Effects of apartment building façade and balcony design on the reduction of exterior noise

The effects of building façade and balcony design on the reduction of exterior noise were investigated by measuring the noise from traffic at an apartment complex located by a road side as well as the sound field characteristics of an area surrounded by four apartment buildings. The efficiency of different balcony forms for reducing exterior noise was determined using a 1:50 scale model and a single spark source. It was found that parapets were more effective in reducing exterior noise than lintels. Based on the measurements of the parapet used for this study and the absorptive materials in the scale model, a maximum noise reduction of 23 dB was obtained. Lastly, a computer simulation was conducted in order to predict the noise reduction level of lintels and parapets. The results of the simulation were compared to the results of the scale model test. Our results indicate that this method of exterior noise reduction can be useful in high-rise buildings where tall barriers cannot be built.     

Retrofit cost-effectiveness: Estonian apartment buildings

The economic viability and investment cost of the energy retrofit of apartment buildings are analysed through different energy efficiency levels. To analyse retrofit policy cost-optimal energy efficiency levels and investment costs, a baseline of measured actual energy usage of apartment buildings was created and then individual energy-saving measures and retrofit packages were composed. The cost-optimal level over a 20-year period for apartment building retrofit was a low-energy-building energy performance level, with an investment cost of €150–170/m². Retrofit to low energy building level would be economically viable but the investment capability of apartment owner associations is found to be insufficient for the necessary investments to achieve low-energy-building energy performance. Therefore, it is necessary to determine what levels of financial support can encourage retrofit to occur. The analysis of the current retrofit shows that subsides will increase investment by apartment owner associations into energy efficiency improvements. The target group for energy efficiency retrofit subsidies should be apartment buildings that reach low energy building performance level or at least match the energy performance requirement for new buildings.     

绿色建筑评价中楼板撞击声隔声指标探讨

绿色建筑评价中对楼板撞击声隔声的要求引用《民用建筑隔声设计规范》,单值评价量有实验室测量的计权规范化撞击声压级Ln,w和现场测量的计权标准化撞击声压级L'nT,w。对撞击声隔声评价指标Ln,w、L'n,w、L'nT,w进行理论分析,并结合现场测量和实验室测量对分析结果进行验证。结果表明：当建筑楼板的撞击声隔声性能较差时,侧向传声对测量结果影响较小,现场测量指标L'n,w与实验室测量指标Ln,w相差不大;L'nT与L'n在接收室体积V=31m3时相等,当接收室体积V＞31m3时,L'nT会小于L'n,因此L'nT,w会低于L'n,w和实验室测量值Ln,w,接收室体积越大偏差越大,按照当前住宅户型的发展趋势,客厅体积一般在60~130m3,采用L'nT,w进行撞击声隔声评价会导致其数值低于实验室测量指标Ln,w,约为3~6dB;采用现场测量指标L'nT,w进行撞击声隔声评价会受到接收房间体积的影响,因此建议在现场绿色建筑楼板撞击声隔声性能评价时同时参考L'n,w的测量结果。     

Aktuelle Ergebnisse zum Schallschutz von Fassaden und Außenbauteilen

New results on sound insulation of facades and external building components. In spite of the strong annoyance by noise, the acoustic quality of external building components is often regarded as requirement of secondary importance. However, a high standard of noise protection is expected by most of the occupants or owners of buildings as the evaluation of numerous complaints in acoustically inadequate buildings shows. The main problem is the poor sound insulation performance of external walls against low frequencies, e.g. caused by traffic noise. Therefore, acoustic improvements have to focus on that topic. Fortunately, an extended range of data, knowledge and solutions is provided within the state of the art. With regard to the acoustic quality of external thermal insulation systems and of hollow bricks the results of recently completed research projects are presented in the paper.     

