scholarly journals Occupants’ Interaction With an Occupant Voting System for Thermal and Indoor Air Quality Feedback – Case Studies in Office Spaces

2021 ◽  
Vol 7 ◽  
Author(s):  
Donya Sheikh Khan ◽  
Jakub Kolarik ◽  
Peter Weitzmann

Occupants can provide valuable feedback on the indoor environmental quality of buildings. Research on occupant voting systems (OVS) has demonstrated that apps or electronic devices can act as viable tools for collecting long-term feedback from occupants. However, previous research has only to a limited extent explored occupants’ interaction with OVS and the impact it might have on the reliability of the collected feedback. The present paper presents three case studies on applying a tangible OVS, denoted TiAQ, to collect feedback on thermal and indoor air quality (IAQ) in office spaces. The main objective of the present study was first to explore occupants’ interaction with TiAQ and their motivation. Second, identifying whether feedback collected with TiAQ could represent occupants’ comfort and discomfort with the thermal environment and IAQ. Thirdly, identifying challenges related to occupants’ interaction with TiAQ that might affect the representativeness of collected feedback. The present study was conducted at three office buildings in up to 7 months and demonstrated that TiAQ was suitable for collecting long-term feedback on occupants’ comfort and discomfort with the thermal environment. On average, one vote was cast per day per occupant. Additionally, in one of the office buildings, 60% of occupants reported to have interacted with TiAQ daily or weekly when, e.g., passing the device going to/from the office spaces. Occupants’ expectations of TiAQ and getting “feedback on feedback” need to be further addressed to identify ways to sustain occupants’ long-term use of the device and reduce “ill-willed” interactions.

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.


Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1481 ◽  
Author(s):  
Michał Piasecki ◽  
Krystyna Kostyrko ◽  
Małgorzata Fedorczak-Cisak ◽  
Katarzyna Nowak

The authors studied the impact of indoor air humidity in the range of 60% to 90% on building user perception in the temperature range of 26 to 28 °C. The research thesis was put forward that the impact of humidity on indoor air quality dissatisfaction of building users in a warm and humid indoor environment is greater than that indicated in thermal comfort models. The presented experiment examined the indoor air quality perception of n = 28 subjects in the test chamber of a nearly zero energy building under ten environmental conditions, together with a thermal comfort assessment. The authors developed an experimental relation for predicting building users’ satisfaction based on the Weber–Fechner law, where the predicted percentage of dissatisfied users (PD) is determined by means of air enthalpy (h), PD = f(h). The obtained results confirmed the sated thesis. Additionally, the intersection points of the experimental function and isotherms resulting from the Fanger model are presented, where the thermal comfort assessment starts to indicate lower user dissatisfaction results than experimental values. The authors recommend the experimental equation for humid air enthalpies in the range of 50 to 90 kJ/kg. The indoor air quality assessment based on the enthalpy value is simple and can be used to determine the overall Indoor Environmental Quality index of a building (IEQindex).


2012 ◽  
Vol 518-523 ◽  
pp. 4435-4438
Author(s):  
Da Hua Jiang ◽  
Zhi Hua Wang ◽  
Fa En Shi ◽  
Ru Shan Ren

It is of great importance to study the impact of the cooking generated contaminants on the indoor air quality in the kitchen since cooking is regarded as the main source of indoor contaminants. This study aims investigate and analysis the indoor air quality of kitchen with using CFD numerical analysis method via the velocity, temperature, humidity CO2 concentration .It is concluded that The temperature distribution are large difference in the kitchen and the maximum value is up to 324K on the work area which near the cooking ,and the CO2 concentration which is close to the stove is 1420ppm,1370ppm, 1470ppm respectively, and it is more than the acceptance criteria (CO2<1000ppm) 42%,37% and 47% respectively. It is serious impact on the staff's physical health.


2015 ◽  
Vol 45 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Ana Mendes ◽  
Ana Luísa Papoila ◽  
Pedro Carreiro-Martins ◽  
Stefano Bonassi ◽  
Iolanda Caires ◽  
...  

Author(s):  
Farhang Tahmasebi ◽  
Yan Wang ◽  
Elizabeth Cooper ◽  
Daniel Godoy Shimizu ◽  
Samuel Stamp ◽  
...  

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.


2020 ◽  
pp. 1420326X2096076
Author(s):  
Pedro F. Pereira ◽  
Nuno M. M. Ramos

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.


Author(s):  
Mohd Saleem ◽  
Mohd Adnan Kausar ◽  
Fahmida Khatoon ◽  
Sadaf Anwar ◽  
Syed Monowar Alam Shahid ◽  
...  

In many aspects of life quality, bio-contaminants and indoor air quality have had catastrophic consequences, including a negative impact on human health with an increased prevalence of allergic respiratory reactions, asthma, and infectious diseases. We aimed to evaluate the quality of indoor air environment and find out the association between human health and indoor air pollution and also to assess the physical health status of a group of Saudi and non-Saudi populations during this pandemic. Also, we aimed to assess the most common health condition or symptoms associated with ventilation. A questionnaire was distributed online to test indoor air quality, ventilation status, common signs and symptoms of any allergy or mental status and their relationship to certain variables. A total of 362 respondents were included. Before living in the current home, flu or Influenza and chapped lips were more prevalent than allergies and chapped lips signs while living in the current home. (12.2% , 10.8% vs. 18.5% , 13.55% before and after respectively) Multiple colds were the second most common symptom (10.2%). Hoarse voice and headaches were the least common symptoms experienced; each constituted 4.4%. During the COVID-19 Pandemic, most respondents wore a facemask, approximately 76.5%; and almost one-third of respondents had bright natural light inside the current home (43.1%). The presence of natural light within the current home was significantly associated with symptoms experienced during living in the current house (p<0.05). Natural sunlight exposure could decrease allergic symptoms and minor health problems associated with poor ventilation and air quality indoors. In current living homes, the majority of respondents never used air purifiers (72.9 percent). In order to get attention from people to enhance the quality and ventilation mechanism of indoor air, special care and awareness of the effects of the use of air purifiers on human health is needed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prince Junior Asilevi ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Bernard Fei-Baffoe ◽  
Yen Adams Sokama-Neuyam

AbstractNon-thermal plasma (NTP) is a promising technology for the improvement of indoor air quality (IAQ) by removing volatile organic compounds (VOCs) through advanced oxidation process (AOP). In this paper, authors developed a laboratory scale dielectric barrier discharge (DBD) reactor which generates atmospheric NTP to study the removal of low-concentration formaldehyde (HCHO), a typical indoor air VOC in the built environment associated with cancer and leukemia, under different processing conditions. Strong ionization NTP was generated between the DBD electrodes by a pulse power zero-voltage switching flyback transformer (ZVS-FBT), which caused ionization of air molecules leading to active species formation to convert HCHO into carbon dioxide (CO2) and water vapor (H2O). The impact of key electrical and physical processing parameters i.e. discharge power (P), initial concentration (Cin), flow rate (F), and relative humidity (RH) which affect the formaldehyde removal efficiency (ɳ) were studied to determine optimum conditions. Results show that, the correlation coefficient (R2) of removal efficiency dependence on the processing parameters follow the order R2 (F) = 0.99 > R2 (RH) = 0.96, > R2 (Cin) = 0.94 > R2 (P) = 0.93. The removal efficiency reached 99% under the optimum conditions of P = 0.6 W, Cin = 0.1 ppm, F = 0.2 m3/h, and RH = 65% with no secondary pollution. The study provided a theoretical and experimental basis for the application of DBD plasma for air purification in the built environment.


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