Too hot to learn? Evaluation of passive design strategies for schools in the warm humid tropics

Thermal preference and comfort assessment in air-conditioned and naturally-ventilated university classrooms under hot and humid conditions in Brazil

The school buildings in Colombia are built based on geographical locations and regional construction systems. However, external weather conditions and building design can have a significant impact on the thermal comfort of students, which affects the academic performance and productivity. This paper investigates the thermal comfort performance for an educational building in a hot and humid city in Cucuta, Colombia, built under national guidelines. This school is a concrete structure without mechanical cooling. However, field observation discovered that 82% of the time students experienced thermal discomfort. To investigate causes and provide mitigation strategies, a whole building energy simulation is conducted. Design Builder is used to evaluate the indoor thermal conditions compared to outdoor data collected. ASHRAE 55 adaptative model is used for the evaluation. It is found that 79% of the time the thermal conditions are outside the acceptable range during the year. The effect of mitigation measures i.e., occupancy, roof insulation, and natural ventilation rates are investigated through simulations. It is found that occupancy and natural ventilation rate have a significant impact on the indoor temperature and relative humidity, and thus the thermal comfort. Passive design strategies are proposed in optimizing the school building design to meet ASHARE-55 requirements.

The thermal comfort conditions of the educational buildings affect students' attention, focus, perception and learning levels. The design of transparent areas is important in the control of solar radiation affecting thermal comfort conditions. The aim of this study is to determine thermal comfort conditions in classrooms with different transparency ratios and to make suggestions for improvements. Classrooms in the same building on the university campus, in the same direction (south) and with different transparency ratios were determined as study areas. Measurements (PMV-PPD) and surveys (AMV-APD) were carried out during a day in heating period. The thermal comfort conditions were evaluated according to the comfort intervals specified in ASHRAE-55 and ISO-7730 standards. The results showed that there were significant differences in thermal comfort between classrooms. If the transparency ratio is more than necessary, it causes discomfort and redundant energy consumption. Suggestions have been made to ensure solar control and thermal comfort conditions.

Acceptable thermal comfort conditions in buildings are necessary to ensure health and wellbeing of occupants, enhance productivity of workers, et cetera. Passive or active strategies can be utilized to achieve these acceptable thermal comfort conditions. Passive methods are encouraged in buildings because they are considered to be environmentally friendly. This research aimed to review passive methods and materials used in traditional, vernacular and modern-day architectures to provide thermal comfort conditions for occupants of indoor spaces in tropical Nigeria. The author systematically reviewed and analysed 29 papers using statistical tables and chart. The findings showed that natural ventilation is the most used passive strategy. The study also indicated that traditional and vernacular buildings depend on the thermal properties of indigenous building materials and climate responsive strategies to provide acceptable thermal conditions for occupants. Modern-day buildings need shading, insulation and covering from the intense solar radiation in the study area compared to traditional or vernacular buildings. Despite their aesthetical appeals, the study concluded that modern-day building cannot be relied upon to provide thermal comfort for building occupants. If modern-day building materials must be used, then appropriate passive strategies must also be deployed to ensure the provision of acceptable thermal comfort conditions for building occupant in the tropics.

Influence of non-uniform distribution of fan-induced air on thermal comfort conditions in university classrooms in warm and humid climate, India

Thermal comfort conditions of shaded outdoor spaces in hot and humid climate of Malaysia

Thermal comfort studies have been a subject of research since the 1930s. Thermal comfort conditions which are of great importance for human health, are also important for energy. Todays due to climate changing and a decrease in energy resources, there is a change in indoor thermal comfort conditions in historic and contemporary buildings. Thermal comfort conditions are the most important factors affecting the use of buildings. So places and spaces where thermal comfort conditions aren’t good are tried to improve to optimal. The historical buildings constitute the majority of the city's building stock in addition to their original and aesthetic architectural qualities, the value for the city. From the planning to the construction process in historical buildings it is observed architectural plan schemes are shaped by considering various environmental and climatic factors such as sun and climate thus it can be said energy uses is taken into account. It is important to use historical structures and to re-function when they are not available with their original function. With re-use, the new details and additional applications that are applied can affect the thermal comfort properties of the building positively or negatively. This study focuses on the thermal comfort properties that come with the restoration of a historic building. In this context, Ali Gav Madrasah which is located in castle borders in the historical city center of Konya in Turkey and restored with a contemporary additional feature that is considered worthy of being examined in terms of thermal comfort. Thermal analysis of the reconstructed Ali Gav Madrasah, which has undergone restoration through integration based on historical documents and excavations and has a top cover made of modern materials, was carried out in August 2018 and January 2019. According to these analyzes, today's thermal conditions are inadequate for all places in Ali Gav Madrasah of thermal comfort conditions. Comments are made on the connection of this insufficient thermal comfort with the restoration/reconstruction. From this point of view, Before the restoration procedures for historical buildings, required feasibility studies and necessary solutions about buildings thermal conditions are investigated. And then architectural details should be produced for this.

Changes in the thermal comfort condition of the living environment of human beings are one of the main concerns related to global warming. While previous studies largely focused on mean temperature and warm/cold extremes, changes in thermal comfort conditions (both comfort and discomfort conditions) have not been adequately revealed. Based on climate projections from the Coupled Model Intercomparison Project phase 6 (CMIP6), future thermal comfort conditions over global land using net effective temperature index that considers the aggregate effects of temperature, relative humidity, and wind on human thermal perception were investigated. The focus was on the projected changes in thermal comfort conditions in different regions based on gross domestic product per capita, an indicator of adaptive capacity. An inequitable impact of escalating global warming on thermal comfort conditions emerges: in high‐income regions (mostly distributed in cool mid‐high latitudes), a diminishing number of cold‐uncomfortable days and an increasing number of comfort days collectively would contribute to an improvement in thermal comfort conditions; however, in low‐income regions (mostly distributed in warmer low latitudes), thermal comfort conditions are expected to worsen as a result of a dramatic increase in the number of warm‐uncomfortable days that greatly exceeds the decrease in the number of cold‐uncomfortable days and a decrease in the number of comfortable days. Moreover, analysis accounting for population exposure suggests that the overall impact of future changes in thermal comfort conditions on the global population is negative. Therefore, prioritized support for climate mitigation and adaptation to developing nations is justified and urgently needed.

