Showing papers in "Building Services Engineering Research and Technology in 2006"
TL;DR: In this paper, test reference years (TRYs) are required for energy analyses and design summer years (DSYs) for assessing natural ventilation in the sum-measure.
Abstract: With the increasing use of simulation for building design, test reference years (TRYs) are required for energy analyses and design summer years (DSYs) for assessing natural ventilation in the summe...
105 citations
TL;DR: In this article, the authors discussed experimental and theoretical investigations and Computational Fluid Dynamics (CFD) modelling considerations to evaluate the performance of a square section wind catcher system connected to the top of a test room for the purpose of natural ventilation.
Abstract: This paper discusses experimental and theoretical investigations and Computational Fluid Dynamics (CFD) modelling considerations to evaluate the performance of a square section wind catcher system connected to the top of a test room for the purpose of natural ventilation. The magnitude and distribution of pressure coefficients (Cp) around a wind catcher and the air flow into the test room were analysed. The modelling results indicated that air was supplied into the test room through the wind catcher's quadrants with positive external pressure coefficients and extracted out of the test room through quadrants with negative pressure coefficients. The air flow achieved through the wind catcher depends on the speed and direction of the wind. The results obtained using the explicit and AIDA implicit calculation procedures and CFX code correlate relatively well with the experimental results at lower wind speeds and with wind incidents at an angle of 08. Variation in the Cp and air flow results were observed part...
55 citations
TL;DR: Recommendations are summarized for the provision of a spatial hierarchy of toilet provision that would both meet user needs and reduce the chances of the public toilets acting as epicentres of germ transmission.
Abstract: This paper discusses the role of public toilets, as transmitters of disease, but also of their importance in contributing to the health and well-being of society. Research has shown that public toilets are vital components in creating sustainable, accessible, inclusive cities. But there is no mandatory legislation requiring local authorities to provide them. Over 40% have been closed in the UK in the last 10 years. The promotion of the 24 hour city, characterized by a male youth drinking culture, along with toilet closure, has resulted in increased street urination, creating the conditions for the spread of previously-eradicated, water borne diseases in city streets. Less visible, but as virulent, has been the effect of toilet closure for women. Women, in response to lack of toilet provision, are likely to ‘hold on’ resulting in urine (and pathogen) retention, and bladder distension increasing the propensity for continence problems. The elderly and people with disabilities may simply not go out for fear o...
43 citations
TL;DR: The Severe Acute Respiratory Syndrome (SARS) outbreak in 2003 triggered concerns regarding the ability of buildings to resist disease transmission as mentioned in this paper. In particular, the outbreak that occurred in the...
Abstract: The Severe Acute Respiratory Syndrome (SARS) outbreak in 2003 triggered concerns regarding the ability of buildings to resist disease transmission. In particular, the outbreak that occurred in the ...
35 citations
TL;DR: In this article, the authors examined the acceptable noise level in an office environment by interviewing 422 occupants about the aural environment being perceived in 61 air-conditioned offices in Hong Kong.
Abstract: This study examined the acceptable noise level in an office environment by interviewing 422 occupants about the aural environment being perceived in 61 air-conditioned offices in Hong Kong. The sur...
34 citations
TL;DR: In this article, the key characteristics of specialist works are identified and their implications are analyzed, and the problems with procuring specialist works through subcontracting are reviewed, and issues that building developers should take note of in deciding to equip a building with a specialist work and in procurement and management of the specialist subcontract are highlighted and discussed.
Abstract: It is envisaged that more and more specialist works will be employed in modern buildings for enhancing performance and sustainability. Subcontracting is an economical way of procuring specialist works for modern buildings but it may also give rise to various kinds of problems. Such problems may originate from the characteristics of the specialist works and from subcontracting as a procurement method. In the paper, the key characteristics of specialist works are identified and their implications are analysed. Through discussing how new technologies penetrate the market, the pricing strategies that vendors of new technologies may adopt together with their implications are unveiled. The problems with procuring specialist works through subcontracting are then reviewed, and the issues that building developers should take note of in deciding to equip a building with a specialist work and in procurement and management of the specialist subcontract are highlighted and discussed.Practical application: By providing...
