In this study, effect of air change rate (air change per hour – ACH) on indoor particle dispersion and deposition in a ventilated room is investigated. A reduced-scale model is designed to conduct experiments. Numerical predictions are performed by using the commercial software ANSYS Fluent 16.0. Four different values of the air change rate (1.73, 2.88, 5.76 and 7.68) and five different values of the

In an indoor environment, many factors may affect the airflow characteristics and thermal comfort. Hence, a lot of research has been carried out in order to investigate the impact of these factors. The purpose of this study is to determine the effect of supply area, with maintaining the same supply airflow rate, on the airflow characteristics and the indoor thermal comfort for a ventilated box prototype

The fire protection design in a large-scale interchange station is always a great challenge. In this paper, a series of numerical simulations were conducted to investigate the performance of emergency ventilation modes for three potential multisource fire scenarios. The parameters that influence passengers’ evacuation were analyzed. The results demonstrated that unreasonable co-operation ventilation

Even in case ventilation system is operating in optimal fashion, indoor air quality could be varied depending on the indoor contaminant release occasions. Thus, accurate and rapid identification of contaminant source locations in indoor environment is critical for occupants’ health as well as building safety and integrity. This study presented a novel method to locate indoor contaminant source using

A novel DCV-system controls the air-change rate for each apartment in multifamily buildings based on two indoor air parameters: 1) the moisture load (supply), and 2) volatile organic compounds. With a central fan, but decentralized control boxes placed outside each apartment, the system controls the air-change rate for each apartment. This paper’s main aim is to determine the potential of this DCV-system

This study deals with the indoor air quality (IAQ) measured and perceived in a demonstration building via a smart sensor. The analysis subject targeted includes the following main air pollutants, viz., CO2, VOCs, formaldehyde, benzene, CO, PM2.5, and comfort parameters such as air temperature, and relative humidity. These were recorded during three campaigns. It turned out that the CO2 level was higher

Over the last few decades, there is a clear target for reducingenergy needs in the building sector. The above objective can be achieved both by renovating the existing building stock and/or by constructing new buildings that will meet the characteristics of zero or nearly zero energy buildings. In order to construct or renovate a building into a zero or almost zero energy building, different passive

An accurate temperature gradient calculation is essential for displacement ventilation (DV) system design since it directly relates to thecalculation of the required supply airflow rate. Inaccurate temperature prediction can cause poor thermal comfort and wrong sizing of the ventilation and cooling systems. A heat balance-based method is usually applied in displacement ventilation (DV) design when

Abstract The indoor air quality is important for the well-being of humans, especially in the case of young babies. This research focuses on the air qualityinside a crib with sleeping infants. The effects of different sleeping positions of the baby on the air quality within the crib were studied by measurements on modelled setup. The breathing of an infant was simulated by means of a baby doll which

A demonstration house was previously built and commissioned in Iqaluit, Nunavut, Canada. The purpose of the overall effort is to develop and integrate technologies and evaluate the performance of a high-performance building located in the Canadian Arctic, while considering the unique social, economic, and logistical challenges associated with its remote location. Previous work consisted of monitoring

Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance ofventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact of infiltration on the heating demand between 2 and 20 kW h/(m2 y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess

Multiple authors stated that, when performing fan pressurization test, Ordinary Least Square (OLS) method should not be used as a regression technique anymore. However, alternative methods require first to quantify components of uncertainty in pressure and air flow rate measurements. This work aims at quantifying the uncertainty in zero-flow pressure approximation, which is mainly due to short-term

Guaranteeing high indoor air quality and high degree of usersatisfaction at the same time is one of the challenges when improving the energy efficiency, namely the energy consumption, of a building. Current non-residential buildings mainly use mechanical ventilation systems to ensure high air quality. Natural ventilation can be an alternative regarding to lower maintenance costs and the psychological

This study aims to experimentally evaluate the influence of the combination of a supply only ventilation, called here positive input ventilation, and innovative active air vents on the Indoor Air Quality of a house. The positive input ventilation draws fresh air from the outside, filters and pre-heats it before supplying it to living areas. Active air vents are small motorised dampers set up in the

With increasing building airtightness, the design of an adequate ventilation system gains importance. The first generation of ventilation systems, based on continuous supply of the nominal airflow rate, are now being replaced by demand controlled ventilation (DCV). These systems, often H2O and/or CO2 controlled, typically do not take into account the emissions of volatile organic compounds (VOCs) to

