Effect of the Orientation on the Comfort of a Building Made with Compressed Earth Block

Thermal comfort is one of the most important requirements that scientists and building designers must meet to ensure the indoor air quality knowing its importance on productivity and the health of occupants. However, it has never been of great concern for architects and architectural historians and seldom explores it. Buildings are the large consumer of the most energy consumption (around 40% worldwide) and generate around 35% of GHGs like CO2 that leads to extreme climate change. Hence, general and specific eco-friendly solutions in the field of building construction are required. Analysis of this study shows that air conditioning consumption can be significantly reduced thanks to the compressed earth bricks and by taking into account the climate and the orientation of the facades. However, this paper establishes viable low-cost option of building energy consumption while maintaining the thermal comfort and good indoor air quality. This work explains the effect of a single residential room orientation, by reducing the thermal amplitude, and improving the thermal phase shift in Ouagadougou climate conditions in April. Internal temperature was modelled with 8 cardinal orientations. The result corresponds to a decrease of thermal amplitude damping greater than 4°C between East-West and North-South sides and, with a thermal phase shift of 4 hours 30 minutes between the Nord and West walls.

Design of Rural Residence Based on Thermal Comfort: A Case Study of Chengdu Area

With the improvement of living standards, peasants have attached increasing attention to quality of living environment, indoor thermal comfort of rural residence has become a functional need of new countryside residence. Chengdu is a foggy area with shorter sunshine hours, humid air, more foggy but fewer windy days, so local residence is likely to be muggy, which influences comfort of residents seriously. According to relevant researches, most rural residences in Chengdu use only natural ventilation, and the indoor thermal comfort is poor. In view of this, this paper tried to improve indoor thermal comfort and quality of living environment from the perspective of residence functional design.

Investigation of Pirnia’s orientation theory (Roon) in Yazd Qajar houses

This paper carefully explains Pirnia’s theory regarding the orientation of traditional Iranian cities and buildings(Roon)and investigates the factors involved in this historic architectural phenomenon.For this purpose,40 traditional Yazd Qajar houses were under study.Most of which are in the Rasteh Roon and close to the southwest direction,and only five contradict the direction that Pirnia had pointed.While the primeval data indicated the theory is strengthening,the investigation followed the fundamental factors behind this event.From the perspective of analysis and discussion on involved factors(climate,topography,aqueducts,urban arteries,politics,trade routes,privacy,noise,view,and religion),it turns out that the direction of the wind and sun had negligible impacts on this orientation,and architects of the Qajar era in Yazd old city did not care about these climate factors.It seems religious factors were more influential.Thus,despite being approvingly referenced in many scientific studies,Pirnia’s orientation theory(Roon)dthe efforts of past Iranian architects to orient buildings in a specific direction due to their unique knowledge of region and climate factorsdbecomes not solid.

Evaluation of Thermal Comfort in the Design of Student Hostel at Federal University of Technology Minna,Nigeria

Buildings are designed to offer protection to the occupants against harsh outdoor environment thereby enhancing optimal indoor comfort.Over the years,there have been a rise in population of students applying for admission into tertiary institution,which has led to an increase in the number of students that resides at the university hostel.These rise in the number of students,has brought about overcrowding and stretching of facilities,with spaces which were originally intended for four students are now been habited by six to eight students thereby causing imbalance in the general indoor climatic condition.The study is aimed at investigating thermal comfort in student’s accommodation in tertiary institutions towards achieving a better thermal condition in the hostel environment.The objective is to evaluate the thermal performance in the student hostel accommodation,and also to identify passive ways of controlling thermal performance in student dwelling buildings at Federal University of Technology Minna main campus,Gidan Kwano.For the purpose of this research work,primary data were collected through the use questionnaire,case studies and observation.Secondary data were collected from available literature,internet,and studying of similar existing facilities.The study revealed that most student hostel possessed few elements of passive cooling technique which in turn deprives students a quality conducive environment.The research recommends that soft landscaping elements should be adopted and deciduous trees planted in the environment for cooling effect during hot and humid period,provision of two openings in each room if possible.This can be achieved through proper building orientation,use of high thermal mass to reduce heat absorption,use of high thermal mass with night cooling,roof,ceiling and attic insulation.Designing in a hot climate area requires lots of consideration,which is mentioned above so as to incorporate a general conducive indoor thermal comfort for the users.

