Indoor Air Quality Analysis Research Articles

Indoor Air Quality Analysis Using Deep Learning with Sensor Data.

Indoor air quality analysis is of interest to understand the abnormal atmospheric phenomena and external factors that affect air quality. By recording and analyzing quality measurements, we are able to observe patterns in the measurements and predict the air quality of near future. We designed a microchip made out of sensors that is capable of periodically recording measurements, and proposed a model that estimates atmospheric changes using deep learning. In addition, we developed an efficient algorithm to determine the optimal observation period for accurate air quality prediction. Experimental results with real-world data demonstrate the feasibility of our approach.

C-4 災害復興新築住宅における多元室内空気質の測定と解析 : 化学物質と自然放射性物質を中心として

C-4 災害復興新築住宅における多元室内空気質の測定と解析 : 化学物質と自然放射性物質を中心として

A-13 ローエネルギーハウスにおける多元室内空気質の長期測定とその解析

A-13 ローエネルギーハウスにおける多元室内空気質の長期測定とその解析

Thermal Comfort and Indoor air Quality Analysis of a Low-energy Cooling Windcatcher

The aim of this work was to investigate the performance of a roof-mounted cooling windcatcher integrated with heat pipes using Computational Fluid Dynamics (CFD) and field test analysis. The windcatcher model was incorporated to a 5m x 5m x3 m test room model. The study employed the CFD code FLUENT 15 with the standard k-ɛ model to conduct the steady-state RANS simulation. The numerical model provided detailed analysis of the airflow and temperature distribution inside the test room. The CO2 concentration analysis showed that the system was capable of delivering fresh air inside the space and lowering the CO2 levels. The thermal comfort was calculated using the Predicted Mean Vote (PMV) method. The PMV values ranged between +0.48 to +0.99 and the average was +0.85 (slightly warm). Field test measurements were carried out in the Ras-Al-Khaimah (RAK), UAE during the month of September. Numerical model was validated using experimental data and good agreement was observed between both methods of analysis.

Analysis of Indoor Air Quality of Facilities with High Frequency Use of Chemicals

Concerns about the health of modern residential living are increasing. Social problems have occurred as a result of chemical products in the environment. While people are concerned about the use of chemical products, they generally are unaware of the formaldehyde (HCHO) and volatile organic compounds (VOCs) contained in chemical products. In addition, it has not been recognized that people are often also exposed to HCHO, VOCs, and hazardous materials that are released into the environment from multi-use facilities. Advanced studies on indoor air quality in multi-purpose multi-use facilities, such as beauty salons, print shops, nail salons, and dry cleaners due to their use of chemical products have not significantly progressed, even though similar studies on facilities such as subway stations, hospitals, and transport terminal facilities have significantly progressed. The aim of the present study is to inform workers of the risks of the high frequency use of HCHO and VOCs in various chemicals such as laundry chemicals used in various facilities.

A Study on the Analysis of Energy Consumption According to Economizer Control Method

The purpose of this study is a comparative study the indoor thermal comfort and air quality analysis and energy consumption according to specific application type of economizer. Our country is becoming increasingly interested in energy saving in building. Economizer is one of energy conservation measures in HVAC system. This research analyzed dry-bulb control and enthalpy control economizer. The economizer control method satisfies all the conditions of indoor thermal comfort, indoor air quality. An enthalpy control economizer showed lower energy consumption than that of dry-bulb control economizer during simulated period.

IMPROVING INDOOR AIR QUALITY USING LOCAL EXHAUST VENTILATION (LEV)

Ventilation is used to control indoor air quality for maintaining the health and performance of human and ensuring healthy environment. It is known that the environmental criteria are dictated by temperature, humidity, and contamination. In a case study at XY company, questionnaires were distributed to the workers and interviews were conducted to find out the level of satisfaction on working conditions in certain areas. 70% respondents reported feeling uncomfortable because of heat, dust and hot environment. An analysis of indoor air quality was carried out to measure the temperature at pouring area. Based on the analysis, the range of temperatures is from 35°C to 43°C. A local exhaust ventilation (LEV) system was design for improve indoor air quality and reduce extreme heat. The LEV system was proposed for the pouring area to capture then discharged heat or contaminants through a series of strategically placed overhead ducts.

