Einführung eines Δλ‐Zuschlags und Quantifizierung des ΔUr‐Zuschlags für Umkehrdächer mit geschlossenen Deckschichten aus Dachbegrünungen,Gehwegplatten und Ortbetonbelägen: Teil 1: Ausgangssituation,meßtechnische Untersuchungen und Modellbildung für XPS‐Dämmstoffe

Introduction of a Δλ‐correction on thermal conductivity and quantification of the ΔU_r correction for inverted roofs with closed coverings as green roofs, paving and concrete slabs. Part 1: Starting point, measurements and analytical model of extruded polystyrene (XPS) boards. Within the European harmonisation of standards the evaluation of the thermal insulation for inverted roofs in EN ISO 6946 will be changed to get a uniform calculation basis in European countries. Annex D4.3 of EN ISO 6946 defines a ΔUr‐correction procedure to consider the additional heat loss due to the water flow off between the thermal insulation and the waterproofing layer, the drainage factor f is not specified yet. Field studies show that accumulation of humidity in the XPS insulation board occurres due to condensation of water vapour by diffusion during the heating period and depending on design and climate conditions, such conducting to a successive increase of the thermal conductivity of the insulation. This increase is not quantified by a Δλ‐correction until now. Based on a model analysis a valuation of the required correction factor is deducted. For a uniform evaluation of the thermal insulation during design life the introduzction Δλ‐correction and adjustments on U_r‐correction in EN ISO 6946 annex D.4.3 are necessary.     

Seasonal heat flux properties of an extensive green roof in a Midwestern U.S. climate

Green roofs, or vegetated roofs, can reduce heat flux magnitude through a building envelope as a result of insulation provided by the growing medium, shading from the plant canopy, and transpirational cooling provided by the plants. This study quantifies the thermal properties of an inverted 325 m² retro-fitted extensive green roof versus a traditional gravel ballasted inverted roof in a Midwestern U.S. climate characterized by hot, humid summers and cold, snowy winters. In autumn, green roof temperatures were consistently 5 °C lower than corresponding gravel roof temperatures. Even during chilly and moist conditions, the heat flux leaving the building was lower for the green roof than the gravel roof. Temperatures at the top of the insulation layer were more variable for both green roof and gravel roof on winter days with no snow cover than on days with snow cover. Variation in temperatures between roof types in spring was similar to those in autumn. Peak temperature differences between gravel and green roof were larger in summer than other seasons (sometimes by as much as 20 °C). Over the course of a year (September 2005-August 2006), maximum and minimum average monthly temperatures and heat fluxes were consistently more extreme for the gravel roof than the green roof.     

Options to reduce the environmental impacts of residential buildings in the European Union—Potential and costs

A typology of buildings representative of the building stock for the EU-25 was developed characterizing 72 building types in terms of their representativity, geographical distribution, size, material composition, and thermal insulation. The life cycle impacts of the building types were calculated for different environmental impact categories both at building and EU-25 level. The use phase of buildings, dominated by the energy demand for heating is by far the most important life cycle phase for existing and new buildings. The environmental impacts were allocated to single building elements. Ventilation, heat losses through roofs and external walls are important for a majority of single- and multi-family houses. Three improvement options were identified: additional roof insulation, additional façade insulation and new sealings to reduce ventilation. The measures yield a significant environmental improvement potential, which, for a majority of the buildings types analyse represent at least 20% compared to the base case. The major improvement potentials at EU-level lie with single-family houses, followed by multi-family houses. Smaller reductions are expected for high-rise buildings due to the smaller share in the overall building stock. For both roof insulation and reduced ventilation, the measures were shown to be economically profitable in a majority of buildings.     

A simplified method for calculating heat losses to the ground according to the EN ISO 13370 standard

Heat losses from buildings through contact with the ground, especially in the case of large buildings, have a strong influence on energy demand. Various methods for calculating these heat losses are available, including one method that is defined by the EN ISO 13370 standard. Due to the complexity of this method, we have developed a method that is presented in this paper. Using our method we have calculated weight factors for buildings with and without basements with a variety of thermal transmittances for the contact between the building and the ground. Also, the number of influential parameters used in EN ISO 13370 is reduced. Our simplified method is particularly appropriate for use in the process of designing the thermal insulation for buildings and determining the specific heat losses from buildings.     

