Apartment Room Research Articles

Relationship between natural ventilation modes and indoor/outdoor ratio of Japanese cedar pollen and Cry j 1 allergen

Japanese cedar pollen and its Cry j 1 allergen are major drivers of hay fever in Japan. This study conducted field measurements in an apartment room in Tokyo (Japan) to investigate the effect of indoor air changes per hour (ACH) on the indoor/outdoor (I/O) ratio of Japanese cedar pollen and Cry j 1 at different locations, as well as the variation in Cry j 1 particle size under four opening modes of the balcony door and window. A total of 220 pollen and 484 allergen samples were analyzed. Japanese cedar pollen and Cry j 1 allergens were present even when all doors and windows were closed. The I/O ratio of the Cry j 1 allergen tended to decrease with increasing ACH, and Cry j 1 particles ≤7 μm in diameter were commonly recorded. This study elaborates on the indoor–outdoor transportation dynamics of Japanese cedar pollen and Cry j 1 allergen in a conventional domestic setting and identifies potential areas for improvement in indoor allergen detection and filtering methods.

Experimental study of active noise control for a full-scale plenum window in a domestic apartment

Plenum windows, also known as ventilation windows, allow for natural ventilation in living spaces while providing noise reduction to improve the health and living comfort of occupants, especially in noise-polluted and tropical/sub-tropical cities. However, while plenum windows can provide acceptable levels of natural ventilation, the passive noise performance of plenum windows when fully opened is still lacking as compared to the conventional closed windows- especially in the low frequencies experimentally. Active noise control (ANC) has shown good performance in several applications for low-frequency control. Thus, the application of ANC using a single-channel and decentralized dual-channel ANC implementation, informed by prior simulation studies is developed and field tested for a plenum window in a domestic setting built to reproduce the environment of a high-rise apartment. The experiments show that the average global attenuation benefit in the apartment room due to a single-channel ANC is 2.9 dB in the 100 Hz – 500 Hz range while the decentralized dual-channel ANC provides up to an average of 4.8 dB reduction in the 100 Hz – 500 Hz range or an average reduction of 3.8 dB in the 100 Hz – 800 Hz range. The decentralized dual-channel ANC is also tested under different noise types and is effective in low-frequency control. Furthermore, the dual-channel ANC remains robust even with an additional mechanical ventilation system operating inside the plenum window, improving the natural ventilation.

Heat Loss Optimization of a Building with Different Window to Wall Area Ratios

Abstract The types of glass and exterior walls and the window-to-wall ratio (WWR) on building façades play a major role in heat losses that occur in every type of building, residential or commercial. The opaque and transparent surfaces of buildings have an important role in terms of both energy losses and energy gains. Windows are the parts of the building envelope where heat losses mostly occur. As the WWR increases on the façades of a building, heat losses increase, but heat gains from solar energy also increase, which assists in free heating of the building. In this study, a detached residential building located in Antalya, Turkey, a province with hot–humid climatic conditions, has been examined. A series of simulations were carried out to detect the effects of WWRs and different glass, frame, and exterior wall types on heat losses of the building. The heat loss values obtained from these simulations were processed by using a special mechanical installation calculation software. Simulations were performed for apartment rooms with levels of WWR ranging from 30 to 60 % of the wall areas facing the façade. In order to minimize heat loss, double-pane glass (or double-glazed glass) was used instead of single-pane glass. The aim of this study was to find the optimum value in terms of applicability and economy. The optimum value was calculated by minimization according to both the linear graphical method and the dual simplex optimization method. The values found in both methods were compared and interpreted. It is believed that the optimized glass, frame, joinery, and exterior wall parameters, which are influential to the energy performance of the building, will make a positive contribution to the architectural design phase in addition to improving the energy efficiency of existing buildings.

