Thermal Comfort Limits Research Articles

PRELIMINARY DATA ON COAT COVERAGE AND GROOMING INTERFERING WITH THE THERMAL COMFORT OF LHASA APSO AND SHIH TZU DOGS

The objective of this report was to investigate the effects of grooming on thermal comfort in Lhasa Apso and Shih Tzu dogs exposed to different ambient temperatures. A randomized block design in a 3 x 2 factorial scheme was used, with 3 different temperatures associated with whether the animal was groomed or not. Six adult dogs, consisting of two Lhasa Apsos and four Shih Tzus, were used. The dogs were exposed to temperatures of 17°C, 25°C, and 33°C both before and after grooming. Physiological parameters (blood pressure, heart rate, respiratory rate, rectal temperature, ambient temperature, ITU, and body surface temperature) were measured using infrared thermography with a portable IRT camera. The images were analyzed using FLIR Tools™ software with an emissivity of 0.97. Variance analysis was performed to evaluate the isolated effects and interactions between the factors of coat coverage and ambient temperature at the 5% significance level. No interaction was found between the treatments, nor were there isolated effects of the factors on the physiological parameters evaluated. A temperature of 33°C was associated with a higher rectal temperature (p<0.05) in the animals. Ungroomed dogs exposed to temperatures of 25°C and 33°C had ITU values above the thermal comfort limit. In terms of body temperature, there was a significant interaction effect between coat coverage and the environment under different climatic conditions (p<0.05). The surveyed grooming dogs exhibited greater body temperatures at all temperatures tested, namely, 17°C, 25°C, and 33°C. Grooming did not reduce the effects of thermal stress caused by different climatic conditions, indicating that grooming is not advisable for these animals

Impact of Energy-Consuming Air Conditioning Systems on People's Thermal Comfort and Preferences: Comparative Study of Iraq and Gulf Cooperation Council Countries

This study investigates the impact of the intense usage of air-conditioning systems on the thermal comfort requirements of building occupants. It compares the thermal comfort requirements of building occupants in Iraq and Gulf Cooperation Council (GCC) countries. Iraqis have limited usage of air-conditioning units, whilst people in GCC countries intensely operate these systems. Research work underpinning this article involved undertaking a year-long thermal comfort survey in Iraq, and an intensive analysis of thermal comfort studies conducted in GCC countries. Results show that, in Iraq, people experience a 2–50 °C annual indoor temperature range, and their annual comfort range is 14–35 °C. In GCC countries, due to the intense usage of air-conditioning systems, the widest recorded annual indoor temperature range is 17.2–31.0 °C, and the widest annual comfort range is 20.0–27.8 °C. These results demonstrate the significant impact of air-conditioning systems on narrowing the thermal comfort limits of building occupants leading to high energy consumption. This study presents a novel comparison between two cases highlighting the impact of air-conditioning systems on the thermal comfort requirements of building occupants. The results of this study can be used to inform the development of thermal comfort standards that better consider people’s adaptation capabilities to help reduce energy consumption for heating and cooling purposes.

Thermal comfort in school children: Testing the validity of the Fanger method for a Mediterranean climate

Thermal comfort is an essential factor when designing or refurbishing schools because it helps to improve wellbeing and academic performance. However, little attention has been paid to assessing the thermal comfort level of children. Previous studies on thermal comfort have mainly focused on adults' perceptions, extrapolating their results to all ages without cross-checking them for relevance. The aim of this research was to determine whether children perceive temperature in a similar way to adults and if their thermal comfort limits are the same. A school in south-eastern Spain was selected as the case study. Thermal comfort surveys of children were conducted and compared with analytical calculations obtained using the Fanger method. The results showed that the Fanger method was not valid for the estimation of children's thermal comfort, especially in girls and younger children. The novelty of this research demonstrates that children have specific thermal comfort requirements that are not covered by current standards and calculation methods, such as the Fanger method. Analysis also determined the correction coefficients necessary for adapting Fanger's analytical method to children according to age and gender in BShs climate.

