Towards the definition of an indoor air quality index for residential buildings based on long- and short-term exposure limit values

The paper investigates the effects on building indoor air quality (IAQ) resulting from the choice of different design ventilation rates. A reference residential building was analysed by means of the multizone modelling software CONTAM, by monitoring the concentration of two pollutants: occupant-generated carbon dioxide (CO2) and total volatile organic compounds (TVOC) from indoor sources. A demand-controlled ventilation strategy based on building occupancy was implemented and users' presence schedules were defined. Specifically, the evolution of indoor pollutant concentrations was investigated when the design ventilation rates, recommended by two IAQ-related standards (the Italian UNI 10339 and the European EN 15251), were implemented through a mechanical ventilation system. Different results regarding the IAQ level were achieved accordingly to the dissimilar ventilation rates. After a statistical analysis on the distributions of CO2 and TVOC concentrations, EN 15251 outcomes showed overall better results of the analysed statistical metrics, i.e. prevalence, sensitivity and accuracy. Indeed, the EN 15251 design airflows led to indoor conditions that were more often classified either in the correct air quality class or in a higher class. Finally, a better alignment between the national and European IAQ standards is recommended, especially in terms of airflows, air quality classes and pollutant limit values.

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Indoor Air Quality: Assessment of Dangerous Substances in Incense Products

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18158086 ◽

2021 ◽

Vol 18 (15) ◽

pp. 8086

Author(s):

Gabriela Ventura Silva ◽

Anabela O. Martins ◽

Susana D. S. Martins

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Indoor Air Pollution ◽

Gaseous Emissions ◽

Limit Values ◽

Cone Type ◽

Guideline Values ◽

Taking Action ◽

At Home

Indoor air pollution has obtained more attention in a moment where “stay at home” is a maximum repeated for the entire world. It is urgent to know the sources of pollutants indoors, to improve the indoor air quality. This study presents some results obtained for twelve incense products, used indoors, at home, and in temples, but also in spa centers or yoga gymnasiums, where the respiratory intensity is high, and the consequences on health could be more severe. The focus of this study was the gaseous emissions of different types of incense, performing a VOC screening and identifying some specific VOCs different from the usual ones, which are known or suspected to cause severe chronic health effects: carcinogenic, mutagenic, and reprotoxic. Thirteen compounds were selected: benzene, toluene, styrene, naphthalene, furfural, furan, isoprene, 2-butenal, phenol, 2-furyl methyl ketone, formaldehyde, acetaldehyde, and acrolein. The study also indicated that incense cone type shows a higher probability of being more pollutant than incense stick type, as from the 12 products tested, four were cone type, and three of them were in the group of the four higher polluters. Benzene and formaldehyde presented worrying levels in the major part of the products, above guideline values established by the WHO. Unfortunately, there are no limit values established for indoor air for all the compounds studied, but this fact should not exempt us from taking action to alert the population to the potential dangers of using those products. From this study, acetaldehyde, acrolein, furfural, and furan emerge as compounds with levels to deserve attention.

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The Improvement of Indoor Air Quality in Residential Buildings in Dubai, UAE

Buildings ◽

10.3390/buildings11060250 ◽

2021 ◽

Vol 11 (6) ◽

pp. 250

Author(s):

Chuloh Jung ◽

Jihad Awad

Keyword(s):

Computer Simulation ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Building Materials ◽

Field Survey ◽

Residential Buildings ◽

Radon Gas ◽

Volatile Organic ◽

Residential Projects

Due to unprecedented urbanization, UAE had built many new residential projects with poor choices of material and ventilation. This social phenomenon is leading UAE to Sick Building Syndrome (SBS) faster than any other countries. The Dubai Municipality regulates the indoor air quality with strict stipulation, but the detailed regulations are still insufficient. The objective of this paper is to measure the indoor air quality of new residential projects in Dubai to suggest the improvement of the regulations for indoor air quality. As a methodology, a field survey was conducted to investigate the status of indoor air pollution in residential buildings. Based on the field survey data, lab experiments for building materials were conducted and a computer simulation on radon gas was conducted. The result had shown that radon gas was mainly detected in new townhouses and labor camp houses, and its concentration was found to exceed the standard. Volatile organic solvents (VOCs) and formaldehyde (CH2O) were mainly detected in showhouses and new townhouses, and the concentration distribution was about 10 times higher than that of outdoors. It was proven that emission concentration of radon gas from various building materials were detected, and the order was red clay, gypsum board, and concrete. Volatile organic solvents (VOCs) are mainly detected in oil paints and PVC floor and the radiation amount of all pollutants increased with temperature increase. In computer simulation, it was found that a new townhouse needs a grace period from 20 days to 6 months to lower the radon gas concentration by 2 pCi/L. This study will serve as a basic data to establish more detailed regulation for the building materials and improve the IAQ standards in Dubai.

