Search results for " thermal comfort"
showing 10 items of 21 documents
Measurements of projected areas of seated and standing people of southern Italy based on a statistical analysis
2006
One of the most important components affecting the human thermal balance is represented by its radiative exchange with the surrounding surfaces. The projected area of the human body is an important parameter of these thermal exchanges. Unfortunately, although the anthropometric measures of people are characterized by significant differences among various populations, the experimental data currently available in the literature refers to a small group of people. Moreover, measurements are generally performed regardless of the statistical significance of the involved subjects with respect to the population to which they belong. In this study, a statistical study is introduced that is based on …
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…
Fifty Years of PMV Model: Reliability, Implementation and Design of Software for Its Calculation
2019
In most countries, PMV is the reference index for the assessment of thermal comfort conditions in mechanically conditioned environments. It is also the basis to settle input values of the operative temperature for heating and cooling load calculations, sizing of equipment, and energy calculations according to EN 16798-1 and 16798-2 Standards. Over the years, great effort has been spent to study the reliability of PMV, whereas few investigations were addressed to its calculation. To study this issue, the most significant apps devoted to its calculation have been compared with a reference software compliant with EN ISO 7730 and the well-known ASHRAE Thermal Comfort Tool. It has been revealed …
Evaluation through adaptive model (ATC) in the levels of thermal comfort in summer in offices in Mediterranea locations.
2014
The design of the building-plant system in the case of office buildings has rarely considered the adaptive model of comfort almost always limited to the control of temperature and humidity and only in some cases of PMV and PPD. Specifically when the building interacts with a climate characterized by high values of external temperature and humidity for long periods, and with high solar radiation in the presence of large glazed areas, it is crucial to take into account relevant aspects of the principle of thermal adaptation. The long stay of the occupants in an air-conditioned environment leads, at the request of colder temperatures very distant from those indicated by the criteria of accepta…
Multi-Agent Systems as Effective Tools for the User-Based Thermal Comfort: an Introduction
2010
Through the paper the characterization of a comfort model, enriching that proposed by Fanger with an adaptive approach, is carried out using a Multi Agent System (MAS). This is a well suited coordinated set of Intelligent Agents, that are software applications interacting in order to follow user in his own needs and preferences in relation to indoor comfort, adapting to the changes of context variables. As a matter of fact, MAS are systems aware of the scenery where users live, following them in their own needs and preferences and adapting to their expectations. Indeed, thermal comfort conditions in the built environment are strictly related not only to the thermal and geometric building fe…
Ventilation systems and thermal conditions in operating rooms
2006
On the assessment of the environmental comfort in operating theatres
2006
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…
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.
An algorithm for the assessment of subjective adaptive thermal comfort conditions based on multi-agent systems
2011
Thermal comfort conditions in the built environment are strictly related not only to the thermal and geometric building features and to air-conditioning systems, but also to the building destination, to its using profile and to the biological-metabolic-psychological characteristics of users. As a consequence, there is a strong claim for new models, both subjective and adaptive to the environment, in a particular holistic vision of the problem, with regards to the novel tern user-plant-building system. In such a frame, through the paper the characterization of an algorithm aimed at subjective adaptive thermal comfort evaluations, enriching the one proposed by Fanger with an adaptive approach…