Thermal Comfort Conditions Research Articles

A Review of Thermally Activated Building Systems (TABS) as an Alternative for Improving the Indoor Environment of Buildings

Among the alternatives for improving the thermal comfort conditions inside buildings are the thermally activated building systems (TABS). They are embedded in different building components to improve the indoor air temperature. In this work, a review and analysis of the state of the art of TABS was carried out to identify their potential to improve thermal comfort conditions and provide energy savings. Furthermore, this study presents the gaps identified in the literature so that researchers can develop future studies on TABS. The articles found were classified and analyzed in four sections, considering their implementation in roofs, walls, floors, and the whole envelope. In addition, aspects related to the configuration of the TABS and the fluid (speed, temperature, and mass flow rate) were analyzed. It was found that when TABS are implemented in roofs, walls, and floors, a reduction in the indoor temperature of a building of up to 14.4 °C can be obtained. Within the limitations of the TABS, the complexity and costs of their implementation compared to the use of air conditioning systems are reported. However, the TABS can provide energy savings of up to 50%.

A novel passive system for providing natural ventilation and passive cooling: Evaluating thermal comfort and building energy

Hybridization of natural ventilation with the passive cooling technique is a feasible approach for reducing the dependency on energy-consuming mechanical HVAC systems. The present study numerically investigated the viability of the application of a novel hybrid system composed of a windcatcher, an earth-to-air heat exchanger (EAHE), and a direct evaporative cooling system in a residential building. The test building was a two-story apartment with an area of 100 m2 (each floor 50 m2). 3-D Computational Fluid Dynamics (CFD) simulations were conducted to determine the airflow characteristics inside and outside the test apartment. Moreover, a computer program was developed and validated with the literature for modeling the thermal performance of the system. The effects of the environmental conditions (wind speed, ambient temperature and relative humidity, and average soil temperature) and the windows opening on the performance of the system were evaluated. The obtained results provided a design guideline that determines the allowable windows opening range for providing the thermal comfort conditions in the test rooms. The studied passive system could fulfil the comfort criteria for the test building under a maximum cooling load of 10000 W and 6500 W, according to adaptive thermal comfort standards (ATCS) and ISO7730, respectively. Finally, the energy metric and environmental analysis were carried out to compare the introduced system with the conventional mechanical cooling equipment during the hot months of the year. It was concluded that utilizing the proposed system could lessen the hourly electrical energy consumption by 0.0194 kW h/m2 compared to split air conditioners and 0.0081 kW h/m2 in comparison with evaporative coolers, resulting in a 20.2815 kg/m2 and 8.4681 kg/m2 annual reduction in CO2 emission, respectively.

The role of design parameters on the performance of diffuse ceiling ventilation systems – thermal comfort analyses for indoor environment

ABSTRACT Thermal comfort conditions profoundly affect the occupants’ health and productivity. A diffuse ceiling ventilation system is an air distribution system in which the air is supplied to the occupied zone with relatively a low velocity through the perforated panels installed in the ceiling. The current study evaluated the impact of diffuse ceiling design parameters, i.e. diffuse panel configurations and heat load distributions, on the thermal comfort condition of the occupants. In this regard, the computational fluid dynamics technique was used to evaluate thermal comfort conditions in a waiting room, meeting room and office. The central and dispersal configuration of active diffuse panels was considered. The PMV-PPD model was applied to evaluate the overall occupants’ comfort, while the draft rate was considered to assess local thermal comfort. The model validation was performed by comparing the collected laboratory measurement data. Overall, the results indicated that the central active diffuse panel configuration had a better thermal comfort than the dispersed one. The evaluation of dispersed configuration in realist scenarios, including office and waiting room, had the highest dissatisfaction, with a PPD value of 9%. Local thermal comfort assessment revealed that dispersed configuration had the highest draft rate of 14% in the office.

Mapping of the Thermal Microenvironment for Dairy Cows in an Open Compost-Bedded Pack Barn System with Positive-Pressure Ventilation.

