Air filters for better indoor air quality.

The need to separate impurities from air or other gases has increased as regards both the degree of separation and the necessity to separate finer particles. An 85% efficiency filter is a prerequisite for the correct functioning of ventilation systems and to improve indoor air quality (IAQ).

Removal of VOC by photocatalytic degradation involving photochemical reaction with O3 under short-wavelength UV irradiation.

Photocatalytic degradation of volatile organic compounds (VOC) with short-wavelength UVlight (254 nm) is an attractive technique in the view of perfect mineralization to CO2. In thisstudy, shorter wavelength of UV light involving 185 nm which generates O3 was used as a lightsource, and as a photocatalyst, titanium dioxide (TiO2) and its mixture with ozonedecomposition catalyst (ODC) was tested to improve photocatalytic activity. Their validity wasevaluated from the removal ratio of toluene by photocatalysis and the size distribution ofgenerated particles by gas-to-particle conversion.

Ventilation and indoor air quality in five Estonian residential buildings: a comparison with Scandinavian conditions.

Measurements of ventilation rates and indoor climate parameters were carried out in fiveEstonian residential buildings. The purpose of the study was to investigate potentialdifferences-between residences in former eastern Europe and Scandinavia, as regards theindoor environment. Air change rates were measured both during wintertime and springtime,and the air temperature and relative humidity were monitored both outdoors and indoors overextended periods of time. A variety of both organic and inorganic air pollutants weremeasured using both passive sampling and continuous monitoring.

Indoor air quality in museums and historical buildings in St Petersburg and in north-west region of Russia.

This presentation deals with the problem of achieving stable microclimate in old buildings ofSt Petersburg - such as churches, museums and palaces. Characteristic traits of such buildingsare rather thick envelops which as a rule accumulate large quantities of heat or cold. Themajority of these buildings are equipped only with central water heating and are naturallyventilated.Experimental study of microclimate in buildings of this kind proves that during cold season(with average temperature -10C) the relative humidity there will be about 30-35% and less.

Improving indoor air quality in dental practices and certain hospital environments with stand-alone air purification systems.

The goal of this study was to investigate the effectiveness of stand-alone modular airpurification systems in improving air quality in dental practices and certain hospital andlaboratory environments. As air pollutant make-up and concentration may vary significantlyin different indoor enviromnents, the air cleaning technologies utilised should be optimisedfor the pollutants targeted in a particular environment. Reduction of mercury vapours andformaldehyde were examined because of their importance for indoor air quality in dentalpractices.

Does the air quality deteriorate during the use of air filters?

Emissions from dust collected in air filters have been investigated using in situ and chambermeasurements. Two air filters (class F6 and F8/9) were exposed to outdoor air for a period ofsix months, after which measurements were carried out during continuous and intermittentoperation. Air samples were taken upstream and downstream of the filters and analysed forseveral substances, including VOCS, formaldehyde, microbial VOCS (MVOC), vital microorganisms,ergosterol and endotoxin.

Do plants in an office have any effect on indoor air microorganisms?

The role of indoor plants as a source of microorganisms was studied in six office rooms.Concentrations of microorganisms (both fungi and actinomycetes) were determined fromindoor air and settled dust before the plants were placed in the office rooms and afterwardswith the plants in the rooms.

Ventilation, energy and IAQ impacts of mechanical ventilation in a US dwelling.

Based on concerns about indoor air quality and trends towards tighter envelope construction,there has been increasing interest in mechanical ventilation of residential buildings in the UnitedStates. This paper reports on a situation study of indoor air quality, ventilation and energyimpacts of several mechanical ventilation approaches in a single-family residential building Thestudy focuses on a two-story house in the northwestern United States and employs themultizone airflow and contaminant dispersal model CONTAM96.

Application of statistical experimental design for parametric simulation studies in building physics, with an emphasis on indoor air.

Parametric studies have often been used for sensitivity analyses in the field of the pharmaceuticaland agricultural sector. All such studies aims at bringing some kind of order out of complicatedrelationships between influencing factors and some response parameter(s). With experimentaldesigns and statistical analysis methods, it is possible to trace and quantify influencesof individual as well as combinations of input factors on the response parameter. Thisprocedure has so far very seldom been used within the building sector.

Impact of teleworking on indoor climate at home.

The greater availability of information and telecommunication technologies and the trend towards flexible working practices allow the home and the workplace to coexist. Many studies mainly emphasize economic and social consequences of teleworking. However, there is no assessment of energy and indoor climate impact of teleworking at home. Furthermore a professional activity is usually not envisaged at home, and home is not built according to the same building design process as offices. Consequently, teleworking at home raises new questions about the evolution of dwellings.

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