South Wall Research Articles

Thermal performance impacts of vented EIFS assemblies in the cold climate of Southern Ontario

One of the key improvements in EIFS/ETICS is the addition of geometrically-defined drainage cavities at the rear of the continuous insulation layer to allow water that has penetrated the outer EIFS lamina to drain out by gravity to the exterior; and to provide an opportunity for enhancing the convective drying ability of the wall assembly by introducing air flow and moisture exchange between the cavities and the exterior environment. EIFS assemblies with such cavities can be either vented or ventilated depending on the vents size, location and distribution. The integration of these cavities has raised questions regarding their impacts on the thermal performance of wall assemblies constructed of EIFS with such cavities. The principal objective of this research was to evaluate the reduction in the whole-assembly's effective thermal resistance due to the use of vented EIFS in lieu of face-sealed EIFS. Thermal numerical simulations were conducted on models that were validated against experimental results of full-scale field tests conducted in the cold climate of southern Ontario. Reductions in the thermal resistances of vented EIFS assemblies were observed in the range of 1.4–5.3% and 0.1–4.6% for south and north facing walls, respectively. Reducing the spacing between the cavities further reduced the thermal resistances due to increased ventilation. It was also found that the thermal resistances of the lightly and medium insulated south-facing EIFS were lower than their northern counterparts, mainly due to the thermal storage ability of the construction materials. However, heavily insulated EIFS reduces this flux of heat and eventually the south-facing walls' thermal resistances overcome their northern counterparts.

Solar energy absorption effect of buildings in hot summer and cold winter climate zone, China

Making full use of solar energy is a feasible way to reduce building heating energy consumption in winter. A mathematical model is developed to investigate the dynamic heat transfer process in building external walls in the hot summer and cold winter zone of China by employing numerical simulation. Solar energy entering rooms through opaque walls is quantitatively analyzed by excluding the influence of outdoor air temperature on the room's net heat gain. The results indicate that solar energy entering rooms through opaque walls is of the same importance as the solar energy entering the room through a window for reducing building heating energy consumption. The solar absorptance of a south-facing room through the opaque wall can reach 17% when the heat-transfer coefficient of the south wall outer surface is low (i.e., under conditions of calm wind or high building density). With the consideration of solar energy entering rooms through the opaque walls, the reduction of the building heat loss index accounts for 20–80% and 10–45% of the total building heat loss index required by the national design standard (JGJ26, 2010) for the wall with internal and external thermal insulations, respectively. Therefore, a significant reduction in building heating energy consumption can be achieved by appropriate building layout such that the wind speed is reduced near the south walls. In addition, semi-empirical formulas for estimating the room solar absorptance through an opaque wall are given for the condition of consecutive sunny days in winter.

Preliminary Stability and Resistance Analysis of the Cheops Boat

The Cheops Boat is the most complete, largest, and one of the oldest boats ever excavated, but it has received surprisingly little study by Naval Architects. The 43-m boat was constructed around 2500 BC and placed, disassembled, in a pit next to the Great Pyramid at Giza in Egypt. Since its discovery in 1954, there has been speculation about its original design, means of propulsion, and purpose. This article presents previously unpublished results of the first tank testing of a model of the Cheops Boat and some preliminary conclusions about the design, propulsion, and function of the original. It is shown that the stability characteristics of the boat make it suited for carrying lightweight cargo and people in the protected waters of the Nile. Towing tests have shown that the boat can be safely rowed in a variety of wind and current conditions. Windward sailing calculations have shown that, if fitted with sail, then boats such as the Cheops Boat perform well downwind, but sail no closer than a beam reach. During the 1954 clearing of debris from the Giza Plateau, it was noticed that the Great Pyramid's north and west enclosure walls were 23.6m from the base of pyramid, but the south wall was 5mcloser to the base. Careful inspection revealed that the south wall had been built in an asymmetrical location to conceal two boat pits beneath it. The two pits were end to end, one covered by 41 massive limestone blocks and the other by 40. When the eastern pit was opened, the remains of the disassembled boat were revealed. Figure 1 shows photographs of some of the pieces as they were removed from the pit. Remarkably, the 4500-year-old cedar had been so well preserved that it was possible to reassemble this boat like a kit. Even the rope was preserved, and looked like what could be bought today.

