Thermal Environment Quality Research Articles

A Review of Thermal Environmental Quality in Residential Areas in Tropical Cities

The development of residential areas in big cities is characterized by a vertical-horizontal growth in the center of the city and horizontal growth in the edge of the city. The growth of the city has changed Land Use and Land Cover (LULC) and significantly altered the thermal environmental quality and urban heat island (UHI). This paper discusses the effects of the change LULC in several cities to their thermal environmental quality due to the development of residential area. We compare the effects of the change of LULC that occurred in residential areas in tropical cities. This study involves some factors such as the character building of residential, land cover, sun, and wind orientation. The results of this study present a map of various issues on the change of LULC in residential areas in tropical cities.

Thermal Environment Prediction for Metro Stations Based on an RVFL Neural Network

With the improvement of China’s metro carrying capacity, people in big cities are inclined to travel by metro. The carrying load of these metros is huge during the morning and evening rush hours. Coupled with the increase in numbers of summer tourists, the thermal environmental quality in early metro stations will decline badly. Therefore, it is necessary to analyze the factors that affect the thermal environment in metro stations and establish a thermal environment change model. This will help to support the prediction and analysis of the thermal environment in such limited underground spaces. In order to achieve relatively accurate and rapid on-line modeling, this paper proposes a thermal environment modeling method based on a Random Vector Functional Link Neural Network (RVFLNN). This modeling method has the advantages of fast modeling speed and relatively accurate prediction results. Once the preprocessed data is input into this RVFLNN for training, the metro station thermal environment model will be quickly established. The study results show that the thermal model based on the RVFLNN method can effectively predict the temperature inside the metro station.

Indoor environment quality in a low-energy residential building in winter in Harbin

Harbin is located in the severe cold area of China with the outdoor mean air temperature reaching lower than −10 °C in January in winter. A passive ultra-low energy residential building was built in Harbin in compliance with the German passive house standard, the first passive house project in the severe cold climate zone of China. A post-occupancy evaluation of indoor environmental quality was conducted in the passive building (PB) during the 2015/2016 heating season. The physical parameters of indoor thermal environment and air quality were measured, in parallel with a subjective occupant survey. For comparative purposes conventional buildings (CBs) in the same community were also evaluated with the same protocols. The results show that the average indoor temperature was higher than the upper limit of thermal comfort range in the PB and low relative humidity resulting from the overheating was observed. The indoor temperature fluctuation is small, and the difference between the inner surface temperature and the air temperature in the PB is lower than that of the CBs due to the high performance envelopes, so that cold radiation was minimized. The air quality in the PB was improved compared to the CBs due to the additional mechanical ventilation system. The fresh air volume was sufficient and CO2, PM10 and PM2.5 concentrations in the PB significant lower than those in CBs. In general, passive house technologies applied in Germany are applicable in the severe cold area of China, but the overheating problem should be avoided by proper operational strategies.

Smart indoor humidity and condensation control in the spring in hot-humid areas

Continuous wet weather occurring in the spring in hot-humid areas causes many inconveniences and discomfort for building occupants. Techniques that control indoor environments well under continuous wet weather are still lacking. A smart, indoor humidity and condensation control logic was proposed based on condensation prevention logic and the adaptations of local people in hot-humid areas. The smart control system was established, and the field test was conducted in an office building in Guangzhou, China, during typical continuous wet weather in 2017. The test confirmed that the expected targets were successfully achieved by the control system with a fault rate of 5%. Compared to the conventional control (dehumidifiers always running and windows freely opened), under the smart control, the indoor air temperature and MRT increased by 0.6–2.1 °C and 0.4–2.1 °C, respectively; the indoor relative humidity and CO2 concentration were similar; the occupants perceived the indoor environment as slightly cooler and wetter and as acceptable in terms of the thermal environment, humidity and air quality; and the daily mean energy consumption on regulating the environment decreased by 90%. The smart control shows great advantages for energy savings by proposing the control logic based on the adaptations of local people, integrating operable windows with dehumidifiers, and fully utilizing natural heat sources.

Impacts of humidification process on indoor thermal comfort and air quality using portable ultrasonic humidifier