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The impact of mechanical ventilation operation strategies on indoor CO2 concentration and air exchange rates in residential buildings

Indoor and Built Environment ◽

10.1177/1420326x20960767 ◽

2020 ◽

pp. 1420326X2096076

Author(s):

Pedro F. Pereira ◽

Nuno M. M. Ramos

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Exchange Rates ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Ventilation Strategy ◽

The Impact ◽

Mechanical Extraction ◽

Air Exchange

In Portugal, residential buildings commonly have their ventilation strategy changed after commissioning. This occurs due to the building managers' willingness to reduce shared costs with the electricity needed for fan operation. However, this option is not technically supported, and the effects of such a strategy on indoor air quality-related to human pollutants are yet to be quantified. CO2 was monitored in 15 bedrooms and air exchange rates were calculated for each room. The air exchange rate values ranged from 0.18 to 0.53 h−1 when mechanical extraction ventilation was off, and from 0.45 to 0.90 h−1 when mechanical extraction ventilation was on, which represents an average increase of 119%. With the current intermittent ventilation strategy, all rooms remain above 1500 ppm for a given percentage of time, and 12 rooms presenting CO2 concentrations above 2000 ppm. Simulations of theoretical CO2 concentrations, for a non-interrupted mechanical ventilation strategy show that no rooms would accumulate CO2 concentrations above 2000 ppm, and only 25% would present CO2 concentrations above 1500 ppm. Pearson correlations between the monitored CO2 and human and spatial factors identified two relevant parameters. Those parameters correspond to ratios between CO2 generation and floor area ([Formula: see text]), and airflow with CO2 generation ([Formula: see text]). The proposed ratios could be used as ways to optimise ventilation costs and indoor air quality.

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Comparison of the indoor air quality in an office operating with natural or mechanical ventilation using short-term intensive pollutant monitoring

Indoor and Built Environment ◽

10.1177/1420326x14530999 ◽

2014 ◽

Vol 24 (6) ◽

pp. 777-787 ◽

Cited By ~ 7

Author(s):

James F. Montgomery ◽

Stefan Storey ◽

Karen Bartlett

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Short Term

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Indoor air quality in low energy residential buildings in Lithuania

Building and Environment ◽

10.1016/j.buildenv.2016.08.018 ◽

2016 ◽

Vol 108 ◽

pp. 63-72 ◽

Cited By ~ 31

Author(s):

Violeta Kaunelienė ◽

Tadas Prasauskas ◽

Edvinas Krugly ◽

Inga Stasiulaitienė ◽

Darius Čiužas ◽

...

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Low Energy

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Study on Indoor Air Quality of Residential Buildings in the Severe Cold Regions of Northeastern China in Winter

Environmental Science and Engineering - Proceedings of the 11th International Symposium on Heating, Ventilation and Air Conditioning (ISHVAC 2019) ◽

10.1007/978-981-13-9520-8_92 ◽

2020 ◽

pp. 897-904

Author(s):

Kailiang Huang ◽

Jiasen Song ◽

Guohui Feng ◽

Qunpeng Chang ◽

Jun Wang ◽

...

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Northeastern China ◽

Cold Regions

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Investigation of window-opening behaviour and indoor air quality in dwellings situated in the temperate zone in China

Indoor and Built Environment ◽

10.1177/1420326x20924746 ◽

2020 ◽

pp. 1420326X2092474

Author(s):

Tingxuan Deng ◽

Xiong Shen ◽

Xiaojie Cheng ◽

Junjie Liu

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Temperate Zone ◽

World Health ◽

Formaldehyde Concentration ◽

Short Term ◽

Night Time ◽

Window Opening

Indoor air quality (IAQ) is a key factor that could affect the indoor environment and people's health. In this study, we report a comprehensive study on IAQ in 30 dwellings in the temperate zone in China. Thirty naturally ventilated dwellings were selected in the urban area of Kunming, which is the largest city in temperate zone in China. In four seasons, short-term measurement of formaldehyde and benzene, toluene, xylenes-volatile organic compounds and air infiltration rate were conducted in these dwellings. A long-term 1-year monitoring of temperature, relative humidity, fine particulate matter (PM2.5), carbon dioxide (CO2), window-opening behaviour and night-time air change rate (ACR) were conducted in 13 of these dwellings by remote sensors. Short-term measurements showed the mean formaldehyde concentration in summer (100.76 μg/m3), benzene concentration in winter (8.46 µg/m3), PM2.5 concentration (80.4 µg/m3) in spring of 2017 exceeded the Chinese standard, the US Office of Environmental Health Hazard Assessment value and the World Health Organization guidelines. The night-time ACR was the highest in summer (2.1 h−1) and the lowest in winter (1.6 h−1) in bedrooms of 13 long-term monitored dwellings due to seasonal time variation in window opening in bedrooms, which was mainly driven by CO2 concentration, indoor temperature and outdoor PM10 concentration.

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Evaluation of Effects of the Humidity Level-Based Auto-Controlled Centralized Exhaust Ventilation Systems on Thermal Comfort of Multi-Family Residential Buildings in South Korea

Sustainability ◽

10.3390/su11174791 ◽

2019 ◽

Vol 11 (17) ◽

pp. 4791

Author(s):

Kwag ◽

Park ◽

Kim ◽

Kim

Keyword(s):

Air Quality ◽

South Korea ◽

Thermal Comfort ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Humidity Level ◽

Exhaust Ventilation ◽

Air Tightness ◽

Ventilation Systems

Building air-tightness has been increased to make energy efficient buildings. However, various indoor air quality issues can be caused by high building air-tightness because it allows low air and moisture transmission through building envelop. In order to solve and prevent these issues, mechanical ventilation systems can be used to control the indoor humidity level. The purpose of this paper is to evaluate the performances of the Relative Humidity (RH)-sensor based auto-controlled centralized exhaust ventilation systems to manage indoor air quality and thermal comfort of multi-family residential buildings in South Korea. A series of field tests were performed for different target zones and for various moisture source scenarios. As a result, it was found that the auto-controlled centralized exhaust ventilation systems were able to control indoor air quality and to maintain the zones thermal comfort faster than the baseline cases that did not operate exhaust vents. The results presented in this paper can show the potential and the feasibility of the auto-controlled centralized exhaust ventilation systems for multi-family residential buildings in South Korea. It is expected that the results presented in this paper would be useful for building owners, engineers, and architects when designing building systems.

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