Thermal comfort and risk of draught with natural ventilation - assessment methods, experiences and solutions

The majority of research and hence the assessment methods and tools for thermal comfort assessment of ventilation systems are not based on findings for natural ventilation solutions and do not take into account the specific characteristics of natural ventilation. This has created a lack of suitable methods for the assessment and performance evaluation of natural ventilation. This paper will focus on the evaluation of assessment methods related to estimating the risk of draught for natural ventilation systems.

Experimental Quantification of Air Volume Flow by Natural Ventilation through Window Opening

In this paper, a new mathematical model was developed experimentally to quantify the air volume flow by natural ventilation through window tilt opening. The experiment was carried out with two test facades in a laboratory building in Aachen, Germany. The test facades are equipped with windows in two different dimensions, and they are located under real weather conditions. The modelling data were determined by means of more than 70 tracer gas measurements with CO2.

The role of ventilation on aerosolized virus in multizone buildings

Ventilation of buildings is a good way of preventing transmission of some virus in aerosolized form as the SARS-CoV-2. In many buildings, prevention strategies as window opening and sealing door have to be considered with a multizone approach. Approach. We modelled a residence equipped with a exhaust-only ventilation system where a family is isolating in a pandemic context, with one infected person. We modelled and analysed the impact of opening the window and sealing the door in the quarantine room on exposures. We tested several window- and door-opening strategies. Results.

Occupant behaviour and obstacles in operating the openings in offices in India

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.

Improved model to simulate air flow rate through an opened window

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.

How to use natural ventilation to cool narrow office buildings

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.

Test cell evalutation of supply air windows to characterise their optimum performance and its verification by the use of modelling techniques

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.

Experimental and theoretical analysis of natural ventilation by windows opening

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.

Double skin façade and hybrid ventilation of the ING house Amsterdam (ING Bank HQ)

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

Experimental and theoretical analysis of natural ventilation by means of windows opening.

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.