Temporal Variation of Indoor (a residential space) and Outdoor PM2.5 in Male’, Maldives

This study aims to assess the Indoor Air Quality (IAQ) inside a one room apartment of about 240 square feet in the Henveiru district in Male’, Maldives. Concentrations of Particulate Matter (PM2.5), one of the most detrimental air pollutants, were measured every 15 minutes from 10-09-2021 to 18-12-2021 using low-cost PM BlueSky sensors inside the building (indoor) and simultaneously outdoor, about 300m away from the indoor sensor. The BlueSky monitors were co-located and harmonized before starting the monitoring. The mean concentrations observed indoor and outdoor for 93 days were 10.1±13.1 µg/m3 and 6.5±4.9 µg/m3, respectively. Both results surpass the annual average of 5 µg/m3 guideline of World Health Organization (WHO). The number of days that surpassed the 24-hour WHO limit was 9 for indoor and 7 for outdoors. The diurnal pattern of PM2.5 shows a drastic accumulation of the pollutant inside the building when the only available ventilation (the window) was closed, which was identified at night and also during the daytime. The recorded PM2.5 levels also aligned with household activities like cooking, cleaning, and dusting. There was a significant moderate correlation (r= 0.48) between outdoor and indoor PM2.5. The I/O ratio was 1.95±3.01 indicating the presence of more indoor sources. This study serves as a preliminary assessment of indoor air quality in Male’, Maldives. Based on its findings, efforts should be directed towards ensuring proper ventilation in residential spaces and continuously monitoring air quality in more location for longer periods to ensure healthy IAQ.

Planning of distribution system considering residential roof top photovoltaic systems, distributed generations and shunt capacitors using gravitational search algorithm

In this paper a Gravitational Search Algorithm (GSA) based multiobjective approach is proposed for optimum sizing and allocation of distributed generations (DGs) and shunt capacitors (SCs) for distribution systems integrated with roof top photo voltaic systems (PV). The capacity of roof top Solar PV systems is designed based on the basic energy consumption requirements of a two-bed room apartment. A normalized multiobjective function is formulated considering the objectives of minimizing substation real power, reactive power, real power loss minimization and voltage profile improvement. The optimum DGs and SCs for three seasons summer, rainy and winter are obtained using GSA by minimizing the multiobjective function to reduce the burden on the substation and simultaneously improving the distribution system performance. A practical 52-bus, 11 kV rural radial distribution system is used to demonstrate the simulation results to show the advantage of the proposed methodology in improving the distribution system performance.

Improving Indoor Occupancy Detection Accuracy of the SLEEPIR Sensor Using LSTM Models

We recently developed a synchronized low energy electronically chopped passive infrared (SLEEPIR) sensor node to detect stationary and moving occupants. It uses a liquid crystal shutter to modulate the infrared signal received by a traditional passive infrared (PIR) sensor and thus enables its capability to detect stationary occupants. However, the detection accuracy of the SLEEPIR sensor can be easily influenced by infrared environmental disturbances. To address this problem, in this paper, we propose two Long Short-Term Memory (LSTM) models to filter infrared environmental disturbance, named baseline LSTM (Base.LSTM) and statistical LSTM (Stat.LSTM). They use the sensor node raw output and statistical features as their respective input. For comparison, we propose two other models: the occupancy state switch detection (SSD) algorithm that directly uses a predetermined threshold voltage value to classify the occupancy state and its status change; and the multi-layer perception (MLP) classifier with statistical feature inputs (Stat.ML). To validate their detection performance, we designed two testing scenarios in different environment settings: (i) Daily occupancy tests and (ii) EDGE case tests. The first scenario intends to restore complex real-life environmental situations as much as possible in the lab and apartment rooms. The second scenario aims to verify their detection accuracy under different environmental temperatures. This scenario also considers different occupancy postures, such as lying down. Experimental results show that the detection accuracy of both LSTM models (> 95%) in both testing scenarios outperforms that of the SSD (around 82% to 94%) and the Stat.ML(around 80% to 90%).

