filtration

A good indoor air quality is necessary to minimize exposure to airborne pollutants. The main source of those pollutants is often outdoor air. Ventilation and air filtration are the main solutions to reduce them.The aim of that study was to investigate the effects of air ventilation and filtration on submicrometer particle concentrations indoors thanks to a simple one zone mathematical model that simulates the time evolution of particle concentrations indoors.

For hospitals, air filtration is obviously a very important point in the control of nosocomial infections. A strategy and reference points are presented .

This article analyses and comments 5 papers presented at Indoor Air 2002 Conference (see Airbase records 14454, 14455, 14539, 14695 and 14697) about indoor air quality and filters, from the point of view of filter changing frequency.

This article describes bacteria and viruses usually considered as candidates for biological weapons. It also presents chemical agents that might be used as chemical weapons. It shows how HVAC systems can be designed with safeguards to protect against entry and/or circulation of these agents. It explains how air filtration can provide an additional defense, using HEPA filters, activated carbon filters, antimicrobial treated filters, ultraviolet light emitters or electrostatic air cleaners with UV emitters.

The paper describes three methods for determination of the fan energy consumption associated to air filter : the hourly method (calculation of the hourly fan power), the segment method (lifespan filter-associated fan energy), the BIN method (estimation of annual filter-associated fan energy). etailed filter installing date and detailed hourly AHU system simulation.
These methods allow in particular to estimate the filter-associated fan energy consumption and the life-cycle cost of filters.

Describes the testing methods of filters intended to be used in ventilation systems, and their classification according to their performance.

In an air-conditioned office building in Singapore, 3 different filtration systems have been evaluated under similar fresh air intake and ventilation rate conditions (electrostatic filtration, electrostatic filtration with chemical adsorption, and media filtration) . Chemical and microbial contamination levels under different filtration strategies have been monitored.

Provision of good IAQ in buildings located close to a busy road requires application of air filtration systems which are efficient for submicrometer and especially ultra fine particles, since traffic emissions are associated with particles in these size ranges. A study has been conducted in which a filtration system of an office building was designed according to measured outdoor air conditions and theoretically predicted indoor air conditions. The performance of the system was then validated by field measurements of particle concentration levels indoors and outdoors.

Several studies have shown that supply air filters in office buildings, schools etc. occasionally get wet due to weather impacts. The aim of this study was to investigate whether performance characteristics, such as pressure drop across the filter and filtration efficiency, change when two different kinds of air filters become soaked and dried. The filters used, were a fiberglass bag filter and a plastic fiber bag filter, each of filter class F7. The study showed that the filter getting wet did not affect the shape of the dried filter material of plastic fibers.

Several studies based on analytical models and numerical simulations have shown that it is difficult to control airborne particle movements in a ventilated room. However, more knowledge and information on particle characteristics and particle movements, in combination with new numerical simulation tools, have recently made it easier to estimate particle patterns. In the present paper new information is used to evaluate the role of filtration and ventilation in the particle elimination process.