Poor Thermal Comfort Research Articles

Finite-element simulation of functional knee sleeves based on three-dimensional modeling of the knee joint

Knee sleeves are one of the most satisfying and widely used items of protective equipment for sports enthusiasts. Achieving an effective balance between functionality and comfort is a key factor in the design of knee sleeves. However, there are still some problems with the knee protection products currently on the market, such as poor thermal and moisture comfort, difficulty in putting on and taking off, slippage during doing sports, and the lack of a timely and effective feedback mechanism that cannot guide the user to actively adjust their movement posture to avoid sports injuries. To improve the function and pressure comfort of the human body after wearing knee sleeves, this study took the knee joint as the research object, established a three-dimensional knee joint model through computed tomography (CT) scanning and Mimics software, and then built a finite-element model under the contact state between the human body and pressure clothing on this basis. Moreover, ABAQUS was used for finite-element simulation to obtain the pressure and displacement distribution of knee joints after wearing knee sleeves. In order to further investigate the stress state and deformation trend of knee joint after wearing knee sleeves, each section of the human body at the knee joint was divided into four regions according to the angle, and the functional relationship between pressure and displacement was obtained by curve fitting. This study has significance for the investigation of the pressure comfort threshold of knee sleeves and the optimization of the design of functional knee sleeves.

Research on Energy-Saving Transformation of Rural Residential Building Envelope Structures and Heating Modes in Northeast China

Rural areas in Northeast China present a large demand for heating energy in winter, but there are problems in such areas with poor thermal performance of building envelopes and poor indoor thermal comfort. In addition, coal-fired boilers are still widely used. China’s “Dual-Carbon Goals” and “Clean Heating” policy call for the creation of a green and comfortable living environment for rural residential buildings. This paper considers the impact of the improvement of the thermal performance of envelope structures on the initial investment of the transformation program and the rated power of the ASHP and proposes an energy-saving transformation method to replace traditional coal-fired boilers with the ASHP on the basis of the improvement of the thermal performance of envelope structures. By establishing a typical rural residential building model in Northeast China, this energy-saving method is simulated based on TRNSYS. The results show that the payback period of investment of the transformation method of “envelope structure + heating system” is not superior to that of the transformation method of only improving the thermal performance of the envelope structure, but it has advantages in the comprehensive life-cycle benefits and it has great advantages in improving the satisfaction of rural residents in the use of heating systems.

Optimization and simulation of a novel multi-energy complementary heat pump system in cold regions

Solar-assisted ground source heat pump systems(SAGSHPSs) and solar- assisted air source heat pump systems (SAASHPSs) are recognized renewable energy technologies for clean and feasible heating and domestic hot water supply. However, in cold regions, the poor thermal comfort of SAASHPSs and the soil thermal imbalance of SAGSHPSs during heating periods must be resolved urgently. Therefore, to provide an efficient and stable heat source, a multi-energy complementary heat pump system(MECHPS) with seasonal heat storage was designed to meet the needs of building energy consumption. The system comprehensively utilizes solar energy and ambient air for seasonal heat storage during non-heating periods, and then directly provides heat coupled with the ground source heat pump during heating periods. The composition and control strategy of the system were introduced. The system was numerically modeled by the simulation software Transient System Simulation Program (TRNSYS), and the main MECHPS modules were experimentally verified. Additionally, to study the optimal capacity of MECHPS in terms of economy and energy savings, the Hooke-Jeeves algorithm was used for MECHPS capacity optimization with the objectives of minimising the annual cost and maximising the annual savings of standard coal. The results showed that compared with traditional SAASHPSs, the MECHPS exhibited better thermal comfort while maintaining the room temperature above 18 °C. Compared to SAGSHPSs, the MECHPS was able to achieve soil thermal balance, and its soil temperature remained largely constant after 15 years of operation. Finally, compared with the initial scheme, the annual cost reduction rate was 4.98 % under the annual cost optimization scheme and an additional 1310 kg of standard coal could be saved under the annual savings of standard coal optimization scheme. The proposed system provides a way to satisfy the building energy supply for widespread application in cold regions.

