The first goal of this paper is to arm the reader with the knowledge necessary to compare filter performance. In that aim ASHRAE standards 52.1.-1992 and 52.2. - 1999 are described first in general and qualitative terms, then with specific details including equations and examples. An application-level knowledge is provided too via discussion and practical considerations.

This paper discusses the result of a field study undertaken in two phases to evaluate and define the role of various filter efficiencies in attaining and sustaining clean HVAC components and distribution systems. Its conclusion is that filter efficiency is a significant factor in preserving system cleanliness, that low efficiency equals low performance for MERV 6 filters, whereas MERV 15/16 filters appear to be the best of all.

This paper is the part 2 of a two-part series. It deals with the electrical and thermal energy savings, in Smith & Wesson's 153-year-old plant located in Massachussets.Thanks to the design and the installation of the new electrical system, the electrical-power demand has been reduced by 72.5 %, the annual electrical-energy consumption by 54.6 % and the annual thermal-energy consumption by 34.6 %. For that the nine electrical motors serving the make-up air units and exhaust fans have been equipped with VFD (variable-frequency-drive).

A comprehensive energy-conservation study that leads to design and installation of ventilation system that improves plating process operating energy efficiency at the plant. The plating area contains 40 process tanks that require an organized removal of contaminants. The plating process requires maintenance of adequate ventilation. Thanks to the installation of an optimally balanced variable volume ventilation, the plating and associated process areas experienced a considerable reduction in ventilation air changes by 27.3 %.

This article deals with the most critical issues and outstanding solutions in the Indoor Air Quality field. The sources of IAQ problems such as indoor pollutants, as well as the resolutions (ventilation standards, control technologies, air quality and green buildings, homeland security) are presented. But more research and development is still needed though progress toward indoor environments that reliably control odors and chemical or biological contaminants to safe and comfortable levels is being made.

In the aircraft cabin environment, the major air pollution source inside the cabin is human bioeffluents. The performance of PCO (photocatalytic oxidation) air cleaners for this group of pollutants at low humidity is not well documented. The aim of that study was to examine the performance of two prototype PCO air purifiers from different manufacturers in a simulated aircraft cabin environment with real human bioeffluents as the main pollution source.

The performance of a particulate air filter is mostly based on the filtration efficiency obtained by weight method (for CPA filter) or dust spot method (for MEPA filter). The primary goal of this study was to obtain the filtration efficiency over airborne microbes of a CPA filter or MEPA filter which are normally installed in Japanese office buildings. In-situ tests were carried out on three air-handling units and one package air-conditioner located in Tokyo.

The fibers in the electret filter are permanently charged, so electrostatic forces act between the charged fibers and the aerosol. The aerosol capture mechanisms of these filters depend on a combination of the electrostatic mechanisms (dielectrophoretic and Coulombic) as well as the conventional mechanisms, including impaction, interception, diffusion and gravitationally settling.
Though many researches have investigated the filtration characteristics of the electret filters, few studies have demonstrated the comparison of influences of different parameters on the aerosol

That laboratory study was conducted to investigate the co-sorption effect of a dessicant rotor as an air-cleaning device and to show its practical value on improving perceived air quality. The air cleaning effect appears independent of air humidity. The observed air-cleaning effect of a dessicant rotor can also decrease energy consumption of HVAC systems that use desiccant cooling.

In this paper, the authors comment on the testing process of portable air cleaners whose test protocol is based on the measured decay rate of contaminant concentrations with the air cleaner operating compared with the measured decay rate when the air cleaner is turned off. The resulting metric, the clean air delivery rate (CADR) allows an intercomparison of performance among various air cleaners along with a comparison of air cleaner operation to other contaminant removal processes.