The effect of climate index on growth values from birth to breeding in Akkaraman sheep.

Under specific agroclimatic conditions, growth is an adaptability parameter resulting in reduced performance with decreasing animal comfort of a sheep breed. In this study, a total of 1011 lambs' live weights (LW) and average daily weight gains (ADG) in 16 different farms between 2018 and 2020 (birth to 18 months) were determined in Akkaraman herds raised in Çankırı Province of Turkey. Comprehensive Climate Index (CCI) was examined to determine the effect of climate. Thermal comfort limits in CCI values were classified as CCI-1.cold (≤ 5 ℃), CCI-2.comfort (5-25 ℃), and CCI-3.warm (≥ 25 ℃). The climatic values that all lambs examined were exposed to according to index value groups in periods from birth to 18 months of age were prepared daily. The lambs were exposed to comfort environment in the majority of the days in the MP0-3 (77.7%) and MP12-18 (50.1%) periods. The lambs mostly in the MP3-6 period (72.2%) were above the warm stress threshold, but in the MP6-12 period, 54.7% were above the cold stress threshold. Overall mean LW of lambs at birth, at 3, 6, 12, and 18 months were 4.29 kg, 35.1 kg, 39.1 kg, 45.4 kg, and 52.6 kg, while the ADG values between birth-3 months, 3-6 months, 6-12 months, and 12-18 months were 341.8 g, 54.5 g, 42.9 g, and 56.8 g respectively. Periodically, CCI values were realized as 10-15, 25-30, and 18-22 in the growth periods of 0-3, 3-6, and 12-18 months, respectively, and ADG values of the lambs were found to be similar within their own periods. However, when the CCI values of the lambs increase to 5 and above in the 06-12-month period, there is a decrease in their live weight. As a result, climatic index values did not have a negative effect on the growth and development values of lambs in cold conditions in general, but warm conditions affected the animals negatively.

Transport distance influenced the proportion of skin lesions in finishing pigs and negatively affected animal welfare

Transport is a relevant process during pigs’ lives because of its impact on animal welfare. Considering commercial conditions, several factors vary between journeys; therefore, it is important to establish the influence of transport distance on skin lesion scores in finishing pigs, considering weather and vibration conditions. Skin lesion score was assessed in 649 finishing pigs at the farms before loading, with a five-point scale (0= none to 4 = ≥ 16 superficial lesions or > 10 deep lesions), and at the slaughterhouse after unloading. Three transport distances were evaluated (short, intermediate and long), in which microclimatic and vibration conditions were monitored from the vehicle’s compartments. Intermediate distances showed higher proportions of worst score (4) at the front part, whereas long distances presented worst score at the middle and hind quarters. Short distances displayed higher proportions of worst score at ears. Temperatures inside the vehicle were above the thermal comfort limit for pigs, providing a heat stress condition. Vibrations were higher sideways than in the vertical and longitudinal directions. Transport under tropical conditions negatively affected the skin injuries score, indicating a higher incidence of skin wounds at the slaughterhouse than in the farms. Body parts can be affected differently by distance, considering skin lesion scores.

Spatial and temporal variations of microclimate and outdoor thermal comfort in informal settlements of warm humid Dar es Salaam, Tanzania

