Relationship between quality of building maintenance management services for indoor environmental quality and occupant satisfaction

Two surveys were carried out to investigate the correlation between building maintenance management services for indoor environmental quality (IEQ) and occupant satisfaction. Each maintenance management organization manager was surveyed using the Evaluation Index of Maintenance Management Service Quality, created by Akira Takakusagi. Seven office buildings in Seoul, Korea were investigated in the first survey, and two buildings from the first survey were selected for analysis in the second survey. One is a building with good maintenance management services but low occupant satisfaction, and the other is an office building with low maintenance management services but high occupant satisfaction.     

Thermal comfort and workplace occupant satisfaction—Results of field studies in German low energy office buildings

The issues of comfort and workspace quality in buildings have gained much importance with the European “Energy Performance of Buildings Directive” of 2001. New energy efficient building concepts and technologies require a revision of comfort standards, which were developed for air-conditioned buildings only. Particularly, the question of recommendable upper indoor temperature limits needs further investigation. In addition, a broader approach to occupant satisfaction in buildings is necessary with respect to overall building performance.     

A comparison of occupant comfort and satisfaction between a green building and a conventional building

It has been argued that “green” buildings have a better indoor environmental quality (as measured by the comfort perceptions of occupants) than conventional buildings and that this translates into a more satisfying workplace for the building's occupants and, in turn, a more productive workforce. To test this we measured the comfort and satisfaction perceptions of the occupants of a green university building and two conventional university buildings with a questionnaire that asked occupants to rate their workplace environment in terms of aesthetics, serenity, lighting, acoustics, ventilation, temperature, humidity, and overall satisfaction. The university buildings at the centre of the study are located in Albury-Wodonga, in inland southeast Australia. The green building, which is naturally ventilated, is constructed from rammed earth and recycled materials. The conventional buildings have heating, ventilating, and air-conditioning (HVAC) systems and are of brick veneer construction. We found no evidence to believe that green buildings are more comfortable. Indeed, the only difference between the buildings was that occupants of the green building were more likely to perceive their work environment as warm, and occupants who felt warm were more likely to describe their work environment as poor. However, the hydronic cooling system of this building was malfunctioning at the time of the study and hence this result cannot be generalised as a difference between green buildings and conventional HVAC buildings. All other aspects of comfort, including aesthetics, serenity, lighting, ventilation, acoustics, and humidity, were not perceived differently by the occupants of the two types of building.     

Influence of building parameters and HVAC systems coupling on building energy performance

The performance of different HVAC systems varies when coupled with different buildings. This paper examines the relationship between building heating and cooling load and subsequent energy consumption with different HVAC systems. Two common HVAC systems in use throughout the UK office building stock, variable air volume (VAV) system and fan coil (FC) with dedicated outside air system, have been coupled with a typical narrow plan office building with and without daylight control and for both cellular and open plan.The results presented in this paper clearly indicate that it is not possible to form a reliable judgment about building energy performance based only on building heating and cooling loads. For the two investigated systems, variable air volume system and fan coil with dedicated outside air system, the difference between system demand and building demand varied from over −40% to almost +30% for cooling and between −20% and +15% for heating. If a heat recovery unit is used, the difference in heating performance is even greater, rising to −70%.     

Indoor environmental quality differences between office types in LEED-certified buildings in the US

The study compared IAQ, thermal quality, and lighting quality between 5 different office types in LEED-certified buildings in relation to employees' environmental satisfaction and their job performance. This was to provide workplaces where workers in each specific office environment could be provided with appropriate office settings regarding these IEQ criteria when organizations comply with LEED standards. The five types of office included private enclosed, private shared, open-plan with high cubicle over 5′, open-plan with low cubicle lower than 5′, and open-plan with no partitions (bullpen) offices. The study found IAQ enhanced workers' job performance in enclosed private offices more than both high cubicles and low cubicles. All four office types had higher satisfaction with the amount of light and visual comfort of light as well as more enhancement with job performance due to lighting quality than high cubicles. There was no difference in thermal quality between the five office types. IAQ and lighting quality were not different between enclosed private, enclosed shared, and bullpen office types, either. The study findings suggest a careful workplace design considering the height of partitions in LEED-certified buildings to improve employee's environmental satisfaction and job performance.     

