People spend most of their time indoors, thus maintaining a good indoor air quality (IAQ) is essential. To this end, one of the most effective methods to follow is the design of efficient ventilation; for this, the study of the local mean age of air (LMA) parameter is necessary. The objective of this research was to assess the influence of the presence of furniture, through validation of the numerical model CFD. The latter was implemented to calculate LMA in a room with two different furniture arrangements. Prior research on LMA calculation according to the arrangement of the furniture within an enclosure is not found in the literature. The tracer gas concentration decay method was used to develop the experimental analysis. The concordance between the data from the experimentation with those obtained in the numerical analysis was assessed. A greater difference was found in the values of the case with more furniture elements, although there was good agreement. In this study, the influence of the geometry of both the space and the furniture, and its arrangement in the room, on the efficiency of ventilation is shown.

People spend most of their time indoors; therefore, maintaining a good indoor air quality and meeting the requirements of comfort and energy efficiency are essential. One of the most widespread strategies to achieve this objective is improving ventilation efficiency; therefore, the main aim of this study was to show an optimization of the ventilation efficiency, in a specific room, considering 47 variations (case studies) in the furniture arrangement. For this purpose, a numerical analysis using computational fluid dynamics techniques, validated by the tracer gas decay technique, was used to assess the distribution of the age of air within the space. The concept of “age of air” was implemented in the computational fluid dynamics code through user-defined functions, using the steady-state method based on the resolution of a transport equation for an additional scalar. Variations up to 5.75% in the ventilation efficiency between the cases studied have been achieved. It is concluded that an improvement up to 1.65% can be obtained when the elements of the study are introduced in a way that facilitates the air movement towards the exhaust; therefore, improvement of the ventilation efficiency through specific furniture distributions is possible, although not significant, according to the outcomes.

In developed countries, presence at home varies between 60% and 90% of the day, sleeping supposes 30%. Therefore, it is essential to ensure good indoor air quality that enhances health and benefits rest and recovery. In this context, it is necessary to achieve a balance between energy efficiency and air distribution parameters; thus, the influence exerted by the furniture of a bedroom on the air exchange efficiency, in the breathing zone during sleep, is assessed in this study. Computational fluid dynamics techniques, experimentally validated by the tracer gas (SF₆) concentration decay method, are used to analyze 52 case studies corresponding to the same space, but varying both the number and the arrangement of the furniture inside. It is concluded that, in order to achieve a significant improvement in the air exchange efficiency, the number of elements included in the bedroom is not relevant, but the position of them. The highest increase in the ventilation efficiency in breathing zone is observed when the furniture is located avoiding the airflow obstruction in the area near the inlet and creating an unfilled volume of air in the area close to the outlet.

Getting a healthy and comfortable indoor environment in homes in southern Europe is a complicated task. In continental climates, with very cold temperatures in winter and very hot in summer, energy consumption greatly increases with air conditioning significant spending. To propose action guidelines for use of natural ventilation and to develop effective design strategies is essential. Therefore, and given a specific building type block of flats in Madrid, this article focuses on establishing what periods of the year natural ventilation is required to reduce energy consumption in air conditioning, also considering the quality of the outdoor environment and the design of the building. To develop this, a statistical study of the chosen type, that allows studying the direction and the wind speed in the area, is performed. Analysis of wind pressures in holes in the facade is performed by means of numerical simulations of fluid flow (CFD) inside to later infer in the natural ventilation rate required within policy parameters. With the data obtained, a study of energy saving is made as a function of natural ventilation rate established for the building type.

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