Current energy efficiency policies in buildings foster the promotion of energy retrofitting of the existing stock. In southern Spain, the most extensive public sector is that of educational buildings, which is especially subject to significant internal loads due to high occupancy. A large fraction of the energy retrofit strategies conducted to date have focused on energy aspects and indoor thermal comfort, repeatedly disregarding indoor air quality criteria. This research assesses indoor air quality in a school located in the Mediterranean area, with the objective of promoting different ventilation scenarios, based on occupancy patterns and carbon dioxide levels monitored on site. Results show that manual ventilation cannot guarantee minimum indoor quality levels following current standards. A constant ventilation based on CO2 levels allows 15% more thermal comfort hours a year to be reached, compared to CO2-based optimized demand-controlled ventilation. Nevertheless, the latter ensures 35% annual energy savings, compared to a constant CO2-based ventilation, and 37% more annual energy savings over that of a constant ventilation rate of outdoor air per person.

In the Mediterranean climate, a large number of educational buildings suffer from discomfort due mostly to energy-deficient thermal envelopes and a lack of cooling systems. Impending climate change is expected to worsen overheating in classrooms, especially during heatwave periods. Therefore, the protection of window openings to reduce incident solar radiation while maintaining adequate indoor environmental quality must be considered a necessary key focus. The main objective of this research is to assess the influence of an egg-crate shading device on the indoor environmental quality of a classroom in Southern Spain. To do so, two classrooms—with and without this shading device—were simultaneously monitored over a whole year. The implementation of an egg-crate shading device allowed for a significant reduction of the incident solar radiation, both in summer and mid-season (around 45–50%), which objectively slightly conditioned indoor operative temperatures. Given the noticeable influence of the user patterns observed, indoor illuminance was also improved, as the rolling shutters tended to be opened at higher aperture levels.

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.

Most educational buildings in southern Spain do not meet current energy requirements as weak thermal envelopes and the lack of cooling systems lead to severe discomfort in classrooms, especially when temperatures are above 30 • C. Given that global warming is expected to worsen this situation in coming decades, one of the first steps to be taken is to protect window openings from high levels of solar radiation by adding shading devices to reduce indoor temperatures and improve visual comfort. The aim of this research is to evaluate the reduction in thermal and lighting consumption in a classroom where a solar protection system in the form of an egg-crate shading device was installed. Two classrooms-one with an egg-crate device and another with no shading system-were monitored and compared for a whole year. The use of an egg-crate device in these classrooms reduced indoor operative temperatures during warmer periods while also improving indoor natural illuminance levels. Moreover, annual electric air conditioning consumption decreased by approximately 20%, with a 50% reduction in electric lighting consumption. These savings in electricity were largely conditioned by the use patterns observed in these ambient systems.Energies 2018, 11, 2790 2 of 17 were therefore considered potential components for the reduction of energy consumption, but this is also conditioned by user patterns, as concluded in the laboratory experiments by Zeiler et al. [7].While solar radiation through glazed surfaces severely affects indoor temperatures and visual comfort, heat gains through window openings improve natural illuminance levels and increase indoor temperatures in winter, causing visual discomfort and overheating in summer. Although solar energy facilitates the passive heating of buildings, excessive solar gains can lead to overheating and glare, so that solar control systems must therefore cover aspects such as thermal and visual comfort and energy saving. Although it should be possible to look out and maintain visual contact with the exterior while respecting the architectural aesthetics of the building, the main function of shading devices is to reduce solar gains in the summer season.Various authors have attempted to establish a classification [8] and comparative evaluation of different solar-control systems [9] using integrated solutions for energy, acoustic, and lighting performances [10]. Much of this analysis focuses on the impact on energy requirements [11] and energy demand [12] in office buildings. Dynamic control strategies are needed to promote optimum performance of these shading devices given the opposing requirements in winter and summer.Eltaweel and Su [13] proposed modifying the position and angle of Venetian blinds, using Grasshopper's plugins to optimize daylight in office buildings, whereas other authors preferred simplified solutions which are easier to apply in building refurbishment. Freewan [14] compared the effect of different external vertical and diagonal fins and egg-crate devices behind a brise-soleil...

Energy retrofitting of the housing stock is a priority in current regulatory standards as a means of reducing energy consumption. The strategies used in retrofitting housing stock ought to respond both to regulatory conditions and to two challenges: specific climate conditions and the improvement of comfort conditions. These issues are especially important in the warmer regions of the Mediterranean, and will be even more so in the future due to climate change. The aim of this paper is to assess the influence that the improvement of facade insulation and the use of ventilation have on the existing housing stock. To do so, an energy evaluation is conducted using on-site monitoring of free-running conditions in test cells reproducing a residential room, both in current condition and with the retrofitted proposal, in Seville (Spain). The results obtained show limited improvement of the facade insulation when outdoor temperatures are high, as well as the influence of ventilation, mainly nocturnal, depending on the ventilation rate and the minimum outdoor temperatures.