Air exchange rates of ten residential buildings were measured according to ASTM-E741-83 using SF6 as a decaying tracer. Air exchange rates were also predicted based on the characteristics of the HVAC system, openings (such as windows), leakage areas, pertaining average wind speed, average indoor/outdoor temperature difference and wind and stack coefficients. It was found that measured air exchange rates were higher by 34% than those predicted if the literature coefficients were used.

The feasibility of designing ventilation routes in the house with passive ventilation system is investigated using the numerical experiments and the measurements on its ventilation rates and indoor air quality. As a result, the ventilation design using the used-air in the rooms on the second floor is proved to be one of the simplest ways to keep good indoor air quality. And the required airtight level of the house with the ventilation design is lower than that with the general ventilation design where the air is supplied to every room.

Energy-saving improvements in the thermal properties of buildings often have an adverse effect on indoor air quality, leading to risks of structural deterioration. In these cases, the air change rate inside dwellings must be increased while ensuring that flued gas appliances continue to function correctly. The proposed ventilation system is a cross between natural draught and controlled mechanical ventilation. It activates natural ventilation of the dwelling by means of the induction principle.

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).