Optimization Strategy for Thermal Comfort in Railway Stations above Ground Level in Beijing

Urban rail transit, a convenient and fast public transportation mode with rapid construction and development, occupies fewer land resources and accommodates large passenger volumes. However, thermal comfort should be given more attention. Stations above ground level experience poor thermal comfort on the platforms, especially in hot summers. This study combines field research with a simulation analysis to propose a strategy for improving thermal comfort on above-ground urban rail transit platforms. This study analyzed the effects of the skylight opening rate, side window opening rate, design of transparent maintenance structure shading, and the platform profile shape on the thermal comfort of above-ground stations using field research, comparative experiments, and a simulation analysis with the PHOENICS (Command Prompt) software. The results indicate that adding longitudinal sunshade louvers to the skylight of the station platform is a cost-effective method to reduce the average temperature and PMV value, thereby improving thermal comfort. Increasing the skylight opening rate can result in a temperature rise. Adjusting the opening rate of the side windows to 20% and adding sun-shading louvers can also significantly enhance the station’s thermal comfort. Taking Wudaokou Station on Beijing Line 13 as an example, the simultaneous installation of additional longitudinal skylight shading and side window shading and increasing the side window opening rate to 20% on the platform resulted in a 2.6 °C decrease in the average temperature, a 4.7% increase in the average wind speed, and a 0.62 decrease in the PMV value, significantly enhancing thermal comfort for passengers. This study confirms that optimizing shading and ventilation systems can significantly reduce the platform temperature and improve passengers’ thermal comfort. This study provides theoretical support and innovative methods for optimizing thermal environments in similar environments.

Laboratorial investigation on optical, thermal and pavement performance of biomimetic dark reflective coatings with composite structure for pavement cooling

The surface temperature of asphalt pavement in summer can reach up to 70 °C, which leads to poor outdoor thermal comfort and exacerbates the urban heat island effect. Reflective coatings can effectively reduce pavement temperature, but their intrinsic light color with high reflectance causes safety issues such as glaring. In this study, based on the biomimetic idea of chameleon skin structure, composite pavement coatings for cooling and anti-glare were developed. Their optical properties, thermal behavior, adhesion and skid-resistance performances were investigated. The results showed that near-infrared reflectance of black and grey double-layer reflective coatings could reach 0.66 and 0.70, respectively (58 % higher than single-layer coatings). The optimal mass fraction of perylene black in the upper black/grey coating was 2.94 % and 0.74 %, respectively. The double-layer dark coatings could decrease the temperature by 14 °C at the depth of 3 cm below road surface, which achieved cooling effect close to that of white single-layer reflective coatings. The adhesion between coating and stone was generally higher than the cohesion of asphalt, therefore, opening traffic for a period of time or carrying out micro-milling before coating could improve the abrasion resistance. Due to increase in the thickness of the double-layer coating, the microscopic texture of road surface was reduced, thereby reducing skid-resistance. However, it still met the standard requirements. This study intends to provide a reference for developing pavement coatings that balance cooling and visual safety to mitigate the heat island effect, and improve the sustainability of transportation infrastructure.

Using the Taguchi Method and Grey Relational Analysis to Optimize Ventilation Systems for Rural Outdoor Toilets in the Post-Pandemic Era

This study addresses the issue of poor air quality and thermal comfort in rural outdoor toilets by proposing a ventilation system powered by a building-applied photovoltaic (BAPV) roof. A numerical model is established and validated through comparison with the literature and experimental data. Based on a consensus, four influential variables, namely, inlet position, outlet height, supply air temperature, and ventilation rate, are selected for optimization to achieve multiple objectives: reduction in ammonia concentration, a predicted mean vote (PMV) value of 0, minimization of age of air, and energy consumption. The present study represents a pioneering effort in integrating the Taguchi method, computational fluid dynamics (CFD), and grey relational analysis to concurrently optimize the influential variables for outdoor toilet ventilation systems through design and simulation. The results indicate that all four variables exhibit nearly equal importance. Ventilation rate demonstrates a dominant effect on ammonia concentration and significantly impacts the age of air and energy consumption, while supply air temperature noticeably influences PMV. The optimal scheme features an inlet at center top position, an outlet height of 0.2 m, a supply air temperature of 12 °C and a ventilation rate of 20 times/h. This scheme improves ammonia concentration by 18.9%, PMV by 6.8%, and age of air by 30.0% at a height of 0.5 m, while achieving respective improvements by 18.9%, 5.5%, and 22.2% at a height of 1.5 m. The BAPV roof system generates an annual electricity output of 582.02 kWh, which covers the energy consumption of 358.1 kWh for toilet ventilation, achieving self-sufficiency. This study aims to develop a zero-carbon solution for outdoor toilets that provides a safe, comfortable, and sanitary environment.

