scholarly journals Development of a Ventilation System Using Window Cavity

2020 ◽  
Vol 12 (20) ◽  
pp. 8391
Author(s):  
Jinuk Lee ◽  
Sanghoon Park ◽  
Taeyeon Kim
Keyword(s):  
Carbon Dioxide ◽  
Particulate Matter ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Measurement Data ◽  
Outdoor Air ◽  
Forced Ventilation ◽  
Negative Impacts ◽  
Carbon Dioxide Co2

A household unit of an existing apartment in which residents lived was selected, and the indoor air quality in each space of the unit was measured for analysis. Analysis of the measurement data indicated that the concentration of carbon dioxide (CO2) constantly increased beyond 1000 ppm when a resident stayed indoors for an hour or more. Specifically, the concentration of CO2 increased when the resident was asleep to a level wherein negative impacts on health were observed. Moreover, the inflow of particulate matter (PM) was mainly caused by natural ventilation from the outside rather than the behavior of indoor residents, which generated an insignificant amount of PM. This study proposes a new ventilation system for solving the above-described problems. According to the system, when a window is closed, the window cavity created between a new frame and the existing frame is utilized as an air path for ventilation. The application of this system ensures a stable amount of ventilation through forced ventilation and prevents the inflow of external PM. Moreover, this system was designed to recover indoor heat through the window cavity and facilitate the pre-heating of outdoor air through heat collection based on solar radiation during the day.

scholarly journals Microclimate in Rooms Equipped with Decentralized Façade Ventilation Device

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 800
Author(s):  
Ewa Zender-Świercz
Keyword(s):  
Carbon Dioxide ◽  
Mechanical Ventilation ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Sick Building Syndrome ◽  
Existing Buildings ◽  
Outdoor Air ◽  
Air Humidity ◽  
Thermal Isolation ◽  
Sick Building

Many building are characterized by insufficient air exchange, which may result in the symptoms of sick building syndrome (SBS). A large number of existing buildings are equipped with natural ventilation, whose work is disturbed by activities going to energy-saving. The thermomodernization activities are about mounting new sealed windows and laying thermal isolation, which reduces the amount of infiltrating/exfiltrating air. In many cases, the mechanical ventilation cannot be used due to a lack of a place in building or architectural and construction requirements. One of the solutions to improve the indoor microclimate is the decentralized façade ventilation. In the article, the internal air parameters in an office room equipped with decentralized façade ventilation device were analyzed. The room was equipped with a decentralized façade unit, which cyclically supplied and removed air from the room. The time of the supply/exhaust was changed to 2 min, 4 min, and 10 min. The temperature and the humidity of the indoor air and the outdoor air and the concentration of carbon dioxide inside the room were measured. The analysis showed that despite the lack of a heater in the device, the air temperature in the workplace and in the central point of the room was in the range of 20–22 °C. The air humidity was in the range of 27–43%.

scholarly journals Indoor air quality in a preschool

2014 ◽  
Vol 13 (4) ◽  
pp. 041-048
Author(s):  
Marek Telejko
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Carbon Dioxide Concentration ◽  
Co2 Concentration ◽  
Maximum Efficiency ◽  
Outdoor Air ◽  
Legal Requirements

The article presents the results of indoor air quality (IAQ) assessment in four local preschools. The natural ventilation system was used in the buildings. Outdoor air was supplied to the premises through a leak in the external walls and air intakes were of maximum efficiency of 30 m3/h. Parameters describing IAQ were measured, such as: temperature, relative humidity and carbon dioxide concentration. Two series of studies were performed in each preschool. On the basis of the survey, it can be clearly stated that the indoor air quality in preschools is considered to be very low very low. All the analyzed parameters describing the quality do not meet the current legal requirements. Reported values of CO2 concentration exceeded three times the value set of the recommended maximum.

An Attempt to Improve Air Quality in Primary Schools

2017 ◽  
Author(s):  
Marek Telejko ◽  
Ewa Zender-Swiercz
Keyword(s):  
Air Quality ◽  
Primary School ◽  
Indoor Air ◽  
Primary Schools ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Co2 Concentration ◽  
School Buildings ◽  
Maximum Value