33 citations
TL;DR: In this paper, the authors describe a number of concepts for free cooling, and the background to the current concept, before detailing field tests on the system that have recently been completed and which demonstrate its effectiveness under real operating conditions.
Abstract: Air conditioning is now seen as a new and major contributor to CO2 emissions in the UK. This is partly due to global warming and partly to the increased use of IT systems. A novel system for reducing or eliminating the need for air conditioning was developed to the proof-of-concept stage under an earlier project at the University of Nottingham. The system makes use of heat pipes to transfer heat into and out of a phase change material which is ‘frozen’ during the night and ‘melted’ during the day. This paper describes a number of concepts for ‘free cooling’, and the background to the current concept, before detailing field tests on the system that have recently been completed and which demonstrate its effectiveness under real operating conditions. Systems were installed in two offices and detailed monitoring of their performance was carried out during the summer months. On the basis of the results obtained it is concluded that the system functions very well and is practically and technically the most attr...
27 citations
TL;DR: In this paper, the authors highlight the function and implications of a strategic maintenance management system in relation to building maintenance performance, and highlight the issues of quality management, contract management, resourcing strategy and the innovation processes required in the organizational drive towards effective and efficient maintenance management systems.
Abstract: This paper highlights the function and the implications of a strategic maintenance management system in relation to building maintenance performance. The paper examines the technical and management functions in building maintenance and highlights the issues of quality management, contract management, resourcing strategy and the innovation processes required in the organizational drive towards effective and efficient maintenance management systems. The paper concludes that innovative solutions to maintenance issues are essential for continued efficiency and are brought about through the creation of an environment in which creativity is able to thrive.
25 citations
TL;DR: In this article, three new cloud-based models have been proposed, and statistical indicators have been developed for assessing the accuracy of estimation of global, diffuse and beam horizontal irradiance, including the slope of the best fit line and the coefficient of determination between measured and calculated values, mean bias error, and root mean square error.
Abstract: Simple radiation estimation models using meteorologically observed input parameters are often used in the applications requiring rough estimations of solar horizontal radiation. One of the parameters employed, cloud cover, is widely available from multiple regional and national weather stations. Kasten and Czeplak, Muneer and Gul, and Lam and Li, have proposed cloud-based models for the estimation of global and diffuse horizontal irradiance. In the current study, three new cloud-based models have been proposed. To compare the validity of the above models, statistical indicators have been developed for assessing the accuracy of estimation of global, diffuse and beam horizontal irradiance. The slope of the best fit line and the coefficient of determination between measured and calculated values, mean bias error, and root mean square error were calculated. In addition, the kurtosis and skewness of error histograms were also obtained. These parameters were used to obtain accuracy indicators for the models und...
25 citations
TL;DR: In this paper, the authors presented a monetary, energy usage and environmental impact assessment for solar water heaters for a developing country like Pakistan where large amounts of hot water are required within industry.
Abstract: Sustainability of building construction and its services is increasingly drawing attention. In this respect CIBSE has issued a number of calls to industry. Solar water heating systems are now economically competitive and are being used throughout the world. Following earlier work of the present authors on the life cycle assessment (LCA) for building components,1,2 this work presents a monetary, energy usage and environmental impact assessment for solar water heaters. It has been shown herein that for a developing country like Pakistan where large amounts of hot water are required within industry, solar water heating offers favorable payback periods on each of the above three counts. It has been estimated that under the tested conditions, the embodied energy payback period for the plain and finned heater is equivalent to 185 days and 169 days respectively. It has also been found that the amount of carbon released during the construction process of plain and finned water heaters is 27.9 kg and 29.7 kg respe...
21 citations
TL;DR: In this paper, the authors compare and evaluate numerical results of the condensation risk calculation under both steady-state and transient conditions using the existing numerical codes, and conclude that transient calculation methods may be necessary under certain circumstances.