Simple SummaryAdequate environmental conditions are essential to ensure the wellbeing and productivity of dairy cattle. The use of compost-bedded pack barn (CBP) systems in dairy farming certainly improves animal welfare conditions, but it is necessary to evaluate and characterize the thermal environment inside the facilities. The main objective of this study was to map the thermal environment inside a CBP system with positive-pressure ventilation. Through mapping, it was possible to identify regions with more challenging conditions for animals in terms of thermal comfort. The results achieved can be used to direct decision-making processes to create adequate environmental conditions for the hosted animals.The objective of this study was to evaluate and characterize the dependence and the spatial and temporal distribution of variables and indices of the thermal environment in an open compost-bedded pack barn system with positive-pressure ventilation (CBPPV) during the winter period. The study was conducted in a CBPPV system located in the Zona da Mata region, Minas Gerais, Brazil. The indoor environment was divided into a mesh composed of 55 equidistant points, where data on dry-bulb air temperature (tdb) and relative humidity (RH) were collected. The collected data were divided into four periods—dawn, morning, afternoon, and night—and mean values were obtained. To evaluate the thermal microenvironment, the temperature and humidity index (THI) and the specific enthalpy of air (h) were used. For spatial dependence analysis, geostatistical techniques were applied. Through the results, a strong spatial dependence was verified for all variables evaluated. Through THI and h maps, conditions of thermal comfort were found for dairy cattle. The highest values of tdb, THI, and h were recorded in the afternoon period in the northwest region of the facility (tdb = 23.2 °C, THI = 69.7, and h = 50.9 kJ∙kg of dry air−1).

Determination of improved climatic conditions for thermal comfort and energy efficiency in electric buses

In electric buses, the heating, ventilation and air conditioning (HVAC) system is responsible for up to 50% of the energy consumption, thereby significantly affecting the efficiency. It is therefore necessary to identify improved thermal settings for the bus cabin to minimize the energy consumption, while guaranteeing good thermal comfort. To achieve this goal, this paper presents the results of climatic measurements in an electric bus in Berlin, Germany. These measurements were performed for outer temperatures between 5.3 °C and 7.8 °C and four cabin temperature settings. During the measurements, several climatic parameters and the energy consumption were measured, whereas the thermal comfort (TC) was evaluated via 71 passengers’ surveys. The results show that the climatic conditions in the bus vary greatly depending on the position (up to 3 K difference in mean air temperature) and height (up to 8 K/m temperature-to-height ratio). Additionally, the surveys show that the mean value of the thermal comfort parameter TC is minimized to a value of 0.15 (corresponding to “comfortable” thermal perception) for a set temperature of 21 °C, whereas the thermal conditions are perceived as acceptable even with heating off.

A comprehensive review of outdoor thermal comfort in urban areas: Effective parameters and approaches

Increased urban air temperature considerably affects the health, comfort and consequently the quality of life in urban spaces. Urban design and planning studies, therefore, face an increasing challenge as they aim to improve Outdoor Thermal Comfort (OTC) and microclimate conditions of urban environments. Analysing OTC is more challenging when compared to indoor thermal comfort since a wider range of interrelated parameters exists in outdoor environments. Therefore, this research aims to classify urban studies that investigate OTC by conducting a comprehensive review based on key metrics such as approaches taken, methodologies and spatial and temporal scales. By extracting the key findings, this research forms an integrated framework of these metrics that presents a thorough view of the OTC concept in the context of climate-sensitive studies. Furthermore, this research elaborates on the main two groups of parameters affecting OTC including environmental and human-based parameters. Exploring the intricate inter-relationships of these two groups of parameters clarifies their contribution to OTC. Results of this study help architects and urban planners to improve their climate-sensitive strategies and support the decision-making process by providing a comprehensive perspective about different aspects of OTC. Finally, recommendations for future research are outlined.