Risk factors in heating, ventilating, and air-conditioning systems for occupant symptoms in US office buildings: the US EPA BASE study

Building-related symptoms in office workers worldwide are common, but of uncertain etiology. One cause may be contaminants related to characteristics of heating, ventilating, and air-conditioning (HVAC) systems. We analyzed data from 97 representative air-conditioned US office buildings in the Building Assessment and Survey Evaluation (BASE) study. Using logistic regression models with generalized estimating equations, we estimated odds ratios (OR) and 95% confidence intervals for associations between building-related symptom outcomes and HVAC characteristics. Outdoor air intakes less than 60 m above ground level were associated with significant increases in most symptoms: e.g. for upper respiratory symptoms, OR for intake heights 30 to 60 m, 0 to <30 m, and below ground level were 2.7, 2.0, and 2.1. Humidification systems with poor condition/maintenance were associated with significantly increased upper respiratory symptoms, eye symptoms, fatigue/difficulty concentrating, and skin symptoms, with OR = 1.5, 1.5, 1.7, and 1.6. Less frequent cleaning of cooling coils and drain pans was associated with significantly increased eye symptoms and headache, with OR = 1.7 and 1.6. Symptoms may be due to microbial exposures from poorly maintained ventilation systems and to greater levels of vehicular pollutants at air intakes nearer the ground level. Replication and explanation of these findings is needed. PRACTICAL IMPLICATIONS: These findings support current beliefs that moisture-related HVAC components such as cooling coils and humidification systems, when poorly maintained, may be sources of contaminants that cause adverse health effects in occupants, even if we cannot yet identify or measure the causal exposures. While finding substantially elevated risks for poorly maintained humidification systems, relative to no humidification systems, the findings do not identify important (symptom) benefits from well-maintained humidification systems. Findings also provide an initial suggestion, needing corroboration, that outdoor air intakes lower than 18 stories in office buildings may be associated with substantial increases in many symptoms. If this is corroborated and linked to ground-level vehicle emissions, urban ventilation air intakes may need to be located as far above ground level as possible or to incorporate air cleaners that remove gaseous pollutants.     

The link between symptoms of office building occupants and in-office air pollution: the Indoor Air Pollution Index

The lack of an effective indoor air quality (IAQ) metric causes communication concerns among building tenants (the public), building managers (decision-makers), and IAQ investigators (engineers). The Indoor Air Pollution Index (IAPI) is developed for office buildings to bridge this communication discord. The index, simple and easily understood, employs the range of pollutant concentrations and concentrations in the subject building to estimate a unitless single number, the IAPI, between 0 (lowest pollution level and best IAQ) and ten (highest pollution level and worst IAQ). The index provides a relative measure of indoor air pollution for office buildings and ranks office indoor air pollution relative to the index distribution of the US office building population. Furthermore, the index associates well with occupant symptoms, percentage of occupants with persistent symptoms. A tree-structured method is utilized in conjunction with the arithmetic mean as the aggregation function. The hierarchical structure of the method renders not only one index value, but also several sub-index values that are critical in the study of an office air environment. The use of the IAPI for IAQ management is illustrated with an example. The decomposition of the index leads to the ranking of sampled pollutants by their relative contribution to the index and the identification of dominant pollutant(s). This information can be applied to design an effective strategy for reducing in-office air pollution.     

