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 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.

scholarly journals FACTORS AFFECTING VENTILATION, INDOOR-AIR QUALITY AND ACOUSTICAL QUALITY IN ‘GREEN’ AND NON-‘GREEN’ BUILDINGS: A PILOT STUDY

2011 ◽  
Vol 6 (3) ◽  
pp. 168-180 ◽  
Author(s):  
Alireza Khaleghi ◽  
Karen Bartlett ◽  
Murray Hodgson
Keyword(s):  
Mechanical Ventilation ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Sound Pressure ◽  
Low Frequency ◽  
Green Buildings ◽  
Noise Levels ◽  
Ventilation Rates

This paper discusses a pilot project involving the direct monitoring of ventilation, indoor-air quality and the acoustical conditions in selected nominally ‘green’ and non-‘green’ buildings located on a university campus. The objectives were to measure parameters quantifying these three aspects of indoor environmental quality, determine the relationships between them and the building-design concepts, and evaluate the implications of the results for ventilation-system design, especially in ‘green’ buildings. Measurements were made in rooms, with and without acoustical treatment, in buildings with natural ventilation or mechanical (displacement and/or mixed-flow) ventilation systems. Measurements were made of ventilation rates (air changes per hour), indoor air quality (respirable-fibre, total-VOC and ultrafine-particulate concentrations), and the acoustical conditions (noise levels and reverberation times). Correlations between the environmental results, the building concept, the ventilation concept and the building window status were explored. In rooms with natural ventilation, low-frequency noise and total sound-pressure levels were lower; however, the rooms had higher ultrafine-particulate counts and lower ventilation rates. Rooms with mechanical ventilation had higher low-frequency and total sound-pressure levels, higher ventilation rates and fibre concentrations, but lower concentrations of ultrafine particulates. It was concluded that, in general, mechanical ventilation can provide better indoor air-quality, but that HVAC noise is an issue if the system is not properly designed. In ‘green’ buildings, noise levels were acceptable when the windows were closed, but increasing the ventilation rate by opening the windows resulted in higher noise levels. The results suggest that the acceptability of environmental factors in buildings depends on the degree of compliance of the design and its implementation with standards and design guidelines (i.e. for ventilation, air quality, thermal comfort, etc.), whether the original design concept is ‘green’ or non-‘green’.

Analysis of Thermal Comfort and Air Quality in the Kindergarten Hart - A Case Study of a Unique Sustainable Building Design

2019 ◽  
Vol 887 ◽  
pp. 500-507
Author(s):  
Matthias Schuss ◽  
Mahnameh Taheri ◽  
Ulrich Pont ◽  
Ardeshir Mahdavi
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Environmental Conditions ◽  
Natural Ventilation ◽  
Building Design ◽  
Present Contribution ◽  
Ongoing Research ◽  
Indoor And Outdoor

The present contribution, reports on the results of ongoing research efforts on performance assessment of a number of buildings designed by the Austrian architect, Konrad Frey. He is a pioneer of energy-efficient architecture, and his designs, those dating back to the 1970s, adapted the principles of modern solar houses. The current study focuses on the Kindergarten Hart, which was especially designed focusing on the availability of cross ventilation option in building. For the purpose of analyzing thermal comfort, indoor air quality, and the occupants’ adaptive actions with respect to natural ventilation, we conducted long-term monitoring under summer and winter conditions. The monitoring efforts covered indoor and outdoor environmental conditions, as well as the state of windows. Thereby, study of the monitored dataset provides a better understanding of the building performance. Moreover, it makes it possible to examine whether the architect’s expectations in terms of thermal comfort and indoor air quality levels are fulfilled or not. In addition, investigation of the occupants’ interactions with windows, together with indoor and outdoor environmental conditions, assists understanding of possible associations between the window opening/closing and environmental parameters, as well as potential optimization of the control-oriented actions.

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 Buildings using CFD: A Brief Review

2019 ◽  
Vol 4 (5) ◽  
pp. 1154-1168 ◽  
Author(s):  
Venu Shree ◽  
Bhanu M. Marwaha ◽  
Pamita Awasthi
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Environment ◽  
Indoor Air Pollution ◽  
Computational Studies ◽  
Being There ◽  
The Impact ◽  
Living Being ◽  
Indoor And Outdoor

The building provides shelter to live and most people spend their 85-90% time indoors. Therefore, it is quite important to ensure that the condition of the indoor environment is healthy for its living being. There are a number of methods to evaluate indoor air pollution of built spaces by performing experiments or doing it computationally. In this study, a review of computational studies carried out to evaluate the impact of different parameters like airflow pattern, indoor and outdoor contaminant concentrations etc., on indoor air quality (IAQ) of different type of buildings was done. Some commonly used software’s for the study of IAQ were also discussed.

Modelling the impact of multizone airleakage on ventilation performance and indoor air quality in low-energy homes

2019 ◽  
Vol 12 (6) ◽  
pp. 1141-1159
Author(s):  
Gaëlle Guyot ◽  
Hugo Geoffroy ◽  
Michel Ondarts ◽  
Léna Migne ◽  
Mallory Bobee ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Low Energy ◽  
Ventilation Performance ◽  
The Impact

scholarly journals Application of Wind as a Renewable Energy Source for Passive Cooling through Windcatchers Integrated with Wing Walls

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2536 ◽  
Author(s):  
Payam Nejat ◽  
Fatemeh Jomehzadeh ◽  
Hasanen Hussen ◽  
John Calautit ◽  
Muhd Abd Majid
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Passive Cooling ◽  
Quality Factors ◽  
Ventilation Performance ◽  
Wing Walls ◽  
The Impact ◽  
Ventilation Systems

Generally, two-third of a building’s energy is consumed by heating, ventilation and air-conditioning systems. One green alternative for conventional air conditioner systems is the implementation of passive cooling. Wing walls and windcatchers are two prominent passive cooling techniques which use wind as a renewable resource for cooling. However, in low wind speed regions and climates, the utilization of natural ventilation systems is accompanied by serious uncertainties. The performance of ventilation systems can be potentially enhanced by integrating windcatchers with wing walls. Since previous studies have not considered this integration, in the first part of this research the effect of this integration on the ventilation performance was assessed and the optimum angle was revealed. However, there is still gap of this combination; thus, in the second part, the impact of wing wall length on the indoor air quality factors was evaluated. This research implemented a Computational Fluid Dynamics (CFD) method to address the gap. The CFD simulation was successfully validated with experimental data from wind tunnel tests related to the previous part. Ten different lengths from 10 cm to 100 cm were analyzed and it was found that the increase in wing wall length leads to a gradual reduction in ventilation performance. Hence, the length does not have a considerable influence on the indoor air quality factors. However, the best performance was seen in 10 cm, that could provide 0.8 m/s for supply air velocity, 790 L/s for air flow rate, 39.5 1/h for air change rate, 107 s for mean age of air and 92% for air change effectiveness.

The impact of design ventilation rates on the indoor air quality in residential buildings: An Italian case study

2016 ◽  
Vol 26 (10) ◽  
pp. 1397-1419 ◽  
Author(s):  
Roberta Moschetti ◽  
Salvatore Carlucci
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Residential Buildings ◽  
Ventilation System ◽  
Residential Building ◽  
Limit Values ◽  
Italian Case ◽  
Ventilation Rates ◽  
The Impact

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.

Sign in / Sign up

Export Citation Format

Share Document