绿色建筑的声环境要求

声环境要求是绿色建筑评价的重要指标。新版绿建规范在室外环境噪声、室内噪声级、建筑构件隔声、防止噪声干扰、专项声学设计等方面进行严格规定,对新版绿建规范中涉及声环境条文逐条解析,通过实例介绍建筑构件隔声计算,以及室内噪声计算。     

建筑隔声与地面辐射供暖

楼板传声是建筑噪声最主要来源之一,现有普通混凝土楼板的计权标准化声压级大多隔声性能不能满足国家标准,需要通过构造浮筑楼板等方式提高楼板隔绝撞击声性能,使其满足国家现行标准要求。地面辐射供暖系统因其特殊的结构形式,其内在具有提高楼板隔绝撞击声性能的优势。本文对建筑楼板隔声现状、地面辐射供暖对建筑隔声的作用以及地面辐射供暖隔声效应的测试方法进行了阐述。     

Experimental study on the performance of insulation materials in Mediterranean construction

It is well known that it is necessary to insulate the buildings to decrease the thermal demand and to decrease the use of heating and cooling. Due to the high cost of fossil fuels and to the necessity to reduce CO₂ emissions, and also due to the new building regulations more attention is paid to the insulation of buildings. Different insulation materials are available in the market. Usually, they are compared by their thermal conductivity and with theoretical calculations, but there are no experimental comparisons available, where the behavior of such insulation materials in a building is compared over time. This is why the authors started a comparison of three typical insulation materials, polyurethane, polystyrene, and mineral wool. For this purpose, four house-like cubicles were constructed (with a size of 2.4 m × 2.4 m × 2.4 m) and their thermal performance throughout the time was measured. The cubicles were built under a conventional Mediterranean construction system, differing only in the insulation material used. During 2008 and the first months of 2009 the performance of these cubicles was evaluated, and the results are presented in this paper.     

Optimum location for fire alarms in apartment buildings

Measurements on the alarm sound distribution in nine apartment buildings showed that if adequate awakening potential is to be provided for sleeping residents, an alarm sounding device must be located within each apartment. Information on the minimum sound level necessary to awaken such a sleeping person is also given. A procedure that can be used to determine sound attenuation within apartment buildings is presented. Examples to demonstrate such a procedure are provided.     

A survey of decorative materials on the energy consumption of mid-rise residential buildings in Mashad, Iran

Polyvinylchloride (PVC) panel is one of the most favorite decorative materials that has been popularly applied as finishing of ceiling in residential buildings. It is about five years that the people incline to redecorate the ceiling of old buildings with PVC panel in big cities of Iran, such as Mashad. In this study, the influence of ceiling PVC panel on the cooling and heating loads of studied apartment were determined by software DeST-h. In addition, the summer natural ventilation of the mentioned apartment is investigated by determining the wind speed into the apartment through the computational fluid dynamics (CFD) software. The evaluation of environment indoor wind velocity showed that most of the apartment space is a comfortable zone. The results of studied building analyses demonstrated that using PVC panel on the ceiling can decline the energy consumption of the penthouse (fifth level) of the investigated building, which is about 3.7% and 7% for studied methods of without and with air layer, respectively. In addition, although the existence of air layer can decline the cooling and heating loads, the increase in air layer thickness did not show significant decrease on building energy consumption. However, the PVC panel is expensive and is not suitable to be used for ceiling thermal insulation, but adding a thin layer of air between ceiling and PVC panel can be a good step toward sustainable building, when the people are inclined to utilize it as a decorative ceiling.     

Characterization of road traffic noise exposure and prevalence of hypertension in central Taiwan

Epidemiological studies have demonstrated that road traffic noise exposure is associated with hypertension in European, but the associations related to traffic sources and in other population are unclear. This study investigated the association between road traffic noise exposure and the prevalence of diagnosed hypertension among 321 male and 499 female resided near main roads in Taichung, Taiwan. Road traffic noise levels and traffic flow rates were measured simultaneously during 0900-1700 on weekdays in 2008. Multivariate logistic regressions were applied to estimate odds ratios (ORs) for hypertension by adjusting for potential confounders. Road traffic noise levels were significantly associated with traffic flow rates of motorcycles, light-duty gasoline vehicles, light-duty diesel trucks and heavy-duty diesel trucks and had the highest correlation with motorcycles. Per one unit (vehicle per hour) increase in the log-transformed traffic flow rate of motorcycles was significantly related to the increment of 7.20 ± 1.40 A-weighted decibels (dBA) in the traffic noise exposure. The high-exposure group (82.2 ± 1.7 dBA, n = 358) had the significantly higher prevalence of hypertension (adjusted OR = 2.15, 95% CI = 1.08-4.26) than the low-exposure group (77.2 ± 1.6 dBA, n = 462). There was an increasing trend (p = 0.023) between the prevalence of hypertension and residents exposed to < 77 dBA, 77-80 dBA, 80-83 dBA and ≥ 83 dBA, respectively. Such an association was pronounced after adjusting for the total traffic flow rate. The study findings suggest that road traffic noise exposure may be associated with hypertension and the dominant source of traffic noise is motorcycles in central Taiwan.     