Basic performance and future developments of BeiDou global navigation satellite system

The core performance elements of global navigation satellite system include availability, continuity, integrity and accuracy, all of which are particularly important for the developing BeiDou global navigation satellite system (BDS-3). This paper describes the basic performance of BDS-3 and suggests some methods to improve the positioning, navigation and timing (PNT) service. The precision of the BDS-3 post-processing orbit can reach centimeter level, the average satellite clock offset uncertainty of 18 medium circular orbit satellites is 1.55 ns and the average signal-in-space ranging error is approximately 0.474 m. The future possible improvements for the BeiDou navigation system are also discussed. It is suggested to increase the orbital inclination of the inclined geostationary orbit (IGSO) satellites to improve the PNT service in the Arctic region. The IGSO satellite can perform part of the geostationary orbit (GEO) satellite’s functions to solve the southern occlusion problem of the GEO satellite service in the northern hemisphere (namely the “south wall effect”). The space-borne inertial navigation system could be used to realize continuous orbit determination during satellite maneuver. In addition, high-accuracy space-borne hydrogen clock or cesium clock can be used to maintain the time system in the autonomous navigation mode, and stability of spatial datum. Furthermore, the ionospheric delay correction model of BDS-3 for all signals should be unified to avoid user confusion and improve positioning accuracy. Finally, to overcome the vulnerability of satellite navigation system, the comprehensive and resilient PNT infrastructures are proposed for the future seamless PNT services.

Analysis of thermal energy storage system for energy saving reconstruction of building in region with heating provision and high sunshine

This research aims to analyze the effect of phase change energy storage wall on the internal thermal environment in high-sunshine passive solar residential buildings. The residential buildings in Lhasa are taken as research objects, and the differences in indoor and outdoor thermal environments of the residential buildings in winter are first evaluated. Then, the energy storage wall model based on phase change material is constructed, the meteorological data of the winter solstice day is used to simulate, and the changes of the thermal environment in the room are detected. The results showed that the average solar radiation intensity of the dwellings in Lhasa is 441.8 W/m2, and the average scattering intensity is 156.3 W/m2. The average humidity and temperature of outdoor air are 24.4% and 1.54?C, respectively. The temperature difference of the indoor south and north bedrooms is 3.3?C, the internal temperatures of the indoor south and north walls are 13.4?C and 7.9?C, respectively, and the temperature difference is 5.5?C. After the adoption of phase change energy storage materials, the indoor temperatures of the south and north walls on the winter solstice day are 16.75?C and 16.52?C, respectively, with a temperature difference of 0.23?C. The inner surface temperatures of the south wall and the north wall increase by 25.0% and 109.1%, respectively, after adopting the phase change energy storage wall, indicating that applying the phase change energy storage wall to the passive solar residential buildings in Lhasa can effectively improve the indoor thermal environment.

