology allows to validate the use of these indicators in rooms with variable size, window size and location, so further investigation is required

Climate change will affect the indoor temperature of historic buildings, impacting the preservation of artworks and the thermal comfort of users, and possibly leading to increased energy consumption. These buildings generate more emissions than new buildings and in most European countries, preservation principles take precedence over energy efficiency and the reduction of emissions. This research is a key topic for the mitigation of climate change and proposes a method for assessing the impact of climate change on the preservation of artworks, thermal comfort, and energy consumption. An experimental method was followed, combining analytical formulations, on-site measure ments, and Heating, Ventilation and Air Conditioning systems in order to identify the adequate hygrothermal parameters for historic buildings. The climate change scenario predicted for 2050 was based on projected tem perature variation. The case studies were Baroque churches, historic buildings located in the south of Europe. Data obtained from a monitoring campaign carried out in these churches was used to validate dynamic simulation models. The churches analysed showed an increase in cooling demand and a decrease in heating demand. Furthermore, in order to ensure human comfort and the preservation of artworks, it was necessary to implement active systems in operation for 12-hour periods. These results suggest an energy overconsumption, as the energy consumption for human comfort and artwork preservation was 50% higher than the energy consumption of active systems for the preservation of valuable historic objects. In addition, the annual energy consumption decreases for future scenarios for 2050 in the case of artwork preservation and thermal comfort, but increases by almost 15% for the preservation of works of art due to higher level relative humidity. Before historic buildings can be adapted.

Abstract Churches, chapels and other places of worship are a major part of European cultural heritage which modern society has decided should be preserved for future generations. The indoor environment of these buildings crucial to conserving construction elements and movable artefacts. In addition, in the Mediterranean the growing demand for thermal comfort from society has made the use of active environmental conditioning systems more common in spaces of worship. However, most of these techniques cannot simultaneously satisfy the needs of heritage preservation, human comfort and energy efficiency. In addition, energy consumption in such spaces tends to be high due to their large size and high thermal inertia. In some Mediterranean countries including Spain the thermal envelopes of these buildings are not contemplated in current environmental conditioning regulations. However, all thermal installations must ensure conditions of wellbeing, safety and energy efficiency. Studies such as European Project Friendly-Heating highlight the problems caused by installing heating in old churches. The case of the Spanish churches in Mediterranean climate is very different from that of the churches in northern Europe. Due to the temperate climate, heating demand is much lower in winter, while in spring and summer the demand for cooling and dehumidification is greater due to the high temperatures and outdoor humidity. This article describes research on environmental conditioning techniques, both passive and active, in spaces of worship in temperate climates. The main aim is to describe different environmental techniques to improve the thermal comfort conditions of the faithful while preserving the cultural heritage of these buildings. Different strategies and regimes were tested using monitoring and simulation. The software used was Design Builder version 3.4.0.041, EnergyPlus 8.1 and the simulation model was validated through measurement. Currently, the church does not present comfort conditions and preservation of the artworks throughout the year. In addition, the exclusive use of passive environmental techniques does not completely eliminate the risks. Finally, the detailed knowledge about the hygrothermal response of the church with a validated simulation model after installing HVAC could lead to energy savings and the improvement of conservation and thermal comfort.