Thermal comfort conditions in traditional and sustainable, low - energy buildings

Nowadays, each of us spends more and more time indoors. The article focuses on research on thermal comfort in a traditional and sustainable building. A sustainable building is equipped with heat pumps, a wind turbine, solar collectors and photovoltaic cells. It also has mechanical ventilation, which helps to minimize energy consumption and lower carbon dioxide emissions. The research was carried out using two methods, anonymous questionnaires and the Testo 400 microclimate meter. Based on the conducted research, the thermal sensations of the subjects and their preferences as to the prevailing conditions in the examined buildings were determined. The study also made it possible to compare the PMV index calculated using the Fanger model with TSV (obtained on the basis of anonymous questionnaires).

Design and Optimization of Energy Consumption for a Low-Rise Building With Seasonal Variations Under Composite Climate of India

Abstract The need for maintaining thermal comfort conditions inside the building is a significant contributor to the total energy requirements of the buildings. Thus far, limited research has offered some strategies to mitigate the effect of ambient conditions on the thermal comfort and the building energy requirements for composite climatic zone in India. In order to address this problem, this study was conducted to evaluate and analyze the impacts of four different passive design strategies, i.e., insulation, cool roof, phase change material (PCM) thermal storage system, and shading, on thermal comfort and energy demand in the two-storey building situated in the composite climate zone of Delhi, India. The results obtained by numerical simulation for four different cities, i.e., Delhi, Jaipur, Lucknow, and Indore, have been compared to study the effect of local climatic and seasonal variations within the composite climatic zones. The simulations were conducted using the Design Builder software to capture results for one year. The results indicate that no single passive design strategy is sufficient to maintain comfortable conditions inside the building. The cool roof provides significant benefits in combination with other passive technologies in all seasons except for December, January, and February. The combination of insulation and PCM is useful for winter conditions. Energy saving of up to 20.5% is possible using the combination of all four passive strategies, whereas the cool roof alone gives an 18% reduction in energy load. The PCM with a melting point of about 32 °C is suggested for the cities under study.

Analysis of a low-temperature small approach open cooling tower integrated with radiant cooling and displacement ventilation for space conditioning in temperate climates

ABSTRACT Evaporative cooling, using cooling tower systems, has the potential to offer an alternative approach for producing high temperature chilled water, particularly for buildings located in temperate climates. The current paper examines the performance of an integrated cooling system, where an open forced draught counter flow cooling tower is used for the provision of chilled water for a radiant cooling and displacement ventilation system. For this purpose, a low temperature low approach direct evaporative cooling tower is used which can provide cooling water with low approach temperatures (1-3 K), which defines the temperature difference between the tower water outlet temperature and ambient wet bulb temperature. The performance of the proposed cooling system has been investigated for internal buildings loads up to 66 W·m-2 in order to examine the limitations of the cooling system. Space thermal comfort conditions and system performance metrics were assessed for four different temperate climate types as follows: cool and dry (Helsinki), cool and semi-humid (Birmingham), warm and dry (Prague), and warm and humid (Paris). The assessment shows that for the proposed system, where a radiant floor was used, can provide acceptable thermal comfort conditions for approximately 80% of the occupant hours over the respective cooling seasons.

Considering transient UTCI and thermal discomfort footprint simultaneously to develop dynamic thermal comfort models for pedestrians in a hot-and-humid climate

A well-being and sustainable urban environment consist of a series of pedestrian walkways for either commuting, exercising, or leisure use. The environmental thermal condition, which affects a person's thermal comfort, of the linear walking paths will inherently influence people's usage probability. The outdoor thermal environment and the human physiological response are both important determinants of thermal comfort during the dynamic process of walking. The traditional assessment of thermal comfort is based on the heat balance of the human body with steady environmental conditions that are rarely true in the constantly changing outdoor environments due to the context of urban morphology. In this research, we propose a novel method by integrating the traditional static thermal comfort index with the dynamic thermal comfort footprint and taking the spatiotemporal variations of thermal comfort conditions during the walking activity into consideration to develop dynamic thermal comfort prediction models for pedestrians. On-site thermal walking experiments with both subjective thermal questionnaires and objective physical thermal condition measurements were conducted on a university campus in different seasons to help establish the models. The proposed models were afterward validated against the measured values and showed that they can predict the dynamic thermal comfort of the pedestrians with satisfactory accuracy. With the proposed model, one could assess the dynamic thermal comfort conditions of a particular walk path with the Universal Thermal Climate Index (UTCI) and help to seek strategies in designing a thermally acceptable pedestrian walkway.

