Human response to local heating for use in connection with low enthalpy ventilation.

This paper presents results on the human response to individually controlled radiant local heating of the body which can be used together with low enthalpy ventilation based on low room air temperature and humidity. Experiments were performed with 18 human subjects to identify the optimum combination and location of local radiant heating panels designed to compensate for cooling of the body at room air temperatures in the range 14-23 °C. The subjects were instructed to change the heating power of the panels and to select the optimum condition that would provide them with thermal comfort.

Prediction of air flow distribution in rooms and associated pollutant transfers by the systemic approach.

The general strategy adopted in the development of a computational tool performing the identification of parametric models based on the Residence Times Distribution (Rm) theory is exposed. Two main aspects of the modelling procedure are presented: the structural discrimination of the various solution schemes, and the parameters estimation step. The structural model determination is solved by a stochastic procedure based on a Simulated Annealing algorithm, while the parametric identification is solved by a nonlinear deterministic procedure.

Interaction of radiation absorbed by moisture in air with other forms of heat transfer in an enclosure.

The impact of the radiation absorbed by room air moisture 011 heat transfer and air temperature distribution was investigated. Both analytical and CFO approaches were used. For large spaces such as atria, industrial workshops, hotel lobbies, and aircraft hangers, the neglect of radiation absorbed by the moisture within the air volume can lead to significant errors.

CFD simulations of contaminant transport between two breathing persons.

Experiments have shown that exhalation from one person is able to penetrate the breathing zone of another person at a distance. Computational Fluid Dynamics (CFO) is used to investigate the dependency of the personal exposure on some physical parameters, namely: Pulmonary ventilation rate, convective heat output, exhalation temperature, and cross sectional exhalation area. Full-scale experimental results are used to calibrate/validate the CFD model. Respiration, although an inherently transient phenomenon, is simulated by steady-state CFD with reasonably good results.

Numerical simulation of ventilation efficiency in commercial kitchen.

 In this paper, the airlfow and temperature distributions in a commercial kitchen are simulated based on the k- E model, and the ventilation efficiency is investigated for three types of ventilation systems. The result of this simulation shows that the suitable supply method of the outdoor air and the conditioned air can give high ventilation efficiency, and thus the kitchen can be kept comfortable with relatively low energy consumption.            

The comparison between air change efficiency and contaminant removal effectiveness under some typical air flow conditions in the room ventilated mechanically.

There are many indices to evaluate the ventilation characteristics of the ventilated rooms. These indices are classified into air change efficiency and contaminant removal effectiveness. In order to know how to use many indjces for a good understanding of the characteristics of the concerned ventilation system, the values of various efficiencies under some typical air flow conditions with isothermal condition are compared. The local mean age distributions and local contaminant concentrations are measured with tracer gas technique in a scaled model of the room ventilated mechanically.

Effects of non-isothermal and intermittent air movement on human thermal responses.

Twenty-four college students are asked about their subjective responses to a dynamic thermal environment with non-isothermal and intermittent air movement. The subjects wear an uniform of 0.6 clo and are sedentary. A rotative air jet can cyclically sweep over the subjects with adjustable air velocity. Each experiment lasts 150 minutes and is performed with three stages.

Pages