Green roof energy and water related performance in the Mediterranean climate

Performance of vegetated roofs are investigated in terms of their expected benefits for the building and the urban environment, due to their recognised energy and water management potential scores. A review of related worldwide experiences is reported for comparison purposes. The investigation is here performed within the specific climatic context of the Mediterranean region. Full-scale experimental results are provided from two case studies, located in north-west and central Italy, consisting in two fully monitored green roofs on top of public buildings. The attenuation of solar radiation through the vegetation layer is evaluated as well as the thermal insulation performance of the green roof structure. The daily heat flow through the roof surface is quantified showing that the green roof outperforms the reference roof, therefore reducing the daily energy demand. As for water management, it is confirmed that green roofs significantly mitigate storm water runoff generation – even in a Mediterranean climate – in terms of runoff volume reduction, peak attenuation and increase of concentration time, although reduced performance could be observed during high precipitation periods.     

倒置式屋面新型隔热防水技术

结合倒置式施工特点 ,介绍了一种利用自行研制的防水隔热块和设置预防水层进行建筑屋面的新型隔热防水工程施工方法。该技术不仅保障了屋面具有优良的保温隔热功能 ,而且隔热块本身的自防水性和设置的预防水层构成复合防水能有效地保证屋面的抗渗漏性 ,有很好的市场推广应用价值和开发前景。     

长沙地区几种屋面隔热性能的测试研究

屋面的隔热性能对顶层住户夏季室内热环境影响很大,因此对几种常用屋面的实际隔热效果进行测试研究,具有实用价值。选择长沙市区某住宅小区两栋相邻的住宅,在2013年夏季按住宅屋面常用构造做法设置了几种实验模块,在外界条件、层高、墙体等都相同的情况下,连续测试各模块屋面的内表面温度、室内空气温度、室外空气温度并进行对比分析。结果表明:种植屋面的隔热效果最好;无隔热措施传统屋面的隔热效果较差,增设保温层后,其隔热效果有一定提高,如果外表面再刷白,隔热性能明显改善;通风屋面有一定的隔热效果,加设保温层后效果更好。     

超隔热屋盖——刚性蓄水屋面的尝试与应用

总结了南方地区屋面隔热层的做法和隔热效果 ,并分析和比较了不同隔热屋面的特点。从理论分析和具体工程实践角度提出了利用现浇混凝土刚性蓄水屋面改善隔热效果的技术。     

Analysis of the influence of installation thermal bridges on windows performance: The case of clay block walls

The building's energy performance is the result not only of material and component performances, but also of the way the components are interconnected. Concerning windows, their energy performance, which is usually evaluated by using the glass and frame heat transfer coefficients and the linear heat transfer coefficients of the glazing spacer, depends also on the frame installation. In this paper the entity of thermal losses due to the frame installation has been evaluated in terms of linear thermal transmittance calculated in accordance with the standard EN ISO 10211:2007 using THERM 5.2. The analysis of thermal bridges between a wooden frame window installed into two different kinds of external clay block walls has been carried out. The linear thermal transmittances have been calculated for three cases regarding the position (external, internal, and intermediate) and three concerning the insulation of the hole perimeter (non insulated, insulated and with insulation over fixed frame). The impact of the window installation on thermal losses has been estimated and its dependence on different sizes has been evaluated. A new graphical representation has been suggested. The frame position and the configuration of the window hole insulation result to have a relevant impact on the overall thermal performance of the considered window.     

Biophysical properties and thermal performance of an intensive green roof

Green roofs have been increasingly enlisted to alleviate urban environmental problems associated with urban heat island effect and stormwater quantity and quality. Most studies focus on extensive green roofs, with inadequate assessment of the complex intensive type, subtropical region, and thermal insulation effect. This study examines the physical properties, biological processes, and thermal insulation performance of an intensive green roof through four seasons. An experimental woodland installed on a Hong Kong building rooftop was equipped with environmental sensors to monitor microclimatic and soil parameters. The excellent thermal performance of the intensive green roof is verified. Even though our site has a 100 cm thick soil to support tree growth, we found that a thin soil layer of 10 cm is sufficient to reduce heat penetration into building. Seasonal weather variations notably control transpiration and associated cooling effect. The tree canopy reduces solar radiation reaching the soil surface, but the trapped air increases air temperature near the soil surface. The substrate operates an effective heat sink to dampen temperature fluctuations. In winter, the subtropical green roof triggers notable heat loss from the substrate into the ambient air, and draws heat upwards from warmer indoor air to increase energy consumption to warm indoor air. This finding deviates from temperate latitude studies. The results offer hints to optimize the design and thermal performance of intensive green roofs.     