PENILAIAN KENYAMANAN TERMAL RUANGAN MENGGUNAKAN PMV (STUDI KASUS PERPUSTAKAAN SDN 27 PONTIANAK UTARA)

Pontianak city has tropical climate and crossed by the equator. This phenomenon has an impact on the level of thermal comfort in a room, especially in North Pontianak District which is close to 0˚ latitude. library of the Public Elementary School (SDN) 27 North Pontianak is one of the examples. This library is located on the equator with coordinates 0˚00˚07N 109˚20'02E which has high temperature and high humidity levels. This condition impact on bad thermal comfort. bad thermal comfort can affect the health of indoor activities. Therefore, the thermal comfort level needs to be research and provide a room's solution to achieve a neutral thermal comfort condition. This research measures the thermal comfort's variables on PMV (Predicted Mean Vote). The variables measured were air temperature, radiation temperature, humidity and wind speed, the observed variables were metabolic values and clothing insulation. The thermal comfort level will be calculated using the Center of Building Environment (CBE) Thermal Comfort Tool. The results of this research indicate that the level of thermal comfort in the library which is calculated using the CBE Thermal Comfort Tool have PMV value ranging 0,07 to 2,96. The value of thermal sensation in library is neutral to hot. thermal comfort conditions can be achieved by the application of cross ventilation.

Influence of the preplacement holding time and feeding hydration supplementation before placement on yolk sac utilization, the crop filling rate, feeding behavior and first-week broiler performance

This study investigated the effects of the broiler chick preplacement holding time and feeding hydration supplementation before placement on yolk sac utilization, the crop filling rate, feeding–drinking behavior and first-wk broiler performance. Broiler hatching eggs were obtained from a commercial broiler breeder flock of Ross 308 at 37 wk of age and incubated in a commercial hatchery. At 510 h of incubation, all chicks were removed from the hatcher and separated into cardboard chick boxes containing 80 chicks each. The chick boxes were randomly separated into two groups with either added commercial hydration supplementation (gel: Hydrogel-95) or the control (no gel). Then, the chicks were randomly distributed into 5 groups with different holding times across each hydration supplementation treatment (gel and control). The preplacement holding times were 6, 24, 48, 60, and 72 h from the pull time from the hatchers in the hatchery to placement in the broiler house on the farm, at which point the chicks were able to access feed and water. There were 10 subtreatment groups comprising 5 chick preplacement holding time groups × 2 hydration supplementation groups. There were 12 replicates (160 chicks per pen) per holding period × gel treatment, with a total of 19,200 chicks placed. The feed and water access time did not influence yolk sac utilization, but the absolute or relative residual yolk sac (g, %) decreased linearly with the duration after the pull time (P < 0.001). Longer preplacement holding times were associated with a higher percentage of chicks with full crops at 3 h after placement (P < 0.001). Chicks with the shortest (6 h) preplacement holding time had a lower percentage of feed-seeking activity compared to the 24, 48, and 72 h holding time groups at 3 h after placement (P < 0.001). The highest chick eating and drinking activity was observed in the 72 h group at both 3 and 8 h after placement. Chick weight at placement was significantly reduced linearly with the duration after the pull time (0.106 g/h; R2 = 0.775), and as expected, the highest and lowest BW were found in the 6 (41.51 g) and 72 h (34.50 g) preplacement holding time groups, respectively. However, BW and BW gain were higher in the 24 h group than in the other preplacement holding time groups (P < 0.001) at 7 d after placement. Mortality within the first 3 d after placement increased only when the preplacement holding time was extended to 72 h (P = 0.002). Mortality during 4 to 7 d postplacement was not affected by the holding time at all, but the 72-h holding time group still had statistically significantly higher mortality cumulatively from 0 to 7 d (P = 0.024). Neither BW nor mortality was affected by feeding the hydration supplement at placement, and the lack of effect persisted through 7 d after placement (P > 0.05).It can be concluded that the BW at 7 d after placement was greater in the 24 h holding time group than in shorter (6 h) or longer (48, 60, and 72 h) preplacement holding time groups. In the present study, a greater number of chicks were raised, and it was clearly demonstrated that mortality, as a direct indicator of flock health and welfare, was not affected by preplacement holding times up to and including a 60 h after take-off under thermal comfort conditions, but holding for a further 12 h to 72 h, mortality at 7 d of age after placement was increased. On the other hand, holding chicks in a short period (6 h) did not improve mortality and the BW at 7 d, suggesting that some delay to placement can be beneficial. In addition, feeding hydrogel during the preplacement holding period had no positive effect on BW gain and cumulative mortality during the first week of the growing period.