Abstract Buildings typically are expected to provide their inhabitants with the opportunity to influence the indoor environment using various control devices. These include, for example, windows, luminaires, radiators, and shading elements. The quality and adequacy of the indoor environment is thus dependent on the availability and effectiveness of such devices. There is arguably a lack of generally

Ventilation is critical in interpreting indoor air quality (IAQ), yet most IAQ assessments do not report ventilation adequately. Most ventilation assessments use tracer gas tests (TGT) to measure total air change rate (ACH), but currently applied TGTs present three shortcomings: limited comparability between ACH and IAQ data, inadequate substances employed as tracer gases and tendency to bias arising

The present paper describes the design improvement of a single-room ventilation unit. This ventilation system presents many advantages, however, several drawbacks exist. The first one is the acoustic disturbance. As the facilities are directly installed within the rooms, the fans’ noise may create discomfort. Furthermore, in the cold or temperate climates, condensation or frost may appear. A dedicated

Vertical shafts are common structures in buildings, which accelerate smoke spread in fires due to stack effect. In this study, fire smoke movement and distribution in a ventilation shaft were studied through analysing temperature distributions, velocity distributions, CO2 concentration distributions and pressure distributions. Four exhaust rates were discussed and compared. It was found that the status

Air conditioning engineers design the inlet or outlet position of a fan coil unit (FCU) system according to thermal comfort and cost. However, the effect of the position on fire growth has not been considered. In this study, the effect of the relative inlet and outlet positions was investigated. Thirty cases were simulated using fire dynamics simulator (FDS). The simulation results revealed that the

This paper reports the results of an interview survey conducted among different stakeholders involved in design, installation and operation of residential ventilation in seven European countries. In total 44 interviews were performed. The results provide a valuable snapshot of current practices and insights into potential barriers and challenges regarding installation of mechanical ventilation in low-energy

In this study, smoke evacuation in two kinds of subway station platform models, namely: an island platform station and a two side platforms station is simulated in a three-dimensional configuration. FDS 6.1.1 (Fire Dynamic Simulator) software has been employed to perform numerical simulations. The results showed noticeable effects of platform architecture on the process of smoke evacuation and emission

With the wide application of electronic surgical equipment, the generation of surgical smoke is inevitable. Surgical smoke will not only obstruct the operator's visibility, but also release toxic and harmful substances into the air, which will make the operator a headache and cause inflammation of the eyes and mucous membranes. In order to evaluate whether the existing operating room ventilation system

This paper proposes an original and sustainable design for a Hybrid solar Air Conditioning-Ventilation-Humidification-Dehumidification (HDH) desalination system. The proposed design permits to produce both thermal comfort and desalinated water for residential buildings. The originality of the system design as well as its operating principle is described in detail. Mathematical models, that govern the

In this paper the FDS 6 code ability to simulate the airflows generated by jet fans in a real road tunnel is studied. A transient model of the 898 m long bi-directional highway Polana tunnel is created including details of the tunnel geometry as emergency lay-bys and traffic signs. The absolute roughness of the tunnel walls of 70 mm is determined to represent the influence of curved tunnel geometry

To study heat and mass transfers inside nuclear facilities equipped with ventilation systems, a methodology was developed to carry out reduced-scale experiments for studying flows induced by thermal and wind effects simultaneously. The methodology was numerically validated on simple configurations and applied to a reference configuration representative of nuclear facilities. The effects of wind and

This study proposed a hybrid ventilation mode for underground subway depot with superstructures and described the construction of a calculation model for estimating the smoke-exhaust efficiency of ventilation systems in such buildings. The hybrid ventilation system consisted of natural ventilation, a flow deflector, and mechanical fans. The smoke-layer height, smoke temperature, gas-flow routes, and

The Grid Convergence Index ( GCI) method requires at least three systematic mesh refinements, each requiring the numerical solution to be in the asymptotic range. When the observed order of accuracy differs from the formal order of accuracy, a lack of numerical precision exists which may result in erroneous conclusions. The aim of the work in this paper is to evaluate the effect the mesh resolution

In this paper, the impact of window parameters (shape, design, sizes, position and orientation) on the building thermal comfort (temperature, relative humidity and discomfort period), energy consumption (lighting loads, heating and cooling loads and total energy consumption) and cost, and environment effect (CO2 emissions) is analysed under hot semi-arid climate conditions. This study considers the

The present study provides an analysis of existing literature encompassing the wind and thermal analysis of football stadia, and how both can be manipulated through the modification of roof geometry. It introduces the potential for cooling strategies to create an internal environment capable of hosting elite-level international football in a hot climate. The motivation for the study stems from an absence

Noise from domestic ventilation systems is currently a little understood problem in the UK. Other European countries that have a longer history of using mechanical domestic ventilation systems have introduced noise limits for these systems. Without mandatory limits for noise in UK, noise is not a factor that is often considered during the design. However, noise can be a significant constraint to the

(2018). Correction. International Journal of Ventilation: Vol. 17, No. 4, pp. II-II.

