Ventilated pitched roof with forced ventilation and flow homogenizer device: Testing and performance assessment

Ventilated tile roofs are common objects in the construction sector of Italy. A preferred type is characterized by a ventilated air space between the upper tile layer and the roof structure below. The air enters through openings at the gutters level, flows up below sheathing in the air space along the pitch and is finally discharged through openings along the ridge. This setup, which leaves the room below the roof sealed and habitable, allows removing the heat brought by the absorbed solar radiation thanks to the flow that is established by natural ventilation in the air space. However, its actual performance is often weak and also unpredictable due to continuously changing buoyancy forces. Nonetheless, a permanent and adequate flow can be ensured even through a relatively thin air space and for whichever irradiance and wind conditions by forced ventilation: a properly designed fan can provide the desired flow rate by extracting the air after this is collected along the ridge by a manifold. A thorough design and manufacturing of the manifold is needed, however, to avoid a highly inhomogeneous flow, which would follow the easiest path and leave most of the pitch practically unventilated. As an alternative, a throttling shutter parallel to the ridge has been proposed to progressively choke the flow entering the manifold through parallel climbing ducts as the fan is approached, possibly allowing onsite adjustment after installation. In this work the solution, developed by means of a small scale test bed, is illustrated in details and some methods to assess the performance are presented

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

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

Thermal Stabilization of Digesters of Biogas Plants by Means of Optimization of the Surface Radiative Properties of the Gasometer Domes

A new incentive scheme for power generation from biogas is favoring in Italy the construction of small plants. These ones, however, have poorer financial viability and biological stability than larger plants. In order to ensure adequate performance and a reasonable payback period it is therefore essential that every aspect of their operations is carefully designed. In this respect, summer overheating of anaerobic digesters due to solar gains must be prevented. A solution relies upon the implementation of a ‘cool’ gasometer dome with properly chosen solar reflectance, whose effectiveness was assessed through the use of a calculation code specifically built and validated by comparison with experimental data

6D physical interaction with a fully actuated aerial robot

This paper presents the design, control, and experimental validation of a novel fully-actuated aerial robot for physically interactive tasks, named Tilt-Hex. We show how the Tilt-Hex, a tilted-propeller hexarotor is able to control the full pose (position and orientation independently) using a geometric control, and to exert a full-wrench (force and torque independently) with a rigidly attached end-effector using an admittance control paradigm. An outer loop control governs the desired admittance behavior and an inner loop based on geometric control ensures pose tracking. The interaction forces are estimated by a momentum based observer. Control and observation are made possible by a precise control and measurement of the speed of each propeller. An extensive experimental campaign shows that the Tilt-Hex is able to outperform the classical underactuated multi-rotors in terms of stability, accuracy and dexterity and represent one of the best choice at date for tasks requiring aerial physical interaction