Urban Heat Island and Thermal Comfort Assessment in a Medium-Sized Mediterranean City

One of the greatest issues nowadays is that of the urban heat island effect on the thermal conditions inside cities. The air temperature inside the city core is warmer than that in suburbs, thus deteriorating the quality of life for citizens and making outdoor spaces uncomfortable in terms of thermal comfort. This phenomenon is usually assessed in large scale cities worldwide and less often in medium-sized towns. The current study aimed to investigate the urban heat island effect and, therefore, to assess the outdoor thermal comfort conditions in a medium-sized city. More specifically, the methodology of the current study includes: (i) the combination of different monitoring techniques to quantify the urban heat island effect in a medium-sized Mediterranean city. Both in situ measurements and remote sensing techniques were applied to assess the urban heat island effect in terms of both the canopy layer (CUHI) and the surface (SUHI); (ii) the identification of the parameters that affect thermal comfort and the identification of the most appropriate bioclimatic indices that determine outdoor thermal comfort in the city of interest. Both questionnaire survey and in situ measurements took place on a sidewalk in the city of Xanthi, Northern Greece, during the summer. The CUHI effect was obvious, especially in the morning and afternoon. Downscaled MODIS satellite images also showed that the intensity of SUHI was higher in the morning and afternoon. Apart from air temperature, important differences in the values of most microclimatic parameters were recorded between the meteorological station placed inside the urban area and those gathered from a nearby meteorological station. The narrow roads, the thermal properties of construction materials, and the absence of greenery characterized the area of interest and may be the key factors creating these differences in climate. Concerning the thermal comfort assessment, the most significant parameters were the air temperature and solar radiation, although, both empirical and direct indices were found to describe the comfort values well. According to the results, downscaling techniques are also important for the SUHI effect to be investigating in detail in medium-sized urban environments.

Adaptation of Users to Future Climate Conditions in Naturally Ventilated Historic Buildings: Effects on Indoor Comfort

User behaviour can significantly affect indoor thermal comfort conditions, as well as energy consumption, especially in existing buildings with high thermal masses where natural cross ventilation is the main strategy to reduce cooling loads. The aims of this paper were: (i) to compare how behavioural changes evaluated by means of rule-based and stochastic models lead to changes in indoor thermal comfort levels, and (ii) to define the patterns of indoor thermal comfort in historic residential buildings in future scenarios. To this end, a historic building located in Molfetta (Southern Italy) was analysed using a dynamic energy simulation engine in five weather scenarios (Typical Meteorological Year, current extreme weather file 2018, predicted weather files for 2020, 2050, and 2080 generated by morphing method), and stochastic and rule-based models for window openings were adopted and compared. The results showed that the stochastic model was more accurate than the rule-based one, resulting in a reduction of discomfort conditions during the summer period between 30% and 50% in all climate scenarios. However, although the differences between predicted discomfort levels using rule-based and stochastic models tended to increase, discomfort levels still appeared to be not acceptable in the 2050 and 2080 scenarios due to the rising temperature driven by climate change.