Most primary school buildings in Poland rely on natural ventilation. This fact is attributed to the age of these buildings constructed more than dozen or even several tens of years ago. Few of them were fitted with a mechanical ventilation system allowing for the adjustment of microclimate parameters. The national requirements for gravity ventilation provide general guidelines, specifying strict description only for the airtightness of windows and doors and the minimum airflow to be supplied to the rooms. The minimum airflow supplied is independent of the number of occupants and purpose of the room. Low indoor air quality (IAQ) can impact occupants’ health and lead to poor productivity or low academic performance. Therefore the provision of good IAQ in classrooms and laboratories is very important. This paper presents the results of the investigation devoted to the quality of indoor air in classrooms of selected Polish primary school. Six primary school in a town with a population of 200 000 inhabitants were involved in the investigations. The participating school buildings were built between 1976 and 1994 and had gravity ventilation systems. The variability of basic IAQ parameters, i.e., temperature, relative humidity and carbon dioxide level, was analysed and the assessment of the classrooms in terms of microbiological purity was performed. The outcomes confirmed the low quality of the indoor air in these buildings. The maximum value of CO2 concentration amounted to more than 4000 ppm. Certain modifications aimed at improving IAQ were proposed during the investigations. Two solutions were implemented. The results of this study indicate that the proposed solution offers the potential to improve IAQ within classrooms.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

scholarly journals Six years of atmospheric CO<sub>2</sub> observations at Mt. Fuji recorded with a battery-powered measurement system

2017 ◽  
Vol 10 (2) ◽  
pp. 667-680 ◽  
Author(s):  
Shohei Nomura ◽  
Hitoshi Mukai ◽  
Yukio Terao ◽  
Toshinobu Machida ◽  
Yukihiro Nojiri
Keyword(s):  
Carbon Dioxide ◽  
Measurement System ◽  
Measurement Data ◽  
Co2 Concentration ◽  
Measurement Unit ◽  
Sources And Sinks ◽  
Charging System ◽  
Carbon Dioxide Co2 ◽  
Stability And Accuracy ◽  
Working Standards

Abstract. We developed a battery-powered carbon dioxide (CO2) measurement system for monitoring at the summit of Mt. Fuji (3776 m a.s.l.), which experiences very low temperatures (below −20 °C) and severe environmental conditions without access to gridded electricity for 10 months (from September to June). Our measurement system used 100 batteries to run the measurement unit during these months. These batteries were charged during the 2-month summer season when gridded electricity was available, using a specially designed automatic battery-charging system. We installed this system in summer 2009 at the Mt. Fuji weather station; observations of atmospheric CO2 concentration were taken through December 2015. Measurements were never interrupted by a lack of battery power except for two cases in which lightning damaged a control board. Thus we obtained CO2 data during about 94 % of the 6-year period. Analytical performances (stability and accuracy) were better than 0.1 ppm, as tested by checking working standards and comparisons with flask sampling.Observational results showed that CO2 mole fractions at Mt. Fuji demonstrated clear seasonal variation. The trend and the variability of the CO2 growth rate observed at Mt. Fuji were very similar to those of the Mauna Loa Observatory (MLO). Seasonally, the concentration at Mt. Fuji was 2–10 ppm lower in summer and 2–12 ppm higher in winter than those at MLO. The lower concentrations at Mt. Fuji in summer are mainly attributed to episodes of air mass transport from Siberia or China, where CO2 is taken up by the terrestrial biosphere. On the other hand, the relatively higher concentrations in winter seem to reflect the high percentage of air masses originating from China or Southeast Asia during this period, which carry increased anthropogenic carbon dioxide. These results show that Mt. Fuji is not very influenced by local sources but rather by the sources and sinks over a very large region.Thus we conclude that, as this system could provide stable measurement data with relatively easy operation for 6 years at Mt. Fuji, it could be a useful monitoring technique for remote background sites elsewhere.

scholarly journals Analysis of Carbon Dioxide Concentration Prediction Model and Diffusion Tendency of Expiratory by Simultaneous Multipoint Sensing

2020 ◽  
Vol 10 (13) ◽  
pp. 4631
Author(s):  
Motokazu Moritani ◽  
Norifumi Watanabe ◽  
Kensuke Miyamoto ◽  
Kota Itoda ◽  
Junya Imani ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Prediction Model ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Predicted Values ◽  
Carbon Dioxide Co2 ◽  
Intellectual Activities ◽  
And Diffusion

Recent indoor air quality studies show that even 1000 parts per million (ppm) concentration of Carbon Dioxide (CO2) has an adverse effect on human intellectual activities. Therefore, it is required to keep the CO 2 concentration below a certain value in a room. In this study, in order to analyze the diffusion tendency of carbon dioxide by breathing, we constructed a simultaneous multi-point sensing system equipped with a carbon dioxide concentration sensor to measure indoor environment. Furthermore, it was evaluated whether the prediction model can be effectively used by comparing the prediction value by the model and the actually measured value from the sensor. The experimental results showed that CO 2 by exhaled breathing diffuses evenly throughout the room regardless of the sensor’s relative positions to the human test subjects. The existing model is sufficiently accurate in a room which has above at least a 0.67 cycle/h ventilation cycle. However, there is a large gap between the measured and the model’s predicted values in a room with a low ventilation cycle, and that suggests a measurement with a sensor still is necessary to precisely monitor the indoor air quality.

