scholarly journals NATURAL VENTILATION AND INDOOR AIR QUALITY IN MULTI-FAMILY RESIDENTIAL BUILDINGS – AN INDICATION OF THE PROBLEM, CASE STUDY

2021 ◽  
Vol 177 (27) ◽  
pp. 234-241
Author(s):  
Magdalena Stolarska ◽  
◽  
Piotr Lis ◽  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Problem Case

scholarly journals Numerical Assessment of Seven Ventilation Systems for Social Residential Buildings based on Indoor Air Quality and Energy Consumption

2021 ◽  
Vol 2069 (1) ◽  
pp. 012181
Author(s):  
Guillaume Sérafin ◽  
Marc O. Abadie ◽  
Patrice Joubert
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Living Room ◽  
Internal Sources ◽  
Controlled Mechanical Systems ◽  
Ventilation Systems

Abstract This work presents a modelling approach for evaluating ventilation systems for their ability to provide good indoor air quality in dwellings. Infiltration and ventilation rates are defined by the conventional French 3CL-DPE standard. The case study is a two-bedroom apartment with a shared or separate kitchen and living room. Three natural ventilation options and four mechanical ventilation systems are compared with respect to exposure to PM2.5, NO2 and formaldehyde. Pollutant concentration levels are assessed in each room based on a scenario of daily occupancy, average annual outdoor concentrations and internal sources. The daily exposure of the occupants to the targeted substances allows the comparison of ventilation systems on the basis of the ULR-QAI index developed at LaSIE laboratory from La Rochelle University. For this case study, it results that controlled mechanical systems are much more efficient than natural ventilation systems, especially in the case of an open-plan kitchen.

scholarly journals Assessment of Indoor Air Quality in Residential Buildings of New England through Actual Data

2022 ◽  
Vol 14 (2) ◽  
pp. 739
Author(s):  
Fernando del Ama Gonzalo ◽  
Matthew Griffin ◽  
Jacob Laskosky ◽  
Peter Yost ◽  
Roberto Alonso González-Lezcano
Keyword(s):  
Air Quality ◽  
New England ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Quality Data ◽  
Improve Energy Efficiency ◽  
Sick Building ◽  
Concentration Levels

Several studies on indoor air quality (IAQ) and sick building syndromes have been completed over the last decade, especially in cold countries. Efforts to make homes airtight to improve energy efficiency have created buildings with low ventilation rates, resulting in the build-up of indoor pollutants to harmful levels that would be otherwise unacceptable outdoors. This paper analyzed the infiltration rates, indoor temperatures, and variations in CO2, 2.5 μm particulate matter (PM2.5), and total volatile organic compound (TVOC) concentrations over the fall of 2021 in several homes in New England, USA. A relationship between outdoor and indoor conditions and ventilation strategies has been set using the results from blower door tests and actual indoor air quality data. Although all case studies lacked mechanical ventilation devices, such as those required by ASHRAE Standard 62.2, natural ventilation and air leakage have been enough to keep VOCs and PM2.5 concentration levels at acceptable values most of the studied time. However, results revealed that 25% of a specific timeframe, the occupants have been exposed to concentration levels of CO2 above 1000 parts per million (ppm), which are considered potentially hazardous conditions.

scholarly journals Seasonal variations and the influence of ventilation rates on IAQ: A case study of five low-energy London apartments

2021 ◽  
pp. 1420326X2110171
Author(s):  
Samuel Stamp ◽  
Esfand Burman ◽  
Clive Shrubsole ◽  
Lia Chatzidiakou ◽  
Dejan Mumovic ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Seasonal Variations ◽  
Natural Ventilation ◽  
Low Energy ◽  
Ventilation Rates ◽  
The Impact ◽  
Indoor And Outdoor

The indoor air quality (IAQ) of five low-energy London apartments has been assessed through the measurement of 16 key pollutants, using continuous and diffusive methods across heating and non-heating seasons. This case study approach aimed to assess the presence of pollutants within low-energy apartments and to better understand the role of ventilation and seasonal variations in indoor air quality. The results indicate strong seasonal variations, driven by increased natural ventilation rates over the summer monitoring period. A combined metric for indoor and outdoor pollutants ( Itot) suggests that the IAQ in the winter ( Itot = 17.7) is more than twice as bad as that seen in the summer ( Itot = 8.6). Formaldehyde concentrations were lower in the non-heating season, indicating increased ventilation rates more than offset increased off-gassing, in contrast to findings in other studies. However, increased summertime ventilation rates were observed to increase the proportion of outdoor pollutants entering the internal environment. This resulted in higher indoor concentrations of NO2 in the summer than the winter, despite significant reductions in outdoor concentrations. These results demonstrate the impact of ventilation practices upon IAQ, the influence of occupant actions and the complex relationship ventilation rates play in balancing indoor and outdoor sources of air pollution.

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

Buildings ◽  
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.

scholarly journals Window operation behaviour and indoor air quality during lockdown: A monitoring-based simulation-assisted study in London

2021 ◽  
pp. 014362442110177
Author(s):  
Farhang Tahmasebi ◽  
Yan Wang ◽  
Elizabeth Cooper ◽  
Daniel Godoy Shimizu ◽  
Samuel Stamp ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Probabilistic Models ◽  
Performance Model ◽  
Outdoor Environment ◽  
Ventilation Strategies ◽  
The Impact

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application: This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.

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

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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