In developing countries, urbanization is dominated by the growth of informal settlements which represents 40–80% of major cities. The challenges brought up by the growth of informal settlements spans from social-economic to environmental. Previously, upgrading of the informal settlements focused on social-economic aspects such as provision of necessary services for the residents, whereas the quality of the outdoor thermal environment has not received much attention. This paper entails to investigate the potential of upgrading the outdoor thermal environment in informal settlements in the warm humid city of Dar es Salaam, Tanzania through examining the influence of addition of trees with different Leaf Area Index (LAI) and incremental increase of buildings heights. The study uses simulation as a method for analysis of the warm season and calculates the Physiological Equivalent Temperature (PET) as a thermal index. Results show substantial improvement of both microclimate and outdoor thermal comfort. Incremental increase of buildings heights in a street canyon to 12, 18, and 24 m leads to the reduction of PET by 2.5, 2.8, and 3.8 °C respectively at 2:00 p.m. Similarly, applying LAI's of 2, 4, and 6 m2/m2 leads to reduction of the mean radiant temperature by 7.9, 10.1, and 12.2 °C; while PET was reduced by 3.9, 4.7, and 5.6 °C respectively at 2:00 p.m. Nonetheless, upgrading of informal settlements shows marginal influence on the reduction of air temperature. Despite the noted thermal improvement in the studied area, the thermal comfort limits of the warm season were difficult to reach. The findings suggest that addition of vegetation is the economically most effective way for upgrading thermal conditions in informal urban fabric areas.

Mejora del desempeño térmico de colegios en la Región Altoandina del Perú. El caso del “módulo prefabricado aula tipo heladas - PRONIED”

Faced with the qualitative and quantitative deficit of educational infrastructure in Peru’s rural high Andean areas, in recent years the Peruvian State has been investing in and supporting modular solutions, seeking efficiency in the construction processes. The specific proposal, with special emphasis on bioclimatic design, is the "Prefabricated Frost-type Modular Classroom". However, users have been expressing discomfort with these new facilities. This study shows the measurement process carried out on a built module, which allowed calibrating and validating the model using simulation software, to propose improvements in the design that may contribute to future constructions. Taking the adaptive thermal comfort model as a reference, it was confirmed that indoor temperatures were below thermal comfort limits in the early hours of the morning and well above them close to noon, by around 6 ºC and 7 ºC respectively. With the application of complementary bioclimatic strategies, it was possible to considerably improve indoor thermal conditions, although not enough to reach comfort early in the morning. This is because the night-time outdoor temperatures are very low, the building is uninhabited all night long, there is no thermal mass in the envelope, and there are no active solar systems or mechanical air conditioning.

Analysis Of Thermal Comfort In L 609 Classroom By Using SST k-ꞷ Turbulence Model

In today's era, more and more people spend most of their time indoors, with artificial climatic conditions, where thermal comfort is a basic factor such as a glazing system (ventilation), both for dimensions and material characteristics, this basic factor is very important because it affects the parameters involved in thermal comfort. One of the requirements for thermal comfort is good air circulation, good air circulation can also prevent the spread of the COVID-19 virus that is currently engulfing the world.Therefore, research is needed to analyze the air flow engineering in the room, especially the classroom to get results that will later be seen whether it has met the demands of room comfort, especially thermal comfort. The purpose of this study is to provide recommendations for the configuration of air circulation in the L609 classroom and perform a CFD analysis on air circulation in the classroom which can create thermal comfort. Based on all the simulation results carried out with 2 outlet configurations and 5 different speed fan configurations, the obtained results are in accordance with the ASHRAE 55 standard in 2020 only in the first configuration with a speed of 0.79 m/s. in the second configuration all the simulation results obtained are not in accordance with the thermal comfort limit according to ASHRAE 55 in 2020 because the speed obtained is more than 0.8 m/s and the temperature obtained is more than 297 K. Considering the COVID-19 pandemic, there must be circulation air in order to break down the aerosol concentration of the COVID-19 virus itself. Therefore, the author recommends using a classroom configuration with an open door so that air circulation can flow properly.

