Stochastic simulation of rain intrusion through small defects due to water rivulet overpressure. Introducing a driving rain leakage potential

There is a need of upgrading the old building stock with respect to the thermal insulation of the building envelope and specifically the façades. There are several systems on the market, and some are quite new and innovative. To bring down the cost some of the systems many are based on prefabricated moisture tight insulated units. This means that in case there is moisture tight barrier on the interior side, two moisture tight barriers surround the wall structure. The leakage of driving rain into the structure then represents a major threat to the durability of these systems. This paper investigates the pressure build up in water rivulets running down a façade acting together with the wind pressure. A driving rain leakage potential is introduced. Using real weather data years and Monte Carlo Simulations, the mean and standard deviation of the annual leakage through small hole is estimated. The examples show that the leakage can reach a level 0-0.5 liter/year for a hole with a diameter of 1-2 mm, and 0.5-3 liter/year for a diameter of 3-4 mm.

Hygro-thermal performance of wooden beam ends: experimental investigations of uninsulated and internally insulated brick wall

Wooden floors were traditionally used in brick apartment houses built at the turn of 20th century in many European cities. Thermal renovation of such houses often involves thermal insulation at interior side of external walls. Internal insulation makes microclimate in the vicinity of wooden beam ends colder and more humid. The real-scale experiment involving a part of wooden floor connected to a 30 cm thick masonry wall was monitored for two consecutive years. Measured data were used to compare microclimate in sealed and open joist pockets. Joist pockets were either placed in the masonry wall with plaster on both sides or placed in the same masonry wall insulated on the interior side (vapour open thermal insulation system). The measured results indicate that the sealing tape alone is not sufficient to keep the relative humidity in joist pockets below 85 % in cold climate and under high internal moisture load. The paper concludes that reasonable trade-off between thermal efficiency, thermal comfort and moisture safety is difficult to reach for masonry with internal insulation and wooden floors. Sealing provisions complemented by tempering of joist pockets are considered as two key technical measures for reliable hygro-thermal performance of wooden beam ends in full-brick masonry with interior thermal insulation in cold temperate climate.

CLOSE-RANGE PHOTOGRAMMETRY PRACTICE: GRAPHIC DOCUMENTATION OF THE INTERIOR OF THE WALLS OF AVILA (SPAIN)

<p><strong>Abstract.</strong> This work presents the results of the photogrammetric survey of the inner side of the walls of Avila. The graphical restitution realized is part of the studies for the Master Plan of the walls of Avila promoted by the Cultural Heritage Institute (IPCE), under the Spanish Ministry of Education, Culture and Sport in 2017. The monument has been extensively drawn throughout history, but there isn’t a complete and detailed planimetric documentation of its whole extent. The huge dimensions of the walls and the different conditions of the visible sectors of the interior side were difficult conditions to overcome. The versatility and great accuracy of photogrammetric method allowed the reconstruction of the interior of the walls in a short time and with accurate results . Moreover the possibility of integrating the results with previous surveys made it possible to present a complete and coherent documentation of the walls. This is an important point and in the research a continuity is sought between restitutions carried out with tools and at different times. In addition, a series of considerations are advanced about the transformation of traditional methods of representation of architectural heritage.</p>

Radiant wall cooling with pipes arranged in insulation panels attached to facades of existing buildings

Radiant systems are being increasingly used for space heating and cooling of buildings. The contemporary research of radiant systems addresses mainly floor and ceiling structures. Research regarding the possibilities of their incorporation in wall structures is lacking, despite their potential advantages. This study addresses a radiant wall system manufactured according to a patent. The patented design involves panels that consist of pipes arranged in milled channels in thermal insulation. The potential advantage of this system is the fact that the thermally active panels can be attached to the facades of existing buildings as a part of their retrofit. Thereby, only minor interventions on the interior side of the retrofitted buildings are needed. To test and improve the design of the wall system, laboratory measurements and computer simulations were performed on a wall fragment for its operation under summer conditions. The results indicate a significant potential for improvement of the patented design by addressing the imperfections in the contact between pipe and wall. Inserting a metal fin between pipe and wall enhanced the cool distribution within the wall fragment considerably. From the three materials of the metal fin considered, using copper led to highest values of the cooling output, followed by aluminium. For these two metals the effect of increasing the thickness of the fin on the cooling output was small. On the contrary, the fin made of steel was the least efficient in terms of cool distribution. In this case the cooling output was most sensitive to the thickness of the fin.

