Daylight Spectrum Index: A New Metric to Assess the Affinity of Light Sources with Daylighting

The current scenario of colorimetry shows a wide variety of different metrics which do not converge in the assessment of the color rendering of light sources. The limitations of the Color Rendering Index have promoted the emergence of new metrics, such as the Color Quality Scale. As in the case of the previous metric, these new concepts are based on the analysis of the deviation of different color samples in a color space, contrasting the results with those obtained with a light source reference, which can vary depending on the color temperature. Within this context, the Daylight Spectrum Index is proposed. This new concept aims to determine the affinity with daylighting of electric light sources, comparing the resulting spectral power distributions of the lamps studied and that observed under natural light. The affinity of an electric light source with daylighting allows for lower energy consumption due to the better performance of human vision. The new metric proposed is evaluated following the results obtained from 80 surveys, demonstrating the usefulness of this new concept in the quantification of color rendering of LED lamps and the affinity of electric light sources with daylighting.Government of Spain BIA2017-86997-

Daylighting Performance of Solar Control Films for Hospital Buildings in a Mediterranean Climate

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

Indoor Air Quality Assessment: Comparison of Ventilation Scenarios for Retrofitting Classrooms in a Hot Climate

Current energy e ciency 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 di erent 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

Solar Decathlon Latin America and Caribbean: Comfort and the Balance between Passive and Active Design

This article contains an overall analysis of the results obtained by the four highest scoring teams in the Solar Decathlon Latin America and Caribbean 2015 collegiate sustainable habitat competition. Considering that the prototypes developed were based on energy self-su ciency when operational, it was considered necessary to propose this analysis based on the degree of suitability of each of these models based on their di erent performances from the perspective of comfort conditions. It was observed that the design of the prototypes did not manage to properly adjust the relationship between passive and active conditioning elements based on the location’s conditions. Accordingly, this article concludes that a balance of the two aforementioned conditioning modes recorded better results based on the measurements taken

Key Production Parameters to Obtain Transparent Nanocellular PMMA

Transparent nanocellular polymethylmethacrylate (PMMA) with relative density around 0.4 is produced for the first time by using the gas dissolution foaming technique. The processing conditions and the typical characteristics of the cellular structure needed to manufacture this novel material are discovered. It is proved that low saturation temperatures (−32 °C) combined with high saturation pressures (6, 10, 20 MPa) allow increasing the solubility of PMMA up to values not reached before. In particular, the highest CO2 uptake ever reported for PMMA, (i.e., 48 wt%) is found for a saturation pressure of 20 MPa and a saturation temperature of −32 °C. Due to these processing conditions, cell nucleation densities of 1016 nuclei cm−3 and cell sizes clearly below 50 nm are achieved. The nanocellular polymers obtained, with cell sizes ten times smaller than the wavelength of visible light and very homogeneous cellular structures, show a significant transparency

Assessment of Indoor Environmental Quality for Retrofitting Classrooms with An Egg-Crate Shading Device in A Hot Climate

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

Las medidas cautelares de aseguramiento en los procedimientos tributarios

El tema de la tutela cautelar es un tema de gran relevancia teórica y práctica en el marco de un Ordenamiento Jurídico complejo, dominado por la lentitud y onerosidad de sus procesos y procedimientos. Esta lección se centra en el análisis de las medidas cautelares tributarias que se pueden adoptar en los procedimientos tributarios con una fi nalidad aseguratoria, sea a efectos del cobro de la deuda o a los efectos de la conservación de pruebas. Su reciente reforma en varios aspectos por la Ley 7/2012, de 29 de octubre, invita a reflexionar sobre los privilegios procesales de la Administración Tributaria que marcan su auténtica posición de supremacía.This article is about the preventive or precautionary measures that can be adopted during administrative tax procedures. It is an important issue in our contemporary judicial systems, named by the slowness and burdensome of its procedures. The issue has been recently reformed in our General Tax Law by Law 7/2012, of the 29th of October and this reform invites us to think about how good it is to maintain administrative procedural privileges

Thermal and Lighting Consumption Savings in Classrooms Retrofitted with Shading Devices in a Hot Climate

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.Spanish government BIA2014-53949-RMinistry of Economy and Competitiveness, Spanish GovernmentEuropean Regional Development Fun