Effect of ultraviolet germicidal lights installed in office ventilation systems on workers'health and wellbeing : double-blind multiple crossover trial

Ultraviolet germicidal irradiation (UVGI) had been used with success to decontaminate the air in hospital operating rooms and ventilation systems. So, Mc Gill Researchers hoped to reduce the levels of workrelated illness in offices by using Sanuvox UV coilcleaners, too. In that aim, they have been studying the effects of those UV coilcleaners in three Montreal offices during 48 weeks on 771 employees. For that double blind study the Sanuvos purifiers were alternatively turned on (4 weeks) then turned off (12 weeks) with that cycle repeated 3 times for a year.

Improving filtration effectiveness

A field study was undertaken to evaluate and define the role of different filter efficiencies in attaining and sustaining clean HVAC componenets and distribution systems. The results of that fiels study are discussed in that article.

Experimental investigation of integrated air purifying technology for bioaerosol removal and inactivation in central air-conditioning system.

The aim of this paper was to check whether an integrated air purifier is suitable for controlling air quality and for the prevention of virus transmission through the central air system. Based upon the integrated technology of high voltage static electricity and UV technologies an air purifying device has been developed. An experimental platform was built to test that device. Measurements, results and conclusion are presented.

Effects of ceililng-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building

To assess the effectiveness of a new generation of three high volume, ceiling-mounted , high efficiency particulate air (HEPA -ultraviolet (UV) air filters (HUVAFs) for the removal or inactivation of bacterial aerosol was the aim of that study. To be tested, those filters have been installed in an indoor therapy pool building during 2 years. Materials and methods used are presented along with the results of the controlled chamber study and indoor therapy pool building studies.

Reduction in MRSA environmental contamination with a portable HEPA-filtration unit

The evaluation of the effectiveness of a portable high efficiency particulate air (HEPA)-filtration unit to reduce MRSA environmental surface contamination within a clinical setting, was the aim of this paper. Contamination rates have been measured at different air filtration rates (60 - 325 m3/h) and compared with no air filtration. It appears that this portable HEPA filtration unit can significantly reduce MRSA environemental contamination within patient isolation rooms and be complementary to existing MRSA infection control measures.

Evaluation of a high-efficiency, filter-bank system

In USA, after the 2001 bioterrorist attack, filtration efficiencies have been evaluated at three US. Postal Service (USPS) facilities. New ventilation and filtration systems (VFSs) including HEPA filters were used to provide an optimal filtration efficiency (at least 99,97 %). In this paper the techniques used for measurement of particle concentration are described (use of optical particle counters GRIMM Type) and the results presented.

Air filtration : green and clean - How to improve indoor air quality -

Thanks to a right air filtration strategy a good IAQ does not have to cost more. Advances in air filtration allow the development of systems that provide superior IAQ with a reduction of energy costs. HVAC filters play an important part in the removal of airborne contaminants, and protect the HVAC equipment from dust. They provide a cleaner and greener air.

Some indoor air quality problems and measures to control them in China

Ventilation rates and main parameters related to IAQ have been tested in some office buildings and residential houses whom occupants complained about the bad indoor air quality. Based on the test results and regulations, some suggestions were made such as elimination and control of the emission of pollutants at their sources , installation of local exhaust ventilation facilities, proper design and construction of the air conditioning and ventilation systems, use of air cleaners, public education.

Strategy to optimise building ventilation to aid rescue of hostages held by terrorists.

One strategy to secure the release of hostages held by terrorists, is to release an anaesthetic agent through the ventilation system. But it is not so easy to apply. The demand concerning the right amount of anaesthetic needed must be analyzed, along with the specific place in the building where it is required. A model has been made formulated to find the most appropriate strategy for this kind of emergency ventilation. The results are presented and recommendations given for applying the model in practice.

Determination of ozone emission from a domestic air cleaner and decay parameters using environmental chamber tests.

The aim of that study was to establish a methodology to quantify the ozone emission rate from electronic air cleaners, along with the ozone decay parameter. For that experiment 3 different portable ionisation-type air cleaners were used . The leakage rate of the stainless steel environmental chamber was measured by a tracer decay gas method. The results and conclustions are presented.

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