Empirical evaluation of demand side response trials in UK dwellings with smart low carbon technologies

Low carbon technologies along with smart control have a role in residential demand side response (DSR) to shift the timing of household energy consumption away from peak times and align it with generation of renewable electricity. This paper empirically evaluates the impact of DSR trials on grid electricity import and resident experience regarding disruption to daily routines, thermal comfort and noise disturbance in 17 thermally efficient social housing dwellings (Barnsley, England). Four types of DSR trials were run through 22 interventions performed in March to April 2021. Each dwelling was equipped with a 5 kWh electro-chemical battery and air source heat pump, and all but one dwelling had solar photovoltaic (PV) panels (1.3–3.0 kWp). Interventions were applied against a flat (single) rate tariff as well as dynamic time-of-use tariffs. On average, secure turn-down interventions between 5 and 7 p.m. resulted in a reduction in grid electricity import of 1.2 kWh per household and a reduction in controllable load (heat pump plus battery energy) of 3.7 kWh per household. The batteries enabled 2.5 kWh per household of electricity to be exported to the grid for these interventions. On average, turn-up interventions between 1 and 3 p.m. resulted in an increase of 2.3 kWh per household in grid electricity import. Individual dwellings showed different levels of demand response depending on the levels and patterns of household electricity consumption.The resident experience was evaluated by means of a series of telephone surveys. Householders were generally accepting of the trials in terms of changes in indoor temperature, hot water availability, noise disturbance and disruption to household routines. However, some general concerns were raised about the energy systems relating to indoor temperature, hot water temperature and energy costs. The general acceptability of automated DSR, conditional on thermal comfort limits and manual override, is promising for the wider application of residential DSR driven by price signals, although ongoing household engagement in DSR schemes will require a continued focus on the householder experience with training and support in using new technologies. A routine period of inspection should be employed to identify any issues with energy system issues ahead of DSR initiation.

Placing of the second oldest red ochre mine in mainland Europe, Lovas, Hungary, to human, paleoenvironmental and paleobiogeographic context

Although the 13.2–13.8 ky old Lovas red ochre mine, Central Transdanubia, Hungary is a very important Upper Palaeolithic archaeological site being the second oldest in mainland Europe, we have little knowledge of the conditions under which and how long the pits were cultivated and the post-mining sedimentation processes. The aim of the study was to study certain human circumstances of the mining activities, reveal the former ecological conditions which influenced the sedimentation processes and investigate how the changing climatic conditions led to the formation of the fossil macrofaunal assemblage of the archaeological site. The removal of ca. 25 m3 of pigment material from the pits was equivalent to a maximum of 8750–11042 transport occasions per person, although the pre-transport processing of the material could notably reduce the weight of the transportable pigment and the time demand. Based on the lower thermal comfort limit, mining activities could be performed predominantly in the summer months. In the relatively humid Bølling-Allerød period, the redeposition of the excavated barren material to the cavity could be rapid after the termination of the mining activity. In the Younger Dryas Stadial and the early Holocene, the recharge and covering of the former pits with sediment could be slow and it started to increase only in the mid-Holocene period. The modelling of the potential distribution range of five macrofaunal elements indicates that all the species occurred at the site in the Bølling-Allerød period in the wider environment of the Lovas red ochre mine. The reconstructed boreal forest biome in the time of cultivation of the mine can explain well the dominance of fossil elk bones found in the fossil assemblage.

A Novel Building Performance Based Climate Zoning for Ethiopia

Climate zoning plays a vital role in the development and implementation of building energy regulations. his paper presents a novel building performance-based approach for climate zoning. By using a high resolution spatial climate dataset, a climate severity mapping of Ethiopia is presented. Ethiopia represents 13 of the Köppen Geiger global climate zones. Real-time thermal performance measurement of representative residential buildings in three climatic locations is presented. Thermodynamic models of these buildings are developed and validated using energyplus software tool. Hourly building simulations of these buildings are performed for 1,490 locations (15 min spatial resolution) across Ethiopia. Cooling and heating discomfort hours, as well as energy performance index, are computed for each of these geolocations. Spatially interpolated building performance metrics and adaptive thermal comfort limits are presented. The relevance of Köppen Geiger's classification in the context of building performance is statistically tested. We observed that the existing climate zones do not considerably represent the building thermal performance and energy footprint. Effect of thermal severity on building performance is described. Further, climate zones are deduced based on the building performance variables using multivariate statistical clustering. In order to evaluate potential climate responsive strategies, bioclimatic zoning of Ethiopia is presented. The bioclimatic zoning is created using an improved Mahoney's method that incorporates solar radiation. This analysis resulted in 21 bioclimatic strategy zones. A comparative assessment of the new climate zoning with Mahoney's bioclimatic classification is presented. The proposed framework will be relevant for regulating building performance and energy conservation measures.