Build orientation determination of multi-feature mechanical parts in selective laser melting via multi-objective decision making

Selective laser melting(SLM)is a unique additive manufacturing(AM)category that can be used to manufacture mechanical parts.It has been widely used in aerospace and automotive using metal or alloy powder.The build orientation is crucial in AM because it affects the as-built part,including its part accuracy,surface roughness,support structure,and build time and cost.A mechanical part is usually composed of multiple surface features.The surface features carry the production and design knowledge,which can be utilized in SLM fabrication.This study proposes a method to determine the build orientation of multi-feature mechanical parts(MFMPs)in SLM.First,the surface features of an MFMP are recognized and grouped for formulating the particular optimization objectives.Second,the estimation models of involved optimization objectives are established,and a set of alternative build orientations(ABOs)is further obtained by many-objective optimization.Lastly,a multi-objective decision making method integrated by the technique for order of preference by similarity to the ideal solution and cosine similarity measure is presented to select an optimal build orientation from those ABOs.The weights of the feature groups and considered objectives are achieved by a fuzzy analytical hierarchy process.Two case studies are reported to validate the proposed method with numerical results,and the effectiveness comparison is presented.Physical manufacturing is conducted to prove the performance of the proposed method.The measured average sampling surface roughness of the most crucial feature of the bracket in the original orientation and the orientations obtained by the weighted sum model and the proposed method are 15.82,10.84,and 10.62μm,respectively.The numerical and physical validation results demonstrate that the proposed method is desirable to determine the build orientations of MFMPs with competitive results in SLM.

A simplified tool for building layout design based on thermal comfort simulations

Thermal comfort aspects of indoor spaces are crucial during the design stages of building layout planning. This study presents a simplified tool based on thermal comfort using predicted mean vote （PMV） index. Thermal comfort simulations were performed for 14 different possible room Layouts based on window configurations. ECOTECT 12 was used to determine the PMV of these rooms for one full year, leading to 17,808 simulations. Simulations were performed for three different climatic zones in India and were validated using in-situ measurements from one of these climatic zones. For moderate climates, rooms with window openings on the south facade exhibited the best thermal comfort conditions for nights, with comfort conditions prevailing for approximately 79.25% of the time annually. For operation during the day, windows on the north facade are favored, with thermal comfort conditions prevailing for approximately 77.74% of the time annually. Similar results for day and night time operation for other two climatic zones are presented. Such an output is essential in deciding the layout of buildings on the basis of functionality of the different rooms （living room, bedroom, kitchen） corresponding to different operation times of the day.

Surface accuracy optimization of mechanical parts with multiple circular holes for additive manufacturing based on triangular fuzzy number

Surface accuracy directly affects the surface quality and performance of mechanical parts.Circular hole,especially spatial non-planar hole set is the typical feature and working surface of mechanical parts.Compared with traditional machining methods,additive manufacturing(AM)technology can decrease the surface accuracy errors of circular holes during fabrication.However,an accuracy error may still exist on the surface of circular holes fabricated by AM due to the influence of staircase effect.This study proposes a surface accuracy optimization approach for mechanical parts with multiple circular holes for AM based on triangular fuzzy number(TFN).First,the feature lines on the manifold mesh are extracted using the dihedral angle method and normal tensor voting to detect the circular holes.Second,the optimal AM part build orientation is determined using the genetic algorithm to optimize the surface accuracy of the circular holes by minimizing the weighted volumetric error of the part.Third,the corresponding weights of the circular holes are calculated with the TFN analytic hierarchy process in accordance with the surface accuracy requirements.Lastly,an improved adaptive slicing algorithm is utilized to reduce the entire build time while maintaining the forming surface accuracy of the circular holes using digital twins via virtual printing.The effectiveness of the proposed approach is experimentally validated using two mechanical models.