EnergyPlus and CHAMPS-Multizone co-simulation for energy and indoor air quality analysis

This paper presents a co-simulation method using EnergyPlus and CHAMPS-Multizone for combined energy efficiency and indoor air quality (IAQ) analysis. The energy simulation estimates the energy consumption of HVAC systems, lights, and electrical equipment. The Indoor Environmental Quality (IEQ) simulation predicts the indoor contaminate concentrations for IAQ, the zone air temperature and relative humidity for controlled zone conditions, the Predicted Mean Vote (PMV) and Predicted Percentage Dissatisfied (PPD) for thermal comfort, and the illumination for daylighting performance. The energy, thermal comfort, and daylighting simulation are performed by EnergyPlus while the CHAMPS-Multizone is used for the IAQ simulation. In each time step, the CHAMPS-Multizone simulates the pollutant balance, and the ventilation rate required to control the contaminant concentrations under pre-established threshold values. EnergyPlus uses the ventilation rate to simulate the heat, air, and moisture balance, and the energy and daylighting performance. The Building Controls Virtual Test Bed is used for the run-time data exchange. Simulation cases using a 3-zone building are used to validate and demonstrate the benefit of the method. The co-simulation model is developed and implemented in a Virtual Design Studio (VDS) software framework with graphical user interface for integrated building system design. The co-simulation method is found to be especially useful in analyzing the interaction between IAQ and energy efficiency measures.

Analysis of Indoor Air Quality for Residential Buildings in Lhasa, China

Adopting the methods of subjective questionnaire and objective test, the indoor air quality (IAQ) of residential buildings in Lhasa were analyzed in summer and winter, and the results were compared with that in Chongqing. Firstly, the data shows that the overall IAQ in Lhasa is better. Excepted total volatile organic compounds (TVOC), the concentration of formaldehyde, carbon dioxide (CO2), PM2.5 are low. Secondly, more than 80% residents accepted the IAQ in Lhasa, which means the satisfaction rate is high. Thirdly, the IAQ in Lhasa is better than that in Chongqing, such that the exceed-standard rate of formaldehyde is only 2.5% in Lhasa, while 85.7% in Chongqing, and residents’ satisfaction rate in Lhasa is higher. Meanwhile, there are some difference about IAQ in different seasons. The overall concentration of indoor pollutants in summer is lower than that in winter, and residents satisfaction rate on the summer IAQ is higher than winter in Lhasa. Finally, the main effect factors on IAQ were analyzed, and some suggestions to improve the IAQ of residential buildings were provided.

Indoor air quality analysis based on Hadoop

The air of the office environment is our research object. The data of temperature, humidity, concentrations of carbon dioxide, carbon monoxide and ammonia are collected peer one to eight seconds by the sensor monitoring system. And all the data are stored in the Hbase database of Hadoop platform. With the help of HBase feature of column-oriented store and versioned (automatically add the time column), the time-series data sets are bulit based on the primary key Row-key and timestamp. The parallel computing programming model MapReduce is used to process millions of data collected by sensors. By analysing the changing trend of parameters' value at different time of the same day and at the same time of various dates, the impact of human factor and other factors on the room microenvironment is achieved according to the liquidity of the office staff. Moreover, the effective way to improve indoor air quality is proposed in the end of this paper.

Variation of Indoor Air Quality among Urban Public Venues in Kaohsiung City, Taiwan

Modern people spent nearly 90% of their time indoor, and therefore, indoor air quality can directly affect our health. Recently, air quality has been much more emphasized than ever. Since 1970s, many studies have shown that the indoor air quality (IAQ) at urban areas can be worse than the outdoor air quality. To investigate the current condition of urban indoor air quality as well as differences between various types of public venues, this study used either a direct-reading instrument or the method proposed by the Taiwan Environmental Administration (TWEPA) for monitoring indoor air quality. The acquired data were used for variation analysis of indoor air quality of different public venues. Fifteen public venues were selected in this study for monitoring their indoor air quality, and among these 15 public venues, four of them are Category I venues, while the remaining eleven are Category II venues. The measurement was conducted twice at each of the public venue, and the monitored pollutants are CO2, CO, HCHO, TVOC, O3, PM10, PM2.5, bacteria, fungi, humidity, and temperature. The results suggested that there were nine public venues in the first sampling and seven public venues in the second sampling with indoor air pollutant concentrations exceeding the standards. Furthermore, the concentrations of CO2, CO, and O3, from the two measurements exceeded the indoor air quality standards. Therefore, CO2, CO, and O3can be considered as the main contributors to the poor indoor air quality of public venues. The high concentrations of CO2and O3indoor are related to population density and the use of O3generating machines, printers, or photocopiers. As for CO, the high concentration is because of the spread of exhaust gases from vehicles or factories may penetrate from outside to the indoor.

