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Airflow rates were measured in one hundred and two newly built single-family houses during 2002-2004. Of the measured houses, 10 % used natural ventilation, 28 % used mechanical exhaust and 61 % used mechanical supply and exhaust. Exhaust airflow rates were measured during the summer period from terminals. Supply airflow rates and sound pressure levels were measured in master bedrooms. During a 2-3 week period in winter, air change rates were measured with a passive tracer gas technique to determine the overall air change rate.

The first and only national norm for residential ventilation in the United States is Standard 62.2-2004 published by the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE). This standard does not by itself have the force of regulation, but is being considered for adoption by various jurisdictions within the U.S. as well as by various voluntary programs. The adoption of 62.2 would require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions.

Personal control over moving air will eliminate the number one complaint in the office environment - thermal discomfort. The use of moving air to cool provides the ability to accommodate different needs among people for comfort due to varying metabolism, efficiency of heat rejection, and clothing. Cooling with moving air saves substantial energy through increased ventilation effectiveness and higher operating temperatures. Increased comfort means increased productivity.

Control-on-demand operation of HVAC-systems can reduce energy for heating, cooling, and the drive energy of fans and pumps resulting in better control at a lower operational cost. Analysis of typical Nordic CAV and VAV systems indicates a potential for substantial sav-ings using new components and alternative system design. Component developments include more efficient motors, variable speed drives, pumps and fans as well as laminar flow heat exchangers and smart air-supply devices.

Air temperature and velocity are the two main factors affecting the thermal comfort indoors. These two values can be easily obtained using computational fluid dynamic (CFD) simulations together with the turbulence kinetic energy value. This paper evaluates methods of calculating thermal comfort indices using CFD. Simulated results are compared against experimental data measured in a purpose build full-scale model room. The results show that CFD data can reliably predict thermal comfort values.

This paper reports on a field investigation of the effect of screening on the induced flow rate in solar chimneys. The solar chimney considered here was a roof solar collector (RSC). It is composed of CPAC monier concrete tiles, an air gap and gypsum board. Two RSC units were integrated into the south-facing roof of a centre single room house of 25 m3 volume. Different types of screening were considered, namely: mosquito net, square net, metal grille and nylon filter.

This paper compares the difference of HEPA/ULPA filter test standards between America andEurope from test procedures, aerosol types and its size, to air filter classification. Both of them adopt MPPS method as their trend. According to EN1822, it is recommended to combine the test rigs for efficiency test and leakage test in practice. Influence of different scanning velocity on sampling accuracy, leakage and efficiency test accuracy need further studied and reasonable scanning velocity should be fixed.

A satisfactory indoor air quality (IAQ) relies, amongst other things, on the availability of clean ventilation air. The outdoor air cleanliness in many urban environments is far from optimum. Fine particles (FPs = 2.5 m) and certainly ultra-fine particles (UFPs = 0.3 m) feature prominently as hazardous constituents of common urban air pollution.

We have performed studies onboard cruise ship to study the particle number concentrations,the commonly used filters and the utilization of novel filtration technologies. We observed that the majority of particles in the indoor air of a ship - and this applies when the ship was sailing in clean or polluted outdoor air - are smaller than 1 micron). We also observed that the commonly used filters mainly filtered particles larger than 1 micron.

While being used for years in industrial applications, gaseous contaminant sorption units suchas activated-carbon filters remain marginal in office and residential buildings. This study deals with models that could help building designers and administrators to design and maintain activated-carbon filters depending on the environmental conditions (pollution load, airflow rate, temperature, humidity) they operate.