Untersuchung des Wärmeschutzes von Außenecken über unbeheizten Kellern in Wohngebäuden – die Achillesferse von massiven Außenwänden mit äußerer Wärmedämmung?

Examination of the thermal insulation characteristics of external corners above unheated basements in dwellings – the Achilles' heel of heavy‐weight external walls with thermal insulation on the outside? External walls in dwellings consist often of a heavy‐weight wall and a thermal insulation fixed outside. With this construction the insulation of the external wall is separated by the plinth of the external wall from the thermal insulation incorporated in the slab above an unheated basement. This results in a thermal bridge along the edge of the basement slab. The most critical point of the construction with regard to thermal protection occurs at the exterior corner at ground floor level, where two linear thermal bridges overlay. For this reason the minimum inner surface temperature of the corner is used to estimate the heat protection of the construction. A number of calculations of the minimum temperature at the interior surface of this three dimensional thermal bridge is performed to evaluate the parameters of the adjacent construction details which affect the minimum temperature at the inner surface of the corner. To reach the minimum temperature at he inner surface of the corner of 12.6 °C demanded by the German standard DIN 4108‐2 as the minimum requirement of heat protection for thermal bridges, thermal resistances of the whole wall construction much higher than 1.2 m²K/W are necessary. For this construction type of exterior walls a thermal resistance of 1.2 m²K/W as demanded in table 3 of the German standard DIN 4108‐2 as a minimum heat insulation for exterior walls can be shown to be insufficient to assure a minimum temperature of 12.6 °C at the inner surface of the corner at ground floor level. Thus it is proposed to add additional notes concerning this construction type in this standard.     

ThermoShield – ein Beitrag zur Wärmedämmung?

ThermoShield – a contribution to thermal insulation? For some time now, so called thermal coatings are being introduced onto the market. Advertisement to these products announce that these coatings reduce heating energy requirement in buildings considerably. These coatings are facade paintings, e.g the product “ThermoShield”, to which microscopic small ceramic bubbles are added. In the product data to these coatings, a heating energy saving up to 30% are mentioned. The manufacturer impute these saving to different effects of the “ThermoShield” coating. To check the upper mentioned promising product properties, the thermal behaviour of test specimens coated with “ThermoShield – Exterieur” are being studied within the scope of a research work at the University of Hannover. The evaluation of the measurement results showed, that the specimens coated with “ThermoShield” did not have the thermal properties expected and that this coating do not show any of the promised thermal insulating properties.     

Dachentwässerungen im Zuge geänderter normativer Anforderungen und sich ändernder klimatischer Einwirkungen – eine Planungsaufgabe?

Roof drainage in the course of changed regulation require‐ments and changed climatic influences – a planning task? The roof and building drainage is supposed to take over the flaw‐less drain of rain water. Still, the roof drainage as planned is “only” designed for a rain of medium intensity. In order to prevent damages through rain of stronger intensity the possibility of an emergency drainage will be planned. The emergency drainage and the ensured roof drainage by regular maintenance are the main drainage requirements. With the new regulation generation, planning and structural design of gutters and fall pipes are first done using basis for assessment of hydraulic nature and statistically backed up rain fall data. Nevertheless, case studies show that there is not enough attention given to the planning and design of roof and building drainage. Not uncommon, the result is water damage to the structure. An analysis of the design method shows that even in this sensitive field of building construction – in opposition to static dimensioning of components – there are usually no safeties planned. However, on the tide of the evolving climatic changes, this would make sense inter alia to prevent overloading and damages.     

Energetischer Wärmeschutz versus hygienischer Wärmeschutz – Sind die derzeitigen Auslegungsklimate für den winterlichen Wärmeschutz geeignet zur Beurteilung der Schimmelpilzgefährdung alter und neuer Bausubstanz?

Energy aspects vs. hygiene aspects of thermal insulation. Are current design criteria for thermal insulation in winter suitable for assessing mould risk in older and new buildings? Determining minimum surface temperatures in affected areas with the aid of thermal bridge calculations is an important basis for analysing mould growth. According to the generally recognised state of the art, calculations are usually based on steady‐state conditions and design data for minimum thermal insulation requirements in winter. This article initially explains the origins of these boundary conditions in the field of thermal insulation and current options and requirements for assessing calculation results. The article then illustrates that, contrary to the conventional view, the “cold, dry” boundary conditions currently used do not necessarily represent the worst case of external climate conditions that can be expected. The authors suggest that the boundary conditions for the calculations should be amended, so that less favourable “mild, damp” external conditions during spring and autumn can be taken into account. Suitable approaches are proposed.     

水域·未来城4^#区域

因：勒·柯布西耶在《走向新建筑》中说：“建筑是体块在阳光下精湛的、正确而出色的表演。”