Abstract: Accurate assessment of both surface and interstitial condensation risk is important not only to reduce the damaging effect of moisture within the structure of buildings, but also to provide a healthy environment free from mould growth The current British Standard (BS EN ISO 13788: 2002) contains an assessment procedure based on the assumption of a steady-state heat flow through the building envelope, neglecting the transient nature of the problem This paper compares and evaluates numerical results of the condensation risk calculation under both steady-state and transient conditions using the existing numerical codes Significant differences are apparent between the predictions of the simple (steady-state) and complex (transient) methods for all construction details modelledPractical application: The current British Standard (BS EN ISO 13788: 2002) gives calculation methods for determining the internal surface temperature of a building component or building element below which mould growth is likely, given the internal temperature and relative humidity-the method can also be used to assess the risk of other surface condensation problems The calculation methods in the Standard are steady-state The paper concludes that for cases where the steady-state method predicts that surface RH values will remain below the key value of 80%, a transient method can predict surface RH values to be above 80% for several hours The practical implications of this work then are that transient calculation methods may be necessary under certain circumstances This is particularly relevant given that the issue of a time period of a few hours is now more pertinent as it relates to a new transient performance standard in the new draft Approved Document F (Building Regulations-England and Wales)
TL;DR: In this paper, a practical evaluation program for water conservation, in particular, a rainwater use system for architectural planning, is presented. And a simplified scheme is proposed using daily rainfall probability to provide a new guideline to water conservation evaluation procedures and link to the National Building Code in Taiwan.
Abstract: Rainwater use as a supplement to the potable water supply has been demonstrated as a practical and promising alternative solution for water shortage. This paper aims to develop a practical evaluation program for water conservation, in particular, a rainwater use system for architectural planning. The proposed system involves a quantitative methodology to evaluate and improve the decision making for rainwater use systems in building design. Furthermore, a simplified scheme is proposed using daily rainfall probability to provide a new guideline for water conservation evaluation procedures and link to the National Building Code in Taiwan. The practical evaluation method could also be of benefit to the comprehensive applications in other countries.Practical application: This article relates to the practice of professionals in building water supply, sanitation and water conservation areas. The paper introduces a practical evaluation program for rainwater harvesting systems for domestic water-use, which can lin...
TL;DR: In this article, the authors focus on the work of the authors in defining key simulation model components that facilitate the prediction of the pressure response of building drainage systems and that thus allow an assessment of trap seal integrity to reduce the risk of infection spread.
Abstract: Identification of the under-performance of the building drainage and ventilation system as a significant contributor to the transmission of the SARS virus in the ‘Amoy Gardens’ outbreak has prompted a re-examination of the methods adopted to ensure appropriate network design, implementation and maintenance. The physical separation between the miasma present within drainage pipe work and the habitable space occupied by the building user is achieved primarily through the use of the (commonly water-based) appliance trap seal. Systems must therefore be designed such that the integrity of this seal is sustained throughout all user or system-imposed operating conditions. This paper focuses on the work of the authors in defining key simulation model components that facilitate the prediction of the pressure response of building drainage systems and that thus allow an assessment of trap seal integrity to reduce the risk of infection spread. The paper draws upon the empirically defined network characteristics and e...
TL;DR: In this article, the authors proposed a scheme to provide poor and very poor peri-urban households with adequate and affordable water supplies and sanitation in rural and periurban areas in developing countries.
Abstract: Inadequate water supplies and inadequate sanitation are responsible for a large proportion of disease transmission in rural and periurban areas in developing countries. Engineering interventions for water supply and sanitation improvements in rural areas are well understood, but not to the same extent in periurban areas. Greater innovation is required to provide poor and very poor periurban households with adequate and affordable water supplies and sanitation. Periurban water supplies can be developed on the large scale required through standpipe co-operatives and yard-tap supplies in conjunction with a sensible tariff structure. Periurban sanitation is only likely to be feasible with the large-scale adoption of simplified (condominial) sewerage in conjunction with innovative sanitation service delivery mechanisms.
TL;DR: In this paper, the authors utilized the calculation of a group of financial and operational indicators to evaluate the performance of water and wastewater utilities in the United States, and found that the key problem in most of the utilities is the absence of performance assessment tools.
Abstract: The key problem in most of the water and wastewater utilities is the absence of performance assessment tools. This research utilized the calculation of a group of financial and operational indicato...
TL;DR: Analysis of experimentally obtained data of the European Report (1992) and, where appropriate, comparison with other data is concerned, and where there are still some elements of doubt, and a few pitfalls which the researchers of the Europe Report were not quite diligent enough to avoid.
