FIELD MEASUREMENT OF NATURAL VENTILATION SYSTEM DESIGNED IN HOSPITAL BUILDING WITH VOID(Environmental Engineering)

The provision requirement of 10% openings of the total floor area stated in the Uniform Building By-Law 1984 Malaysia is essential for natural lighting and ventilation purposes. However, focusing on natural ventilation, the effectiveness of thermal performance in landed residential buildings has never been empirically measured and proven, as most of the research emphasized simulation modeling lacking sufficient empirical validation. Therefore, this paper drawing on field measurement investigates natural ventilation performance in terraced housing with an air-well system. The key concern as to what extent the current air-well system serving as a ventilator is effective to provide better thermal performance is to be addressed. By adopting an existing single-story air-welled terrace house, indoor environmental conditions and thermal performance were monitored and measured using HOBO U12 air temperature and humidity, the HOBO U12 anemometer, and the Delta Ohm HD32.3 Wet Bulb Globe Temperature meter for a six-month duration. The results show that the air temperature of the air well ranged from 27.48 °C to 30.92 °C, with a mean relative humidity of 72.67% to 79.25%. The mean air temperature for a test room (single-sided ventilation room) ranged from 28.04 °C to 30.92 °C, with a relative humidity of 70.16% to 76.00%. These empirical findings are of importance, offering novel policy insights and suggestions. Since the minimum provision of 10% openings has been revealed to be less effective to provide desirable thermal performance and comfort, mandatory compliance with and the necessity of the bylaw requirement should be revisited.

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Comprehensive validation of experimental and numerical natural ventilation predictions based on field measurement with experimental house

Building and Environment ◽

10.1016/j.buildenv.2021.108433 ◽

2022 ◽

Vol 207 ◽

pp. 108433

Author(s):

Hong Hu ◽

Hideki Kikumoto ◽

Ryozo Ooka ◽

Chao Lin ◽

Bingchao Zhang

Keyword(s):

Field Measurement ◽

Natural Ventilation

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Three-Dimensional Simulation of Wind-Driven Ventilation Through a Windcatcher With Different Inlet Designs

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4045513 ◽

2019 ◽

Vol 12 (4) ◽

Author(s):

Peter Abdo ◽

Rahil Taghipour ◽

B. Phuoc Huynh

Keyword(s):

Wind Speed ◽

Average Velocity ◽

Natural Ventilation ◽

Ventilation System ◽

Three Dimensional ◽

Cfd Modeling ◽

Ansys Fluent ◽

Wind Velocities ◽

Dimensional Simulation ◽

Convergent Inlet

Abstract Windcatcher is an effective natural ventilation system, and its performance depends on several factors including wind speed and wind direction. It provides a comfortable and healthy indoor environment since the introduced fresh air decreases the moisture content and reduces the pollutant concentration. Since the wind speed and its direction are generally unpredictable, it is important to use special inlet forms and exits to increase the efficiency of a windcatcher. In this study, computational fluid dynamics (CFD) modeling is implemented using ansys fluent to investigate the airflow entering a three-dimensional room through a windcatcher with different inlet designs. Three designs are studied which are a uniform inlet, a divergent inlet, and a bulging-convergent inlet. The airflow pattern with all inlets provided adequate ventilation through the room. With all the applied wind velocities (1, 2, 3, and 6 m/s) at the domain's inlet, the divergent inlet shape has captured the highest airflow through the room and provided higher average velocity at 1.2 m high enhancing the thermal comfort where most of the human occupancy occurs. With 6 m/s wind velocity, the divergent inlet has captured 2.55% more flow rate compared to the uniform inlet and 4.70% compared to the bulging-convergent inlet, and it has also provided an average velocity at 1.2 m high in the room of 7.16% higher than the uniform inlet and 8.44% higher than the bulging-convergent inlet.