Numerical Evaluation of Ventilation Efficiency of Window Type Ventilation Systems

2019 ◽  
Vol 27 (03) ◽  
pp. 1950027
Author(s):  
Young Kwon Yang ◽  
Min Young Kim ◽  
Jin Woo Moon ◽  
Jin Chul Park
Keyword(s):  
Mechanical Ventilation ◽  
Indoor Air ◽  
Numerical Evaluation ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Adverse Pressure Gradient ◽  
Building Energy ◽  
Window Opening ◽  
Ventilation Efficiency ◽  
Air Purifier

Ventilation in buildings is the simplest and most convenient way to purify indoor air. However, when the ventilation is not enough due to natural ventilation, it should be cleaned by mechanical ventilation or air purifier. This process requires building energy. Therefore, it is possible to save the energy of the building by merely increasing the natural ventilation efficiency. This study conducted airflow analysis simulations to investigate the effects of changes in the shape of ventilation openings and louvers on the ventilation efficiency of a window ventilation system. The streamlined window opening exhibited a greater increase in airflow (41.3%) than did the conventional window (24.3%) for the ventilation model with four openings. It was also observed that flow separation and wakes were generated by the adverse pressure gradient arising from the increased airflow speed when a louver was employed. Based on these results, it can be concluded that using a louver as a wind augmentation device is an obstacle to improving the airflow in a window ventilation system.

scholarly journals Exposure Assessment in Nail Salons: An Indoor Air Approach

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Cora Roelofs ◽  
Tuan Do
Keyword(s):  
Carbon Dioxide ◽  
Exposure Assessment ◽  
Indoor Air ◽  
Ventilation System ◽  
Ventilation Rate ◽  
Self Report ◽  
Adequate Ventilation ◽  
The Common ◽  
Traditional Approaches ◽  
Nail Salons

Due to the complexity of the nail salon work environment, traditional approaches to exposure assessment in this context tend to mischaracterize potential hazards as nuisances. For this investigation, a workable “indoor air” approach was devised to characterize potential hazards and ventilation in Boston, Massachusetts area nail salons which are primarily owned and staffed by Vietnamese immigrants. A community-university partnership project recruited salons to participate in a short audit which included carbon dioxide measurements and evaluation of other air quality metrics. Twenty-two salons participated. Seventy-three percent of the salons had spot carbon dioxide measurements in excess of 700 ppm, the level corresponding to a ventilation rate recommended for beauty salons. Fourteen salons (64%) did not have a mechanical ventilation system to provide fresh air and/or exhaust contaminated air. The lack of adequate ventilation is of significant concern because of the presence of potentially hazardous chemicals in salon products and the common self-report of symptoms among nail technicians. Community and worker health may be improved through adoption of recommended ventilation guidelines and reduction in the hazard potential of nail products.

scholarly journals Comparison of indoor air pollutants concentration in two Romanian classrooms

2018 ◽  
Vol 32 ◽  
pp. 01023
Author(s):  
Vasilica Vasile ◽  
Alina Dima ◽  
Elena Zorila ◽  
Andrei Istrate ◽  
Tiberiu Catalina
Keyword(s):  
High School ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Pollutants ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Experimental Campaign ◽  
Air Pollutions ◽  
Hybrid Ventilation ◽  
Indoor Air Pollutants

This paper investigates the air pollutions in space ventilated in two High School classrooms. The analysis consists of comparison of one classroom with hybrid ventilation system and another one stander-by classroom with natural ventilation. Several studies regarding indoor air quality during the experimental campaign have been done for VOC, CO2, CO, other pollutants, keeping monitored for humidity and temperature. The experimental demonstrated that the highest value for CO2 in stander-by classroom is 2691 ppm and in classroom with hybrid ventilation is 1897 ppm, while values for CO are 1.1 / 1.1 ppm and VOC 0.14 / 0.06 ppm, better use hybrid ventilation.

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