Ventilation is the most effective procedure to reduce indoor air pollutant. Volatile organiccompounds (VOCs), which cause health related symptoms, are often detected in the indoorenvironment. The way of ventilation should be decided depending on the level of VOCs. Thelevel of VOCs and ventilation rate are usually measured individually. This study will proposea simple method to measure both the ventilation rate, by perfluorocarbon tracer gas technique(PFT), and VOCs concentration immediately by using a single sampler.
This paper describes the results of indoor air quality and ventilation rate during winter in 12Japanese houses that are suspected to be sick houses, judging from the occupants healthcondition. Three methods of measuring the ventilation rate, i.e. the PFT method, the constantconcentration method and the measurement of airflow at inlet/outlet, are compared. Each ofthe methods has its own characteristics and differences in the results obtained are shown. Forindoor air quality, formaldehyde and VOC concentration in the air and the spaces in the insidewall are measured.
Following a comprehensive review of research over the 150-year history of mechanical ventilation, the recent European Multidisciplinary Scientific Consensus Meeting (EUROVEN) considered that only 20 studies relating ventilation (i.e. outside air supply rate per person) to human response were conclusive. From them, a small number of conclusions were drawn, and some very large gaps in our knowledge of this important area of research were identified. Taking these as the starting point, this paper formulates a strategy for evaluating IAQ effects on people.
A manufactured home has been installed on the NIST campus for ventilation, energy andindoor air quality studies. The primary purposes of the facility are to study mechanicalventilation requirements for U.S. manufactured homes and to investigate the systems used tomeet these requirements. In addition, the building will be used to investigate moisture issues,indoor air quality impacts of combustion appliances, and VOC emissions from buildingmaterials and furnishings. The first phase of this multiyear effort has focused on airtightness,system airflows and air change rates.
This article is a study of the air quality at a bus terminal. Presence and concentration of indoor air quality indices were determined by field surveys and sampling. Bus emission rates, occupational exposure and ventilation requirements to have a correct indoor air quality were simulated by mathematical model.
The results show that the natural ventilation rates are too low for having a good indoor air quality, and that pollutants emission varies with the temperature.
Carbon dioxide concentration, indoor air temperature and relative air humidity are studied in 7 schools with natural ventilation systems, during 58 days on one year. The results show that the level of 1500 ppm of CO2 is exceeded in 39 days. A software programme was developed to calculate the CO2 concentration level according to the number of pupils and the ventilation rate.
Health problems may result from a too low ventilation rate.
The intent of this paper is to show that using Equation 6-1 from ASHRAE standard 62 based on occupancy is a non sense if used as a control algorithm in so far as up to now no sensors can physically count each individual in the space. Equation 6-1 describes how to calculate the amount of outdoor air required from an air-handling unit serving multiple spaces for system design purposes.
The question is if the dedicated outdoor air systems can meet ASHRAE's air change design criteria. The standard 62 air change per hour design criteria does not inhibit the use of a separate constant volume ventilation air system (DOAS). This article shows the strong benefits of DOAS : this system with high induction diffuserscan exceed the performance of a conventional all-air VAV system under design conditions from a diffuser performance, space air mixing, and ADPI perspective.
For the study of single-sided natural ventilation, a CFD model along with analytical and empirical models have been used, to determine the effects of buoyancy, wind, or their combination on ventilation rates and indoor conditions.
This paper shows that it is possible to calculate the optimal outdoor air rate at different outdoor temperatures in the economiser cycle. The price of heat must increase 3 times before the optimal outdoor air rate during heating gets lower than during cooling. The optimal outdoor air rate during heating is determined primarily by the price of heat. The optimal outdoor air rate during cooling is determined primarily by the price of cooling capacity.
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