Impact of varying area of polluting surface materials on perceived air quality

The impact of the concentration of pollutants in the air on emissions from building materials is the subject of that study.Different building materials were studied in ventilated small-scale test chambers. The experiment allowed the changing of the dilution factor or the changing of the area factor.The results showed that more ventilation in a given space may increase the emissions from the inner surfaces.

Assessing CO2 control in retrofits

A methodology for assessing the potential for a CO2 retrofit on an existing building is presented in this paper. A case study is described, the subject building is an Energy Star rated building that has a Direct Digital Control (DDC) system. The complexity of a CO2 ventilation control retrofit is related to the type of building control system currently in place. Significant energy savings are possible through the application of a well-conceived executed ventilation control strategy.

Modeling ventilation and radon in new Dutch dwellings

The model estimations aimed at identifying the most important parameters that determine air change rate along with predicting the indoor radon concentration to be expected in new Dutch dwellings under different ventilation conditions.Measurements were compared to the model estimations. To increase infiltration and thus to decrease radon concentation, opening the air inlets and inside doors proved to be efficient.

Control strategies for sub-micrometer particles indoors : model study of air filtration and ventilation

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.

The ABCs of DOAS (Dedicated Outdoor Air Systems)

Up to now, the use of a single HVAC unit to handle ventilation along with mechanical cooling was the aim of designers : it permitted to curb the cost of a building's mechanical system. In this article the author suggests a new design approach to treat the ventilation air and to manage the latent cooling load for the building. It consists in "splitting" the building's total cooling load with a DOAS. This approach allows each component of the HVAC system to do what it does best.

Air quality in working areas. Some regulation aspects and prevention.

In France, air quality in working areas is a matter of preoccupation for both the industry and the welfare state, that is in charge with the application of the rules and regulations in that field. The Labour Legislation and the Institution of Prevention, bring advice and assistance to the companies and final users.20 practical guides dealing with ventilation are listed at the end of the article.

Three examples of improvement of ambient conditions in industrial premices

Three experiments aiming at improving the atmosphere in industrial premices are described in this paper. The working conditions of the staff have been improved along with an amelioration of the process and quality of fabrication.The third example proves that a well adapted technical approach allows the improvement of working conditions coupled with an energy control.

Thermal comfort. NF ISO 7730 a standard to discuss

The technical literature very often refers to the international standard ISO 7730. That reference seems to have been accepted too quickly several years ago, without consulting the experts of the profession and without a real critical examination.Now we are facing a difficult situation because the profession recommends (and it is right) temperatures that are lower of several degrees to the ones advised by the standard. Furthermore, an important number of concrete researches demonstrate the very big uncertainties of the data the standard relies on. A serious warning is necessary.

Comfort and air quality. Existing standard in offices

Today the term of comfort includes the different aspects of indoor air quality, thermal, acoustical and visual comfort.Standardisation working groups have already worked in those different fields, and some standards already exist but it will certainly take several years to adapt them according to the countries and continents. Anyway environmental quality is a subjective perception and depends on many interactions. The aim is to insure comfort to the majority of people, but a personal adaptation of the user will always be necessary.

Comfort notions. The control of indoor atmospheres

The notion of comfort is not easy to define. As it relies on elements partly subjective, a statistical approach of the user requirements is necessary.In order to reach the optimum reduction of the causes of discomfort, the profession in charge with the indoor air quality has adopted a certain number of rules that working groups of standardization try to improve and complete.

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