室内环境质量的检测及防治

介绍了室内空气污染物的种类及其对人的危害,提出了室内环境质量检测的取样条件和方法,给出了检测采用的现行国家标准及结果判定,最后就室内环境质量的防治措施进行了探讨,以保障公众健康、维护公共利益。     

Investigation of volatile organic compounds in office buildings in Bangkok,Thailand: Concentrations,sources, and occupant symptoms

To conserve energy, office buildings with air-conditioning systems in Thailand are operated with a tight thermal envelope. This leads to low fresh-air ventilation rates and is thought to be partly responsible for the sick building syndrome symptoms reported by occupants. The objectives of this study are to measure concentrations and to determine sources of 13 volatile organic compounds (VOCs) in office buildings with air-conditioning systems in the business area of Bangkok. Indoor and outdoor air samples from 17 buildings were collected on Tenax-TA^™ sorbent tubes and analyzed for individual VOCs by thermal desorption-gas chromatography/mass spectrometry (TD–GC/MS). Building ventilation was measured with a constant injection technique using hexafluorobenzene as a tracer gas. The results show that the VOC concentrations varied significantly among the studied buildings. The two most dominant VOCs were toluene and limonene with average concentrations of 110 and 60.5 μg m⁻³, respectively. A Wilcoxon sum rank test indicated that the indoor concentrations of aromatic compounds and limonene were statistically higher than outdoor concentrations at the 0.05 level, while the indoor concentrations of chlorinated compounds were not. Indoor emission factors of toluene and limonene were found to be highest with the average values of 80.9 and 18.9 μg m⁻² h⁻¹, respectively. Principal component analysis was applied to the emission factors of 13 VOCs, producing three components based on source similarities. Furthermore, a questionnaire survey investigation and field measurements of building air exchange pointed to indoor air complaints related to inadequate ventilation.     

Energy and demand implication of using recommended practice occupancy diversity factors compared to real occupancy data in whole building energy simulation

Whole building energy simulation tools have become increasingly useful in assessing and improving existing and designing new high-performance buildings. Occupancy diversity factors are one category of parameters needing additional consideration in energy modelling as they can have a large impact on the output of the simulation. In this study, two sources of occupancy diversity factors, American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) references and measured data from Duarte, Van Den Wymelenberg, and Rieger. [2013a. “Revealing Occupancy Patterns in an Office Building Through the Use of Occupancy Sensor Data.” Energy and Buildings 67 (December): 587–595. doi:10.1016/j.enbuild.2013.08.062], are used in three Department of Energy (DOE) reference office building models and four calibrated models of existing buildings. The total energy consumption between the two schedules for an assumed private office dominate floor plan layout ranges between 21.5–39.1% and 0.8–5.8% for an open office dominate plan in reference buildings. Calibrated models range from 5.5% to 16.8%. These results are meant to represent a reasonable range of potential impacts of occupancy diversity factors, and are thus derived by applying occupancy profiles directly to occupancy, lighting, plug load, and ventilation schedules.     

Associations between indoor CO2 concentrations and sick building syndrome symptoms in U.S. office buildings: an analysis of the 1994-1996 BASE study data

Higher indoor concentrations of air pollutants due, in part, to lower ventilation rates are a potential cause of sick building syndrome (SBS) symptoms in office workers. The indoor carbon dioxide (CO2) concentration is an approximate surrogate for indoor concentrations of other occupant-generated pollutants and for ventilation rate per occupant. Using multivariate logistic regression (MLR) analyses, we evaluated the relationship between indoor CO2 concentrations and SBS symptoms in occupants from a probability sample of 41 U.S. office buildings. Two CO2 metrics were constructed: average workday indoor minus average outdoor CO2 (dCO2, range 6-418 ppm), and maximum indoor 1-h moving average CO2 minus outdoor CO2 concentrations (dCO2MAX). MLR analyses quantified dCO2/SBS symptom associations, adjusting for personal and environmental factors. A dose-response relationship (p < 0.05) with odds ratios per 100 ppm dCO2 ranging from 1.2 to 1.5 for sore throat, nose/sinus, tight chest, and wheezing was observed. The dCO2MAX/SBS regression results were similar.     

