Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (...Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (naturally and mechanically ventilated) office buildings in Accra, the Capital city of Ghana using Fanger’s Predicted Mean Votes (PMV) and Predicted Percentage of Dissatisfied persons (PPD) model. The model relates to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (which gives an acceptable temperature range of 23℃ - 26℃) and the International Standards Organization (ISO) 7730. Indoor environmental parameters (temperature and relative humidity) of 4 multi storey office buildings were recorded over a 10 month period. The environmental parameters were analyzed using PMVcalc_v2 software which resulted in the generation of PMV-PPD values. The findings reveal high PMV-PPD values in the Naturally Ventilated Building (NVB) whiles the Mechanically Ventilated Buildings (MVB) fall within the comfort zone. Meanwhile, the Actual Mean Votes (AMV) by the occupants suggest all four buildings are relatively comfortable with the mechanically ventilated offices being more comfortable. Additionally, it is recommended that buildings are orientated with their longer sides facing north-south, with enough shading in order to improve the thermal comfort conditions of work spaces.展开更多
Auditorium buildings are special structures needing much attention for it to function properly. Generally, consideration should be given to seating, sightlines, and acoustic requirements. In addition, the design shoul...Auditorium buildings are special structures needing much attention for it to function properly. Generally, consideration should be given to seating, sightlines, and acoustic requirements. In addition, the design should ensure performer-audience intimacy as much as possible. The focus of the study is to review design strategies for auditoria on the Kwame Nkrumah University of Science and Technology, Kumasi campus towards compliance and to develop solutions for improvements that will enhance the performance of 4 selected auditorium facilities. Case study, observation and measurements were the main strategies used. The results revealed that the approaches involved in auditorium designs are shape, volume, surface boundary dimensions and materials, stage, seating, foyers and sightlines. These parameters are grouped under acoustical, functional and programmatic parameters. Reverberation time calculated was high which indicated speech intelligibility problems, hence, improvement efforts were made to change the floor materials from polished tiles to carpeted floors, and high absorption wall claddings. In the process, the reverberation time was reduced from 1.47 - 2.23 to 0.84 - 1.73 for the studied buildings. The study recommends strict adherence to standards and guidelines, and for designers to have a keen focus on designing these special buildings. A renovation effort when undertaken, will lead to improvements in the performance of the selected buildings.展开更多
文摘Amidst the recent development in the usage of curtain walls for office buildings, high utilization of energy and poor thermal comfort issues have become paramount. This paper assesses thermal comfort in multi storey (naturally and mechanically ventilated) office buildings in Accra, the Capital city of Ghana using Fanger’s Predicted Mean Votes (PMV) and Predicted Percentage of Dissatisfied persons (PPD) model. The model relates to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (which gives an acceptable temperature range of 23℃ - 26℃) and the International Standards Organization (ISO) 7730. Indoor environmental parameters (temperature and relative humidity) of 4 multi storey office buildings were recorded over a 10 month period. The environmental parameters were analyzed using PMVcalc_v2 software which resulted in the generation of PMV-PPD values. The findings reveal high PMV-PPD values in the Naturally Ventilated Building (NVB) whiles the Mechanically Ventilated Buildings (MVB) fall within the comfort zone. Meanwhile, the Actual Mean Votes (AMV) by the occupants suggest all four buildings are relatively comfortable with the mechanically ventilated offices being more comfortable. Additionally, it is recommended that buildings are orientated with their longer sides facing north-south, with enough shading in order to improve the thermal comfort conditions of work spaces.
文摘Auditorium buildings are special structures needing much attention for it to function properly. Generally, consideration should be given to seating, sightlines, and acoustic requirements. In addition, the design should ensure performer-audience intimacy as much as possible. The focus of the study is to review design strategies for auditoria on the Kwame Nkrumah University of Science and Technology, Kumasi campus towards compliance and to develop solutions for improvements that will enhance the performance of 4 selected auditorium facilities. Case study, observation and measurements were the main strategies used. The results revealed that the approaches involved in auditorium designs are shape, volume, surface boundary dimensions and materials, stage, seating, foyers and sightlines. These parameters are grouped under acoustical, functional and programmatic parameters. Reverberation time calculated was high which indicated speech intelligibility problems, hence, improvement efforts were made to change the floor materials from polished tiles to carpeted floors, and high absorption wall claddings. In the process, the reverberation time was reduced from 1.47 - 2.23 to 0.84 - 1.73 for the studied buildings. The study recommends strict adherence to standards and guidelines, and for designers to have a keen focus on designing these special buildings. A renovation effort when undertaken, will lead to improvements in the performance of the selected buildings.