太阳能集热器在平屋面住宅上的应用

文章以太阳能集热器在住宅平屋面上的应用实例,对我国多数住宅建筑的平屋面结构,既解决了室内的节能保温,也利用了能源解决热水的使用。     

Investigation of green roof thermal performance in temperate climate: A case study of an experimental building in Florianópolis city, Southern Brazil

Green roofs have been investigated as a bioclimatic strategy to improve the energy efficiency of buildings. Quantitative data on this subject are still needed for many specific climatic conditions. This paper deals with the investigation of the green roof thermal performance of an experimental single-family residence in Florianópolis (SC, Brazil), a southern city with a temperate climate. Field measurements during a warm period (01-March-2008-07-March-2008) and during a cold period (25-May-2008-31-May-2008) included internal air temperature of rooms, internal and external surface temperature of three types of roofs (green, ceramic and metallic), heat fluxes through these roofs, green roof's temperature profile, water volumetric content in substrate layer and meteorological data. During the warm period, the green roof reduced heat gain by 92-97% in comparison to ceramic and metallic roofs, respectively, and enhanced the heat loss to 49 and 20%. During the cold period, the green roof reduced heat gain by 70 and 84%, and reduced the heat loss by 44 and 52% in comparison to ceramic and metallic roofs, respectively. From the derived data it has been confirmed that green roof contributes to the thermal benefits and energy efficiency of the building in temperate climate conditions.     

Messtechnische Analyse flachgeneigter hölzerner Dachkonstruktionen mit Sparrenvolldämmung — Teil 2: Nicht belüftete,extensiv begrünte Dächer mit Zellulose‐ und Mineralwolledämmung

Im gegenständlichen zweiten Teil dieser Aufsatzreihe werden die Messwerte aus zwei Gründachelementen, welche zum einen mit Mineralwolledämmung und feuchteadaptiver Dampfbremse und zum anderen mit Zellulosedämmung und Vliesdampfbremse ausgeführt sind, diskutiert. Dabei zeigt sich, dass die Temperatur auf der Dachabdichtung neben den Witterungsbedingungen auch vom Bewuchsgrad des Gründaches abhängt. Aufgrund der geringen sommerlichen Umkehrdiffusion der Gründächer kommt es zu erhöhten Luftfeuchten im Gefach. Dies führt beim Gründach mit Mineralwolledämmung zu erhöhten Materialfeuchten. Das Gründach mit Zellulosedämmung weist diese erhöhten Materialfeuchten hingegen weniger stark auf. Trotz der teilweise lang andauernden hohen Feuchtelast im Gefach der beiden Gründächer konnten weder Schimmel‐ noch holzzerstörende Pilze in diesen entdeckt werden. Measuring investigations of the hygrothermal behaviour of timber flat roofs — Part 2: Non‐ventilated green roofs with cellulose and mineral wool insulation. In the second part of this article serial the measuring values of two green roof elements made of mineral wool insulation with a moisture adaptive vapour retarder and cellulose insulation with a fibrous vapour redarder are discussed. It is shown that the roof surface temperature, beside the weathering conditions, depends on the level of plant coverage. Because of very low drying potential of green roofs high air humidity occurs in the cavity. This leads to higher material moisture content in the element with mineral wool insulation. The green roof element with cellulose insulation shows this higher material moisture content less pronounced. Despite high moisture loads in the cavities of both green roof elements no mould or rot could be found in the investigated roofs.     

Lineare Wärmebrücken in vakuumgedämmten Konstruktionen

Linear thermal bridges in vacuum insulated constructions. Continuously rising demands on the structural thermal insulation of heated buildings lead under certain conditions to high efficient insulation materials, which achieve its efficiency by using the vacuum technology. Inside these elements there is a medium vacuum that has to be durable to guarantee the excellent heat insulating characteristic. For that purpose a non‐permeable enveloping of the core material is essential, which breeds around the element edges increased heat losses, especially referring to the element joints concerning large vacuum insulated areas. This paper quantifies these additional heat losses for different constructions based on measurements.     