The transient development of natural displacement ventilation in a warm space with a localized source of heat is investigated theoretically to understand the fluid mechanics in detail. One of four flow modes, A, B, C and D, may develop during the transient evolution. The flow pattern of mode B, C or D can be further subdivided into two cases respectively according to a critical value of the reduced

Following the increasing energy performances of building, ventilation systems are being considered as key actors in reaching both energy and indoor air quality targets. Despite several pollutants that can be used as airflow modulation inputs, French demand control ventilation for dwellings, is mainly realized using water vapour and passive sensors. A variable opening section is modulated through the

A macroscopic zone model is used to analyze buoyancy-driven natural ventilation in one storey connected with an atrium. The height ratio between the storey and atrium can be variable as well as the heat ratio between the two heat sources, one in storey and the other in atrium. Both the steady-state and time-dependent flow rate through the storey and atrium are investigated. The transient process from

In the paper, study on quantitative analysis between particle penetration and air change was made. In situ experiments in a practical office room were carried out. Through recording concentration of indoor and outdoor CO2 and PM2.5, particle penetration coefficients (Fp) corresponding to different air change rate (ACH) were obtained by fitting method. The uncertainty analysis by Monte-Carlo method

Infiltration through windows accounts for a significant heat loss in buildings during winter, leading to the need to minimize uncontrolled air flow. Improvement of window air tightness is important for reducing heat loss by infiltration through windows. In this study, infiltration is measured for general sliding (GS), parallel sliding tilt (PST) and lift sliding (LS) windows according to ASTM E283

In indoor applications, computed tomography is the process of transforming a network of intersecting attenuation measurements into a spatially resolved two-dimensional concentration map. In this study the Low Third Derivative method (LTD) was numerically evaluated and optimized for different conditions. A modified version of the LTD algorithm (LTDm) was proposed and evaluated against the original version

Due to the importance of air-conditioning system in public transport vehicles, some researches focused on improving the efficiency of Air Conditioning (AC) systems, especially in urban and high speed trains. This study investigates the induced airflow in long corridor of metro train in accelerating and decelerating modes, analytically and experimentally. The simplified governing equation of Navier-Stokes

(2018). Erratum. International Journal of Ventilation: Vol. 17, No. 4, pp. I-I.

Buildings’ smoke extraction systems are commonly designed according to guidelines and standards. This approach does not take all boundary conditions into account that may occur within the lifespan of a building. We introduce a novel approach for evaluating the robustness of smoke extraction systems that incorporates realistic boundary conditions by means of the Monte Carlo CFD simulation method. We

As ventilation systems become more sophisticated (or ‘smart’) standards and regulations are changing to accommodate their use. A key smart ventilation concept is to use controls to ventilate more at times it provides either an energy or IAQ advantage (or both) and less when it provides a disadvantage. This paper discusses the favorable contexts that exist in many countries, with regulations and standards

This study presents extensive experimental measurements in a modern Finnish ice rink arena including temperature, relative humidity, carbon dioxide, air speed, air flow and pressure difference measurements in addition to smoke tests. Furthermore, the air exchange rate (ACH), air-exchange efficiency, and mixing factor were calculated. The main aim was to determine ventilation effectiveness, vertical

Few field studies have evaluated ventilation strategies, such as temporarily increasing the ventilation rate, to counter the high pollutant-load from off-gassing of volatile compounds from new materials in these buildings. We reviewed longitudinal studies that measured both ventilation rate (i.e. fresh air change rate) and airborne concentration of total volatile organic compounds (TVOC). Rates of

Temporarily enhanced natural ventilation of indoor environments can be achieved by opening windows and/or doors, i.e. airing. In this study, wind driven airing rate through doors was measured by tracer gas at a building model in a wind tunnel. Both single opening and cross flow airing was investigated, with doors placed in centrally on the long side of an elongated building model. It was found that

