Types Of Ceilings Research Articles

Design solutions to optimise acoustic requirements for specific work activities in open-plan offices

A high level of concentration is required in open-plan offices, which entails an optimized acoustic environment. The aim is to create a fit-employee environment in which speech privacy is guaranteed without compromising the sense of cooperation among occupants. The purpose of this study is to investigate the design solutions which optimize the acoustic requirements of ISO 3382-3 for a specific work activity defined in ISO 22955, such as non-collaborative work, collaborative work between people and mixed between collaborative and non-collaborative. The case study is one open-plan office occupied by 12 workers, which was not compliant with the standard. Acoustic measurements were used to calibrate the acoustic model in the Odeon software. Two screen and cubicle heights, three types of ceilings and two wall absorption configurations have been tested in a matrix of solutions for the office in the simulation model. This allowed us to investigate the design solutions that guarantee optimal values for the acoustical parameters chosen for each specific activity.

METHODS FOR THE PRESERVATION AND RESTORATION OF DUNHUANG WALL PAINTINGS: FOREIGN EXPERIENCE

This article examines the genesis of planning solutions and ceiling designs of Dunhuang cave shrines. Based on the methods of defining features, graphic-and-analytical and system-and-structural analysis, the spread of types of plans and ceilings from dynasty to dynasty has been traced. Using auxiliary methods of historical, mathematical, and comparative analysis, a general picture of the development of the planning structure and constructive schemes of Dunhuang shrines from the Northern Lian period to the Yuan period has been created. By counting the types of plans and ceilings in each period, a group of the most common types of plans was determined: with a combination of larger and smaller rectangles (where the smaller is the altar part of a square or rectangular shape), a plan in the form of a square with a protruding trapezoidal altar, an altar in outline close to a rectangle or trapezoids with rounded corners, a horizontally elongated plan rectangle, based on squares with protrusions. The most common type of ceiling is fu-dou-ding with modifications.

Genesis of the Planning Structure And Ceilings of Dunhuang Sanctuaries

The article is devoted to the study of the genesis of the plans and ceilings of the Dunhuang cave sanctuaries. Based on the methods of graphic-and-analytical, defining features and system-structural analysis, the spread of types of plans and ceilings from dynasty to dynasty has been traced. With the help of a group of auxiliary methods of historical analysis, mathematical analysis and comparative analysis, a general picture of the development of the floating structure and constructive schemes of the Dunhuang sanctuaries from the Northern Liang period to the Yuan period was created. By counting the types of plans and ceilings in each period, a group of the most common types of plans was determined: with a combination of larger and smaller rectangles (where the smaller is the altar part of a square or rectangular shape), a plan in the form of a square with a protruding trapezoidal altar, an altar in outline close to a rectangle or trapezoids with rounded corners, a horizontally elongated plan rectangle, based on squares with protrusions. The most common type of ceilings is fu-dow-din with modifications.

Evaluation of External Light Shelf Performance in Relation to the Ceiling Types Used in Indoor Spaces

A light shelf is a type of natural daylight system that brings natural light from the outside into an indoor space through a reflector and a ceiling surface. The introduction of light shelves has led to studies evaluating their efficiency. However, past studies on light shelves did not consider the diversity of ceiling types when evaluating their performance. Therefore, this study derives fundamental data involving external light shelf designs by evaluating light shelf performance based on the ceiling type present using a light environment simulation method. This study analyzed the indoor illuminance distribution with Radiance to evaluate the performance according to light shelves and indoor space types. The results derived from this study are as follows: (1) In the case of a flat ceiling, the performance of an external light shelf can be improved by increasing its angle and width. However, adjusting the external light shelf angle to 30° during the middle of the season and 20° in winter is ineffective because natural light is not reflected by the ceiling surface. (2) The performance of a light shelf can be improved by increasing the slope and curvature of the ceiling types specified in this study. However, setting the light shelf angle to 30° during the middle season and to 30° and 20° in winter, when external natural light entering the indoor space is not reflected by the ceiling surface, is ineffective due to the low levels of daylight performance, regardless of the type of space. (3) To increase uniformity levels in gable ceilings and curved ceilings, it is advantageous to increase the number of reflections and diffusion areas on the ceiling’s surface due to the uniqueness of these ceiling shapes. Furthermore, the optimal external light shelf angle for these ceiling types differs from that of other types. (4) Regarding the appropriate external light shelf size according to a particular ceiling type, installing an angle-controllable external light shelf with a width of 1.2 m can improve daylight performance.