A Model for Determining the Thermal Comfort of Fishermen’s Houses on Coasts with Humid Tropical Climate

Fishermen’s houses on the coastal area of Dusun Karama Tengah, located at coordinates 119° 23’ 0” with 119° 23’ 9” BT, and 5° 13’ 28” LS with 5° 13’ 36” LS, with a humid tropical climate, has poor thermal comfort, and is not in the 22,8°C-27,1°C comfort category. Residents and house occupants feel stifled, hot, and uncomfortable during the day. Environmental factors, use of materials, construction, and the architecture of the fishing houses greatly contribute to the thermal comfort, apart from weather and climate factors. The aim of this research is to develop an innovative model for determining the thermal comfort of the fishermen’s homes. This research uses survey methods and observations of several factors that contribute to the thermal comfort during the day. It also uses expert system analysis techniques, certainty factors, based on Geographic Information System (GIS). A total of 107 fishermen’s housing units studied had poor thermal comfort, especially at 11:00-13:00 WITA or at 03:00-05.00 GMT. The poor thermal comfort of the fishermen’s houses is because they do not apply the principles of eco-building, green-architecture, and the lack of: facade, overhang, insulation, trees and parks, as well as the large use of low-density building projects in the form of zinc and triplex ceilings. This research has not taken into account the level of heat reduction of the house materials and the environment, so it is expected to be done in the upcoming research.

Optimization Design Methods for Thermal Environment Problems in Chinese University Teaching Buildings at Various Periods

Chinese universities have gone through three periods of centralized construction and significant differences in the design of teaching buildings in different periods may cause various thermal environment problems. This study takes a city in a cold region in northern China as an example and selects three teaching buildings built during three concentrated construction periods: 1950s to 1960s, 1980s to 1990s, and early 21st century as common cases. Based on field research, thermal environment measurement, APMV and PMV-PPD evaluation, and DeST simulation methods, it was found that the average summer APMV of the three teaching buildings was 1.37, indicating poor thermal comfort. In winter, the ambient temperature of the classrooms was below 18 °C for about 30% to 40% of the whole year, the average PMV value was −2.36, and the PPD value was obtained as 83.28%, far exceeding the standard requirements. The obtained results form a design strategy to optimize the thermal environment of teaching buildings. By considering the teaching building of historical architecture from the 1950s to 1960s as an example, the optimization design was carried out from three aspects to improve the indoor thermal environment and reduce the building’s cooling and heating load. The cumulative load of the building throughout the year was reduced by 21%, the cumulative heat load was reduced by 28.3%, and the cumulative cooling load was reduced by 10.1%. This research is anticipated to be of great reference significance for enhancing the thermal comfort of existing buildings, promoting energy conservation, and reducing carbon emissions. At the same time, it contributes to the protection and optimal use of historical buildings.

Embodied Energy and Thermal Performance of Alternate Walling Materials in Affordable Housing in the Composite Climate of Delhi

Meeting the affordable housing shortage in India in a short time has its environmental and social challenges. It not only requires huge resources but is also a big social responsibility to provide economical and comfortable housing for the marginalized section of society. Improper selection of construction materials may lead to the locking up of massive energy as embodied energy of materials and uncomfortable indoor living conditions. The present study focuses on the need for consideration of both embodied energy and thermal performance in the selection of materials for the building envelope in naturally ventilated affordable housing in India. Walling materials form a major part of the building envelope and thus it's crucial to assess their performance. This paper presents an analysis of embodied energy and thermal performance of fly ash Bricks, AAC blocks, and RCC precast panels as walling options in comparison to conventional walling material of burnt clay brick in the composite climate zone of Delhi. This analysis is being carried out for the alternate walling solutions in practice or emerging for mid to high-rise EWS housing construction in this region. The embodied energy values per cubic meter are compared for each wall assembly for the lifecycle stage cradle to gate. Thermal simulation results are presented in terms of indoor operative temperatures achieved by each wall type material and compared with the comfort temperature range prescribed by the comfort model IMAC-R, 2022 to find out the ‘discomfort degree hours’. The results of the study underscore the suitability of fly ash bricks and AAC blocks as sustainable alternatives due to their lower embodied energy compared to traditional burnt clay bricks base case. Fly ash bricks even outperform the base case in terms of thermal comfort. The study discourages the use of burnt clay bricks due to very high embodied energy. The study also strongly discourages the use of RCC panels in the composite climate as they exhibit both poor thermal comfort and high embodied energy. The study findings would help government agencies to make environmentally and socially conscious decisions about the use of walling materials on a large scale in meeting the affordable housing demand.