工地隔声大棚的设计与施工技术

对城市建筑工地施工噪声的治理实例进行了分析,并根据施工噪声源的特点,对临时隔声棚的隔声、吸声等处理技术进行了介绍,提出了防治施工噪声扰民的有效方法,解决了建筑工地施工噪声扰民的问题。     

Measurements of occupancy levels in multi-family dwellings—Application to demand controlled ventilation

The occupancy level of dwellings is an important parameter to know to determine the energy efficiency, energy use and indoor air quality, especially in low-energy buildings where the user-related energy uses, such as household electricity and domestic hot water heating, are significant parts of the energy balance in a building. For residential buildings, there is a lack of occupancy level data, which also needs to be resolved over time, in a way so that both short term and long term variations can be described. As a part of an ongoing study, occupancy levels were measured as building average levels in 18 apartment buildings containing 342 apartments in total with readings every 30 min for more than a year. Averages and standard deviations of occupancy level, and variation in occupancy during the year, week and day respectively are presented. The results show a highly varying occupancy level over time, which indicates the potential of demand controlled ventilation in dwellings.     

3A住宅楼板隔声的工程实践

针对住宅楼板隔声的重要性,阐述了楼板中噪声的传播和控制措施,介绍了3A住宅楼板隔声的施工,楼板隔声测试结果表明：客厅橡胶颗粒隔声方案和卧室木地板改进做法隔声方案均能起到明显的降低楼板撞击声的效果。     

A performance comparison of passive and low-energy buildings

This paper compares apartments in two residential blocks in Vienna; one passive and the other one low-energy. These blocks were constructed simultaneously in the same location and with comparable building construction features and floor plans. The main difference between the two blocks (other than the higher thermal insulation level in the passive building) lies in the ventilation system: passive buildings deploy controlled ventilation, whereas the low-energy buildings rely mostly on user-operated natural (window) ventilation. We measured indoor environmental conditions (indoor air temperature, relative humidity, and CO₂ concentration) in two units of each block over a period of five months. Additionally, the buildings were compared in view of operation and embodied energy use, CO₂ emissions, and construction costs.     

哈尔滨历史街区声源及声喜好研究

声环境是历史街区物理环境的重要组成部分,但相关研究还不多见,为了解历史街区声环境的特征及不同人群对街区声环境的主观喜好,该文选择了哈尔滨具有代表性的4个历史街区进行实证研究。在这4个街区内布置了53个测点,对街区内不同地点的等效声压级进行实地测量,并随机发放了543份问卷,以调查各街区内声源及人们对不同声音的态度。结果表明：在4个街区内有83%的测点等效声压级都超过60dBA,交通噪声是非交通管制历史街区的主要噪声源,在交通管制地区商业噪声为主要声源,叫卖声比重较大;在以休闲旅游功能为主的街区,音乐是主要声源。人们对自然声音及传统有意义的声音较喜欢,对工业噪声最不喜欢。     

Schallschutz mit schalldämmenden Lüftungsgittern

Sound protection using sound‐absorbing ventilation grilles. Sound‐absorbing ventilation grilles are used for supply and exhaust air openings in buildings, in naturally ventilated multistorey car parks, and for screening noise‐emitting equipment requiring a flow of air. The sound insulation of different ventilation grilles was measured in the laboratory. A nomogram taking account of the gap length and width was developed for estimating the weighted sound reduction index of typical sound‐absorbing ventilation grilles. Suggested spectrum adjustment values for the weighted sound reduction index are provided.     

