The strongest justification for lowering ventilation rates would be epidemiological studies that link ventilation and health effects in several building types. In the past 25 years, few studies addressed that question in USA. But Swedish studies that revealed that health risks increased in residences when ventilation rates were reduced could serve as a model for the epidemiological study we need. In the meantime, we must be cautious and not reduce our minimum standards for ventilation rates until the efficacy of these reductions should be demonstrated.

Ashrae 62.1 and 62.2 standards set minimum ventilation rates that provide acceptable indoor air quality (IAQ) in occupied places. But these rates contribute to building mold problems in hot, humid climates. The aim of this paper is to see if those minimum ventilation rates should be lowered in those regions, or if other options could mitigate the problem, including energy recovery ventilators, stand-alone dehumidifiers, and low sensible-heat-ratio air-conditioning equipement being developed by the industry.

This paper describes the performance of a comprehensive experimental study to evaluate the capabilities of 6 different air-cleaning devices that included either HEPA filtering or electrostatic precipitation. Five were portable and were intended to provide air cleaning for bedroom-sized rooms. The sixth was situated in front of the headboard to affect the particulate population for sleeping persons. To ensure a completely objective study, a special laboratory facility was constructed.

Five ionic air purifiers - two wearable and three stationary - producing unipolar air ions are evaluated in this study.The aim is to check their ability to reduce aerosol exposure in confined indoor spaces.The data suggests that the unipolar ionic air purifiers are particularly efficient in the breathing zone when used inside confined spaces with a high surface-to-volume ratio, but a periodic cleaning of those indoor surfaces is needed.

According to the authors, there is a way to increase levels of filter efficiency while reducing the expense of the upgrade. The objective is to define the lowest cost system and not the lowest price system : to determine the best filter for the best cost. The 3 major components to life-cycle costing formula are initial investment and maintenance (that can easily be computed), energy consumption and disposal (that are more complicated to analyze). Examples are given.

In this article a conventional DX system is compared to three other all-electric enhanced dehumidification DX system packages to provide insight into their respective preformance capabilities. The author's conclusion is that augmenting a conventional DX cooling coil with enhanced dehumidification components (such as a wraparound heat pipe heat exchanger, a desiccant dehumidifier in a wraparound configuration too, or a post coil desiccant dehumidifier regenarated by condenser waste heat) can substantially increase an integrated system's moisture removal capacity.

The SEF (system effect factor) causes loss of capacity of fan volume attributed to poorly designed and installed duct fittings at the inlet or outlet fan. It is the interaction of the air with obstructions such as elbows, guards, drive sheaves or dampers, that create SEF.
So SEF must be considered at the design stage of a fan system, it must be included as a separate item in the fan equipment schedule. Ignoring SEF has heavy cost implications.

In the first part of this paper, the techniques that allow the reduction of the radon exposure in buildings are presented. And in the second part, the authors present the results of studies that have shown the links between radon exposition and health. In conclusion, the authors assert that the risk of lung cancer due to a domestic exposure to radon is obvious.

Ashrae 52.1 and 52.2 test standards have been of great value in providing classification methods to compare and contrast filter performances. But they were criticized too, becauset the exposure of electrostatic filtration media to "real world" air results in a performance below the efficiency determined by the Ashrae 52.2. Test.

In this paper the development of international standards for filters used in general building ventilation and for gas turbine intake air cleaning is examined. CEN (Comit Europen de Normalisation) and ISO (International Standards Organisation) have working groups with European or worldwide membership to write european or international air filter standards and rating systems.