Search results for "THERMAL COMFORT"
showing 10 items of 68 documents
A correlation linking the predicted mean vote and the mean thermal vote based on an investigation on the human thermal comfort in short-haul domestic…
2015
Abstract The results of an experimental investigation on the human thermal comfort inside the cabin of some Airbus A319 aircrafts during 14 short-haul domestic flights, linking various Italian cities, are presented and used to define a correlation among the predicted mean vote (PMV), a procedure which is commonly used to assess the thermal comfort in inhabited environments, and the equivalent temperature and mean thermal vote (MTV), which are the parameters suggested by the European Standard EN ISO 14505-2 for the evaluation of the thermal environment in vehicles. The measurements of the radiant temperature, air temperature and relative humidity during flights were performed. The air temper…
The vegetation for mitigating the microclimate and designing livable and healthy public spaces in Palermo City Centre
2018
Urban morphology and increasing building density play a key role in the overall heat and energy balance of our cities. The urban environment and CO2 emissions resulting from human activities cause a local increase of temperature, a phenomenon known as Urban Heat Island (UHI). This is also due to the reduction of vegetation in urban areas. The benefits that green spaces have in urban planning have been widely acknowledged. In particular, in temperate and hot contexts, plants help to reduce the extreme summer temperatures, improving people’s outdoor and indoor thermal comfort and, at the same time, reducing the buildings’ energy demand for cooling. The way plants affect urban climates is gene…
Evaluating the thermal-radiative performance of ENVI-met model for green infrastructure typologies: Experience from a subtropical climate
2022
Abstract Microclimate knowledge has been intensively integrated into urban planning and design to improve the buildings’ energy performance and outdoor thermal comfort. To assess the climatic mitigation strategies, numerical modeling is gaining higher relevance. ENVI-met, a microclimate model to simulate the complex surface-vegetation-atmosphere interactions in the built environment, is receiving increasing popularity. This study aims to systematically evaluate the thermal-radiative performance of the ENVI-met model based on its recent updates. First, a field measurement was conducted in a subtropical city. Thermal-radiative parameters were collected besides three green infrastructure (GI) …
The spatial evaluation of the radiative human body heat exchanges: An effective contribution for limiting energy consumption and achieving better ind…
2018
Abstract Radiative heat exchanges inside buildings remarkably affect the thermal balance of the human body in confined spaces and the related thermal comfort sensations of people. The mean radiant temperature is an important component of this balance. Unfortunately, it is usually computed by means of too simplified relationships, which significantly influence the comfort evaluations. Such simplified approaches are also accountable for a less effective design of HVAC systems which, in turn, could result in high energy consumption in the climatization of buildings. However, an accurate evaluation of the mean radiant temperature, especially when high intensity sources are present in a given in…
The calculation of the mean radiant temperature of a subject exposed to the solar radiation – A generalised algorithm
2005
Abstract The thermal sensation experienced by a subject in a confined environment is significantly affected by the radiative heat exchange between the human body and the surrounding surfaces: it contributes as far as 30% of the whole thermal exchanges of the subject. Besides, the presence of high-intensity radiation sources like, for example, the sun, may appreciably modify the radiant field to which people are exposed. As a consequence, this could alter notably the comfort conditions. In order of properly taking into account this issue, a simple analytical method is introduced in this work, that allows the easy evaluation of the thermal radiant field induced by the presence of the solar ra…
Research on ecological design to enhance comfort in open spaces of a city (Valencia, Spain). Utility of the physiological equivalent temperature (PET)
2013
For many years now, research has focused on issues concerning making cities easier to live in and some of the most important of these concern climatology and thermal comfort issues. There is also a growing awareness of the importance of open spaces and green areas, as key elements in providing opportunities for human interaction, leisure and physical exercise. They are important for all inhabitants, but particularly so for children and the elderly population. Of especial interest are the studies which have examined the interaction of comfort with the urban climate. This issue was studied throughout the twentieth century, but recently the role which can be played by biometeorological indices…
Angle Factors and Projected Area Factors for Comfort Analysis of Subjects in Complex Confined Enclosures: Analytical Relations and Experimental Resul…
2008
This paper addresses an important problem in the evaluation of the thermal comfort of people living or working in the sort of confined spaces typical of current architecture. In the details, a new algorithm is proposed for the evaluation of the angle factors of people within rooms characterized by complex shapes, where the envelope components are not always mutually orthogonal. The algorithm is based on field data obtained by means of an experimental photographic apparatus which allows measurements of projected area factors of seated or standing people in such complex confined environments.
A Proposed Methodology to Control Body Temperature in Patients at Risk of Hypothermia by means of Active Rewarming Systems
2014
Hypothermia is a common complication in patients undergoing surgery under general anesthesia. It has been noted that, during the first hour of surgery, the patient’s internal temperature (Tcore) decreases by 0.5–1.5°C due to the vasodilatory effect of anesthetic gases, which affect the body’s thermoregulatory system by inhibiting vasoconstriction. Thus a continuous check on patient temperature must be carried out. The currently most used methods to avoid hypothermia are based on passive systems (such as blankets reducing body heat loss) and on active ones (thermal blankets, electric or hot-water mattresses, forced hot air, warming lamps, etc.). Within a broader research upon the environment…
Natural ventilative cooling in school buildings in Sicily
2016
The paper shows analysis of the impact on thermal comfort of natural ventilation in a nonresidential Mediterranean case-study. Results are based on the EN 15251 approach on adaptive comfort. Different scenarios are proposed, granting an improvement of up to 10% in the number of summer comfort hours.
Modelling relationship among energy demand, climate and office building features: A cluster analysis at European level
2016
Abstract More than one-third of the energy demand of industrialised countries is due to achieving acceptable conditions of thermal comfort and lighting in buildings. Energy demand in buildings depends on a combination of several parameters, such as climate, envelope typologies, occupant behaviour, and intended use. Indeed, assessing a building’s energy performance requires substantial input data describing constructions, environmental conditions, envelope thermo-physical properties, geometry, control strategies, and several other parameters. This has been a very active area of research in recent years, and several numerical approaches have been developed for building simulation; furthermore…