Experimental studies on the effect of ceiling materials on the sound environment of underpass concourse using the station simulator

Sound environments in railway stations are often noisy because of sound-reflective materials and many noise sources. Especially in underpass concourses, structure-borne sounds are radiated from the ceiling due to vibrations when trains pass by. This results in a high noise level, which often interferes with listening to the announcements. In this study, to examine interior materials that effectively reduce such noise in railway stations, the following measurements and laboratory experiments were carried out: 1) Field measurements of vibrations of the ceiling and environmental sound in stations in Tokyo. 2) Reproduction of vibrations and sounds in the station simulator (full-scale mock-up of a station building), under the four different types of ceilings. 3) Auditory tests to evaluate the noisiness of train passing sounds and environmental sounds, using reproduced sounds in the station simulator as test sounds. As a result, the ceiling with damping material was effective for structure-borne sound, while the ceiling with porous sound-absorbing material was effective for air-borne sound. This result suggests that it is important to consider the placement of ceiling materials according to the noise situations.

Ceiling damage detection and safety assessment in large public buildings using semantic segmentation

To solve the limitations of traditional on-site inspections by professionals, an automatic method using the semantic segmentation network Deeplabv3+ with transfer learning (TL) is proposed for rapid detection and safety assessment of damaged ceilings in large public buildings after an earthquake. A total of 1389 ceiling images of various scenes are used as the dataset after being manually labeled and divided into four ceiling types: intact, fall-off, suspension, and crack. The model performed excellently in damage detection and location with a pixel accuracy (PA) of 97.23% and a mean intersection over union (mIoU) of 84.18%. Considering the dangerousness of different damage types, the interaction between different damage types, and the ceiling fall-off rate calculated by semantic segmentation results, the safety of the ceiling region is assessed with an accuracy of 98.56%. Some influences are discussed to enhance the detection and assessment ability of the model.

Large-Scale Enclosure Fire Experiments Adopting CLT Slabs with Different Types of Polyurethane Adhesives: Genesis and Preliminary Findings

This paper provides understanding of the fire performance of exposed cross-laminated-timber (CLT) in large enclosures. An office-type configuration has been represented by a 3.75 by 7.6 by 2.4 m high enclosure constructed of non-combustible blockwork walls, with a large opening on one long face. Three experiments are described in which propane-fuelled burners created a line fire that impinged on different ceiling types. The first experiment had a non-combustible ceiling lining in which the burners were set to provide flames that extended approximately halfway along the underside of the ceiling. Two further experiments used exposed 160 mm thick (40-20-40-20-40 mm) loaded CLT panels with a standard polyurethane adhesive between lamella in one experiment and a modified polyurethane adhesive in the other. Measurements included radiative heat flux to the ceiling and the floor, temperatures within the depth of the CLT and the mass loss of the panels. Results show the initial peak rate of heat release with the exposed CLT was up to three times greater when compared with the non-combustible lining. As char formed, this stabilised at approximately one and a half times that of the non-combustible lining. Premature char fall-off (due to bond-line failure) was observed close to the burners in the CLT using standard polyurethane adhesive. However, both exposed CLT ceiling experiments underwent auto-extinction of flaming combustion once the burners were switched off.

Analysis of ceiling type to produce energy efficient residential buildings: case study on housing design of puskim pu-bandung city