Eight new astrometry results of 6.7 GHz CH3OH and 22 GHz H2O masers in the Perseus arm

We report astrometric results for seven 6.7 GHz CH3OH and one 22 GHz H2O masers in the Perseus arm with VLBA and VERA observations. Among the eight sources, we succeeded in obtaining trigonometric parallaxes for all sources, except G098.03+1.44 at 6.7 GHz band. By combining our results with previous astrometry results (Choi et al. 2014), we determined an arm width of 0.41 kpc and a pitch angle of 8.2 ± 2.5 deg for the Perseus arm. By using a large sample of the Perseus arm (26 sources), we examined the three-dimensional, non-circular motions (defined as U, V and W) of sources in the Perseus arm as a function of the distance (D) perpendicular to the arm. Interestingly, we found a weighted mean of <U > = 12.7 ± 1.2 km s−1 for 14 sources with D < 0 kpc (i.e. sources on the interior side of the arm) and <U > = −0.3 ± 1.5 km s−1 for 12 sources with D > 0 kpc (i.e. sources exterior to the arm). These findings might be the first observational indication of the ”damping phase of a spiral arm” suggested by the non-steady spiral arm model of Baba et al. (2013). The small pitch angle of the Perseus arm (< 10 deg) also supports the damping phase, based on ”pitch angle vs. arm amplitude” relation shown in Grøsbol et al. (2004).

Applicability Analysis of Selected Methods of Determining the Moisture Content of Highly Porous Thermal Insulations

Spray foam thermal insulations are one of new materials, which are now considerably applied in building practice and which are therefore also the aim of current research. In building practice is an effort to apply these materials to very rugged surfaces in both the external and the internal side of the structure. On the interior side, however, the application is connected with the risk of condensation, which is difficult to verify by the measurement. The contribution is focused just on the comparison of methods and measuring devices designed for immediate detection of moisture in the material of sprayed polyurethane foam. The samples of thermal insulation, which have undergone exposing of humidity in accordance with Czech Standards, were compared by the experimental assessment. The obtained results were compared and evaluated, while as expected, the moisture measuring of highly porous thermal insulation is significantly more difficult than the measuring of thermal insulations made of conventional homogeneous building materials.

Analysis of Thermal – Moisture Problems in Massive Wooden Sandwich Structures

This article focuses on hygrothermal problems in massive wooden sandwich structures. Wood in sandwich structures is already artificially dried before processing, and therefore does not further shrink, as it does in the case of log cabins. Analysed sandwich structure is composed from three layers, and is formed of wooden beam in interior side, thermal insulation and wooden beam in the exterior side. The composition of analysed structure is considered in different thickness with respect to the required heat transfer coefficient. Massive wooden beam on the exterior side causes troubles which exhibits in the reducing capacity of diffusion of water vapor. It is therefore possible that water vapor condenses on the interface of wood and the thermal insulation under certain boundary conditions. Therefore, it is appropriate to place massive wooden beam closest to the interior side. This solution would improve the balance of the diffusion permeability to water vapor permeating from the interior side to the exterior side.

The Conscious and the Unconscious in History:Lévi-Strauss, Collingwood, Bally, Barthes

Claude Lévi-Strauss holds that history and anthropology differ in their choice of complementary perspectives: history organizes its data in relation to conscious expressions of social life, while anthropology proceeds by examining its unconscious foundations. For R. G. Collingwood historical science discovers not only pure facts but considers a whole series of thoughts constituting historical life. Also Lévi-Strauss sees this: “To understand history it is necessary to know not only how things are, but how they have come to be.” However, Lévi-Strauss does not perceive the double-sense of history, which can first be a record of historical “conscious” facts and second, a chain of unconscious or half-conscious acts. Like Lévi-Strauss, Charles Bally has derived the main theses of his theory from Saussure. However, contrary to Lévi-Strauss, Bally does not find structures at the inside of the phenomena but at their outside: “Our attention is drawn to the expressive side and not to the interior side of the facts of language.” Bally calls those structures not “history” but “style.” In Roland Barthes’s attempt to establish a structuralist system of fashion we can find a definition of style very similar to Bally’s. In the end, however, none of these thinkers addresses the fact that unconscious relations within historical life are constantly interlocked with conscious elements.