Dynamic analysis of daylight factor, thermal comfort and energy performance under clear sky conditions for building: An experimental validation

This work focuses on daylighting performance analysis and its energy savings potential for residential building by using dynamic simulation and its experimental validation. The thermal performance of nano building material and its comparison with conventional building material has also been analyzed. The daylight factor was found in between 1 and 11% and 1–21% for the floor and wall, which is within the thermal comfort limit. The theoretical model results are compared with experimental values. The best building orientation was found to be 180° from the north or towards the south. Wind speed was found to be more than 30 kmph, which is used effectively in the natural ventilation of the building envelop. It leads to optimization of the room temperature. The heat transfer parameters, including the quantity of heat lost and gained through fabrics, thermal properties of nanomaterial have been compared with conventional building materials. The U value (heat loss coefficient) of building material defines building performance at a particular orientation. The U- values decreased to 8 times in-wall and 8.67 times in the roof of the building envelope compared to conventional building material. The model was experimentally validated, and there is close agreement between simulated and experimental daylight factor values with root mean percentage error of 1.24%. The total uncertainty in experimental measurement was found out to be 0.1421%, which is within the expectable range. Present study can be implemented in any building design with minimum modifications in any part of the world.

Thermal comfort environment for migrants: a long-term follow-up climate chamber experiment

Migration between different climate regions may change people’s thermal experience and their thermal adaptation. However, few studies have explored the thermal adaptation process and the suitable indoor thermal environment of migrants. In this study, we conducted a long-term tracking comparative experiment on thermal adaptation of migrants moving from severe cold (SC) regions, hot summer and cold winter (HSCW) regions, and hot summer and warm winter (HSWW) regions to cold region of China. A two-year climate chamber experiment was conducted to follow migrants’ progressive thermal adaptation, such as different weeks, months and seasons after they migrated. The results show that the thermal sensation of migrants was significantly associated with their origin, the time after migration and air temperature. In addition, with the increase time after migration, the thermal sensitivity of HSCW and SC migrants showed a significant upward and downward trend, respectively. Two years after migration, the thermal comfort limits of migrants from SC, HSWW and HSCW were almost identical at 23.5-27.8°C, 23.8-27.8°C, and 23.5-27.6°C. The results provides insight to the progression of thermal adaptation and helpful to guide the design of indoor climate for immigrants with different thermal experiences.

Passive cooling design strategies as adaptation measures for lowering the indoor overheating risk in tropical climates

Year-round high temperatures and humidity in the Tropics, coupled with poor design decisions and climate change, can cause indoor environments to overheat, affecting health and increasing energy demand and carbon emissions. Passive cooling could help lower the indoor overheating risk. Given the gap in the relative influence of passive cooling design strategies on lowering the indoor overheating risk in tropical locations, this study investigated their impact in two warm tropical cities (i.e., Tegucigalpa and San Pedro Sula), considering both current and future climate scenarios, with a total of 3840 thermal simulations performed. Indoor overheating risk in apartment-type dwellings was assessed using two metrics (i.e., hours of exceedance and the indoor overheating degree), and considering fixed and adaptive thermal comfort limits. Simulation results show that the overheating risk can be significantly lowered in these tropical contexts using solely passive cooling strategies as heat adaptation measures. Multivariate regression models demonstrate that natural ventilation, wall absorptance, the solar heat gain coefficient, and semi-outdoor spaces have the greatest impact in lowering the risk in vertical social housing projects. This study emphasizes the importance of passive cooling and overheating protection design strategies in tropical building codes and building design while considering current and future risk.