声强测量隔声技术及其在绿色建筑评价中的应用

首先分析了声压法测量隔声量的原理,指出其存在的不足。结合声强法的研究进展和声强法测量隔声量的原理,指出声强法具有较高的信噪比、能抑制侧向传声和探测隔声薄弱环节等优点。通过对门缝密封前后门的隔声量的现场测量,证明声强法对探测隔声薄弱环节的有效性。建筑和建筑构件隔声量的声强法测量有望为绿色建筑声环境评价提供新的更可靠的手段,测量结果可为改善隔声量提供重要信息。     

基于ASA的节能建筑围护结构传热系数实测与分析

随着国家对节能减排及可持续发展战略的实施.一种基于ASA的新型建筑材料被引入国内市场.以北京昌平某一采用该技术的生态节能示范房为研究对象.分别采用热箱法和热流计法进行围护结构传热性能测试.测试结果表明,基于ASA的新型节能建筑具有较好的节能效果,其外墙传热系数平均测试结果为O.716 W/(m2·K),传热系数平均测试结果比理论计算值高19%.     

Predictors of noise annoyance in noisy and quiet urban streets

Objectives

Although noise annoyance is a major public health problem in urban areas, there is a lack of published data on predictors for noise annoyance in acoustically different urban environments. The aim of the study was to assess the predictive value of various factors on noise annoyance in noisy and quiet urban streets.

Methods

Equivalent noise levels [Leq (dBA)] were measured during day, evening and night times in all of the streets of a central Belgrade municipality. Based on 24-hour noise levels, the streets were denoted as noisy (24-hour Leq over 65 dBA), or quiet (24-hour Leq under 55 dBA). A cross-sectional study was performed on 1954 adult residents (768 men and 1186 women), aged 18-80 years. Noise annoyance was estimated using a self-report five-graded scale. In both areas, two multivariate logistic regression models were fitted: the first one with nighttime noise indicators and the other one with parameters for 24-hour noise exposure.

Results

In noisy streets, the relevant predictors of high annoyance were: the orientation of living room/bedroom toward the street, noise annoyance at workplace, and noise sensitivity. Significant acoustical factors for high noise annoyance were: nighttime noise level [OR = 1.02, 95%CI = 1.00-1.04 (per decibel)], nighttime heavy traffic [OR = 1.01, 95%CI = 1.00-1.02 (per vehicle)]; or day-evening-night noise level (Lden) [OR = 1.03, 95%CI = 1.00-1.07 (per decibel)]. In quiet streets, the significant predictors were: noise sensitivity, the time spent at home daily, light vehicles at nighttime or heavy vehicles at daytime.

Conclusions

Our study identified subjective noise sensitivity as a common annoyance predictor, regardless of noise exposure. Noise levels were important indicators of annoyance only in noisy streets, both for nighttime and 24-hour exposure. We propose that noise sensitivity is the most relevant personal trait for future studies and that nighttime noise levels might be as good as Lden in predicting annoyance in noisy urban areas.     

Optimum insulation thicknesses for building walls with respect to cooling and heating degree-hours in the warmest zone of Turkey

Thermal insulation is one of the most effective energy conservation measures for cooling and heating in buildings. Therefore, determining and selecting the optimum thickness of insulation is the main subject of many engineering investigations. In this study, the determination of optimum insulation thickness on external walls of buildings is comparatively analyzed based on annual heating and cooling loads. The transmission loads, calculated by using measured long-term meteorological data for selected cities, are fed into an economic model (P₁−P₂ method) in order to determine the optimum insulation thickness. The degree-hours method that is the simplest and most intuitive way of estimating the annual energy consumption of a building is used in this study. The results show that the use of insulation in building walls with respect to cooling degree-hours is more significant for energy savings compared to heating degree-hours in Turkey's warmest zone. The optimum insulation thickness varies between 3.2 and 3.8 cm; the energy savings varies between 8.47 and 12.19 $/m²; and the payback period varies between 3.39 and 3.81 years depending on the cooling degree-hours. On the other hand, for heating load, insulation thickness varies between 1.6 and 2.7 cm, energy savings varies between 2.2 and 6.6 $/m², and payback periods vary between 4.15 and 5.47 years.