Investigation on Summer Thermal Comfort and Passive Thermal Improvements in Naturally Ventilated Nepalese School Buildings

Abstract

Students require a comfortable thermal environment for better academic learning and health in general. In Nepal, the majority of school buildings are constructed using local materials, but little consideration is provided to the thermal environment required for comfort. Therefore, this study demonstrates the advantages of using passive design measures through a simulation that can be used either in the early stages or as a retrofit to determine how the building performs in terms of comfort and the thermal environment. First, the thermal environment of school buildings and thermal comfort of students were evaluated through field surveys. Subsequently, a simulation was performed to investigate the operative temperatures in the classroom of a school building in Kathmandu. DesignBuilder software was used to create the base model and the simulated operative temperature was validated using the measured globe temperature. Subsequently, passive strategies, such as natural ventilation, insulation, and thermal mass, were applied and analysed. The field survey showed that the indoor globe and outdoor air temperatures were correlated, and the students perceived a hotter environment and preferred a cooler environment. Within this context, the average comfort temperature was 26.9 °C. The simulation results showed that the operative temperature was reduced to below 27 °C with a maximum reduction of 3.3 °C due to the integrated design impact, which is within the comfortable limit required during school hours. This study helps to design Nepalese school buildings in a better way by considering passive design strategies during architectural design to make classrooms more thermally comfortable.

Field Study to Compare and Evaluate Summer Thermal Comfort of School Buildings with Different Moderate Thermal Mass in Their Building Elements

“…Thermal mass is most appropriate in a climate with a larger diurnal temperature range. Recent studies of the impact of thermal mass on the summer indoor thermal environments of school buildings [7,[17][18][19][20] were mainly carried out in hot-dry or semi-arid climates, with larger diurnal temperature ranges (over 10 • C), or more severe summer conditions than Auckland has. Auckland has a temperate climate and a relatively comfortable warm and dry summer with a 7.6-7.9 • C summer diurnal temperature ranges (Table 9) within the medium diurnal temperature range (6-10 • C).…”

“…There are also limited data and studies on measurements of the indoor environment quality of New Zealand schools, especially for indoor thermal conditions and indoor air quality [16]. There are recent studies of the impact of thermal mass on summer indoor thermal environment related to occupants' thermal comfort of school buildings in other countries [7,[17][18][19][20]. Research methods used for those studies on summer indoor thermal environment of school buildings are mainly building simulations (mathematical model) [17][18][19][20] and limited field studies of indoor thermal environments [7].…”

“…There are recent studies of the impact of thermal mass on summer indoor thermal environment related to occupants' thermal comfort of school buildings in other countries [7,[17][18][19][20]. Research methods used for those studies on summer indoor thermal environment of school buildings are mainly building simulations (mathematical model) [17][18][19][20] and limited field studies of indoor thermal environments [7]. Research methods for students' thermal comfort are survey questionnaires.…”

Assessment of Occupants Thermal Comfort in University Classrooms on the basis of gender preferences

“…Students spend about 30% of their time in classrooms so an optimized day lighting and energy performance plays critical role. 48 Therefore, classroom Design decisions in architecture like geometry, shallow plan buildings, wall to window ratio, orientation and other passive design strategies 49 are vital factors that effects students and building energy consumption in long term. In addition, its considerable impact is evident on student's health and learning ability.…”

Improving the Thermal Performance of Secondary School Buildings by Using Passive Techniques at Hyderabad

“…[2] [3] Achieving thermal comfort in buildings requires the consideration of various design and operational parameters, such as building envelope insulation, ventilation systems, and occupant behavior. [4]As students spend half of the day in schools where they are highly vulnerable towards an adverse indoor air quality, particularly considering secondary school students. [5]Therefore it is important to thoroughly.…”