Many houses that exist on this earth. Therefore, it is necessary to have tactical and intelligent thinking in designing a home. Many things are rarely considered related to the effects of the design of building elements when related to the temperature or the energy produced. Existing background regarding efforts to reach a comfortable temperature can not only be solved in terms of mechanical systems, but the architectural approach can help and provide a comfortable effect for its inhabitants. This research was conducted to determine the level of thermal comfort or temperature in the room of a residential design that would be related to the size of energy consumption by applying several alternative designs or ceiling forms. This type of research is research using simulation methods through a computer model. The results showed the use of ceiling type Vaulted Ceiling was able to increase the Surface Inside Temperature value by 3 ° C when compared to the type of drop ceiling. The Mean Radiant Temperature value when using the ceiling vault type rises 0.6 ° C and on the acquisition of Operative, Temperature rises 0.3 ° C. The use of insulation material on the roof can significantly reduce Mean Radiant Temperature and Operative Temperature at 1.7 ° C at Mean Radiant Temperature and 0.8 ° C at Operative Temperature. Seeing the results of the simulation in this study, the recommended ceiling type is to use the drop ceiling type because it is quite capable of keeping the temperature in the room not too high so that thermal comfort can be achieved. However, if you want to apply a ceiling design with a model or type of drop ceiling, it is better to use additional insulation material so that the heat transmission temperature is not too high in the room.

Assessment of Natural Radioactivity for Some Secondary Ceilings Samples in Iraq

This research focuses on measuring of specific activity of natural radioactive sources (238U, 232Th and 40K) in some types of secondary ceilings that used as a decorate material and available in Iraqi markets. The measurements were done using gamma ray spectroscopy system that based on NaI(Tl) Detector. Also, the radiological hazard indices have been assessed for all samples in present study. The results show that the specific activity vary from 8.7±0.6 to 32.9±2.3 Bq/kg for 238U, 2.9±0.2 to 40.3±1.5 Bq/kg for 232Th, and 117.4±2.6 to 649.1±7.9Bq/kg for 40K. The latter levels were compared with the world mean values that reported by the UNSCEAR 2008. It was found that all values of 238U and 232Th were below the world wide published values, while the values of only two samples of 40K were above the upper range of the world wide published values. Regarding the average values of radiological hazard risk were found to be within the permissible limit according to the OECD, UNSCEAR 2000, and ICRP. It can be concluded that natural radioactivity levels together with radiological hazard risk studied from the most of the secondary ceilings samples available in local markets of Iraq within natural rates of permissible limits and may not cause any danger to the human when being used.

Effect of different types of ceilings on floor impact sound insulation performance in CLT model building

The floor impact noise generated in a building often causes problems among residents. The floor impact sound insulation performance of timber construction buildings is lower than that of concrete construction. However, due to the large supply of wood and the stress-relieving effects of wood, the use of wood is being promoted around the world. In Japan, the Act on the Promotion of the Utilization of Wood in Public Buildings was enforced to promote the use of CLT (Cross Laminated Timber) for the effective use of wood. We have been experimentally investigating the effect of floor finish structure in CLT model building. In this paper, we report the measurement results of the change in floor impact sound insulation performance when the suspended ceiling structure was changed. As results, it was confirmed that the effect of the sound-absorbing material in the ceiling cavity and the effect of the double-layer ceiling board were effective. In addition, it was clarified that the dry-type double floor structure with rubber vibration insulator on its legs is an effective floor finish structure for improvement of heavy and light weight floor impact sound insulation performances.

The effects of acoustical ceiling panel type and penetrations for services on vertical sound isolation inside buildings

Attenuation of sound transmitting between rooms oriented over one another inside buildings is studied. Transmission loss and sound transmission class were measured by an independent, accredited, acoustics laboratory with and without a variety of modular acoustic ceilings suspended under a baseline concrete floor structure. Ceiling panel material types include stone wool, fiberglass and mineral fiber. Ceilings were tested with and without the presence of service penetrations for supply air diffusers, return air grilles and light fixtures. Some ceilings were also scanned with a sound intensity probe and the resulting color sound maps are used as a supplemental method of evaluating both isolation and absorption performance of the individual components of the ceiling systems. Results show that while the effects of ceiling panel type on absorption performance, and thus room acoustics, is substantial, the material type and weight of the ceiling panels do not substantially affect the overall isolation performance of the floor-ceiling assembly.

Study on the influence of ceiling tunnel angle on the gas shunting efficiency of urban highway tunnel

In order to analyse the feasibility of setting up a ceiling type purification and ventilation system in an urban highway tunnel and study the parameters of ceiling passage, this paper used Fluent software to carry out the 3D numerical simulation. The velocity and pressure distribution in the tunnel and the shunting efficiency were analysed under different angles between the ceiling passage and the main tunnel. Also, by comparing the velocity and CO concentration distribution in the tunnel, the purification efficiency under different conditions is verified. The results showed that the purification efficiency of a purified system is related to angles. With the increasing of angles, the shunting efficiency decreases. The equipment of the ceiling type purification and ventilation system in the urban highway tunnel can effectively reduce the CO concentration. The results show that it is feasible to install a ceiling type purification system as a new tunnel ventilation method, and it can provide a reference for future engineering design.