Field measurement and numerical investigation of natural cross-ventilation in high-rise buildings; Thermal comfort analysis

The importance of climate change mitigation and energy efficiency as a growing global concern has intensified the development of techniques to reach and improve thermal comfort and energy efficiency of buildings. The study of the effect of the height of the openings on the internal natural airflow in one-story buildings can be found in many studies; However, studies on the effect of this important factor on providing thermal comfort in high-rise buildings equipped with DSF are not available. This paper focuses on natural-ventilated buildings based on wind-driven and buoyancy-driven forces. The aim of this study is to use passive strategies in high-rise office buildings in hot and dry climates. In this research, two methods of field studies and numerical modeling have been used in order to provide accurate results. In order to achieve optimal patterns in the design of natural-ventilated buildings; CFD simulation and PMV thermal comfort index have been used in the evaluation of various configurations. The results of the present study show that although the cooling energy demand in high-rise buildings in hot climates is high and the use of natural ventilation systems is beneficial, but these systems alone are not able to provide thermal comfort conditions. However, the accurate and correct location of the openings is effective in improving thermal comfort by increasing the volume flow.

Thermal performance analysis of clay brick mixed with sludge and agriculture waste

Nowadays, the decarbonization of buildings is one of the most critical and immediate challenges facing the construction industry. Given that, agricultural and human residues have become a popular choice for manufacturing building materials due to their cost-effectiveness and environmental friendliness, making them viable for achieving sustainability in the construction sector. This research investigates the thermal properties of several proposed brick samples produced by mixing clay, sludge, and sugarcane bagasse ash and studies the feasibility of using these brick samples to reduce energy consumption. First, four clay brick samples containing different proportions of water treatment sludge and sugarcane bagasse ash were prepared and tested experimentally to measure their thermal conductivity and physical properties. Subsequently, a comparative simulation analysis using EnergyPlus has been conducted to illustrate the feasibility of adopting proposed brick samples in a case study building and demonstrate the effect of the diverse construction materials on the thermal performance and energy consumption. The experimental results showed a significant improvement in the thermal conductivity of the brick samples produced by mixing clay, sludge, and sugarcane bagasse ash (0.11 to 0.26 W/m.K) compared to the traditional brick types (0.33 –1.6 W/m.K). Numerical results show the superiority of adopting the proposed materials, which leads to an average 64% reduction of the heat flow compared to the conventional wall systems. In this sense, the annual energy consumption was reduced by 16.5% in the building with the proposed brick walls compared to traditional clay bricks. Additionally, average thermal comfort conditions increased by 6.3% (16.3 to 22.6%). The findings of this research can serve as a start reference for practitioners and researchers endeavouring to find solutions for further improving the overall quality of thermally insulated waste-incorporated bricks, paving the way for more focused research on waste utilization in the development of replicable and energy-efficient buildings.

Optimization of return vent height for stratified air distribution system with impinging jet supply satisfying threshold of |PMV| &lt; 0.5

The stratified air distribution (STRAD) ventilation system addresses much attention due to the less cooling energy consumption than conventional mixing ventilation systems in maintaining a proper indoor environment. In recent literature, the vent height of STRAD systems has been studied. However, in previous studies, the impacts of over-cooling and/or over-warming on cooling load as well as, consequently, on the optimal return vent height were not systematically considered. In practice, the indoor environment (e.g., predictive mean vote PMV, indoor air quality IAQ) is sensitive to the supply condition (e.g., supply temperature) and the return vent height. This study aims to optimize the return vent height of a STRAD ventilation system with impinging jet supply under a general thermal comfort condition, i.e., threshold of |PMV| < 0.5. The evaluated indices include the cooling coil load, the temperature difference between the head and ankles, the average CO2 concentration, the average mean age of air, and the predicted percentage of dissatisfied. The research outcomes indicate that: a) the increase of supply temperature generally avoids overcooling and reduces cooling coil load; b) the cooling coil load increases and c) the IAQ generally upgrades as the return vent height rises; d) the optimal return vent height with the impinging jet ventilation is recommended as 2.625 m (i.e., near the ceiling), which is different from previously suggested mid-level return vent. Under this optimal return vent height, the supply temperature can be increased to 22 °C with resultant |PMV| < 0.5, lower cooling coil load, and better IAQ comparing to the recommended case of mid-level return vent with a supply temperature of 18 °C.

