Conventional Building Energy Performance and Actual Energy Costs: A Critical Reflection

Energy Performance Certificates (EPCs) provide information about the energy consumption of the building under conventional climate and use conditions. The calculation method compares the envelope efficiency, energy consumption and carbon emissions of the building with those of a “reference building”, of the same location, size, geometry, use and boundary but with thermo-physical characteristics corresponding to the minimum energy requirements in force. Due to its intrinsic definition, the reference building might actually be highly energy-consuming and costly, allowing the actual building to reach a higher energy class thanks e.g., to the use of renewable energies or more performing windows or walls. This study proposes an in-depth analysis of the actual energetic and economic sustainability of buildings on top of the conventional energy classification concept. By exploring variables such as glass surfaces, imported energy consumption and architectural design, the study aims to develop a novel approach to EPCs, based on a novel concept of reference building. The work aims to contribute to the evolution of the EPC definition, providing a more complete overview of the energy and economic performance of buildings. New qualitative indicators are proposed to be included in the EPCs, depicting a more informative picture of the building energy performance. Results show that for the selected case studies, according to the actual EPC methodology, the quality of the envelope would be medium-high, while the novel indicators would present a rather worse envelope performance. The divergence is particularly evident in the case of highly glazed buildings

Solar Spectrum Reflectometer Measurements on Profiled and Small Samples: Design and Testing of Adapters

Testing solar reflective building materials is mainly performed in laboratories using Solar Spectrum Reflectometer (SSR) or spectrophotometry. To obtain aged materials values, after exposing materials in test farms for natural ageing or applying ASTM-D7897, treated samples shall be tested again using SSR. On-site measurements of new and aged surfaces is allowed using pyranometers or albedometers, which present issues caused both by high-pitched roof and by solar and sky requirements in several locations such as at southern and middle Europe latitudes, where clay tiles are a typical coverage of roof surfaces. The use of battery-powered SSR offsite could be a solution to obtain reliable measurements in every climate, lighting, and slope condition. However, the shape of roof surfaces remains an issue since most of the tiles are characterized by elaborated morphologies that cannot fit the measurement head of the SSR. In this study, two sets of cylindrical adapters for SSR, made via Fused Deposition Modeling and coated with solar reflective white diffuse paint or specular reflective coating were produced and tested to overcome this problem. The adapters were attached to the top of the measurement head and measurements were performed according to ASTM-C1549. These adapters were tested with samples characterized by ASTM-C1549, analyzing the output from all 6 detectors of SSR, and by spectrophotometry according to ASTM-E903, using both AM1GH and ASTM E891-87 irradiance spectra. Aluminum-coated adapters proved ideal due to non-impact on measurements. Solar reflectance showed strong linear correlation for 30–50 mm adapter lengths, indicating minimal signal damping. They will allow testing most of the samples that cannot be tested with standard methods, especially aged ones, without altering their surface

Maison CBET - A comprehensive full scale test bench for comfort and energy analysis of buildings

An innovative test bench has been developed in the framework of the Project CBET - Cross Border Energy Trainings, funded by the Interreg ALCOTRA 2014-2020 Program of the European Union and aimed to increase the educational, training and professional skills on energy efficiency, renewable energy sources and green buildings in the cross-border area between Italy and France. The test bench, called Maison CBET, consists of a transportable standard container modified in a heated, ventilated and air-conditioned habitable office. The opaque and glazed components of the thermal envelope can be easily modified from uninsulated to well insulated, with a wide range of options, as well as shielded against solar radiation. A complete HVAC system is also installed. This is based on electric devices that can be switched on selectively and are powered by separate power lines, continuously monitored by a real time data acquisition system. Weather data and internal comfort parameters are contemporarily monitored. This paper presents a prototype of the test bench that is currently under construction and will be installed in the campus of the Lycée Léonard de Vinci at Antibes, France

Analysis of combined low-level indicators for the hot-season performance of roof components

A single performance indicator, the solar transmittance factor (STF), has been proposed in previous works, together with the derived solar transmittance index (STI). It is aimed at evaluating the summer performance of the roofing system and allowing the selection of the most effective mix of surface and mass properties. It is easily calculated from low-level indicators such as U-value, module of periodic thermal transmittance, and solar reflectance. In the present work, the correlation between STF and the cooling energy demand, integrated over a reference period, was studied, as well as the peak of ceiling temperature increase with respect to the indoor temperature, relevant for thermal comfort. In particular, the thermal behavior of different roof types with variable insulation was calculated numerically by TRNSYS 17 for a wide set of locations and environmental conditions. Unlike other commonly used indicators, to which the analysis has been extended, a strong correlation with STF was found for both cooling energy demand and ceiling temperature rise

Preliminary testing of a simplified methodology for indoor environments evaluation correlated to airborne transmission: The case of a university classroom with vertical low-velocity ventilation

Abstract This work presents and tests a simplified evaluation methodology for indoor environments in relation to airborne transmission. The tests were carried out in a university classroom with vertical low-velocity ventilation. The methodology is focused on aerosols that are one of the most dangerous carriers of infectious disease being able to transport pathogens for long distances. It consists in tracing the aerosols generated through an ultrasonic emitter as well as in the correlation between their dispersion and the artificial ventilation. The methodology aims to identify the critical zone of an indoor volume and to give useful suggestions on how to improve the ventilation of the environment. The tests carried out in a university room show a negligible difference between the deposition occurred with and without ventilation, accordingly with the extremely low velocity measured. These results show that in the specific case study the actual ventilation system does not alter the propagation of small droplets in the environment and does not create critical spots, therefore it is advisable to maintain the ventilation turned ON.</jats:p

How accelerated biological aging can affect solar reflective polymeric based building materials

Among the main issues concerning building materials, in particular outdoor ones, one can identify the colonization by microorganisms referred to as biological aggression. This can affect not only the aesthetical aspect but also the thermal performance of solar reflective materials. In order to improve the reliability of tests aimed to assess the resistance to biological aggression and contextually reduce the test duration, an accelerated test method has been developed. It is based on a lab reproducible setup where specific and controlled environmental and boundary conditions are imposed to accelerate as much as possible biological growth on building materials. Due to their widespread use, polymeric materials have been selected for the present analysis, in the aim of reaching an advanced bio-aged level in a relatively short time (8 weeks or less) and at the same time comparatively evaluate different materials under a given set of ageing conditions. Surface properties before, during and after ageing have been investigated by surface, microstructural and chemical analyses, as well as by examination of time progressive images to assess bacterial and algal growth rate

Gentling and welfare of lambs

In traditional sheep production systems, lambs are suckled by their mothers and then gradually weaned at 35 days of age. However, the increased size of intensive dairy sheep flocks to obtain greater amounts of ovine milk for cheese making, is promoting the diffusion of artificial rearing programs involving early separation of lambs from their mothers. Maternal deprivation soon after birth can have detrimental effects on lamb immune functions, and lead to altered cortisol secretion and behavioural responses to isolation (Napolitano et al., 1995). Human-animal interactions have been documented to play a role in sustaining the welfare and production of domestic animals (Hemsworth, 2003). In addition, gentled animals are less difficult to be handled and less susceptible to the stress induced by management practices involving human contacts (Lensink et al., 2000). The aim of the present trial was to investigate the effects of gently handling newborn lambs on their behavioural, immune and endocrine responses, and on their growth rate when mothered or artificially reared