A study of Köppen-Geiger system for comfort temperature prediction in Melbourne city

Weather and climate affect human and several aspects of the planet Earth. The Köppen-Geiger system is widely used for describing and analysing thermal comfort according to climate. However, little is available about the Köppen’s system in predicting and evaluating the comfort temperature. This investigation addressed some observed issues in using the Köppen-Geiger system for thermal comfort studies. The origin data of the present case study is from the RP-884 database. The selected location is Melbourne city. The climate of Melbourne city was categorised (Cfb). The subjects of the case study were mostly exposed to dry environment. Long-term projections showed that the climate will shift from (Cfb) to (Cfa). Despite the wide range of the indoor air temperature, the shift from neutrality to slightly cool or slightly warm was very narrow. Major issues of Köppen’s system in evaluating neutral temperatures according to climate types in Melbourne city were also addressed. The use of GIS for future thermal comfort meta-analysis was recommended

Comparative study of natural and artificial wind for thermal comfort studies

Wind speed is widely known factor affecting human thermal perception and comfort. However, little is available about the dynamic characteristics of natural and artificial wind. Currently, some investigators addressed the dynamic aspect of natural and artificial wind speed for thermal comfort according to power spectrum slope. However, there is little information about the dynamic characteristics of wind direction (wind azimuth) and elevation. The aim of this study is to investigate some of the characteristics of natural versus artificial wind at various sampling time. Measurements of natural and artificial wind were made using ultrasonic anemometer. The study location is Kota Kinabalu, Malaysia. Wind speed, wind direction, wind elevation and air temperature are the recorded parameters. In the present case study, the artificial wind is referred to the indoor wind generated by air conditioning and USB fan simultaneously. Several differences were observed between natural and artificial wind at various sampling time. The power spectral slopes of natural wind speed, wind direction, wind elevation and air temperature were higher than the case of artificial wind

Review on Koppen-Geiger System for Indoor Thermal Comfort

Several research studies were carried out in recent years for monitoring climate change and heat island effect in the world. Many authors addressed the effect of climate on thermal comfort by referring to Koppen-Geiger climate classification. However, little information is available on the effect of climate types on thermal comfort. A review of four climate classification systems are described and discussed in this study. Additionally, the Koppen-Geiger climate system in terms of its classification criteria and impact on thermal comfort are portrayed in the present publication. The shifts in climate types did not necessary affect the predicted indoor neutral temperatures. Given that the identified climate types in some cases are different when using the Kottek and the Peel methods, this study recommends reporting the employed Koppen-Geiger classification method. The year (s) or the time period of climate identification is also required. This study also recommends investigating in the near future thermal comfort requirements for climate type A for generalization of the conclusions

Investigation on the Dynamic Characteristics Of Natural Wind For Thermal Comfort Studies.

The main purpose of this article is to investigate the dynamic characteristics of natural wind for thermal comfort studies. A primary and secondary data were used. For the primary data, field study was conducted at the Universiti Malaysia Sabah, East Malaysia. The measurements were made under a tree. The site location of the collected secondary data is at Tracy. The site is flat and windy. Wind data of both case studies were recorded using ultrasonic anemometers. The wind speed data were analysed by using descriptive statistics, Weibull distribution and the power spectral analysis. Turbulence intensity was also included. The assessment of rapid increasing wind speed was also addressed in this study. A new method was developed to assess the rapid increasing wind speed for thermal comfort research studies. A comparison was made between both case studies

Energy Efficiency through Building Envelope in Malaysia and Singapore

The optimisation of fossil fuel consumption for generating electricity for building cooling is among the objectives set by most of the countries in the world. Currently, the American and European standards are among the most referred standards in the world for optimising heat transfer through the building envelope. However both standards do not reflect climate specifications of some countries such as those located in the humid tropics. The divergence in the approaches adopted by several Asian countries in minimising the heat transfer through the building envelope added another complexity to the topic. Other complexities are the divergence of European and American standards and the additional issue about the lack of validated weather data (TRY) in the humid tropics such as the case of Malaysia and Singapore. Those and other relevant issues on energy efficiency through the building envelope were addressed in the present article. Additionally a worked example and Excel sheet formulas were developed while considering Malaysian and Singaporean codes. Some recommendations were also suggested in the present article when deemed necessary

A conceptual review on residential thermal comfort in the humid tropics

In the era of increasingly expensive fuel and with the theoretical complication and the limitation of comfort prediction in naturally ventilated buildings based on thermal balance approach, researchers were motivated to go beyond heat balance approach to predict occupants’ thermal comfort using statistical approach known by adaptive models. The most established recognized model was developed mostly from the worldwide database recorded in office buildings. This poses validity problem when the model is applied for residential buildings. From a practical point of view using this model for the determination of neutral temperature in residences is likely to leads to errors in prediction which in turns are likely to have detrimental effect on occupants’ satisfaction, not to mention the potential effect in terms of energy consumption. This paper presents a conceptual review on indoor thermal comfort based on heat balance and adaptive models. The validity of international thermal comfort standards for residential buildings for neutral temperature prediction specifically in the hot-humid tropics is addressed. The need of database from field studies in residential buildings is emphasized

Field Study for Prediction and Evaluation of Thermal Comfort in Residential Buildings in the Equatorial Hot-Humid Climate of Malaysia

An extensive field study has been carried out in non-air-conditioned residences in Kota Kinabalu city, in Malaysia for the prediction and evaluation of the effect of the indoor thermal environment on occupants' thermal comfort. A total of 890 responses over one year were gathered. The hot-humid indoor climates of the surveyed buildings have been described and analyzed in terms of air temperature, globe temperature, relative humidity, wind velocity. The clothing insulation ensemble and metabolic rate of the occupants were also characterized. In the aim to assess the comfort temperature in residential buildings in the hot-humid tropics, each analyzed variable was thoroughly compared with the results of two field studies located in the hot-humid tropics, one conducted in Jakarta by Feriadi and Wong [1] and the second in Singapore by de Dear et al. [2]. Multiple and stepwise regressions were applied for the selection of the independent variable for neutral temperature prediction. Air temperature was chosen as an index for the indoor thermal comfort. The comfort temperature was determined using various approaches. The predicted temperature was found to be nearly 30 °C regardless of the adopted approach. The indoor comfort temperature was close to the recorded mean indoor air temperature of all responses having a difference of about 0.7 °C. The mean and the recorded indoor range temperatures seem to have effect in the prediction of comfort temperature

The hydrological performance of lightweight green roofs made from recycled waste materials as the drainage layer

Green roofs can be used for promoting infiltration and provide temporary storage spaces. Hence, in urban stormwater structural design, the investigation of the hydrological performance investigation is often required. Thus, this paper presents the results of a hydrological investigation in term of peak flow reduction and green roof’s weight using 0, 2, and 6% slope for three specimens drainage layer in green roofs. Three types of recycled waste are selected for each test bed which is rubber crumbs, palm oil shell, and polyfoam. Another test bed without a drainage layer as a control. The result indicates that rubber crumbs can be used as a stormwater control and runoff reduction while ensuring a good drainage and aeration of the substrate and roofs. From the results obtained shows that rubber crumbs are suitable as a drainage layer and a proposed slope of 6% are suitable for lightweight green roofs

Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

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