Field analysis of indoor air quality in high rise and low rise green offices with radiant slab cooling systems in Malaysia

Even though the green building concept is fairly new in Malaysia, the development of this industry has been growing in recent years prior to the launch of Malaysia’s own standard, namely the Green Building Index (GBI). One of the criteria assessed in the GBI is the energy efficiency, which takes about 21% of the overall assessment. Considering this, the passive design has been included in the green building concept to reduce the energy usage without compromising occupant thermal comfort. This study attempts to assess the passive design effectiveness in terms of indoor air quality in green office buildings in the tropics. Two green office buildings that incorporated the radiant slab cooling and conventional cooling system have been selected as case studies. A detailed assessment in terms of thermal comfort parameters (temperature and relative humidity), indoor pollutants’ concentration (carbon dioxide, carbon monoxide and formaldehyde) and air movement was carried out. The results showed that the thermal comfort parameters fall within the Malaysian Standard (MS1525:2007) and ASHRAE Standard-55 2010 except for the air movement in both buildings. Based on the results obtained, future buildings using the radiant slab cooling can have a better comfort level from the lesson learned from both buildings.

Analysis of Indoor Air Quality for the Split-Type Air Conditioner with Air Change Function in an Office Environment

As Taiwan is located in subtropical zone, it has a high temperature and high humidity climate, and the mean annual relative humidity is higher than 70%. Therefore, the air conditioning products are daily necessities. The split-type air conditioner was used extensive. However, as limited to its mechanical structure, most of split-type air conditioners lack the air change function, so that the air quality in the air conditioned space declines. At present, the split-type air conditioner with air change function has been developed and commercialized. This paper attempts to experiment tested the air conditioner in an office work environment, and measured the concentration of CO2 under different conditions, so as to validate the fitness of this equipment in office work environment. It is found that after two hours, the CO2 concentration have been over 2600 ppm in the office without outdoor air inlet. The split-type air conditioner with air change function can reduce the CO2 concentration and accumulate, the indoor CO2 concentration can maintain 500 ppm when one person within office environment.

Penalized multivariate Whittle likelihood for power spectrum estimation

Nonparametric estimation procedures that can flexibly account for varying levels of smoothness among different functional parameters, such as penalized likelihoods, have been developed in a variety of settings. However, geometric constraints on power spectra have limited the development of such methods when estimating the power spectrum of a vector-valued time series. This article introduces a penalized likelihood approach to nonparametric multivariate spectral analysis through the minimization of a penalized Whittle negative loglikelihood. This likelihood is derived from the large-sample distribution of the periodogram and includes a penalty function that forms a measure of regularity on multivariate power spectra. The approach allows for varying levels of smoothness among spectral components while accounting for the positive definiteness of spectral matrices and the Hermitian and periodic structures of power spectra as functions of frequency. The consistency of the proposed estimator is derived and its empirical performance is demonstrated in a simulation study and in an analysis of indoor air quality. Copyright 2013, Oxford University Press.

Multizone airflow models for calculating infiltration rates in commercial reference buildings

Sixteen reference building models were created in the multizone airflow and contaminant transport program CONTAM in order to support physically based airflow calculations, as well as indoor air quality analyses, that are not possible using the existing EnergyPlus input files of these buildings. The EnergyPlus models were created for assessing new technologies and supporting the development of energy codes in pursuing building energy efficiency improvements. These models employed an oversimplified approach to infiltration in which infiltration rates were input as constant values. A number of additional inputs had to be defined for the CONTAM models to realistically account for airflow, including the addition of several building zones. Annual airflow simulations were performed in CONTAM for six of the sixteen reference buildings. There are clear relationships between the infiltration rates calculated by CONTAM and weather, which are not exhibited in the EnergyPlus results. In addition, the building envelope airtightness values assumed in either approach have a major impact on calculated infiltration rates. The results of this study provide a baseline for subsequent use of these models to investigate design approaches and technologies that are intended to reduce building energy consumption, improve indoor air quality, or both.