Abstract: Prior to the 1990s, pressure loss factors of ductwork components had almost invariably been quoted as single values, invariant with either size (diameter) or air speed (Reynolds Number). Unlike pipework components, where size has been known to be a factor for some time, with ductwork components there seemed to have been a tacit assumption that neither size nor velocity would affect the value of the non-dimensional pressure loss factor ζ. Enough data is now available for us to know that this assumption was false. The major part of this paper concerns analysis of experimentally obtained data of the European Report (1992)1 and, where appropriate, comparison with other data. The components analysed are shown in Figure 1.Pressure loss factor ζ is defined by the relationship:[ILLEGIBLE]Practical application: This paper places in the public domain the most pertinent data obtained from the European Research Project.1 It will be of particular use to authors of technical guides seeking to have more recently obtaine...
TL;DR: In this article, the authors present a series of field studies developed with the aim of assessing the performance of ventilation systems currently in use in public houses where smoking is permitted, and the effectiveness of the ventilation systems is clearly demonstrated.
Abstract: This paper reviews previous studies and reports on the first stage of a series of field studies developed with the aim of assessing the performance of ventilation systems currently in use in public houses where smoking is permitted. Established ventilation theory is used to hypothesize the behaviour of these systems predicting that exposure to environmental tobacco smoke will be substantially reduced. The problems associated with conducting field studies in buildings of this nature are discussed, and the results of some representative studies are presented. The effectiveness of the ventilation systems is clearly demonstrated. Limitations of the study are identified and further work is proposed. Practical application: This paper informs the current debate on the value of ventilation systems in spaces where smoking is permitted. Despite the proposed ban on smoking in public places in England and the ban in Scotland there will be a variety of exemptions where the building is also someone's place of residence...
TL;DR: In this paper, the authors describe an approach that has been undertaken to improve the airtightness of a number of plasterboard-lined load-bearing masonry dwellings that were constructed in the early 1970s.
Abstract: This paper describes an approach that has been undertaken to improve the airtightness of a number of plasterboard-lined load-bearing masonry dwellings that were constructed in the early 1970s. Such dwellings are likely to be broadly representative of many of the dwellings that will be refurbished in the UK over the next decade or so. The airtightness of the dwellings was improved by undertaking a two-stage programme of general and targeted airtightness work, in parallel with a basic domestic refurbishment programme. The results illustrate that prior to the refurbishment, the dwellings were in a poor state of repair and had an air permeability of between 24 and 26 m3/h per m2at 50 Pa, which is substantially in excess of the UK mean of 11.5 m3/h per m2at 50 Pa. The condition of the dwellings also suggests that the air permeability of these dwellings is likely to be considerably higher than that which would have been experienced when they were first built. Following the refurbishment programme, it was possible to reduce the air permeability of these dwellings by almost 55%, to a mean of just over 11 m3/h per m2at 50 Pa. The paper also identifies a number of factors that limited the effectiveness of the airtightness work. These factors included: wear and tear of the plasterboard-lining; detailing and workmanship during the refurbishment programme; and, the partial nature of the refurbishment programme. Had it been possible to address a number of these factors during the refurbishment programme, the authors are reasonably confident that an air permeability of less than 10 m3/h per m2at 50 Pa could have been achieved in all of the dwellings. Despite the small size of the sample (only 12 dwellings were tested), the results suggest that the airtightness of existing plasterboard-lined load-bearing masonry dwellings can be improved to a level that is comparable to the current UK Building Regulations (Approved Document Part L1) requirement for new dwellings. Practical application: Airtightness is crucial to improving the energy performance of buildings. In the UK, existing dwellings tend to be very leaky compared to some of their international counterparts. The use of plasterboard-lining as an internal finish to external and party walls makes a significant contribution to this poor performance, particularly where it is not edge sealed. Air leakage measurements reported here for dwellings built in the 1970s suggest that if this construction is allowed to deteriorate, very high leakage rates may result. Considerations of the impact of choice of construction on future robustness and durability of airtightness of new housing is likely to be an important practical consideration, particularly for social housing providers. Separating the air barrier function from the plasterboard lining appears to provide a more reliable and probably more durable solution. The paper goes on to describe how injecting expanding polyurethane foam into the cavity between the inner leaf of blockwork and the plasterboard-lining to form continuous ribbons of foam can seal the plasterboard lining and prevent air movement within this cavity. If this approach is undertaken in parallel with a domestic refurbishment programme, the air leakage rate of existing plasterboard-lined masonry cavity dwellings was shown to be reduced to a level comparable with the requirements of the current Part L1 for new dwellings. © The Chartered Institution of Building Services Engineers 2006.