Thermal performance of a novel traditional Chinese personal heating device (Huotong) combined with PCMs

Chinese traditional individual heating equipment with a history of hundreds of years “Huotong” was widely used in rural areas. The Huotong consisted of a closed wooden barrel-shaped outer wall and an iron basin with combustion layer. However, the traditional Huotong had problems of low energy utilization efficiency and poor thermal comfort. Thus, a novel Huotong combined with phase change materials (PCMs) was proposed. The basic model of novel Huotong was designed and manufactured. The thermal performances of the novel Huotong under two kinds of heat sources of charcoal heating and electric heating were investigated. The results showed that: (1) Under the method of charcoal heating, the heat storage and thermal comfort performance of the novel Huotong were higher than that of the traditional Huotong. Under the three-charcoal mass of 0.15, 0.25 and 0.5 kg, the heat storage performance of the novel Huotong was 1.36, 1.43 and 1.52 times of the traditional Huotong, respectively. The average PMV values of the novel Huotong was 0.92, 1.17 and 1.31, while for the traditional Huotong was 0.87, 1.32 and 1.58, respectively. (2) Under the four electric heating methods, the thermal efficiency of the novel Huotong was 1.63, 1.61, 1.47 and 1.39 times of the traditional Huotong, respectively. The heat storage performance was 1.72, 1.67, 1.47 and 1.28 times than that of the traditional Huotong. The average PMV values of the novel Huotong was 1.25, 1.22, 0.69 and 1.68, while for the traditional Huotong was 1.64, 1.53, 0.87 and 2.03, respectively.

Research on the evaluation of the renovation effect of existing energy-inefficient residential buildings in a severe cold region of China

The renovation of existing energy-inefficient residential buildings is an important measure to improve building energy efficiency and achieve CO2 emission reduction strategic tasks. At present, existing energy-inefficient residential buildings suffer from high energy consumption for heating, low efficiency, and poor indoor thermal comfort. It is necessary to implement energy-saving renovation on existing residential buildings and evaluate the renovation effect. This article took existing energy-inefficient residential buildings as the research object and selected a targeted evaluation system. Based on expert research, the hierarchical-grey correlation degree method was used to determine the weight of indices. Actual testing was conducted on the three nodes of the heat exchange station, secondary network, and the building ontology during the heating seasons of 2015–2016 and 2016–2017 (before and after renovation). Based on measured data, a fuzzy membership degree evaluation model was constructed, and the evaluation results were determined using a linear weighted method to form a complete evaluation system. The evaluation system covered 12 evaluation indices, and the evaluation indices with the largest weight in the criterion and index layer were energy consumption (0.308) and economic contribution rate (0.183), respectively. The average linear weighted evaluation scores before and after the renovation of each node were 14.16 and 29.04, respectively.

Optimizing building spatial morphology to alleviate human thermal stress

Achieving urban cooling from a sustainable perspective requires strategic planning of building area (S) and height (H). However, there is a lack of human thermal stress assessment and it is not clear how to optimize the layout of building spatial morphology to alleviate human thermal stress. We simulated the Universal Thermal Climate Index (UTCI), characterizing high spatial resolution human comfort, by machine learning, and analyzed the relationship between building spatial morphology and UTCI to determine the feasible layout of building spatial morphology. Our findings indicated that the study area experienced poor human thermal comfort, with residents facing high thermal stress (average UTCI of 36 °C). Zoning analysis revealed that an increase in S resulted in a simultaneous rise in UTCI, while an increase in H leaded to a trend of UTCI that initially rose and then declined. An increase in S-rating had a more pronounced impact on elevating UTCI (0.29 °C on average) compared to an increase in H-rating (0.11 °C on average). To maintain UTCI within the UTCI threshold that characterized ideal human comfort, a trade-off relationship between S and H should be maintained, which was further influenced by the stationary and plunge intervals in their relationship curve. The findings have the potential to provide valuable insights for policymakers and stakeholders, aiding them in making informed decisions in urban planning to alleviate human thermal stress.