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In vitro growth of Cattleya nobilior Rchb. f.: culture media, sealing systems and irradiance

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632021v5167131 ◽

2021 ◽

Vol 51 ◽

Author(s):

Kaliana Gottschalk de Freitas ◽

José Carlos Sorgato ◽

Jackeline Schultz Soares ◽

Luan Marlon Ribeiro

Keyword(s):

Plant Height ◽

Natural Ventilation ◽

Culture Medium ◽

Culture Media ◽

Ventilation System ◽

Light Condition ◽

Leaf Length ◽

In Vitro Growth ◽

Randomized Design

ABSTRACT Some factors may influence the in vitro culture of native orchids, especially the culture medium, sealing system and light condition. This study aimed to evaluate the addition of banana pulp and peel in the formulation of culture media, sealing system and irradiance, in the in vitro growth of Cattleya nobilior Rchb. f. A completely randomized design was used in a factorial scheme with five culture media [Murashige & Skoog supplemented or not with banana pulp or peel (100 or 200g L-1)], two light conditions [3,000 K LED lamps (43 µmol m-2 s-1 or 86 µmol m-2 s-1)] and two sealing systems (natural and conventional ventilation), with six replicates of one vial each. The plant height, diameter of the largest pseudobulb, length of the largest root and of the largest leaf, fresh weight and number of leaves, roots and shoots were evaluated. The use of both the banana pulp and peel as additives in the culture medium formulation promoted the C. nobilior growth. The natural ventilation system increased the plant height, pseudobulb diameter and leaf length, while the conventional system promoted tillering.

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An Attempt to Improve Air Quality in Primary Schools

Proccedings of 10th International Conference "Environmental Engineering" ◽

10.3846/enviro.2017.051 ◽

2017 ◽

Cited By ~ 2

Author(s):

Marek Telejko ◽

Ewa Zender-Swiercz

Keyword(s):

Air Quality ◽

Primary School ◽

Indoor Air ◽

Primary Schools ◽

Natural Ventilation ◽

Ventilation System ◽

Co2 Concentration ◽

School Buildings ◽

Maximum Value

Most primary school buildings in Poland rely on natural ventilation. This fact is attributed to the age of these buildings constructed more than dozen or even several tens of years ago. Few of them were fitted with a mechanical ventilation system allowing for the adjustment of microclimate parameters. The national requirements for gravity ventilation provide general guidelines, specifying strict description only for the airtightness of windows and doors and the minimum airflow to be supplied to the rooms. The minimum airflow supplied is independent of the number of occupants and purpose of the room. Low indoor air quality (IAQ) can impact occupants’ health and lead to poor productivity or low academic performance. Therefore the provision of good IAQ in classrooms and laboratories is very important. This paper presents the results of the investigation devoted to the quality of indoor air in classrooms of selected Polish primary school. Six primary school in a town with a population of 200 000 inhabitants were involved in the investigations. The participating school buildings were built between 1976 and 1994 and had gravity ventilation systems. The variability of basic IAQ parameters, i.e., temperature, relative humidity and carbon dioxide level, was analysed and the assessment of the classrooms in terms of microbiological purity was performed. The outcomes confirmed the low quality of the indoor air in these buildings. The maximum value of CO2 concentration amounted to more than 4000 ppm. Certain modifications aimed at improving IAQ were proposed during the investigations. Two solutions were implemented. The results of this study indicate that the proposed solution offers the potential to improve IAQ within classrooms.

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Efficiency of Natural Ventilation in Central Greenhouse of Botanical Garden in Kosice

Proccedings of 10th International Conference "Environmental Engineering" ◽

10.3846/enviro.2017.263 ◽

2017 ◽

Author(s):

Martin Kovac ◽

Katarina Kovacova ◽

Anna Sedlakova

Keyword(s):

Indoor Environment ◽

Natural Ventilation ◽

Ventilation System ◽

Botanical Garden ◽

Simulation Tool ◽

Summer Period ◽

Radiation Level ◽

Glass Panels ◽

The Right ◽

Calculated Model

The object of paper is analysis of natural ventilation system in central greenhouse of Botanical garden in Kosice. The greenhouse was refurbished in 2015. The existing greenhouse covering from glass panels was replaced for polycarbonate panels. The ventilation system of central greenhouse is natural and there are used openings in covering (wall, roof). It is combination of thermally and wind driven ventilation. The main aim of contribution is to analyse different modes of natural ventilation during summer period mainly. The important factors that influence efficiency of natural ventilation in greenhouse are location and area of openings, temperature stratification in greenhouse, solar radiation level, wind speed and direction too. If the greenhouse is ventilated naturally only through external windows (roof windows are closed) the efficiency of ventilation is very poor. The defined modes of natural ventilation search the right location and size of opened windows in order to achieve the most efficiency ventilation of indoor environment. For this purpose the progressive dynamic simulation tool DesignBuilder is used where the geometrical and specific calculated model of whole central greenhouse was created.

