In this paper the potential of night ventilation techniques is investigated. Extended real scalemeasurements have been performed, in three buildings, under free floating and airconditioned operation. Two of the buildings have been studied by using a theoretical modeldeveloped in TRNSYS [1] software. Simulation results have been validated by using themeasured data. Specific studies concerning the indoor air temperature and the cooling load ofthe buildings have been carried out in order to identifj the influence of night ventilationtechniques on the buildings thermal performance.
In France, mechanical cooling is increasingly used in office buildings. This situation isrelated to a demand for a better comfort, the increase of the thermal insulation and internalgains, and the changes in the building design.Nevertheless, in many cases, it is possible to achieve a thermally comfortable environmentby passive means - as thermal inertia, and solar protection of the external envelope - and useof low energy techniques as night or evaporative cooling.
The planning parameters of a cooling system for ventilation, for example the vaporization andcondensing temperatures, heat capacity flow rates, design temperatures and designtemperature differences have a strong influence on the investment and operating costs.The target of this research is to find economically optimized design parameters byminimizing the present value of investment and the operating costs of the cooling system.
There are a number of methods available concerning with distribution of air in buildings. Within control research, one can find new control algorithms which have not yet been used in practice. These new algorithms open the possibility of developing andimplementing of new demand controlled ventilation systems.In a building the internal air motions are due both to differences in temperature andpressure differences caused by the ventilation system.
IEA Annex 27 "Evaluation and Demonstration of Domestic Ventilation Systems" has been engaged in developing the evaluation tools for various aspects of their performance. This paper describes the evaluation tool for thermal comfort impact by ventilation systems. The tool is based on the experiment by using inside artificial climate chamber, focusing upon the temperature difference and cold air supply rate into the room. As the evaluation index, the percentage of living space volume where a specified thermal comfort condition is satisfied is used.
An investigation of some Indoor Air Quality (IAQ) parameters in a significant office of the State in the area of Rome was undertaken. The aim, in future, will be to cover a wide range of situations in various buildings and organisations, to achieve data to improve the working conditions, to have a more healthy working environment, to optimize energy consumption and energy management.
The work discussed here concerns the conditions of comfort obtained in a room cooled by a fan coil in relation to the form of air flow obtained. It is based both on practical experiment and on numerical simulation using CFD code. Combining these methods allowed a large number of configurations to be studied, in association with different operating conditions for the appliance. Using the results in combination enabled a relation to be established between the problem data, the device characteristics and the comfort conditions obtained.
The aim of the study was to investigate the operation of different types of ventilation in placesconstructed underground and ground level; the effect of ventilation on indoor radon levels wasalso examined. Air exchange rates and radon concentrations were measured in underground(n=73) and ground level (n=64) workplaces. Air exchange rates, designed exhaust ventilationflows, ventilation rates per person and area were sigmficantly higher in underground placesthan places constructed on the ground level.
A passive tracer gas technique - the homogenous emission technique was utilised formeasuring the air distribution in a part of an office building with displacement ventilation.Measurements were made during one winter period and one summer period. During thewinter period the ventilation was run continuously, while on/off regulation was used duringthe summer period.
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