土质及石灰剂量与室内击实试验关系之浅谈

以江苏昆山地区典型粘土和粉质粘土为例,分别对黄色粘土、灰色粘土、黄色粉质粘土、灰色粉质粘土在不同灰剂量条件下的重型击实试验结果进行了介绍,研究了土质及石灰剂量与室内击实指标的关系,所得成果对指导现场施工有一定的指导意义。     

The effect of a redesigned floor plan, occupant density and the quality of indoor climate on the cost of space, productivity and sick leave in an office building–A case study

The aim of this study was to examine changes in the overall costs of an office when the efficiency of space use is increased. The variable in the examination was a space index, calculated as the floor area per employee. The quality of indoor climate was also a variable in the analysis. The overall cost analysis of a given case building showed that when space use is boosted significantly, measures must be taken to guarantee a sufficient quality of indoor climate. The study indicates that investment in the quality of indoor climate is cost-effective when the economic effect of indoor climate to health and productivity are taken into account in addition to the costs of investment, operation and maintenance. Insufficient ventilation without mechanical cooling may cause a substantial loss of productivity. The importance of good ventilation and air-conditioning increases with a more efficient use of space especially in conjunction with high value of work.     

Chloroform in indoor swimming-pool air: Monitoring and modeling coupled with the effects of environmental conditions and occupant activities

Human exposure to chloroform in indoor swimming pools has been recognized as a potential health concern. Although environmental monitoring is a useful technique to investigate chloroform concentrations in indoor swimming-pool air, in practice, the interpretations of measured data would inevitably run into difficulties due to the complex interactions among the numerous variables, including environmental conditions and occupant activities. Considering of the relevant variables of environmental conditions and occupant activities, a mathematical model was first proposed to predict the chloroform concentration in indoor swimming-pool air. The developed model provides a straightforward, conceptually simple way to predict the indoor air chloroform concentration by calculating the mass flux, J, and the Péclet number, Pe, and by using a heuristic value of the indoor airflow recycle ratio, R. The good agreement between model simulation and measured data demonstrates the feasibility of using the presented model for indoor air quality management, operational guidelines and health-related risk assessment.     

Relationship between outdoor and indoor air quality in eight French schools

In the frame of the French national research program PRIMEQUAL (inter-ministry program for better air quality in urban environments), measurements of outdoor and indoor pollution have been carried out in eight schools in La Rochelle (France) and its suburbs. The buildings were naturally ventilated by opening the windows, or mechanically ventilated, and showed various air permeabilities. Ozone, nitrogen oxides (NO and NO(2)), and airborne particle (particle counts within 15 size intervals ranging from 0.3 to 15 mum) concentrations were continuously monitored indoors and outdoors for two 2-week periods. The indoor humidity, temperature, CO(2) concentration (an indicator of occupancy), window openings and building permeability were also measured. The temporal profiles of indoor and outdoor concentrations show ozone and nitrogen oxides behave differently: NO and NO(2) indoor/outdoor concentration ratios (I/O) were found to vary in a range from 0.5 to 1, and from 0.88 to 1, respectively, but no correlation with building permeability was observed. On the contrary, I/O ratios of ozone vary in a range from 0 to 0.45 and seem to be strongly influenced by the building air-tightness: the more airtight the building envelope, the lower the ratio. Occupancy, through re-suspension of previously deposited particles and possible particle generation, strongly influences the indoor concentration level of airborne particles. However, this influence decreases with particle size, reflecting the way deposition velocities vary as a function of size. The influence of particle size on deposition and penetration across the building envelope is also discussed by analyzing the I/O ratios measured when the buildings were unoccupied, by comparing the indoor concentrations measured when the buildings were occupied and when they were not (O/U ratios), and by referring to previously published studies focussing on this topic. Except one case, I/O were found to vary in the range from 0.03 to 1.79. All O/U are greater than one and increase up to 100 with particle size. PRACTICAL IMPLICATIONS: Assessing children's total exposure requires the knowledge of outdoor and indoor air contaminant concentrations. The study presented here provides data on compared outdoor and indoor concentration levels in school buildings, as well as information on the parameters influencing the relationship between outdoor and indoor air quality. It may be used as a basis for estimating indoor concentrations from outdoor concentrations data, or as a first step in designing buildings sheltering children against atmospheric pollution.     