Periodic Local Multi-way Analysis and Monitoring of Indoor Air Quality in a Subway System Considering the Weekly Effect

Indoor air quality (IAQ) is one of the major concerns to people who spend most of the time in an indoor environment, as many hazardous pollutants are emitted from the buildings or underground spaces, or enter from outside sources through the various vents and other entry/exit points. In particular, the IAQ in subway stations have periodic variations in indoor air pollutants, depending on the numbers of passengers and trains, as well as the previous IAQ. Global and weekly models (divided into weekday and weekend model) have been developed and compared with one another using parallel factor analysis to consider the periodic characteristics, as IAQ shows changeable aspects within a day or the week, owing to differences in the passengers’ travel patterns. The IAQ monitoring results of the weekly model showed that the proposed monitoring method could detect abnormal IAQ conditions in a timely manner when compared to the global model. The proposed monitoring method could identify not only the most active time periods but also the main contaminant sources resulting in the abnormality of the IAQ, based on fault detection.

Analysis of Indoor Air Quality in Different Exhaust Conditions in Residential Buildings in Winter

The research analyzes the residence buildings in winter in China which use toilet exhaust units and kitchen ventilator in various combinations as the existing exhaust system, meanwhile, set adjustable air intakes above bedroom and living room windows respectively. In order to provide certain security to solve the comfortable living environment, the indoor transient CO2 concentration distribution is simulated in different exhaust conditions by software Airpak.

Indoor air quality analyses of commercial reference buildings

Sixteen commercial reference buildings were created in the multizone airflow and contaminant transport program CONTAM in order to support airflow and indoor air quality (IAQ) analyses, which are not possible using the existing EnergyPlus input files for these buildings. Annual airflow and contaminant simulations were performed in CONTAM for six of the buildings. Contaminant analyses were performed for occupant-generated carbon dioxide (CO2), volatile organic compounds (VOC) from indoor sources, outdoor particulate matter, and outdoor ozone. In all of the selected buildings and zones, the simulated indoor ozone and PM 2.5 concentrations did not exceed indoor limits set by the World Health Organization. For CO2 and VOC, for which no similarly relevant indoor concentration standards or limits exist, the simulated concentrations were within expected ranges based on published field measurements in commercial buildings. The results of this study provide a baseline for subsequent use of these models to investigate approaches to building ventilation and other technologies that are intended to simultaneously reduce building energy consumption while maintaining or improving indoor air quality.

CHAMPS-Multizone—A combined heat, air, moisture and pollutant simulation environment for whole-building performance analysis

A computer simulation tool, named “CHAMPS-Multizone,” is introduced in this article for analyzing both energy and indoor air quality (IAQ) performance of buildings. The simulation model accounts for the dynamic effects of outdoor climate conditions (solar radiation, wind speed and direction, and contaminant concentrations), building materials and envelope system design, multi-zone air and contaminant flows in buildings, internal heat and pollutant sources, and operation of the building HVAC systems on the building performance. It enables combined analysis of building energy efficiency and indoor air quality. The model also has the ability to input building geometry data and HVAC system operation related information from software, such as SketchUp and DesignBuilder via IDF file format. A “bridge” to access static and dynamic building data stored in a “Virtual Building” database is also developed, allowing convenient input of initial and boundary conditions for the simulation and for comparisons between the predicted and measured results. This article summarizes the mathematical models, adopted assumptions, methods of implementation, and verification and validation results. The needs and challenges for further development are also discussed.

Analysis of indoor air quality in surgical operating rooms using experimental and numerical investigations

The present work fosters experimental measurements and mathematical modelling techniques to primarily determine the thermal and the relative humidity characteristics in the air-conditioned surgical operating room. The present work also demonstrates the effect of the various designs of surgical operating rooms and operational parameters on the flow pattern and temperatures characteristics. This study is a part of a more comprehensive investigation of the more important factors affecting the air environments in surgical operating room. Measured and predicted temperatures and relative humidity profiles are shown to be in good agreement. The present paper introduces several recommendations regarding the optimum design requirements of operating rooms to provide hygiene and comfort environment. Low humidity affects comfort and health. The present work offers examples of measured relative humidity profiles in an operating room in (New Kasr El-Aini Teaching Hospital – 1200 beds – Cairo University – Egypt). These experimental results were carried out to verify the proposed numerical procedure and particularly in the vicinity of the supply outlets and operating table.