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Acoustical Improvements with Natural Air Ventilation in the Liu Institute for Global Issues at the University of British Columbia

Journal of Green Building ◽

10.3992/jgb.6.1.114 ◽

2011 ◽

Vol 6 (1) ◽

pp. 114-122

Author(s):

Zohreh Razavi ◽

Max Richter ◽

Murray Hodgson ◽

Alireza Khaleghi

Keyword(s):

Natural Ventilation ◽

Ventilation System ◽

Green Building ◽

Optimized Design ◽

Global Issues ◽

University Of British Columbia ◽

Air Ventilation ◽

The University ◽

Building Designs

Low speech privacy in shared and private offices in one of the early generation of a “green” building resulted in occupants' dissatisfaction. This problem is experienced in Liu institute with a natural-ventilation system. Such a system requires low air-flow resistance which is achieved by large openings which will result in noise transmission between various spaces within the building. The poor acoustical quality in this building resulted in occupants' noise complaints which were further investigated by way of relevant acoustical measurements. CATT-Acoustic software was utilized to modify the acoustical quality of the building without any disturbance to the occupants. The optimized design of the transfer box above the office door was selected based on CATT-Acoustic predictions. The acoustical measurements were conducted after installation of the transfer box above the office door. The measurements' results agreed with the predictions which led to improved speech privacy to an acceptable level between the office and the corridor in Liu Institute. More work should be done to improve the acoustical quality of natural-ventilated building to conform to ANSI standards.1The results of this study strongly support including acoustics in “green” building designs with natural ventilation to avoid users' complaints.

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Influence of the Inlet Size on the Natural Ventilation System Operation in a Residential Multi-storey Building

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/661/1/012130 ◽

2019 ◽

Vol 661 ◽

pp. 012130

Author(s):

Elena Malyavina ◽

Kaminat Agakhanova

Keyword(s):

Natural Ventilation ◽

Ventilation System ◽

System Operation ◽

Storey Building

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IMPROVEMENT OF THERMAL COMFORT INSIDE A MOSQUE BUILDING

Jurnal Teknologi ◽

10.11113/jt.v78.9579 ◽

2016 ◽

Vol 78 (8-4) ◽

Cited By ~ 3

Author(s):

Fawaz Ghaleb Noman ◽

Nazri Kamsah ◽

Haslinda Mohamed Kamar

Keyword(s):

Thermal Comfort ◽

Natural Ventilation ◽

Ventilation System ◽

Side Wall ◽

The West ◽

Cfd Simulations ◽

Interior Space ◽

Flow Simulations ◽

Computational Fluid Dynamics Cfd ◽

Cfd Method

A combined natural ventilation and mechanical fans are commonly used to cool the interior space inside the mosques in Malaysia. This article presents a study on thermal comfort in the Al-Jawahir Mosque, located in Johor Bahru, Malaysia. The objective is to assess the thermal comfort inside the mosque under the present ventilation system by determining the Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD). These values were then compared to the limits stated in the ASHRAE Standard-55. It was found that the PMV varies from 1.68 to 2.26 while the PPD varies from 61% to 87%. These show that the condition inside the mosque is quite warm. Computational fluid dynamics (CFD) method was used to carry out flow simulations, to identify a suitable strategy to improve the thermal comfort inside the mosque. Results of CFD simulations show that installing four exhaust fans above the windows on the west-side wall of the mosque is the most effective strategy to improve the thermal comfort inside the mosque. Both the PMV and PPD values can potentially be reduced by more than 60%.

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