Suitable roof constructions for warm climates—Gazimağusa case

This research aims to find the suitable roof constructions for warm climates. The research has been carried out at Gazimağusa, North Cyprus. With the limited research budget 14 different roof constructions were selected and tested on a test house. These constructions included the types which are widely used in Cyprus and also the new ones. The roof constructions were tested under continuously air-conditioned and non-acclimatised regimes. They were also tested for the risk of condensation.Most of the research on similar aspects were done in terms of energy loss and gain. This research has been designed to study the roof constructions in terms of thermal comfort of the users. Naturally, the roof constructions which have the highest thermal resistance will result in lowest heat gain and loose. In this study instead of finding the roof constructions which gain the least amount of heat during the hottest days of summer or the ones which loose the least amount of heat during the coldest days of winter, it was aimed to find how much they provide thermal comfort throughout the year.In this respect, the roofs with thermal insulation showed the best performance. The location of the thermal insulation materials towards the inner surface of the section increased the performance. Inclined timber roof constructions on reinforced concrete ceiling save the buildings from solar bombarding in summer. However, to prevent the humidity accumulated, the attic space should be very well ventilated. On flat roofs, not only the thermal resistance of the roof section, but also the light reflectance of outside surface materials effected the thermal performance. Outside surface materials with very high light reflectance reduced heat gain in summer considerably.In buildings which are air conditioned in summer, there is condensation risk. The defects due to this condensation can be avoided by the use of thermal insulation materials which are not effected from water. There is also condensation risk for winter. However, it was found that this condensation can dry if the building is ventilated.     

中航工业园11号机加厂房屋面防水设计与施工

以中航工业某航空工业园机加厂房屋面为例,介绍了TPO单层屋面系统在大型厂房金属板屋面上的应用情况.屋面防水采用TPO卷材作为主要防水材料,塑料套筒加螺钉机械固定,结构板之上设置隔汽层后再铺设保温层,保证项目屋面防水保温系统的稳定可靠.     

硬泡聚氨酯防水保温复合屋面的工艺与特性

介绍了一种以硬泡聚氨酯和聚合物砂浆组成的新型防水保温复合屋面 ,该复合屋面与传统的屋面相比 ,具有自重轻 ,强度高 ,整体性好 ,保温、防水能力强 ,施工迅速 ,操作简便的特点 ,可适用于任何形状的屋面。     

玻化微珠保温砂浆屋面保温技术研究

结合目前屋面保温材料存在的问题,探索使用具有良好保温、防火作用的玻化微珠保温砂浆作为屋面的保温层。主要介绍了玻化微珠保温砂浆的性能、屋面保温层的构造做法、与普通保温材料的热工性能对比以及工程应用,证明了玻化微珠保温砂浆在屋面节能中的可行性。     

屋面保温隔热材料在我国村镇住宅中的应用研究

在分析我国农村屋面保温隔热材料现状的基础上,从材料的角度分析了适合我国村镇住宅使用的屋面保温隔热材料。我国广大村镇地区屋面能耗损失占建筑总能耗的比例远远高于城市,减少村镇住宅的建筑能耗,对于推动新农村建设和发展具有重要意义。     

土壤含湿量对绿化屋顶隔热性能影响的数值研究

绿化屋顶因其特有的蒸发作用而展示出独特的隔热性能,其能力就如同给建筑增加了被动降温装置一样。本文用数值模拟的方法来分析土壤水分在绿化屋顶隔热系统中的作用,比较分析了间歇灌溉、连续灌溉和不灌溉三种模式下不同含湿量对屋顶传热的影响。研究得出：绿化屋顶隔热能力与土壤湿度呈正相关;采用间歇灌溉,屋顶热流密度对土壤湿度反应更敏感,在土壤含湿量不超过0．2时,随着湿度的增大,热流显著降低,在含湿量超过0．3后,热流反应较为迟钝;采用连续灌溉,屋顶的隔热性能较间歇灌溉提高3—4倍。