Improvement of Human Comfort in Rural Cave Dwellings via Sunrooms in Cold Regions of China

Economic development limits the living quality of rural residents. In particular, the residential buildings in northern China generally have poor thermal comfort in winter, which affects the physical and mental health of residents. Because of the separation of rooms, residents who live in cave dwellings often have to enter and leave rooms in the course of their daily lives, which leads to worse thermal feelings in winter. Because of the low price and the wind insulation and heat storage, sunrooms are widely used in renovations of rural houses. The traditional purpose of the addition of a sunroom is to provide a buffer room between outdoor and indoor spaces. This manuscript focuses on improving the degree of thermal comfort by means of a sunroom connecting all rooms. This study selected two families with the same number of members and similar daily activities as the study cases. One of the families had a sunroom built to connect its bedroom, living room, and washroom. The household’s air temperature and human comfort were measured both on holidays and on workdays. It is demonstrated that adding a sunroom can significantly stabilize the thermal environment and increase the air temperature in both the bedroom and the living room. Adding a sunroom can increase the air temperature of a cave dwelling’s main room by 1.0 °C on workdays and 4.3 °C on holidays. A cave dwelling with a sunroom can also provide residents with a decent level of human comfort for 24.4% of their daily time on workdays and 39.1% of the time during holidays. This research demonstrates that a sunroom can not only increase the air temperature in cave dwellings but also enhance the stability of human comfort. The conclusion provides new renovation ideas for improving the living comfort of cave dwellings.

An Investigation of the Energy-Saving Optimization Design of the Enclosure Structure in High-Altitude Office Buildings

Concerning the double carbon national strategy, the energy-saving renovation of old buildings has become one of the most important tasks of energy conservation and emission reduction in construction in China. There are many problems, such as high energy consumption, thermal environment, and poor thermal comfort. Taking Lhasa as an example, this study adopts field research, questionnaire interviews, on-site measurements, numerical simulations, and other methods to propose suitable energy-saving potential excavation points and thermal optimization strategies for office building envelopes in Lhasa through software simulation. Additionally, typical office buildings are selected to carry out the energy-saving renovation of envelopes with the goal of improving indoor thermal comfort to validate the feasibility of the energy-saving renovation strategies. The results show the following: (1) The measured and predicted thermal neutral temperatures of the office population in Lhasa are 16.5 °C and 18.9 °C, respectively. The 90% acceptable temperature range is from 16.10 °C to 21.77 °C, and the occupants of the office buildings in Lhasa have a higher tolerance for cold than predicted. (2) The passive measures adapted to Lhasa are prioritized in the order of passive solar energy, high-heat-capacity materials, and nighttime ventilation. (3) Through the optimization of the enclosure structure of existing office buildings, the improvement of the heat storage capacity of the outer enclosure structure, and the increase in the window opening area to increase natural ventilation, the indoor thermal comfort of the renovated buildings is effectively improved.

Flexible and breathable textile-based multi-functional strain sensor for compressive sensing, electromagnetic shielding, and electrical heating

The textile-based sensors have drawn increasing attention in wearable smart electronics, owing to the comfort, breathability, and elasticity. However, the low compressive strain response range, poor thermal comfort and electromagnetic shielding performance hinder severely the application of textile-based sensors in the complex environments. To address these issues, we chose a weft-flat knitted textile with a large gap as a flexible substance, graphene nanosheets (GNS), and Ag nanowires (Ag NWs) as conductive fillers, and treated the textile with a simple dip coating strategy to obtain TPU/GNS/Ag NWs@textile (TAG@textile). The prepared TAG@textile sensor not only exhibits 90% compressive strain response range and high sensitivity (GF=9.25), but also exhibits an efficient electromagnetic shielding performance of 61.68 dB. In addition, the TAG@textile sensor has excellent Joule thermal performance (it can reach 104 °C at a low voltage of 4 V). In brief, this work integrates human motion detection, electromagnetic shielding, and electrical heating, showing a great potential in future multifunctional wearable electronic devices.

Low-grade energy-bus air conditioning system using energy efficient three-fluid heat exchange terminals

Typical air conditioning terminals mainly focus on room temperature control, often neglecting adequate satisfactory room humidity management, resulting in poor thermal comfort. In addition, the direct heat exchange between refrigerant and air in these terminals cannot facilitate free-cooling using natural or waste cooling capacities. This study proposes a low-grade energy bus system that connects three-fluid heat exchange terminals, allowing for simultaneous control of room temperature and humidity. Furthermore, it enables the direct circulation of anti-icing fluid to each terminal for free cooling. Considering an office building in Nanjing, China, as an example, the annual operational performance of the proposed system is numerically studied and compared with two typical systems. The results reveal the following. 1) The three-fluid heat exchange terminals used can accurately regulate the room temperature and humidity, even when there are significant differences in the indoor cooling and dehumidification loads. 2) The annual system coefficient of performance (COP) of the proposed system increases from 3.3 to 3.9, leading to an annual energy saving rate of 14.4% compared to a typical water loop heat pump system in a typical office building in Nanjing, China. 3) Compared to commonly used room air conditioners, the proposed system is more energy-efficient.