Development of a Soft Actor Critic deep reinforcement learning approach for harnessing energy flexibility in a Large Office building

This research is concerned with the novel application and investigation of ‘Soft Actor Critic’ based deep reinforcement learning to control the cooling setpoint (and hence cooling loads) of a large commercial building to harness energy flexibility. The research is motivated by the challenge associated with the development and application of conventional model-based control approaches at scale to the wider building stock. Soft Actor Critic is a model-free deep reinforcement learning technique that is able to handle continuous action spaces and which has seen limited application to real-life or high-fidelity simulation implementations in the context of automated and intelligent control of building energy systems. Such control techniques are seen as one possible solution to supporting the operation of a smart, sustainable and future electrical grid. This research tests the suitability of the technique through training and deployment of the agent on an EnergyPlus based environment of the office building. The agent was found to learn an optimal control policy that was able to minimise energy costs by 9.7% compared to the default rule-based control scheme and was able to improve or maintain thermal comfort limits over a test period of one week. The algorithm was shown to be robust to the different hyperparameters and this optimal control policy was learnt through the use of a minimal state space consisting of readily available variables. The robustness of the algorithm was tested through investigation of the speed of learning and ability to deploy to different seasons and climates. It was found that the agent requires minimal training sample points and outperforms the baseline after three months of operation and also without disruption to thermal comfort during this period. The agent is transferable to other climates and seasons although further retraining or hyperparameter tuning is recommended.

The Significance of the Adaptive Thermal Comfort Practice over the Structure Retrofits to Sustain Indoor Thermal Comfort

Any building’s design should sustain thermal comfort for occupants and promote less energy usage during its lifetime using accurate building retrofits to convert existing buildings into low-energy buildings so that the heating and cooling loads can be minimized. Regarding the methodology adopted in this research, an energy model of an educational building located at the German Jordanian University in Jordan was constructed utilizing DesignBuilder computer software. In addition, it was calibrated utilizing real energy consumption data for a 12-month simulation of energy performance. Subsequently, a computerized evaluation of the roles of building envelope retrofits or the adaptive thermal comfort limits in the reduction of the overall building energy consumption was analyzed. The results of the study show that the current building’s external wall insulation, roof insulation, glazing, windows, and external shading devices are relatively energy-efficient but with high cost, resulting in significant financial losses, even though they achieved noticeable energy savings. For instance, equipping the building’s ventilation system with an economizer culminated in the highest financial profit, contributing to an annual energy savings of 155 MWh. On the other hand, in an occupant-centered approach, applying the adaptive thermal comfort model in wider ranges by adding 1 °C, 2 °C, and 3 °C to the existing operating temperatures would save a significant amount of energy with the least cost (while maintaining indoor thermal comfort), taking over any retrofit option. Using different adaptive thermal comfort scenarios (1 °C, 2 °C, and 3 °C) led to significant savings of around 5%, 12%, and 21%, respectively. However, using different retrofits techniques proved to be costly, with minimum energy savings compared to the adaptive approach.

Effect of Phase Change Materials on the Thermal Performance of Residential Building Located in Different Cities of a Tropical Rainforest Climate Zone

This study aims to investigate the thermal performance of PCM and PCM combined with nighttime natural (NV) and mechanical ventilation (MV) applied to a residential building located in eight cities of tropical rainforest climate zone (Af). The analysis was accomplished using numerical simulations and developing a unique methodology for selecting the PCM melting temperature based on the thermal comfort limits. The thermal performance of the PCM integrated building was quantitatively evaluated using the concept of peak temperature drop. Additionally, a novel indicator of Total Temperature Drop (TTD) was introduced to determine the overall impact of the PCM and PCM combined with NV/MV on the thermal comfort conditions inside the building. The results showed that PCM 28 was the most efficient in improving the thermal performance of the building located in the Af climate zone, achieving a TTD of up to 356 °C per year. The usage of PCM 28 combined with nighttime natural ventilation improved the TTD values by up to 15%, whereas the integration of PCM 28 combined with mechanical ventilation resulted in a TTD values increase of up to 45%. Conclusively, mechanical ventilation showed its superiority over natural ventilation in the tropical rainforest climate, and PCM 28 applied together with mechanical ventilation could be used as the optimum combination for the whole climate zone.