Poverty Status of Madagali and Michika Farm Families of Adamawa State Nigeria: Aftermath of Boko Haram Insurgency

The study analyzed the effect multidimensional poverty of farm families in Madagali and Michika local government areas of Adamawa State, Nigeria after the Boko Haram Insurgncy of 2014. Specifically, the study described the socio-economic characteristics of the farm families and examined the multidimensional poverty status of the farm families in the study area. Multistage and simple random sampling techniques were employed in drawing 100 respondents from various communities. Data were analyzed using descriptive statistics and Foster-Greer-Thorbecke (FGT) poverty indices. Results showed that majority (57.58%) of the farm families were females, 47.89% were aged between 20 to 29 years, 79.8% were married, 55.56% had SSCE/GCE/Teachers Grade ii, 69.47% had farming as primary occupation, 33.33% had trading as secondary occupation, 61.46% had between N1100 – 10000 as income from primary source, 56.47% had between N1100 – N10000 as income from secondary source, 95% of the respondents owned land, 91.92% owned house. Majority (48.96%) of the respondents roofed their houses with thatch while 61.22% had mud as the wall material of their house. Majority (89.55%) of the respondents used firewood as cooking fuel, 49.47% leaved in a single room apartment, 63.53% had borehole as main source of drinking water, 46.24% used uncovered pit latrine and 71% of the household leaved without electricity. Monthly income of respondents, farm size and age of household head were the determinants of food security in the study area. The Foster-Greer-Thorbecke (FGT) headcount ratio/poverty incidence (α = 0) was 0.78. The study analyzed that there were cases striking multidimensional poverty issues in the study area which call for immediate government intervention in the study area.

Can you really put a price on a good night's sleep?

This article focuses on estimation of willingness of people to pay extra price for increased sound insulation quality. As a case study a typical 3 room apartment in Bratislava was chosen. Online listening tests were used as a tool to understand the preferred price-quality ratio. The primary financial value of a case study apartment was estimated on real estate market in the third quarter of 2020. Later, nine (9) different variants of sound insulation of partition walls separating dwellings were considered. These walls were chosen on basis of different construction system (1) heavy weight brick walls, (1) light-weight gypsum board walls and (2) double walls. Each construction base was divided into three categories of defined by weighed sound transmission index Rw (53 dB, 55 dB and 59 dB). The four types of sounds (pink noise, cough, quarrel, party noise) were filtered through the frequency spectra R(dB) of chosen walls. These sounds were presented during the online listening test along with a total price for the particular apartment. The test subjects were asked to decide, which apartment they would choose based on an increased acoustic comfort and increased price of the apartment. In total, 60 subjects performed the test.

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Effects of building height on the sound transmission in cross-laminated timber buildings – Airborne sound insulation

Buildings constructed with cross-laminated timber (CLT) are increasing in interest in several countries. Since CLT is a sustainable product, it can help the building industry to reduce greenhouse gas emissions. Furthermore, buildings constructed with CLT are increasing in building height, thereby increasing the load on the junctions and structural building elements further down in the building. Several studies have investigated how the load impacts the sound transmission between apartments. The majority found that an increasing load could have a negative effect on the vertical sound insulation. However, the findings are limited to a few measurements or building elements, and the studies only investigate junctions with resilient interlayers. This article aims to investigate if the building height, and thereby the load, affect the vertical airborne sound insulation between apartments on different stories in different cross-laminated timber buildings, with or without the presence of viscoelastic interlayers, and to quantify the effect. Four CLT buildings with different building systems, building heights, and the presence of viscoelastic interlayers in the junctions were measured. The airborne sound insulation between different apartment rooms was measured vertically for stories on the lower and higher levels. The difference in airborne sound insulation was calculated separately for each building, and the measurements indicate that the vertical airborne sound insulation reduces further down in the buildings. Therefore, results show that increasing load, by an increasing number of stories, has a negative effect on the vertical airborne sound insulation.