TL;DR: In this article, a humanized adaptive baseline information technology (HABIT) algorithm is proposed to enable fine-tuning according to the occupants' feedback to optimize the acceptance of the indoor environment.
Abstract: A building management system (BMS) established to control the system of building services would not incorporate records of occupants’ views nor integrate real-time occupants’ response for any system fine tuning to satisfy individual demands in a dynamic manner. This study proposes a humanized adaptive baseline information technology (HABIT) algorithm to enable such fine tuning according to the occupants’ feedback to optimize the acceptance of the indoor environment. Apart from solving the complaints from occupants, the proposed algorithm also integrates the collective real-time feedback from end-users with a balance of the imposed design conditions to determine the optimum operation condition of the system. In the study, the temperature set point of an air-conditioning system in certain Hong Kong offices was used as an illustrative example to demonstrate the operation of the algorithm. Survey results on occupants’ views and indoor environmental conditions of the offices were used to determine the input pa...
TL;DR: Given the risk of infectious disease and chemical poisons from contaminated water, it is obvious that access to safe drinking water is a fundamental requirement for human existence and the availability of water also has wider implications through its contribution to other aspects of human life.
Abstract: Provision of safe drinking water and the effective removal of bodily waste are vital for human health and well-being. The United Nations Covenant on Economic, Cultural and Social Rights, signed by over 140 countries, now includes a special reference (General Comment 11, November 2002), which declares that ‘Water is a limited natural resource and a public good fundamental to life and health. The human right to water is indispensable for leading a healthy life in human dignity. It is a prerequisite to the realization of other human rights.’ Unfortunately, political realities are often opposed to the aims of this fine declaration: political expediency often pushes the claims of water supply to the bottom of the priority list; wars and local conflicts may destroy significant infrastructure for the supply of safe drinking water and the removal of waste. Since 2000, the increasingly independent (and even isolationist) stance of the USA has weakened the ability of international agencies such as the United Nations and the World Health Organization to respond to the needs of developing countries. Despite a wealth of rhetoric on the importance of globalization, many western countries maintain agricultural subsidies and tariffs which feed a climate of mistrust, and which lead to an unwillingness to contribute to others. About 3.4 million people die each year from illnesses associated with contaminated water supplies and inadequate waste removal. The diseases associated with water contamination are malaria, cholera, dysentery, hepatitis A, and schistosomiasis. Lack of safe drinking water is the major factor underlying the deaths of over 1.5 million infants and children from diarrhoea each year. While contaminated water is a major cause of infectious disease, it also has an impact on health through the spread of organic and inorganic chemicals that are harmful to health. These include chlorinated solvents (which cause cancer), trihalomethanes (which cause liver and kidney damage), heavy metals such as lead (which causes nerve and brain damage, and birth defects), and polychlorinated biphenyls (PCBs) (which cause liver damage, and may also cause cancer). Given the risk of infectious disease and chemical poisons from contaminated water, it is obvious that access to safe drinking water is a fundamental requirement for human existence. However, the availability of water also has wider implications through its contribution to other aspects of human life. Lack of availability of clean water correlates strongly with poverty. In many societies, women and girls are solely responsible for collecting water, and the task is enormous when the water source is many kilometres away. Many hours each day are spent carrying water containers Address for correspondence: Professor Charles Watson AM, Division of Health Sciences, Curtin University of Technology, GPO Box U1987, Perth WA 6845, Australia. E-mail: c.watson@curtin.edu.au Building Serv. Eng. Res. Technol. 27,2 (2006) pp. 85 /89
TL;DR: The types of microorganisms associated with growth in water and with faecal material and how these organisms are spread are reviewed.