(1) The association of the indoor environmental conditions in classrooms with illness-related absenteeism (IRA) was not well investigated. In addition, studying the association between heating and non-heating seasons were very limited; (2) To fill this knowledge gap, a research team collected various indoor air quality (IAQ) and thermal comfort conditions (TC) of 85 elementary classrooms in two school districts from the Midwestern United States throughout an academic year; in total, 255 classroom visits were performed. A negative binomial regression model was implied to associate the classroom’s IAQ and TC with IRA, separating for heating and non-heating seasons; (3) During non-heating season, a 3% increase of IRA was estimated with 1,000,000-counts/L increase of particles that had a diameter less than 2.5 μm (PN2.5); during the heating season, a 3% increase of IRA were expected with 100 ppm increase of room averaged CO2 concentration; and (4) These results suggested that the IAQ and TC factors could associated with IRA differently between heating and non-heating seasons.

Status of thermal comfort in naturally ventilated classrooms during the summer season in the composite climate of India

Radiant floor heating panels of a room with different locations is modeled by using CFD. All cases is simulate by employing k-ε equation turbulence model. After validation of code, average room air temperature, vertical air temperature difference and velocity of room air are used to predict the thermal comfort conditions in the occupied zone. Effect of indoor room air temperature and radiant floor heating panel locations on thermal conditions in occupied zone is studied. The results present that both the indoor room air temperature and radiant floor heating panels locations have effect on thermal comfort conditions and at low indoor temperature the radiant floor heating panel is insufficient to achieve thermal comfort conditions but can be reduced heating load.

Courtyards as a passive strategy in semi dry areas. Assessment of summer energy and thermal conditions in a refurbished school building

The present study intended to evaluate thermal comfort conditions in microclimates of the urban historical areas of Isfahan, Iran during a heatwave. The thermal comfort conditions of different historical sites were compared during the daylight hours to determine the best time to visit each historical site. Using the results of this study, tourists can select the best timeframe with appropriate thermal conditions to visit the historical sites of Isfahan. Along with performing field measurements in the intended historical sites, a questionnaire was used to determine the thermal comfort range of tourists. ENVI-met is used in order to properly simulate the outdoor thermal environment of the historical touristic areas in Isfahan during the hottest as well as the most touristic month of the year. The results of questionnaire and simulations are compared with each other. It was shown that three historical sites with higher thermal stress experience an unpleasant thermal condition. The results of questionnaire show that the comfort range of tourists is within 23.06–29.73 °C PET. The thermal conditions of Si-o-Se Pol, Hasht Behesht and Naqsh-e-Jahan are within the thermal comfort range at 19,20 and 21 p.m. respectively. During the daytime, thermal comfort conditions varied from 4.9 °C PET at 8 a.m. to 8.1 °C PET at 3 p.m. Early morning hours were the most comfortable time to visit the historical sites of Menar-e-Jonban, Masjed-e-Jame and Vank Cathedral in Isfahan. During the peak hours of heat, the priority of thermal comfort goes to Masjed-e-Jame, Menar-e-Jonban and Si-o-Se Pol, respectively.

This paper investigates the thermal comfort level of an office room through various windows-door opening arrangements in hot and humid climate. To determine the windows-door opening performance, 14 opening configurations have been considered and the combination of opening arrangements was carried out in an air-conditioned office at UPM, Malaysia. After conducting objective measurement for each condition, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD) were calculated. The concentrations of carbon dioxide (CO2) were also monitored. Subjective survey involved questions on the thermal environmental perception and indoor air quality for office occupants for this study. Objective data analysis showed that in most of conditions office had thermal conditions falling within the comfort zone of ASHRAE standard 55, and in all of conditions neutral temperatures are higher than ASHRAE standard requirements. Subjective results revealed that staff has higher thermal comfort level as compared to what PMV has predicted. Practical application: It is believed that the results in this paper will contribute to knowledge that international standards are not applicable in hot and humid climate. Fanger equations would give the results for European conditions, people in hot- humid climate have some cultural preferences that are different from the Europeans hence modifying these equations and standards for this climate are necessary. In terms of the use of climatic control to modify the indoor environment it is found that when the occupants have the freedom to modify the environment, and make necessary adjustment, they always use windows-door opening arrangements to compensate for the less comfortable thermal condition and increase air movement.

Mosques are distinguished from other types of buildings by having an intermittent operation schedule. They are partially or fully occupied five times a day and the maximum occupancy is expected to occur on Friday prayers. As buildings with intermittent occupancy may not perform the same thermally as typical commercial and residential facilities, thermal comfort conditions and perception of occupants have to be investigated. This paper presents the results of a study monitoring indoor environmental conditions of a mosque in order to assess thermal comfort conditions. A historic mosque, which is located in a hot and humid climatic region of Turkey, was selected as a test building and thermal comfort conditions were monitored during two Friday prayers in August and September. Indoor air temperature, relative humidity and air velocity were collected via data loggers. The predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) indices were calculated and evaluated using the ASHRAE 55-2010 standard. In addition to this, a questionnaire based on Fanger’s seven-point scale was conducted to understand the thermal sensation and preference of occupants. A comparison is provided to highlight the difference between the calculated and perceived satisfaction of occupants.