The Corridor

The Corridor Ryan Eric Dull (bio) Alex greer was ready for a change. His job in Baltimore was directionless and his relationships were stale and more and more he felt himself pulled back to Providence, where everything had been fresh and everyone had been alive with passionate intention. On slow afternoons, Alex looked up maps of old streets he half remembered. He perused job listings, applied to a few. He didn’t seriously consider that he might get an offer until he got one, and then it was all scrambling and panic. He was sixty miles out from Rhode Island with a U-Haul full of furniture before he found an apartment ad that seemed all right. Nine hundred square feet on a street he thought he could remember, a nice street, with personable old buildings and a lot of brick. The ad was completely misleading, and the building manager seemed to know it. The apartment was a studio, barely five hundred square feet. “New floor,” the building manager said as they stepped inside. “New moldings.” “This is small,” said Alex. “Oh no,” said the building manager. “No, it’s big.” “It’s not. Look at it.” She looked. An apology flickered in her expression, but she didn’t say anything. She looked and looked. She was an older woman, and small, and she was wearing a huge, gauzy scarf, like something from another century. It would have taken a lot of work for Alex to be mad at her, and he was exhausted. “I can see how it would seem small,” she said. “Thank you.” “But there’s more.” “Where?” The building manager walked Alex to the near corner of the east wall. She gestured, fingers together, to a gap between the east wall and the south wall that stretched from the floor to the ceiling and couldn’t have been more than six inches wide. Alex sighed. The building manager continued to gesture, stabbing toward the gap until Alex came over to look at it more closely. The gap was, in fact, a corridor maybe twenty-five feet long and never wider than about six inches. It had no lights, and so after the first few feet it was dim, nearly dark at the halfway point. At the far end, it opened into another room, only a sliver of which was visible. Alex could see sunlight on a hardwood floor. He leaned into the corridor. His ears brushed the walls. The sharp smell of fresh paint tickled his brain. “How do I get over there?” “However you like.” “Is there another door, or—?” [End Page 99] “No. Just this hallway.” Alex furrowed. “This isn’t a hallway. You can walk through a hallway.” “It connects two rooms. Look at it. It looks like a hallway.” “But how am I supposed to get through?” “You’re not supposed to. You can do it or you can not do it. Whatever you like. Personally, I think it’s nice to have a little extra space, even if you don’t end up using it.” Alex stepped back from the corridor. He was dizzy and tired and he wanted very badly for this transaction to somehow be acceptable so that he could unpack the van and be done moving. “Why is it this way?” he asked. “Why did they do this?” “Before all the renovations, this used to be the middle of the building. And this,” the building manager said, reaching toward the east wall but not touching it, “used to be the elevator. Maybe you can imagine it.” Alex could. Now that he knew to look for it, the apartment had very clearly once been the hallway near an elevator. The east wall dimpled slightly where the door had been covered over. “That elevator was no good. Dingy. And small. The new elevators are beautiful. You saw them. They’re beautiful. You should have seen the party when we opened them. And we freed up all this space. Of course, you can’t get rid of an elevator shaft, not really.” “But why not just extend the wall?” The building manager shifted. “People like to hear nine...

Analysis of optimum insulation thickness for external walls at different orientations based on real-time measurements

In this study, the optimum insulation thickness was calculated for the heating season for external walls in the different directions of a building. For this reason, a building used for housing in Istanbul, Turkey was taken as model. The indoor and outdoor temperatures, along with the interior and exterior surface temperatures of the building?s external walls, were continuously measured using thermocouples and recorded in four different directions throughout the year. The effects of solar radiation, which vary based on the direction, were assessed for the heat transfer through the external walls. The results of this study indicate that the optimum insulation thickness for the north, south, west, and east facing walls should be 6.47, 2.87, 6.97, and 6.98 cm, respectively, based on the differences in the amount of solar radiation exposure of the walls in the different directions. The optimum insulation thickness of the building?s external wall was calculated as 5.25 cm, regardless of its direction. An economic analysis of the thermal insulation cost was conducted using the P1-P2 method, and then the payback periods were calculated. The heating energy consumption of the building designed using the optimum insulation thicknesses, as identified separately based on the direction, decreased by 17%, compared to the present building with 3 cm of thermal insulation.

Fire tests of South African cross-laminated timber wall panels: fire ratings, charring rates, and delamination

Cross-laminated timber (CLT) is a product consisting of multiple timber layers (lamina) face-glued together to form structural wall and flooring systems. Internationally its use is growing rapidly, although its fire resistance is a topic of ongoing research. This study investigates the fire resistance of CLT wall panels manufactured locally from South African pine and eucalyptus, the most commonly used timber species for CLT in South Africa, through SANS10177-2 compliant fire tests of two 100 mm (33-33-33) thick CLT wall panel samples with dimensions of 0.9 m x 0.9 m. In addition to insulation and integrity fire resistance ratings, the study characterises the charring rate and delamination behaviour of CLT. The recommended integrity and insulation fire resistance ratings for the 100 mm thick SA pine and eucalyptus CLT samples is 60 minutes and 90 minutes respectively. The average charring rate calculated for the SA pine CLT and eucalyptus CLT panels was 0.95 mm/min and 0.76 mm/min respectively. These values are higher than charring rates for bulk timber, due to significant delamination observed in both tests. Associated structural fire resistance rating was estimated for each CLT panel by rational design, giving structural resistance times of 29 mins and 36 mins for the SA pine and eucalyptus CLT, respectively. These times are notably smaller than the insulation and integrity fire ratings reported above, but are only relevant to load-bearing walls. As a result, the tested CLT panels can only be used in multi-storey timber buildings as non-loading bearing walls.