Abstract: Some microorganisms can grow in water while others merely survive. The use of the water may result in the creation of aerosols which can disseminate the products of microbial growth or the microorganisms themselves. In the home, toilets, sinks and showers can provide a reservoir for microorganisms to survive and grow. Intermittent use of disinfectants alone may not be adequate to control these microorganisms unless regular cleaning and brushing is practiced. Similar problems occur in hospitals, offices and public buildings. Here control is much more important. In these environments infections can potentially spread readily to large numbers of people from the creation of aerosols both in sanitary equipment and the sewerage system associated with it. Control is helped by regular cleaning but much more attention needs to be placed on proper construction, servicing and maintenance of the infrastructure. This article reviews the types of microorganisms associated with growth in water and with faecal material a...
TL;DR: In this article, a two-phase mathematical model is described for the packed bed which includes heat dispersion in the fluid, and heat loss to the environment, and a numerical method for obtaining a solution is proposed and implemented.
Abstract: The cooling system at the Harare International School uses a packed bed system for storing the coldness of the night-time to be used later for day-time airconditioning. A two-phase mathematical model is described for the packed bed which includes heat dispersion in the fluid, and heat loss to the environment. This is in contrast to other studies, where at least one of these terms is neglected to simplify the mathematical model. A numerical method for obtaining a solution is proposed and implemented. Using measured inlet temperatures, the measured and predicted outlet temperatures of the bed show good trend agreement. The differences in detail are examined through sensitivity analyses for both the heat convection transfer and air velocity. It is apparent that adjusting these parameters can increase the agreement between the predicted and measured data. A parametric study for heat storage with various materials and bed sizes is given, which indicates how the code may be used as a tool for improving design a...
TL;DR: In this paper, the authors applied the software package Transient Systems Simulation Program (TRNSYS), to estimate the air state and the energy consumption of a typical operating theatre located in a tropical building.
Abstract: This study applies the software package Transient Systems Simulation Program (TRNSYS), to estimate the air state and the energy consumption of a typical operating theatre located in a tropical building. For the simulation, typical meteorological year (TMY) data for the Kuala Lumpur area (Malaysia), and an operating theatre located in the University of Malaya Medical Centre (UMMC) (Kuala Lumpur), are used. The current heating, ventilating and air conditioning (HVAC) system for the operating theatre was found to be inherently energy-inefficient and could be improved with heat pipe heat exchangers (HPHXs). The impact on energy consumption of a custom-built air handler unit (AHU) was simulated with one or two 6-row HPHXs installed in the HVAC system, compared to a pre-cooling heat exchanger installed in the same system.Based on this investigation, it is recommended that a double HPHX system (Plant C) be applied in tropical HVAC systems for the reduction of energy consumption and dehumidification enhancement.P...
TL;DR: In this paper, the authors discuss the influence of water conservation on the behavior of water-based trap seals in drainage systems utilizing different types of ventilation, and show that the venting system capacity to limit the internal pressure in the drainage system, in order to maintain the integrity of the water seals, reduces the risk of infection spread in buildings.
Abstract: Considering the water conservation programmes that promote a reduction in WC flush volume, and given the concern with the safe use of new concepts and techniques to avoid the transmission of serious disease via the drainage system as in the case of SARS, this paper discusses the influences of said reduction on the behaviour of water-based trap seals in drainage systems utilizing different types of ventilation, as allowed by Brazilian standards. The paper shows that the venting system capacity to limit the internal pressure in the drainage system, in order to maintain the integrity of the water seals, reduces the risk of infection spread in buildings.
TL;DR: In this paper, a three-dimensional numerical simulation of transient heat transfer behavior measured during a full-scale experiment is presented, where the experimental data, provided by others, was measured at a purpose built, fullscale test-house, over a 5-year period.