Optimal cost-efficiency solution of acoustic treatment for a complex meeting room

Achieving high acoustic quality in meeting rooms is important for intelligibility therefore several measures are needed especially in reflective high volume rooms. This article tackles the method and the solution to renovate a complex enclosure. The study is divided in multiple stages: development of the 3D room model exported in ODEON acoustic software, validation of the actual condition of the room with measurements, proposing and analysing different acoustic ceiling tiles and finally selecting the optimum solution based on the cost and efficacy in reducing the reverberation time (RT). The measured RT was four times higher (3.45 sec at f=1kHz) than the recommended value (0.9 sec at f=1kHz). The numerical simulation results were in accordance with the experimental measurements with errors of less than 0.2 sec. Using the difference between the RT obtained with the acoustic measures and the optimum RT we were able to calculate an efficiency that was later on compared with the cost of the solution. As a conclusion, due to a large diversity of acoustic ceiling types with different prices and sound absorption coefficients it is important, especially for complex room geometries, to run simulations and to perform a cost-efficiency analysis.

Characterisation of air permeability of common ceiling linings and penetrations

PurposeAir permeability of ceiling linings is an important element in understanding air and moisture flux from living spaces into the roof cavity. Ideally, these two spaces are decoupled to avoid transportation of moist indoor air into the attic space, where it can lead to condensation on the cold roof cladding. The purpose of this paper is to experimentally characterise the air permeability of a variety of common ceiling types. The results are given as leakage functions. Characteristic leakage data are also given for several ceiling penetrations. A case study illustrates the relevance of these data.Design/methodology/approachA specially designed test facility allows the installation of different ceiling types of up to 38 m2 in area. Laminar flow elements are used to measure the volumetric flow across the ceiling while recording the pressure difference. The experimental data are fitted to the leakage function equation Q =c (ΔP)n. Ceiling penetrations are characterised in a similar way. For the case studies estimating the transport of moisture into the roof cavity, indoor climate data have been obtained using humidity and temperature sensors.FindingsAir leakage functions are given for a number of common ceiling linings and ceiling penetrations. These data can be used in simulations aimed at modelling moisture flux into the roof cavities. In the case study, the authors also give indoor climate data of residential dwellings in New Zealand.Originality/valueThis paper addresses the need for robust ceiling air permeability data in whole-house temperature and moisture transport simulations.

Experimental and numerical investigation of cooling performance of a cold storage in a pharmaceutical industry

This paper describes the study of cooling performance of cold storage in a pharmaceutical industry. It was intended to investigate the temperature distribution inside the storage that is an important performance factor in pharmaceutical industry cold storage. Cold storage that used is a ceiling type with the liquid bottle loading.Temperature distribution and the storage cooling performance were studied using experimental measurement and numerical simulation. Some variation of bottle arrangement and rack arrangement have been observed to show the impact of distribution temperature and cooling performance of cold storage. Surface temperatures of the bottles were measured with different bottles and rack arrangement. The temperature of cold storage was set to 5°C. In numerical simulation, a transient three dimensional Computational Fluid Dynamic (CFD) model was developed to investigate the cooling performance and temperature distribution inside bottle.At this stage, the results showed that rack arrangement that parallel with the cold room fan and V shape bottle layout has given a good cooling performance (it takes 1480 minutes to reach a stable temperature at the setpoint) and an optimum temperature distribution (with temperature difference of 0.58 °C). For the measurement of the distribution of temperature in the bottle, the mean deviation value between the simulation and the experiment on the measurement of 2 coordinate points (X = 0,1 m, Y = 0,3 m, Z = 0 m and X = -0,1 m, Y = 0,3 m, Z = 0 m) were 5,5 % and 7,6 %.

