thermal comfort

Space conditions are directly controlled by terminal boxes in variable air volume (VAV) air handling unit (AHU) systems. The terminal box either modulates airflow or adjusts discharge air temperature. Conditioned space will have thermal discomfort by less air circulation if the airflow and discharge air temperature are not suitable. The objective of this study is to estimate an optimal value of the airflow and discharge air temperature, which maintains room thermal comfort.

This study tested the feasibility of employing artificial neural network (ANN)-based predictive and adaptive control logics to improve thermal comfort and energy efficiency through a decrease in over- and under-shooting of control variables. Three control logics were developed: (1) conventional temperature/humidity control logic, (2) ANN-based temperature/humidity control logic, and (3) ANN-based Predicted Mean Vote (PMV) control logic.

The paper presents a study on the thermal behavior of a solar greenhouse set against one apartment of a residential eco-sustainable building in a temperate climate. Particular attention was given to the analysis of the contribution of solar radiation in winter heating in relation to natural ventilation. This study makes use of a transient energy simulation system named ESP-r (Environmentals System Performance - research).

An urban heat island results in higher urban temperatures than the surrounding area and is considered as the most documented phenomenon of climate change. This increase in urban temperature has a serious impact on the energy consumption for cooling and also contributes to higher urban pollution levels. Athens suffers from high summer temperatures that affect the quality of life of citizens. In response to the problem, a major rehabilitation plan was designed and applied, based on the use of advanced mitigation techniques.

Stratified ventilation systems use a fundamentally different approach to supply heated or cooled air through a building than the ‘fully mixed and dilution’ ventilation systems found in the majority of non-residential buildings. Stratified air distribution creates a non-uniform environment in terms of temperature and pollutant distribution, and acceptable conditions in the occupied zone. Previous research has shown that this type of system works well for regions where buildings require year-round cooling.

As compared to mixing ventilation systems, the personalized ventilation system (PV) can help to create a healthy and comfortable working environment with a simultaneous reduction of energy consumption. This latter aspect should be of particular significance for employers and investors who bear responsibility for office space conditions. The parameter which is of paramount interest for this group of people is productivity as it translates into a company’s revenue.

It is still difficult to confirm from available data if global warming and climate changes have played a role in increasing heat-related injuries. However, it is certain that global warming can increase the frequency and intensity of heat waves, which can cause discomfort to the human body and, in the worst case, can lead to more heat illness casualties. Recent worldwide natural disasters, such as the Tohoku earthquake in Japan, flooding in Thailand, and the Pakistan heat wave show that climate change is truly a fact.

European CEN Standard EN 15251 (2007) requires indoor thermal comfort conditions to be assessed and to fall within a category system for different levels of expectation and building purpose.  The COMMONCENSE project has prepared and provided information about the energy implications of the Standard and in particular whether the Standard is encouraging high-energy buildings in the case of new buildings and major rehabilitations.

The temperature of human skin is determined by the human thermoregulatory system which reacts to changes in the thermal balance between a human body and the environment. For this reason, skin temperature can be used as the quickest predictor for the assessment of local comfort or discomfort. This paper presents the outcome of case study experiments carried out to determine which of the skin temperature measurement points (specified in accordance with the ISO 9886 standard) can be used to determine local and general thermal comfort.

The scope of the research described in this paper is to develop, evaluate and propose a new empirical index, the so-called Index of Workplace Comfort (IWC), which quantifies the overall comfort sensation of a user in an office building. The proposed Index of Workplace Comfort is calculated on the basis of both environmental and psychological properly weighted sensation votes of workplace occupants.