Abstract: A three-dimensional numerical simulation of transient heat transfer behaviour measured during a full-scale experiment is presented. The experimental data, provided by others, was measured at a purpose built, full-scale test-house, over a 5-year period. The paper addresses some of the practical problems associated with undertaking multi-dimensional simulations, even when the problem is reasonably well defined. Comparisons are made between numerical results and measured data over an annual cycle. Good correlation of results has been achieved. Phase lag of ground temperature variations was also accurately represented in the simulation. The need to pre-condition the simulation to arrive at realistic initial conditions is shown to be necessary in this class of problem. Practical application: At the design stage a predictive assessment of building energy consumption and dissipation is clearly of value. However, the accuracy of any simulation fundamentally depends on the precision with which relevant factors are included. Above-ground insulation of buildings has steadily improved and as a consequence thermal losses due to earth-contact have become proportionally more important. Within this context, this paper aims to provide a case study for validation of models against full-scale field-measured data. The work will also contribute to innovative design that may utilize the thermal mass of foundation materials to achieve the required thermal performance.
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TL;DR: In this paper, a mathematical model for determining the skin layer temperature due to incident radiant heat flux is examined with experimental verification, and the results showed that the predictions were slightly higher than the measured values and the mathematical model would be useful in hazard assessment for some fire environments involving exposure of humans to a thermal radiation.
Abstract: Skin pain and burns at an elevated skin layer temperature due to incident heat flux could be used to evaluate thermal hazards for some enclosed fire environments and mathematical expressions were proposed in literature for fire safety evaluations. In this work, a mathematical model for determining the skin layer temperature due to incident radiant heat flux is examined with experimental verification. Heat balance on the skin layer due to the heat flux and conductive heat transfer through it is considered. Specifically, the skin layer temperature at the head portion of an artificial thermal manikin was measured at certain incident radiant heat flux and compared with that calculated from the mathematical model. The results showed that the predictions were slightly higher than the measured values and the mathematical model would be useful in hazard assessment for some fire environments involving exposure of humans to a thermal radiation. Practical application: This paper presents the temperature measurement ...
TL;DR: In this article, the suitability for measurement of mixed-phase fluid flow in building (DWV) systems utilizing a particle tracking velocimetry (PTV) flow measurement technique is investigated.
Abstract: Within building drainage, waste and ventilation (DWV) systems, airflow measurement within and across the cross-section of the stack is problematic due to the multiphase and unsteady nature of the flow. This paper investigates the suitability for measurement of mixed-phase fluid flow in building (DWV) systems utilizing a particle tracking velocimetry (PTV) flow measurement technique. PTV is a non-intrusive optical flow measurement technique that supplies an instantaneous sample of velocity throughout a 2D plane in the flow field. The results of the PTV investigation can then be utilized for comparison with the results of previous investigations.Practical application: Development of a remote sensing technique capable of discriminating between phases in DWV stack systems would benefit researchers and code bodies by allowing more robust and comprehensive models to be developed. These models could be used in sensitivity tests for code changes.
Journal Article•
TL;DR: In this article, the impact of window area on the energy balance of a building was investigated by simulations in DEROB-LTH and the results showed that if energy efficient window alternatives are chosen the flexibility of choosing the glazed area and orientation is higher.
Abstract: The impact of window area on the energy balance of a building was investigated by simulations in DEROB-LTH. The glazed area was varied in three types of buildings with different types of glazing and for several climates.One low energy house was compared to a less insulated house but identical in size and layout. Three different types of glazing were used; uncoated double glazing, double glazing with one low-e coated pane and triple glazing with two low-e coated panes. Climates with variations in solar radiation, mean temperature, altitude and latitude were chosen.The results show that if energy efficient window alternatives are chosen the flexibility of choosing the glazed area and orientation is higher. Choosing a larger area facing south resulted in a higher heating demand for uncoated double glazing in the standard house. An increased area also resulted in an increased peak load for heating for all the simulated cases. Choosing the energy efficient glazing type gave a decrease in heating demand for increased south facing glazed area in the standard house. In the low energy house the difference in heating demand between different areas was smaller than for the standard house. An office module with two types of switchable glazing and one solar control glazing unit was used in three different climates; Stockholm, Brussels and Rome. Larger window areas increase the cooling demand but if glazing types with lower solar transmittance are used, the difference in cooling demand between different window areas decreases. An extremely large window area, however, increases the peak load both for cooling and for heating and should therefore be avoided. Energy can be saved by using switchable windows instead of solar control or in particular standard glazing.