Influence of the type of thermostat on the energy saving obtained with adaptive setpoint temperatures: Analysis in the current and future scenario

Building energy performance should be improved to reduce the impact of climate change. The energy saving potential has been recently proved with adaptive setpoint temperatures. However, the accuracy of thermostats hinders the achievement of the energy saving obtained in previous studies. For this reason, this paper studies the influence of three types of thermostats according to their configuration accuracy: 0.1, 0.5, and 1 °C. Two case studies (with and without retrofitting) were analysed in three cities in the current scenario, in 2050, and in 2100. The results showed that the implementation of adaptive setpoint temperatures in thermostats of 0.1 °C virtually obtains the same savings as the direct application of thermal comfort limits. Nevertheless, obtaining considerable energy savings in the other two thermostats depends on the type of energy consumption, climate, and the category of the thermal comfort model. The application of adaptive setpoint temperatures in air conditioning systems obtains energy savings greater than 40%, regardless of the type of thermostat and category, whereas in heating systems, only the category III obtains energy savings with old thermostats.

Energy poverty risk mapping methodology considering the user's thermal adaptability: The case of Chile

Today, identifying energy poverty is one of the scientific community's challenges. In this sense, using Geographic Information Systems (GIS) assumes getting to know which areas are the most vulnerable. This study considers the development of a new territory energy poverty evaluation indicator, called Poverty Adaptive Degree Hourly Index (PADHI). The novelty of this indicator is that it combines the number of inhabitants in poverty with the hourly heating and cooling degrees of each climate, determined using adaptive thermal comfort limits based on ASHRAE 55-2017. The area studied focuses on Chile and its 346 municipalities. The application of the adaptive comfort model can exceed 90% in the north of the country and be below 20% in the most meridional areas. The results also outlined that the municipalities defined as PADHI's 10th decile are those which have a higher risk of energy poverty in their population, a higher percentage of income poverty and climatic severity. A cluster analysis was also run for this decile, identifying two risk groups with the aim of identifying the critical areas. This methodology applied to Chile, but international in nature, allows identifying priority areas on which the measures needed to reduce energy poverty can be focused.

The Effects of Clothing Insulation and Acclimation on the Thermal Comfort of Underground Mine Workers

Excessive heat exposure is among the health and safety hazards that have adverse effects on the mine workers. The very nature of the underground climate makes it a convenient avenue for heat generation and accumulation from several heat sources including autocompression, equipment, and heat from strata. This study investigated the effects of clothing insulation and acclimation on the thermal comfort of mine workers who are exposed to heat in underground working environments. Several clothing ensembles have been considered to analyze the effect of the thermal resistance of clothing on the thermal comfort of workers. To investigate the impact of the clothing insulation, the thermal comfort limit of an underground miner was calculated in the form of maximum allowable exposure time for an 8-h shift. Parametric analyses were subsequently performed using an already developed thermal comfort model using MATLAB software. The results demonstrate that clothing insulation has a significant effect on the thermal comfort of mine workers. Increase in the clothing insulation decreases the maximum allowable exposure time of mine workers. This is especially true for the new and non-acclimated workers. Since acclimatized workers can tolerate a higher level of the dehydration and are capable of losing more water by sweat per shift, the maximum allowable exposure time for the acclimated workers are higher than non-acclimated workers. These analyses have shown that acclimated workers can have more continuous work per shift compared with non-acclimated workers. For example, in an environmental condition with clothing that a non-acclimated worker cannot work more than 5 h, an acclimated worker can work a full 8-h shift.