通过某教学楼的结构设计浅析《建筑抗震设计规范》与GB50011-2010和GB50011-2001（2008版）的区别

近几年来,各地频发地震甚至超过设防烈度的强烈地震,为此我们付出了沉痛的代价。政府也高度重视这个问题：如何做好城乡抗震防灾建设,把震害带来的各种损失降到最低,2010年5月政府发布了新修订的《建筑抗震设计规范》（GB50011-2010）。通过对华侨大学音乐舞蹈学院教学楼的结构设计,探讨了修订后的新规范与旧规范的部分区别...     

Quantitative relationships between molecular structures,environmental temperatures and octanol-air partition coefficients of PCDD/Fs

In Thailand, human excreta might be recycled into agricultural soils as a supplement to commercial fertiliser and thereby enrich the general fertility of the soils. However, for Thailand an adequate knowledge of the quality of human excreta, in order to assess its fertiliser potential, is not available. A literature survey revealed only very limited information of the chemical composition and generation rate of human excreta in South East Asia. Data from other parts of the world also lacked specific information on collection and analytical methods, or the studies were typically 20-30 years old. In the present study the composition of human excreta has been studied in three case study areas in Southern Thailand: Kuan Lang, Phattalung and Prik. The inhabitants of the three areas represent people of Southern Thailand by age, sex, occupation, religion and type of residence. Human excreta was collected and stored for 1 week from five persons in each area, who each had their own toilet and collection bucket. In parallel, a septic tank at the Observation and Protection (O&P) Centre of Songkhla (a boys prison institution) adjacent to the three study areas was used as a daily sampling point, to obtain data on average amounts of human excreta and chemical composition. Information on average values of generation rate and chemical composition was obtained as well as inter-human variation. However, no significant variation was found between the results for human excreta at the O&P Centre or from the 15 individuals. Furthermore, there was no significant influence of age, sex, occupation or religion on the chemical composition. The only significant variation was that the older people excreted larger amounts of total wet matter than the younger, which could be due to a higher water intake, in order to reduce the risk of constipation. The generation rate found was 0.6-1.2 1 urine/cap/day and 120-400 g wet faeces/cap/day. The generation rate of the elements in the excreta was 7.6-7.9 g N/cap/day, 1.6-1.7 g P/cap/day, 1.8-2.7 g K/cap/day, 1.0-1.1 g S/cap/day, 0.75-1.5 g Ca/cap/day, 0.25-0.4 g Mg/cap/day, 9-16 mg Zn/cap/day, 1.4-1.5 mg Cu/cap/day, 0.3 mg Ni/cap/day, 0.02-0.03 mg Cd/cap/day, 0.07-0.14 mg Pb/cap/day, 0.01 mg Hg/cap/day and 0.8-1.1 mg B/cap/day. The metals (Ca, Mg, Zn, Cu, Ni, Cd, Pb, Hg) are mainly excreted via the faeces and the remaining elements (N, P, K, S, B) are mainly excreted via the urine. It can be concluded that human excreta constitutes a large fertiliser resource, which presently is not utilised in Thailand.     

中小学建筑室内电气设计探讨

针对中小学建筑室内电气设计进行了探讨,提出在对教室的照明设计中,除进行照度计算外,还应采取眩光限制,并分别阐述了如何避免频闪效应,减少眩光及满足教室内课桌面的照度等内容,以指导实践。     

高层民用建筑防排烟设计探讨

对高层民用建筑的防排烟设计的各种情况进行分析和探讨,根据规范要求,商讨具体的解决办法。     

公共建筑热工设计及权衡计算若干问题探讨

新的公共建筑节能设计标准已经执行,随着节能工作的不断深入及对在新标准实际执行中反映出的热点话题以及对建筑热工设计及权衡计算的几个方面进行了分析,试图提出对新标准的一些理解和建议。