Optimization of External Environment Design for Libraries in Hot and Dry Regions during Summer

To address the poor thermal comfort of library exteriors in hot and dry regions during the summer, this study takes the libraries of universities in Xinjiang as its research object. It corrects the range of the perceived environmental temperature (PET) index for evaluating comfort in Xinjiang by combining subjective and objective methods. It explores the impact and adjustment mechanism of physical parameters on PET through field measurements and simulations. Finally, it determines the optimal external environmental design based on PET. The research results show that the neutral temperature of PET in Xinjiang during the summer is 27.44 °C, and the optimal comfort temperature range is 25.52–29.36 °C. The correlation between meteorological and physical parameters and PET is as follows: Tg > G > Ta > RH > SVF > reflectance > Va. The optimal PET design includes a combination of a water body in the upwind direction on the south side, an asphalt underlay, grass, and large-leaved wax vegetation. In the optimal scheme, PET decreased by 6.73 °C, or 12.59%, compared with Case 0 at 18:00. This study provides a reference for the design of external environmental conditions in hot and dry regions during the summer.

Unlocking energy savings and emissions reduction: A comparative study of fixed-speed and variable-speed room air conditioners in high ambient temperature environments

Developing countries, particularly those with high ambient temperatures (HAT), are experiencing a surge in air conditioner (AC) installations. Fixed-speed ACs, which rely on on–off control, are the most used. However, fixed-speed ACs lack humidity control and experience compressor cycling, leading to poor thermal comfort and increased energy consumption. Variable-speed compressor technology eliminates compressor cycling, which increases the effective coefficient of performance, especially at part-load conditions. This study compares the transient performance of variable-speed and fixed-speed AC units in Cairo, Egypt, as an example of a HAT environment. During a 2-month experimental investigation, the variable-speed unit provided 41% electrical energy savings while maintaining a comfortable environment. Analytical modeling using a machine learning model trained by the experimental measurements predicted annual energy savings of 473 kWh/year and an overall electrical energy savings percentage of 30.5%. The study also explored different scenarios for implementing variable-speed ACs in Egypt, a developing HAT country. With a 60% market penetration for variable-speed AC as the most probable scenario, the electrical energy savings up to the year 2032 add to 1.33 TWh, leading to 79.3 million USD in cost savings and 2.64 MMT of CO2 emissions reduction.

Analysis of Heating Energy Consumption of School Buildings in Shigatse, Tibet

This paper is launched against the background of excessive heating energy consumption in China, continuous calls for sustainable development, and unsatisfactory heating energy use in primary and secondary schools in Shigatse, Xizang. Through field research on the existing school buildings in Shigatse, Xizang, a large number of first-hand materials were obtained, and then through targeted summary and classification of the data, the key problems leading to high energy consumption, low clean energy utilization rate and poor thermal comfort of school buildings in Shigatse, Xizang were found. On this basis, further analysis will be conducted to address the issue, seeking ways and methods to utilize clean energy technologies such as solar heating to solve the heating problem in school teaching buildings.

A Comprehensive Assessment of Indoor Air Quality and Thermal Comfort in Educational Buildings in the Mediterranean Climate

Maintaining good indoor air quality and thermal comfort is a challenge for naturally ventilated educational buildings, as it can be difficult to achieve both aspects simultaneously. Nonetheless, most of the existing studies only focus on one aspect. To explore the potential of balancing indoor air quality and thermal comfort, both topics must be investigated concurrently. This study assessed indoor air quality and thermal comfort in 32 naturally ventilated classrooms of 16 primary and secondary schools in the Mediterranean climate, based on a large on-site measurement campaign lasting one year that gathered over 460 hours of data. The research investigated occupants’ adaptive behaviors, analyzed the actual thermal comfort of around 600 students, and characterized the representative scenarios leading to good and poor indoor air quality and thermal comfort by clustering analysis. The results showed that poor indoor air quality was mainly due to closing windows and doors in winter, while thermal discomfort mainly occurred in summer because of the high indoor temperature. The findings suggested that a proper ventilation protocol is the key to balancing indoor air quality and thermal comfort.