Multicriteria assessment of selected types of ceilings

The paper compares three systems of the rib-and-slab ceiling: Vector, Rector and Teriva. The following comparison criteria were selected: the tare weight of ceiling beams, execution time, slab faulting, sound insulation, thermal insulation and aesthetics of the lower surface. The results of the multicriteria comparative analysis clearly indicated the advantage of the Vector ceiling, assuming the same weights for all criteria taken into account.

The influence of profiled ceilings on sports hall acoustics: Ground effect predictions and scale model measurements

Over the last few years, reverberation times and sound pressure levels have been measured in many sports halls. Most of these halls, for instance those made from stony materials, perform as predicted. However, sports halls constructed with profiled perforated steel roof panels have an unexpected very low reverberation time in the 125 and 250Hz octave bands. The aim of this study was to provide an explanation for this low-frequency anomaly. A 1:20 scale model of a sports hall was constructed and placed in a small anechoic chamber. The roof could be equipped with differing ceiling types: a flat non-absorbing ceiling, a flat absorbing ceiling, two different profiled non-absorbing ceilings and a profiled absorbing ceiling. With a spark sound source and a small microphone, the impulse-response of the scale model could be registered and analysed. Moreover, a Matlab model was constructed to simulate the acoustic behaviour of the sports hall. This model included the ‘ground effect’ of the roof surface, an effect typically not included in commercial ray-tracing programs. The measurements and the simulations showed that the high sound absorption values of a perforated panel roof structure at 125 and 250Hz can be (partly) explained by its shape. The diffusing properties of the corrugated roof have an effect similar to sound absorption. Because the roof is the largest absorbing surface in a sports hall, this effect can have a significant effect on the low-frequency reverberation time.

PCM cooling ceilings in the Energy Efficiency Center—passive cooling potential of two different system designs

In the Energy Efficiency Center—the new R&D building of the ZAE Bayern—two different PCM cooling ceiling types are installed and monitored in two office rooms. The ceilings are connected to a water circuit and can be used for heating and cooling. The PCM ceilings are prototypes which differ in the positioning of the PCM layer: ceiling type 1 with the PCM on top of and ceiling type 2 with the PCM below the water pipes. It was found, that cooling ceiling type 2 had a better thermal connection between PCM and room. Nevertheless, the passive cooling power of the two different system designs was quite similar when measured as a function of the globe temperature. Passive cooling powers of 10–15W per m2 PCM cooling ceiling area were measured for a globe temperature of 26°C.

Waktu Dengung Ruang Sholat Masjid Desa Berdasarkan Perbedaan Bentuk Plafon

Mosque’s prayer hall needs optimal reverberation time to get clear sound in the mosque, especially during praying. Praying rites need clear sound . “Desa’s” mosques are dominant in quantity in Indonesia. They had many different types. The difference of geometric form affected acoustic performance. In this study, Desa’s mosques would be observed according to their space form: dome, tajug (crown), and flat ceiling. This study would observed six samples of prayer hall, with two samples for each type/form of ceiling: two samples for prayer hall with dome ceiling, two samples for prayer hall with crown ceiling, and two samples for prayer hall with flat ceiling. The result shows that there were no space-ceiling that have optimum reverberation time (RT). All space ceiling type have higher RT than the RT standart. It shows that all the samples perform bad quality of acoustic. According to this research, the best form of ceiling was flat ceiling, while dome ceiling was the worst ones. Keywords: reverberation time, prayer hall of mosque, form of ceiling

A novel method of reverse engineering using axiomatic design

Reverse engineering has been widely used to analyze existing objects such as software systems, products, etc. The main purpose is obtaining information by disassembling a product and finding an improved design. Based on the disassembling work, research for a systematic analysis has been well developed, but reverse engineering has been rarely employed in finding a new (an improved) design of a complex and large scale product. Therefore, even though the ultimate goal of reverse engineering is an improved design (or redesign), the opportunity to make a new feature is rarely given. A novel method of reverse engineering is proposed by using the axiomatic design viewpoint. The method not only keeps the fundamental concept of reverse engineering, but also realizes a new (or improved) design according to proposed procedures such as inference, design improvement module and a qualitative evaluation. A complex and large scale product (a ceiling type air conditioning system) is chosen as a case study to validate the proposed method. As a result, useful information for a new (or improved) design is obtained and also a new part (filter cleaning system) is proposed. The methodology provides a good way to design a new (or improved) product.