Indoor Air Quality: CIAT Tracking Fine Particles and Chemical Pollutants in Tertiary Buildings

Thursday, August 21, 2014

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By Xavier BARON, System Manager, CIAT Group The air quality objectives are all too often summarized by an air exchange rate and a filtration on the introduction of fresh air, whereas the Quality of Indoor Air ( QAI) concerns the control of pollutants inside a building, and mainly CO2, chemical compounds, and fine particles.

As a result of many years of research and development, CIAT now offers technologies to control these pollutant levels, like the EPURE function, which has a filtering surface 11 times higher than a conventional filter, the development of particulate sensors , Or Smart CIATControl, a tactile tablet that incorporates a patented depollution algorithm.

The health regulations recommend a CO2 level below 1000ppm. On this point, the air flow modulation offers are already proposed by the HVAC manufacturers either individually or centrally at the new air intake station.

As regards chemical pollutants such as benzene and aldehydes, their concentration has been regulated since November 2011 for all public establishments. Within the framework of various national (MIGAS 2) and European research projects (VOCids, ESEE), CIAT is working on the integrated management of the measurement of these pollutants. An office test site in Lyon is instrumented to study the levels of these pollutants with the aim of proposing scenarios of depollution of the building on these compounds.

The treatment of fine particulate matter (PM2.5) is one of the QAI components that will also soon be regulated. To date, this treatment is limited to a filtration level (minimum F5) at the fresh air intake station. This filtration is unfortunately insufficient to guarantee an environment below the threshold of WHO recommendation, fixed at 10?g / m3.

Faced with the health impact of fine particles (70% of public health problems, linked to poor IAQ, are problems related to fine particles), governments have resumed in their regulatory projects the threshold value of 10 ?g / M3 on PM2.5. This announcement is a real challenge for the world of HVAC when it is known that during peaks of pollution, the concentration value of fine external particles can reach 150?g / m3 in the major French agglomerations, that is to say 15 times more than the recommendation.

From a particulate point of view, the introduction of fresh air (window opening, increased flow on the air handling unit) may increase the concentration of fine particles inside the building. Effectively combating fine particles involves the purification and recycling of air inside the building.

As early as 2009, CIAT offered an Epure function in its comfort unit offering, combining filtration efficiency with coanda diffusion. With a filtering surface 11 times greater than a conventional filter, this purification function was carried out without any additional cost in terms of energy consumption. This new media technology with high retention power also makes it possible to space filter maintenance operations (replacement every 3 years on average).

As part of the VAICTEUR AIR2 research project, CIAT pursued this research line by co-developing reliable particulate sensors that can be integrated into a system.

Faced with these challenges, CIAT now markets the "Epure dynamic®" solution. Smart CIATControl, a tactile tablet that connects all HVAC devices in the building, provides a historical tracking of PM2.5 concentrations and incorporates a patented depollution algorithm. The purification action is carried out automatically. If the threshold is exceeded, the particle level is lower than the regulatory threshold values.

This efficient purification is possible by adopting transmitters of the comfort unit type equipped with the EPURE function.

A second QAI function has also been integrated into Smart CIATControl. It is a question of being able to follow and act on the rate of CO2 at the scale of the building, or per zone of building. In the same way, SMART CIATControl proposes a historical monitoring of the concentrations as well as an automatic action of modification of flow of hygienic fresh air introduced at the level of the central air of new air, according to a critical threshold of CO2.

The proposed system is therefore a system of measurement, logging and dynamic purification in order to achieve an air quality closest to the recommendation thresholds, whether for fine particles or CO2.

The health issues linked to the control of pollutants inside buildings are already quantified: In 2012, 1% of premature deaths are linked to pollution (source Les Echos of 26 March 2014).

The European Aphekom study published in March 2011 by the Institute for Public Health Surveillance (InVS) presents the health and economic benefits that could be obtained in Europe if the average annual levels of fine particles (PM2.5) were lowered to 10 Micrograms per cubic meter - guideline value recommended by the World Health Organization (WHO):

• Approximately ? 31.5 billion in savings on expenses related to health, absenteeism and the costs associated with the loss of welfare, quality and life expectancy;

• a life expectancy which could increase to 22 months (persons aged 30 years and over), depending on the city and the average level of pollution.

At the scale of the buildings, the still timid regulations put in place today, will have to ensure a balance between the energy labeling and the labels of air quality of the buildings.
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