English

Air flow patterns and temperature distribution within courtyard have been studied. Wind and thermally driven flow have been thoroughly analysed as a function of the depth to width ratio (Aspect ratio) as main parameter. CFD results show a quite similar behaviour regarding to velocity profiles for all the cases, though temperature profiles are highly affected by dimensions of the courtyard. The whole study can be extrapolated to urban canyons, where air flow patterns are quite similar as a result of having the same geometry.

Over the last decades, a great importance has been given to thermal insulation, in technological designing of building envelope. Lately, a basic requirement of indoor air quality, strictly related to ventilation control strategies, has been highlighted. Then, it is necessary to evaluate correctly, during the design phase, the air permeability of enclosures through validated methods, to assess new technologies through laboratory tests on prototypes and finally to verify real performances through on-site testings.

Indoor and outdoor concentrations of various pollutants were measured in a naturally ventilated building in the West End of Edinburgh during and after the period of the Commonwealth Heads of Government Meeting (CHOGM) to assess the effect upon indoor pollution levels of the closure of some streets in the city. The relationships between indoor and outdoor air qualities in respect of traffic-generated pollutants were studied and the building's relative attenuation of external pollution levels investigated.

Achieving optimized partial improvements of the indoor climate may often be better than to know all optimal levels. The purpose of this study was to investigate the relative importance of temperature, noise, draft and window area. 30 heat-acclimatized subjects participated in 10 exposures in single person climate chambers. Each exposure lasted three hours. During an exposure, the subject was free to optimize the operative temperature at a link to either draft, noise or window area. For each pair of parameters, three linear links were tested.

The use of tracer gas is of great help in measuring airflow rates and detecting shortcuts in air handling units, and is essential for ventilation efficiency measurement. However, the planning of experiments, that is choosing tracer gas injection locations and air sampling locations, is not straightforward. Moreover, the mathematics used for interpretation are quite complex, and require elaborate calculations. Therefore, a measurement protocol and the corresponding interpretation algorithms are being developed and implemented in a user-friendly computer program.

Since the beginning of this decade, natural ventilation in office buildings is receiving specific interest. There are two sorts of application. Natural ventilation can be a strategy for indoor air quality control. Besides it can be used as night ventilation during warm or hot periods. In this case the objective is to cool down the thermal mass and improve the thermal summer comfort. The EC JOULE NatVent project wanted to identify the barriers to the application of natural ventilation in office-type buildings in moderate and cold climates and to provide solutions.

The acoustic environment was examined in an office building with a high prevalence of symptoms typical of the sick building syndrome (SBS). Levels of ventilation noise exceeded 70 dB in many rooms. The peak was often found in the region below 20 Hz, which is the infrasound region and generally regarded as inaudible at these levels. Symptoms attributed to exposure to low frequencies include nausea, headache, choking, coughing, visual blurring and fatigue, which appear to overlap with some of the symptoms of SBS.

This paper describes a European project to produce comprehensive design guidance on urban layout to ensure good access to solar gain, daylighting and passive cooling. The project involves:

The purpose of this work is to evaluate the air infiltration through the high buildings and in the same time to determine the exchange of the air between the rooms and the influence of the heat transmission for these exchanges. The method of approach for this problem is a network model. This is a grid system in which the nodes are the rooms or zones of the building and the connection between two nodes simulates a flow path of a given resistance. It was built a computer program for predicting the interactions between different zones which was applied for a given case of a building.

A simplified natural ventilation model for dwellings is developed and used to determine the impact of different ventilation strategies on the building loads and zones temperatures. It deals with the sensitivity of loads and temperatures to classical default parameters as : wind velocity, wind coefficient value, building environment and shielding conditions, and the actual cross section of the openings. All the simulations are performed using the TRNSYS 14.2 simulation software, TYPE56.