Adaptive Control of Energy Storage Systems for Real-Time Power Mediation Based on Energy on Demand System

The concept of i-Energy as a new smart demand-side energy management system is proposed, which can realize the versatile and efficient control of e-power flows between distributed generators, numerous appliances, and energy storage systems in the home domain, factories, offices, and local communities. The Energy on Demand (EoD) system is proposed, which is the automatic power control and management system that supplies power to home appliances based on the power demand requests issued from the home appliances. The EoD system can guarantee the reduction in total power consumption by implementing a ceiling control while keeping the quality of life (QoL) of the home user considering the limitation of power supply. This paper proposes an adaptive battery storage management and control method based on the EoD system, which we call the “storage-supported EoD system”. In particular, the storage-supported EoD system can handle multiple power generators, including storage batteries. The overall goals of this paper are not limited to the extension of multiple power supplies only; rather, it provides additional contributions, which are (i) extend the existing power consumption control of home appliances and peak demand shift control (i.e., EoD system) by adding a second power source, i.e., a storage battery system; (ii) propose adaptive storage system design and management for the EoD system; (iii) realize minimum storage capacity for large peak power consumption; and (iv) minimize the home user’s discomfort level due to the limited power supply of one power source. The simulation results have shown the effectiveness of the proposed algorithm with a couple of experiments using real-life data in the smart apartment room. Additionally, simulation results are presented to compare and evaluate the proposed system performance with the EoD system.

The Effect of Architectural Area Standards on Living Room’s Spatial Functional efficiency for Low- Prize Residential Complexes in Sulaymaniyah City

Generally, residential building standards cover numerous aspects or phases of the building process. Instances are planning standards, design standards, space standards, and technical building standards. This study concentrates on space standards and their effect on the functionality of low-income family housing interior spaces in low-rise residential complexes in Sulaimani. This addresses the minimum area standards of living-dining spaces as one of the most significant indicators of architectural space standards and its consideration for achieving the spatial functionality of interior spaces in low-income residential complexes in Sulaimani. This research seeks to determine how spatial standards affect the functionality of living-dining areas. The first hypothesis is that architectural area standards consideration has a significant impact on the achievement of primary functions in the living-dining rooms of low-rise apartments designed for low-income families in Sulaimani city. The second hypothesis is that architectural area standards achievement has a significant impact on the achievement of secondary functions in the living-dining room of low-rise apartments designed for low-income families in Sulaimani city. Appearance of practically inefficient living-dining areas in the low-rise apartments of Sulaimani's residential complexes is a prominent problem. The particular problem is the lack of some of these primary and secondary functions in the Living-dining room 's inner spaces of low-rise apartments in Sulaimani. This research realized that there are the significant effect of spatial standards considerations and functionality achievements. Also addressed the positive relationship between architectural spatial standards consideration and primary-secondary functionality achievements.

EFFECTS OF AIRCRAFT NOISE ON RESIDENTIAL PROPERTIES RENTAL VALUE AROUND MAIDUGURI INTERNATIONAL AIRPORT, BORNO STATE, NIGERIA

This study examined the effects of aircraft noise on residential properties rental value around Maiduguri International Airport Area in Borno State. The data was collected through the administration of 363 structured questionnaire to selected household heads residing in the neighbourhoods around the airport. It utilized mean ranking, the simple regression analysis toanalyze the data collected. The result of the simple regression analysis revealed that aircraft noise negatively influences residential property value around the airport and that aircraft noise does not really depreciate residential property rental value, the noise level for the day-eveningnight time depends on frequency of flights as well as distance from the airport and the time of the day and also showed that rental values of residential properties in the study area fall within the range of 50,000 Naira and below for one room apartment. The study also found that tenants are willing to stay in the neighbourhood due to the presence of Air Force Base (security personnel) in the area. The study therefore recommends among other things, that investors and propertydevelopers embarking on property development should take into account the effects of noise on rental value of residential property to avoid wasting of funds in such ventures, also upgrading of the sound insulation of buildings will be a useful technique for reducing the negative impacts of aircraft noise to enhance the quality of urban life of residents. Government through urbandevelopment board should ensure the enforcement of land use and physical planning laws to mitigate and minimize the negative impacts of airport noise in the airport areas.

