Submitted by Maria.Kapsalaki on Wed, 07/02/2014 - 11:56
There is limited information available about occupant’s window opening behaviour in India. Operating doors and windows is a vital adaptation mechanism in warm climates. This paper reports on a field study which collected and analysed data on the use of openings, comfort responses and the simultaneous temperatures in Indian offices. Occupants in naturally ventilated buildings used the windows and doors adaptively as the seasons changed and the temperature varied. We found that 50% of the windows would be opened at an indoor air temperature of 30 °C, using logistic regression.
The author describes how to improve the usual formula to calculate air flow rate through an opened hopper window.Improvements consist in better taking into account the geometry of such windows when estimating their opened area and also in adapting to this type of windows the model used to take into account the influence of wind and of thermal draught.Improved model gives a good comparison with on site measured data from the literature.
There is a resurgence of interest in naturally ventilated offices. Most of the time, cooling the buildings is possible with the opening of windows. Simulations with the softwere TAS were made and showed that window opening allow a sufficient day or night ventilation rate, even if wind characteristics are not favourable. The optimal size, shape and location of the window apertures to reach sufficient ventilation rates has been studied along with the impact of the wind orientation and the building degree of protection on these ventilation rates.
A supply air window enables the pre-heating in winter of ventilation air before it enters the room.The window device must entrain into the room the air flow that would otherwise escape, it allows the absorption of the solar radiant energy and a low emissivity coating within the glazing assembly must be correctly located. To achieve a better performance of the window, tests were carried out. A simulation model was built and comparison of the results were made.
After a review of CFD models and a simplified (zonal) models predictions, a simplified procedure, based on charts and non dimensional groups, is proposed in order to evaluate the ventilation rate through an open vertical window.
CFD calculations and laboratory measurements in a full-scale model were carried out to assess the performance of a full transparent second skin façade intended to equip an office building, composed of very low solar energy transmittance glass, and being v
The purpose of this paper is to improve our understanding of the transient behaviour of airing by window opening. While a few simple models exist to analyse the results of window opening, its transient behaviour is not yet well understood, in its effects on air change rates, air temperature and ventilation efficiency. The paper achieves its purpose in the first place by using a synthesis of numerical modelling activity. Then a critical analysis of the methods of calculation is undertaken, comparing both detailed (CFD) analysis results and simplified or zonal models predictions.
The aim was to develop a simple dynamic model for predicting air exchange caused by short time single-sided ventilation and necessary window opening time in classrooms. Tracer gas measurements have been made in a full-scale room. The comparison indicates that the model can be used when rough estimates of air exchange are of interest.
The simulation of room airing (ventilation by means of door/window opening) by means of CFD techniques requires a specially skilled user, because a number of difficulties arise since the first stage of simulations development, when the user is asked to choose the calculation domain and the time step, and choices which in principle appear correct may frequently lead to meaningless results. This work is centered on the 20, transient analysis of a single side enclosure where the ventilation is only due to temperature differences. Wind effect has not been taken into consideration.