Ciklus Svetog Dimitrija u Pećkoj patrijaršiji - I

Ciklus Svetog Dimitrija u Pećkoj patrijaršiji - I

Electronic equipment measuring device for heat quantity through a flat wall

In the paper, an experimental study for calculation the heat quantity through a flat wall by electronic system has been presented. The aim is temperature measurement on outer and inner walls of a room for 20 days at 1-minute interval of measurement. A transient regime has been considered. The data measured has been collected on a non-insulated south wall of a Technical University of Varna campus building. The wall layers parameters have to be known for the choice of surrounding area. In order to reduce errors of the outer side of wall temperature measurement caused by the solar radiation, the temperature sensor has been painted grey. The experimental equipment for the heat quantity measurement consists of two plates, each with 4 temperature fixed in a rectangle. The sensors are situated in а flat area in order to obtaining more precise results of experimental study. The problem has been solved by finding decision of the classic heat conduction equation. The experimental temperatures are treated by microprocessor’s platform based on Arduino board. As a result, the average temperature of each plate with sensors has been estimated.

Experimental Study of Using Thermal Insulation In Buildings Walls To Reduce Heating Load In Al - Kut City

Experimental study has been carried out on a small room model constructed from sandwich panel in Al-Kut city to reduce the heating load in winter season. Three types of thermal insulation were used; (Glass wool, Air gap and Sawdust). The room model dimensions were (2m length x2m width x2.4 m height). Room's south wall includes two openings of 0.3m width, 1m height. The first opening is closed by common bricks only, while the second opening is built with double walls from brick separated by thermal insulation of thickness 2cm. The results show that the maximum energy saving of heating load at night time when using thermal insulation were.69%, 58.4%, and 53.6%for glass wool, sawdust and Air gap respectively.

Steady-state and time-dependent heat fluxes through building envelope walls: A quantitative analysis to determine their relative significance all year round

The selection of the best type of building envelope wall for a given location and the calculation of the heat flux exchanged with the exterior environment are key issues in avoiding undesirable heat losses and gains, thus contributing to energy saving. The total heat flux transmitted by conduction through opaque envelopes, driven by daily and seasonal variations in the outdoor air temperature and solar irradiance, can be regarded as the sum of steady-state and time-dependent contributions. This paper presents a novel analytical method to calculate and compare both heat fluxes for a full year and the most significant south and north wall orientations, considering the materials used and the location of the construction. The purpose is to provide builders with objective information to optimise the choice of the building envelope materials during the design stage, taking advantage of both steady-state and dynamic features of the walls. The quantitative analysis is applied to three types of envelope walls of buildings located at an intermediate latitude in the southern hemisphere and low altitude above sea level, but it can be extended to any other type of building envelope and geographical site. The effects of solar irradiance on heat conduction are considered using the equivalent sol-air temperature. The results show how the relative significance of each heat flux depends on the type and orientation of the wall and, consequently, the early comparison between the steady-state and dynamic heat approximations ensures the most suitable building envelope for the specific construction purposes.

Hatshepsut’s Punt Reliefs: Their Structure and Function

The article examines the layout of Hatshepsut’s Punt reliefs, proposing a new interpretation of their internal structure and ideological function within the decorative programme of the Deir el-Bahari temple. The author argues that the reliefs form a cycle of subsequent scenes, starting at the southernmost end of the west wall, continuing through the south wall up to the northern part of the west wall. As for the scenes represented on the northernmost end of the west wall and on the north wall, it is argued that they should be viewed as forming a single ideological entity, which at the same time corresponds to the long historical inscription placed on the easternmost end of the south wall. That way the reliefs reflect both aspects of Egyptian eternity: the linear (in the cycle of subsequent episodes) and the circular one (in the ideological link between the southern- and northernmost extremities of the Punt Portico). As for the function of the reliefs, it is argued that they were supposed to magically repeat Hatshepsut’s Punt expedition and thus provide her divine father Amun-Ra with all exotic products necessary in his cult. The author also tries to demonstrate, how Hatshepsut was gradually identified with the goddess Hathor in her aspect of the Lady of Punt and the female counterpart of Amun-Ra throughout the Punt reliefs.