Solar Chimneys as an Effective Ventilation Strategy in Multi-Storey Public Housing in the Post-COVID-19 Era

This paper studies the effectiveness of a solar chimney for improving ventilation and air-exchange rates in multi-storey public housing in tropical climates for the potential mitigation of airborne disease transmission. Virtual models of a typical apartment room with natural cross-ventilation, replicated across four levels to mimic a multi-storey block, were set up with six internal wind velocity sensor points per floor. The simulation software Energy2D was then used to evaluate the performance of the models, first testing the presence of a solar chimney, and then additionally the degree to which the solar chimney model was affected by a complementary ceiling fan. Wind velocity was also measured, as this is a variable that affects ACH rates. Using a non-parametric Wilcoxon signed-rank test, the introduction of a solar chimney was found to have a significant impact on air-flow rates (a variable that positively affects air-exchange rates), resulting in a p-value of 0.000 and Z-value of −3.920. Regression analysis determined that the solar chimney’s effect was enhanced when complemented by a ceiling fan (R-squared value of 0.4687). Consequently, we propose several design strategies that may enable the adoption of the solar chimney concept to improve natural ventilation in residential units.

Automated Layout Design Approach of Floor Tiles: Based on Building Information Modeling (BIM) via Parametric Design (PD) Platform

Building Information Modelling (BIM) technology has been widely used in the construction industry in recent years. However, to date, it still cannot sufficiently meet the requirements of construction practitioners in terms of the layout design of floor tiles. Recently, the BIM-based Parametric Design (PD) platform has presented considerable potential in automatically generating and optimizing floor tile layout design. In this paper, we propose a workflow to generate and optimize the layout design of floor tiles globally. To develop the workflow, we first formalize the design algorithm of floor tiles according to the trade know-how cutting and planning rules. Then, we combine the design algorithm with an evolutionary algorithm (EA) to generate and optimize the layout design for floor tiles automatically while minimizing material wastage. A prototype system is established in the ArchiCAD (BIM) and Grasshopper (PD platform) software. An apartment room tiling layout is used to demonstrate the feasibility and effectiveness of the proposed approach. Compared with the existing design methods, the proposed approach (1) reduces the material waste rate by 14.58% and 11.46%; and (2) improves the calculation efficiency and reduces the required computation time by 17.3 s to 50.0 s. Moreover, this research improves the existing design algorithm, enabling the BIM- and PD-based approaches to be used reliably in optimizing floor tile planning with arc-shaped boundaries. The outcomes are summarized in order to provide valuable insights in terms of floor tile waste reduction for further sustainable construction practice.

Numerical Analysis of the Effect of Afterburning on Damage to the Concrete Structure Under Interior Explosion

A numerical simulation was performed to analyze how afterburning affects damage to a concrete structure when an explosive detonates inside a room. TNT was used as the explosive for the interior explosion. A reduced scale structure of a Korean apartment room was constructed with reinforced concrete and used as the target room for this research. Interior explosion experiments were performed using TNT 2 kg and TNT 3 kg explosives, to obtain data to verify and calibrate the numerical model. The numerical model was constructed to precisely simulate these interior explosions, especially considering the effect of afterburning, which is a significant phenomenon in enclosed spaces. Numerical simulations were performed with and without the effect of afterburning, and compared with the experiment results. The results showed that the numerical model could well simulate the effects of afterburning in an interior explosion, and that afterburning effects must be considered to more accurately analyze the damage to concrete structures.

