In order to estimate air change rates (ACH) on Natural Ventilation (NV) processes a number of factors should be known as general and openings dimensions, pressure distribution over the facades, internal heat sources (or sinks) and head losses. The atmospheric boundary layer (ABL) characteristics change with the terrain roughness and affect the pressure distribution. Construction features determine infiltration rates, flow regimes through openings and its head losses so affecting the internal airflow.

Describes wind tunnel investigations made with Kr as a tracer.

One sixth of the total energy consumed in Taiwan is for building operation, mainly for summer cooling. The energy consumed for summer cooling can be greatly reduced if naturalventilation can be exerted in Taiwanese urban apartments. To explore the feasibility ofapplying stack ventilation in urban apartments during warm season of Taipei, this studyexamines the ventilation volume induced by the combined wind and stack effect in a twostory building.

Particle characteristics in indoor environments are strongly related to the characteristics ofoutdoor particles. The aim of this work was to investigate how submicrometre particle numberconcentration changes with the distance from a road.

Computer simulation of building airtightness measurements shows the effect of changes inpressure distribution across the building envelope due to wind force and temperature differenceon measurement accuracy. The wide range of leakage distributions, wind directions and velocitiesconsidered give information on the boundaries of these uncertainties. For wind velocities on siteof v(site) ~= 3 m/s, the additional uncertainty in the flow rate at 50 Pa (Q50) found is comparable tothe uncertainty due to standard pressure gauges or operator (about 3%).

Measurements of ventilation rates and indoor climate parameters were carried out in fiveEstonian residential buildings. The purpose of the study was to investigate potentialdifferences-between residences in former eastern Europe and Scandinavia, as regards theindoor environment. Air change rates were measured both during wintertime and springtime,and the air temperature and relative humidity were monitored both outdoors and indoors overextended periods of time. A variety of both organic and inorganic air pollutants weremeasured using both passive sampling and continuous monitoring.

Air temperature, air humidity and ventilation has been measured in a Swedish baroque castle. Results are presented for a measurement campaign comprising four periods under varying climatic conditions. A passive tracer gas method, known as the homogeneous emission technique has been used to measure the ventilation rates and air distribution in the building. As the palace is essentially unheated, wind pressure is the main driving force for ventilation. The air change rate is highly varying and differs considerably in different parts of the building (0.5-1.5 ACH).

In recent years, increasing importance has been placed on energy efficiency in residentialbuildings. This has resulted in tighter buildings, which raises concerns about the amount ofventilation required to provide acceptable indoor air quality. Relatively few studies have beenconducted on multifamily buildings, where the multiple zone interaction makes testing andanalysis difficult. In order to address this problem, detailed testing of air flows, pressures, andtemperatures was done at three electrically-heated multifamily buildings in the U.S.

The paper presents a study on application of pressurisation tests of selected apartments as a base for analysis of natural ventilation in multi-family building. The analysis has been performed for 5-floor building constructed in late sixties. 10 apartments from a total number of 45 have been selected for pressurisation tests. The discussion presents estimations of windows' air tightness, the influence of additional air sealing on windows' infiltration coefficient and flow rates at reference conditions.

The Building Components Technology Department of ICITE, the Central Institute forIndustrialization and Technology in Building of the Italian National Research Council hasstarted an experimental research on natural controlled ventilation devices.Today the air quality of an indoor environment may have several effects on our health, due tothe presence of polluting and extremely noxious agents in the places we most frequently use.That is the reason why ICITE has undertaken to develop a research and an experimentationstudy aimed at establishing a device for the controlled natural ventilation of