An efficient ventilation system is characterised by a well-organised and turbulence-controlled airstream that rapidly corrects disturbances in air quality and thermal comfort in the ventilated space.Air supply and exhaust conditions are investigated here in order to find stable flow conditions andan efficient elimination of both gas and solid phase contaminants. Heat and thermal comfortrequirements are also included.

The influence of natural convection on the thermal properties of insulating porous medium with air cavity is studied. Here, the combined effect of air movement in the air cavity and the air movement inside the insulation is evaluated with the help of numerical analysis. The influence of total natural convection on the thermal properties of mineral wool, loose-fill insulation, insulation made of small and large polystyrene ball with air cavity are studied. The results are presented in terms of dimensionless numbers and the temperature distribution across the insulation.

There is a growing demand for buildings to have a high indoor air quality environment. Twoof the main elements that contribute to this quality are temperature and air distribution withinthe occupied space. In modern office buildings particularly in hot climates, care must be takento design the most economical air distribution system that provides comfort for the occupants.There are many techniques available to predict the air distribution patterns in the space atdesign stage, but these are often not very accurate.

The Paper deals with numerical computations, carried out, in order to predict the effects of natural convection on the thermal performance of porous material. In this paper the effect of natural convection in a horizontal porous layer will be discussed. The study of the above configuration is essential to understand the functioning of insulation of the type used in attics. The influence of natural convection on the thermal properties of mineral wool, loose-fill insulation, insulation made of small and large polystyrene balls are studied.

House-dust mite antigens are a major contributor to allergic sensitisation. Since temperatureand humidity are crucial to house-dust mite physiology, there is considerable interest inreducing mite populations by controlling the indoor environment.

This study is to investigate the characteristics of indoor air temperature distributions and airflow patterns with three air diffusing systems in heating period and to find the methods which can predict those indoor environmental conditions effectively. A series of measurements and corresponding numerical analysis were done. Selected three air diffusing systems for this study are as follows; 1) ceiling supply-ceiling exhaust, 2) ceiling supply-floor exhaust, 3) floor supply-ceiling exhaust.

Investigation the modelling of the mathematical model of expediency of project decisions of building materials including the human safety the asbestos. The asbestos is most widely used in the production of roof cover-slate. At this moment the building materials in which composition the asbestos is used, become the actual ecological and economical problem of the country.

Parametric studies have often been used for sensitivity analyses in the field of the pharmaceuticaland agricultural sector. All such studies aims at bringing some kind of order out of complicatedrelationships between influencing factors and some response parameter(s). With experimentaldesigns and statistical analysis methods, it is possible to trace and quantify influencesof individual as well as combinations of input factors on the response parameter. Thisprocedure has so far very seldom been used within the building sector.

The necessity to provide and maintain high cleanness of air in the rooms of the highestcleanliness classes requires a proper adaptation of selection and designing methods for airfilters. The level of air cleanliness for such rooms is defined numerically by the determinationof the permissible number of dust particles whose diameters are equal or higher than the givenlimit values.

New thermodynamic energy "water potential" based on the chemical potential of a component of mixture gases is defined as the driving force of gaseous phase water flux. Adhesive power, which is a kind of stress call "capillary attraction" and a part of the water potential, is proved as the driving force of liquid phase water flux. Then numerical model of coupled heat and water transfer using the water potential is introduced and influences of stress such as gravity and stationary pressure on water flux are clarified from the viewpoint of thermodynamics.