Effect Of Window Position Research Articles

Effects of Window Position and Exhaust Flow Rate on Residential Kitchen Hood Performance: A Validated Numerical Approach

Effects of Window Position and Exhaust Flow Rate on Residential Kitchen Hood Performance: A Validated Numerical Approach

Development of a Predictive Equation for Ventilation in a Wall-Solar Chimney System

A solar chimney is a natural ventilation technique that has potential to save energy consumption as well as to maintain the air quality in a building. However, studies of buildings are often challenging due to their large sizes. The objective of this study was to determine the relationships between small- and full-scale solar chimney system models. Computational fluid dynamics (CFD) was employed to model different building sizes with a wall-solar chimney utilizing a validated model. The window, which controls entrainment of ambient air for ventilation, was also studied to determine the effects of window position. A set of nondimensional parameters were identified to describe the important features of the chimney configuration, window configuration, temperature changes, and solar radiation. Regression analysis was employed to develop a mathematical model to predict velocity and air changes per hour, where the model agreed well with CFD results yielding a maximum relative error of 1.2% and with experiments for a maximum error of 3.1%. Additional wall-solar chimney data were tested using the mathematical model based on random conditions (e.g., geometry, solar intensity), and the overall relative error was less than 6%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model, and that the newly developed mathematical equation can be used to predict ventilation conditions for a wall-solar chimney.

Effects of window position in vertical direction on wind driven natural cross ventilation

Natural ventilation system can be considered as one of the zero energy building systems. The comfort of occupants can be achieved if the buildings are designed in favourable and satisfactory ambient conditions. The replacement of any mechanical ventilation system may not only save the electric cost but also contribute to the reduction of the pollutants that are generated during the electricity production stages. The effects of window position in vertical direction on the wind driven natural (WDN) cross ventilation of a full scale building has been investigated using the computational fluid dynamics (CFD) technique after validating the numerical methodology through a satisfactory comparison with an experimental work when RNG κ-ε has been chosen to resolve the turbulence phenomenon. The numerical results have been completely analysed and it is found that ventilation performance is significantly influenced by the vertical window position.

Effects of Window Position on the Air Flow Distribution in a Cross-Ventilated Residential Bedroom

Results of an investigation of the effects of window position on the airflow characteristics for a typical bedroom setting in Taiwan are presented. Four different window positions were examined in the experiment which used a full-scale laboratory bedroom model with a single bed. A three-dimensional ultrasonic anemometer was used to measure airflow distribution and the results of flow measurements at two height levels are presented. Computer simulation of the airflow distribution was performed using the standard k-ε turbulence model. The measurements and the computer calculations resulted in similar airflow distributions for all positions of window openings. Close congruence between the results of calculations and those of the measurements shows the validity of using such a computer simulation in the airflow design of a residential bedroom. The results also show that the positions of window openings have appreciable effects on the airflow distribution. Proper window position is therefore an important factor in the design of ventilation for a cross-ventilated bedroom.