Back-Analysis of the Bingham Canyon South Wall: A Quasi-static Complex Slope Movement Mechanism

A 610-m-high portion of the South Wall of the Bingham Canyon open pit has experienced slow-moving slope deformations several times during spring melt until the movement was stabilized approximately 7 years ago. To develop and optimize life of mine slope designs, an understanding of the mechanism(s) and associated material strength parameters, was required. A back-analysis and calibration of the strength parameters for the salient rock mass and structural features was undertaken. The back-analysis consisted of understanding the conditions and trigger for the slope movement and adjusting strength parameters to match available monitoring data (time-domain reflectometer cables, inclinometers, interferometric radar data, etc.). The trigger for the movement was attributed to the spring high-perched water levels in the upper part of the wall. A FLAC3D model was built to back-analyze and capture the complex behavior of the slope during the high deformation period (August 2011). The back-analysis was consistent with the conceptual model and indicated that the slide was composed of mixed mechanisms, namely, a structurally controlled mechanism for the upper wall and a rock mass controlled mechanism for the lower wall (toe). The analysis supported by a converging FLAC3D model, were used to guide mining engineers in developing robust pit design in the South Wall. Today, the O-Slide instability is being fully managed by rigorous monitoring, implementation of a toe buttress, successful dewatering efforts, and unloading of the movement mass as another slice of mining advances down the South Wall.

Design, optimization and performance analysis of an asymmetric concentrator-PV type window for the building south wall application

The development of PV type window for building south wall integration is a promising concept, which provides a solution to the energy crisis and environment pollution problem. Thus in this paper, an asymmetric concentrator is proposed, and through the simple concentrator array optimization process, the asymmetric concentrator-PV type window can be designed, which provides the electricity generation and incorporates the function of daylighting at the same time. The optical models for the concentrator design and daylighting analysis are built and experimentally validated. The optical performance of the asymmetric concentrator has been analyzed. Considering that the incidence angles of sunrays on the building south wall remain at a high level throughout the year, the shading effect should be seriously considered. In order to reduce the shading effect between each concentrator array, the shading effect has been predicted and an arrangement optimization strategy by setting gaps between each concentrator array is presented. It was found that these gaps could alleviate the shading effect, which will also further allow the function of daylighting. Through the simulation analysis, it was found that the asymmetric concentrator can attain a large acceptance range of 10°–85° while maintaining high optical efficiency and the asymmetric concentrator-PV type window can achieve the daylighting efficiency of 4.0% to 21.8%, thus it can confirm good annual concentrating PV and daylighting performance. At last, a typical office room (the length, width and height are 3.4 m × 3.0 m × 3.3 m) installed with the asymmetric concentrator-PV type window is modelled and the illuminance distribution on the ground floor at various incidence angles is determined with the solar irradiance set at 500 W m−2. Besides of that, the energy distribution for the electricity generation and daylighting at various incidence angles is also indicated. Through the analysis, the asymmetric concentrator-PV type window is proved suitable for building south wall integration, which can efficiently use the solar energy for the domestic use, in the forms of electricity and daylighting.

Simulative optimization on energy saving performance of phase change panels with different phase transition temperatures

A new type of a phase change material (PCM) room containing CaCl2·6H2O-Mg(NO3)2·6H2O/expanded graphite (EG) with different phase transition temperatures was proposed. PCM panels with a lower phase transition temperature were active in heating seasons, and PCM panels with a higher phase transition temperature were active in cooling seasons. The effects of the PCM panels and different parameters on the thermal behavior of concrete rooms used for annual energy management were investigated by using the validated numerical model. The energy demand was used as an evaluation index. The results indicated that a smaller energy demand could be obtained by placing the PCM panels inside the room. The energy demand was affected by the phase transition temperature. The PCM panels suitable for the roof and south wall were CaCl2·6H2O-2wt%Mg(NO3)2·6H2O/EG and CaCl2·6H2O-15wt%Mg(NO3)2·6H2O/EG, respectively. As the thickness of the PCM panels increased, the energy demand decreased, but the optimal types of PCM panels for the roof and south wall remained the same. Different climate regions influenced the choice of PCM panels. A climate region with large temperature differences between day and night minimized the energy demand. It is revealed that the PCM rooms exhibited better thermal behavior in both cooling and heating seasons.