Natural Ventilation Optimization Study in Mechanically Ventilated Studio Apartment Room in Surabaya

After Covid-19, residential has become the main space for every activity, including work, education, and leisure. Therefore, comfort in residential space is crucial to the occupant. As researchers have found traces, that the virus is airborne, the air quality in the residence must be highlighted, especially for people who live in a centralized cooling system residence. When the cooling system is well maintained, there is no significant risk of viral transmission, but not all residential building has HEPA-filters, nor a well-maintained system. This research focuses on the studio room apartment unit, as it has the smallest opening area compared to other room types. A small one-sided opening is not ideal for the wind to move throughout the room. A few design suggestion is simulated under three air-flow speed, to prove that natural ventilation is possible to be adapted, to reach comfort while minimizing the risk of viral transmission. The result is, the indoor wind speed can be enhanced the most at the overall unit area by modifying the fixed window to an operable window, giving upper horizontal opening in the wall across the existing opening, and using gauze doors on both door openings. The furniture layout is proved to affect wind distribution in the room. This research can also serve as an alternative strategy to optimize the use of natural ventilation to decrease energy use for cooling in the tropic area, after the pandemic. © 2021 Tamkang University. All rights reserved.

Reliability of water fittings in operating conditions

Water fittings are an integral part of the internal water supply system. The reliability of their work under operating conditions largely influence on the continuity of water supply to the population. The reliability indicators of sanitary fittings allow the services responsible for the technical condition of the indoor water supply of houses to pay priority attention to the factors that determine the uninterrupted water supply of the population and reduce the loss of drinking water. In this study, the results of indicators of operational reliability of faucets for sinks in kitchens and washbasins in toilet rooms of apartments of multi-store residential buildings in a residential neighborhood are presented. The study was performed based on the analysis of records in the logs of data on valve failures for 2016-2018. The main malfunctions are established, the random coincidence of which leads to failures. The reliability of sanitary fittings is affected not only by their structure and the characteristics of the materials, as well as by the exploitation conditions. The probability of failure-free operation of sanitary fittings in exploitation conditions for a time not exceeding the duration of the reduction of water supply to consumers in residential buildings is the basic parameter of its reliability.

Active Control of Low-Frequency Noise through a Single Top-Hung Window in a Full-Sized Room

The push for greater urban sustainability has increased the urgency of the search for noise mitigation solutions that allow for natural ventilation into buildings. Although a viable active noise control (ANC) solution with up to 10 dB of global attenuation between 100 Hz and 1000 Hz was previously developed for an open window, it had limited low-frequency performance below 300 Hz, owing to the small loudspeakers used. To improve the low-frequency attenuation, four passive radiator-based speakers were affixed around the opening of a top-hung ventilation window. The active control performance between 100 Hz and 700 Hz on a single top-hung window in a full-sized mock-up apartment room was examined. Active attenuation came close to the performance of the passive insulation provided by fully closing the window for expressway traffic and motorbike passing noise types. For a jet aircraft flyby, the performance of active attenuation with the window fully opened was similar to that of passive insulation with fully closed windows. In the case of low-frequency compressor noise, active attenuation’s performance was significantly better than the passive insulation. Overall, between 8 dB and 12 dB of active attenuation was achieved directly in front of the window opening, and up to 10.5 dB of attenuation was achieved across the entire room.

Analysis of Effects of House Rodents among Farmers in Jos North Local Government Area of Plateau State, Nigeria

The study analyzed the effects of house rodents among farmers in Jos North Local Government Area of Plateau State, Nigeria. Data were collected from primary source through the administration of structured questionnaire on 190 farmers' selected using a purposive random sampling technique. Data were analyzed using descriptive statistics and Logit regression. Results revealed that females were 66.3%, 61.6% aged 20-30 years, 51.1% were married, 47.7% had the household size of 6-10 people, 53.3% had an estimated annual income of < ₦100,000.0. The results further indicated that 46.3% were civil servants, 49.5% occupied 4 rooms apartment, 84.2% furniture was destroyed, 76.3% used rodent glue pad for control, inconveniences ( = 3.04) was one of the major factors that influenced the method used for control of rodents and lack of finance ( = 3.15) was one of the major constraints faced in controlling house rodents. The results of Logit regression showed that sex (4.216) and major occupation (3.328) positively and significantly influenced the choice of method used for control at p < 0.005 and p < 0.010. It is recommended that public enlightenment on proper sanitation and methods of control should be carried out regularly to reduce the menace.