Thermal Comfort—Case Study in a Lightweight Passive House

Saving energy while maintaining a high-quality internal environment is an increasingly important scientific and technological challenge in the building sector. This paper presents the results from a long-term study on thermal comfort in a passive house situated in the south of Poland. The building was constructed in 2010 with the use of prefabricated, lightweight technology. The main energy source is a ground source heat pump which powers the floor heating and DHW. The building is also equipped with a mechanical ventilation system with heat recovery and a ground source heat exchanger. A lightweight building structure which has active systems with limited capabilities (especially for cooling) is a combination which increases the difficulty of maintaining a proper inner environmental condition. Extensive experimental investigations on hygrothermal performance and energy use have been carried out in the building for several years. The measurement results, such as inner air temperature and humidity, as well as the inner surface temperature of partitions, could be directly used to determine basic thermal comfort indicators, including PMV and PPD. Any missing data that has not been directly measured, such as the surface temperature of the windows, floors, and some of the other elements of the building envelope, have been calculated using WUFI®PLUS software and validated with the available measurements. These results are not final; the full measurement of thermal comfort as an applied methodology did not consider human adaptation and assumed constant clothing insulation. Nevertheless, in general, the results show good thermal comfort conditions inside the building under research conditions. This was also confirmed via a survey of the inhabitants: 2 adults and 3 children.

Prediction Indoor Thermal Comfort in Traditional Houses of Shiraz with PMV/PPD model

: In the current study, the passive strategies in traditional houses of Shiraz were investigated and correlation between PMV/PPD model and environmental parameters have been evaluated topredict thermal comfort in traditional houses. In this study, firstly a traditional house as a case study was selected and the thermal comfort conditions of the talar room were analyzed with the PMV/PPD model by DesignBuilder software. Results revealed that PMV of talar room in May, June, September, and October were in the range of -1 and 1 which shows thermal comfort condition has been convenient. Additionally, PMV possessed the highest correlation coefficients with Ta (r = 0.84), Tr (r = 0.84), Top (r = 0.84), Tout (r = 0.82) and lowest correlation coefficients with RH (r = 0.69). It has been discovered that PMV is more similar to PPD (r = 0.95).

Thermal comfort conditions in Brazil: A discriminant analysis through the ASHRAE Global Thermal Comfort Database II

The Predicted Mean Vote (PMV) created by Fanger in the 70's is the most common model for estimating the thermal sensation in a group of individuals. The PMV contains some discrepancies related to the thermal reality of the environments where it is applied; thus, several researchers have developed alternative models over the past years in order to reduce these differences. This research aimed at analyzing thermal comfort conditions in Brazil by applying the PMV model and alternative models through a statistical discriminant analysis. By using the ASHRAE Global Thermal Comfort Database II, the environmental and personal variables of thermal comfort were applied in order to calculate the responses of each model and thus compare them to the responses of thermal sensation reported by people in four Brazilian cities: Brasília, Recife, Maceió and Florianópolis. The models used in this research were selected by applying the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) method. A discriminant analysis was performed in order to classify people according to their thermal sensation in different groups, through the development of discriminant functions; this procedure allowed a better visualization of these groups. With the results, the discrimination of individuals was verified according to their thermal sensations, where the models were right to classify individuals into groups with 96.1% for Brasília and Recife; 99.1% for Florianópolis and 99.8% for Maceió, thus showing the effectiveness of the models.