Coupling Effect of Space-Arrangement and Wall Thermal Resistance on Indoor Thermal Environment of Passive Solar Single-Family Building in Tibet

In areas where solar energy is abundant, such as the Tibetan plateau, passive solar buildings are attracting more and more attention and becoming a popular form of rural building. However, it is often difficult to achieve the satisfactory indoor thermal environment in a local rural passive solar single-family house. In order to improve the indoor thermal environment of passive solar buildings through building design, a systematic study of rural single-family buildings in Tibet was conducted. The basic parameters were investigated on the outdoor thermal environment, space-arrangement, envelope structure, and the indoor thermal environment. The building model considering space-arrangement modes was developed based on the survey data in multi-space passive solar buildings. The general physical and mathematical analysis models of multi-space passive solar buildings were established based on the heat transfer theory. Furthermore, the effects of space-arrangement and exterior wall thermal resistance on indoor air temperature were analyzed by numerical simulation. Results show that the indoor air temperature of the passive solar building is influenced by space-arrangement and wall thermal resistance together. When the space-arrangement of the building model was changed from “north-south through type” (mode a) to “through and separation combination” (mode b) and “north-south separation” (mode c), the indoor air temperature of the living room increased from 8.8 °C to 10.6 °C and 11.6 °C, with increases of 20.5% and 31.8%, respectively. In addition, equally increasing the thermal resistance of exterior walls in different orientations has different effects on the indoor air temperature. In the space-arrangement mode c, comparing with the temperature increment of the living room and bedroom caused by increasing thermal resistance of the south wall and north wall, the temperature increment of the living room caused by increasing thermal resistance of the east/west wall increased by 151.7% and 32.7%, and that of the bedroom increased by 609.1% and 239.1% respectively. This study can provide a reference for the optimal design of passive solar buildings in solar energy abundant areas.

안악3호 서측실 남벽의 동수부인과 시녀복식 연구

안악3호 서측실 남벽의 동수부인과 시녀복식 연구

Kanatlı Olarak Betimlenen Vaftizci Yahya Figürü

This article contains the theological substructures and the iconographic analysis of the Winged Saint John the Baptist figure. The answer to the question of why John the Baptist was thought as a winged, has been sought out by using the references of Holy Books, examining not only his mission and identity but also his life story It has been established that despite having roots in the 4th century, the first example of Saint John the Baptist as winged was founded at the South transept wall of Saint Achilles Church in Serbia from 13th century. Moreover this special depiction had been included in the iconographic program during the Post-Byzantine period. The icon examples of Winged Saint John are classified into 4 sections as follows: the front, the profile, the part of the composition with other saints and as a secondary figure in his own birth scene. This classification is composed according to the formal differences of those icons.

Thermally responsive coating on building heating and cooling energy efficiency and indoor comfort improvement

Optic-Variable Wall (OVW) using thermally responsive coating on the façades of high-rise residential buildings is assessed by dynamic simulation. Evaluation criteria are energy consumptions (heat flux) during heating and cooling seasons as well as human thermal comfort. For the latter, Discomfort Hours and Discomfort Degree Hours during intermediate seasons are assessed according to the reference comfort zone given by ASHARE adaptive model. Two different cities, Shanghai and Paris, are studied to comparatively assess the effect of using such a coating under the two distinct climates. Results confirm the significant energy saving potential in the order of 8% for actual-stage coating and as high as 15% for the ideal one. Thermal Discomfort Degree Hours as well as Discomfort Hours are also reduced thanks to the tuning effect of the coating. The potential use of the temperature sensitive coating at the south wall (or facing equator) has better effect than walls of other orientations. Compared with the cold climate in Paris, Shanghai has comparable heating and cooling demand and is more adapted to the future deployment of OVW: the same OVW is doubly tuned (17% v.s. 8%) in Shanghai than in Paris, contributing to HVAC saving and improved comfort.