Potrooms are elongated buildings in which hundreds of aluminum smelting pots are housed, and have the particularity, among others, to be naturally ventilated. A CFD model simulating a potroom is developed to study its thermal comfort when the aluminum smelting pots take in less volume of air so as to facilitate waste heat recovery from the pot draft. The influences of wind and buoyancy on the ventilation

This paper presents and discusses numerical simulation of the wind velocity's effect on infiltration rates in an individual building using multi-zone modelling. The governing equations are expressed in terms of unknown pressures at points where flow paths connect. Their implementation was achieved using an advanced numerical model, which was developed via the MATLAB environment. Such a numerical approach

A series of experiments were carried out in a full-scaled model room to verify the characteristics of the air-conditioning system with ceiling induction diffusers. By the step-up tracer gas method and decay method, 10 cases with three varying parameters (the positions of exhausts, the heights of the exhaust ports and the states of the curtains around the beds) were designed to examine the influence

As a result of recent research at the Eduardo Torroja Institute for construction sciences, a new wording for the indoor air quality (IAQ) regulations for dwellings included in the Spanish Building Code has come into force with the main goal of adapting required ventilation rates to real needs to consequently achieve a reduction of energy demand with no negative impact on indoor air quality or on condensation

Minimum airflow rates are either recommended or required based on the number of occupants, the intended use of the space or the floor plan area. This paper focuses on a new proposal for Spanish Technical Building Code based on limitations of the ventilation using the CO2 concentration as an indicator. The aim of the proposal is to introduce indoor air quality criteria in order to determine the design

In axial fan simulation using multiple reference frame (MRF) method, an inappropriate size of rotating zone may affect the accuracy of results. In order to study the influence of axial and radial sizes in a wide flow rate range, five rotating zone sizes were investigated at seven flow rate points from 0 to 11.3 m3/s in a simplified fan setup configuration. Comparing the fan characteristic curves, it

The 3D fan zone model is a recently developed variant of the actuator disk models, based on an input fan curve to simulate the fan effect. However, the fan curves are typically obtained in experimental situations under common standards, which could be different from the operating scenario in simulation, specifically, the definitions of flowrate and the fan appurtenances effect. In order to adapt the

Good air quality is one of the main requirements of human health. Jet fan ventilators are often applied for pollutant removal in large enclosures, where lack of fresh air is significant. During the design phase, computational fluid dynamic (CFD) techniques are most often used to verify the effectiveness of ventilation. However, reliable designs based on CFD, require accurate jet fan airstream modelling

This paper focusses on identifying the information needs of modern-day architects seeking to design low-energy naturally ventilated buildings. We present the results of a survey conveying the personal views of international MA/MSc/MArch student architects at the Architectural Association School of Architecture, London, UK. The aim was to gain insight and raise awareness of architects’ current information

This study presents some field measurements in an operating room of air velocity, ambient temperature and particle counts on the operating table. Moreover, computational fluid Dynamics analyses of the operating room were performed and compared with the measurements. Measurements were taken under the preferred operating conditions by surgical staff (at 19 °C) and then at different ambient temperatures

Recently, a new type of ventilation method known as protected zone ventilation has been studied for application to the prevention of indoor contaminants transported from one zone to another. The use of a downward plane jet plays a key role in a protected zone ventilation system. The objective of this study is to examine the transmission of contaminants through a downward plane jet in a room with gaseous

The ventilative cooling potential tool (VC tool) aims at assessing the potential effectiveness of ventilative cooling strategies by taking into account also building envelope thermal properties, occupancy patterns, internal gains and ventilation needs. The analysis is based on a single-zone thermal model applied to user-input climatic data on hourly basis. For each hour of the annual climatic record

In this study the thermal comfort, the local thermal discomfort and the air quality levels, experienced by two occupants seated at a classroom desk are analysed. The desk is equipped with personalized ventilation systems and is positioned nearby a window subjected to solar radiation. Experimental observations are based on a manikin study and results are compared with CFD analysis using the k-epson

An important challenge for low energy buildings lies in the need to master airflows through the building envelope. This paper describes a campaign on 21 low-energy houses. First, we carried out an aeraulic measurement campaign on every dwelling including visual survey, airflow or pressure at the air-vents, ventilation duct airleakage, and acoustics measurements. Then, we selected 10 dwellings to carry

Compared with the mechanical ventilation, natural ventilation is an effective, low cost and low maintenance way for smoke control in many buildings. In this paper, a new method of setting shafts was proposed to realise the natural ventilation in a common subway station. The theoretical analysis and the numerical method were used to assist the design strategy. Results show that when setting shafts for