Human exposed to low level of indoor humidity will have dryness (for skin, pharyngeal, eye etc.) or respiratory symptoms, which are closely related with indoor thermal comfort and air quality. To increase indoor humidity, portable humidification facilities (e.g., ultrasonic humidifiers) are widely applied in residential buildings due to their economy and convenience. Most of the available indoor humidity-related studies were associated with health issues induced by humidity and airborne pollutants generated by humidifier. However, the studies are rarely focusing on the effects of unsteady humidification (water vapor and droplet-induced from portable humidifier) on indoor thermal environment (i.e., air temperature, humidity, thermal comfort) and indoor air quality (e.g., TVOC, particles). Thus, this work aimed to investigate the impacts of humidification process on indoor environment by experiments in an isothermal chamber. The results show that portable ultrasonic humidifier increased humidity and decreased temperature simultaneously. The unsteady air temperature curve had “ladder-like” pattern. If RH increased from 34% to 60%, air temperature and PMV (Predicted Mean Vote) were decreased by 1.5 °C and 0.2 respectively. The obvious spatial stratification phenomenon was observed for both temperature and humidity field. We also found the obvious decrease of PM and TVOC concentrations during the entire humidifying process. Compared to traditional steam humidification system, indoor portable ultrasonic humidifier could save 70% of energy consumption and 18% of exergy loss. These qualitative characteristics of indoor humidification process would facilitate for indoor humidity control in the perspectives of human health and thermal comfort.

Performance assessment of a ductless personalized ventilation system using a validated CFD model

The aim of this study is twofold: to validate a computational fluid dynamics (CFD) model, and then to use the validated model to evaluate the performance of a ductless personalized ventilation (DPV) system. To validate the numerical model, a series of measurements was conducted in a climate chamber equipped with a thermal manikin. Various turbulence models, settings, and options were tested; simulation results were compared to the measured data to determine the turbulence model and solver settings that achieve the best agreement between the measured and simulated values. Subsequently, the validated CFD model was then used to evaluate the thermal environment and indoor air quality in a room equipped with a DPV system combined with displacement ventilation. Results from the numerical model were then used to quantify thermal sensation and comfort using the UC Berkeley thermal comfort model.

Indoor Air Quality and Thermal Comfort in School Buildings

This paper presents results to thermal comfort and environment quality questions in 21 school building rooms. Results show that about 80% of the occupants expressed satisfaction with their thermal comfort in only 11% of the buildings surveyed. Air quality scores were somewhat higher, with 26% of buildings having 80% or occupant satisfaction. With respect to thermal comfort and air quality performance goals set out by standards, most buildings appear to be falling far short. Occupant surveys offer a means to systematically measure this performance, and also to provide diagnostic information for building designers and operators. The odours from building materials as well as human odours were studied by field measurement. The odour intensity and indoor air acceptability were assessed by a sensory panel. The concentrations of total volatile organic compounds and carbon dioxide were measured. The odours from occupancy and building materials were studied under different air change rate. The case study of indoor air acceptability concerning to indoor odours and its effect on perceived air quality are also presented in this paper.

非空調の大空間作業室の改修による熱環境改善効果に関する研究 (その4)天窓・シーリングファン利用が冬期の室内熱・空気環境に及ぼす影響

非空調の大空間作業室の改修による熱環境改善効果に関する研究 (その4)天窓・シーリングファン利用が冬期の室内熱・空気環境に及ぼす影響

PROPOSAL FOR AN ERGONOMIC CONFORMITY INDEX FOR EVALUATION OF HARVESTERS AND FORWARDERS

ABSTRACT Context: In mechanized forestry work, the ergonomic conditions of the workplace affects operator's health, performance and productivity. Originality: A comparison of different forest machines becomes complex in case where it is required analysis of several ergonomic factors simultaneously. There are several methods of ergonomic analysis however, a more complete methodology that considers several ergonomic factors and produces an index that represent the ergonomic condition of the machine is needed. Objective: Propose a methodology to determining an Ergonomic Conformity Index to evaluate Harvesters and Forwarders of different brands. Methodology: The ECI was determined initially basing in four relevant ergonomic factors: noise, vibration, thermal environment and air quality. These factors were evaluated utilizing four Harvesters and two Forwarders in eucalyptus timber harvesting operations. For each factor, a score was given according to its compliance with the established parameters. The ECI was obtained from an average of the scores given to each factor. The index ranges from zero to one, so that lower values indicate worse ergonomic conditions. Results: All the analyzed machines had continuous noise between 75.0 and 82.6 dB (A) and whole-body vibration between 0.27 and 0.70 m s-2. HV1 and HV2 presented thermal environment in accordance with the established criteria, other machines showed deficiencies in this regard. All the machines presented non-conformities in the air quality, except HV2. The ECI of Harvesters HV1, HV2, HV3 and HV4, were 0.83; 0.88; 0.71; 0.63. The ECI of Forwarders FW1 and FW2 were 0.58 and 0.79. Conclusion: The determination of the ECI allowed an evaluation and comparison between analyzed forest machines. The machine with the higher ECI had only one non-conformity, and it was related to noise inside the cab. The machine that got the lower ECI presented non-conformities for all the factors.

Geothermal heat pumps for sustainable farm climatization and field irrigation

In intensive breeding farms, maintaining an adequate indoor thermal environment and air quality is crucial in order to establish healthy conditions and increase productivity. In the EU, fossil fuels and electricity are the main energy sources adopted for this purpose, yet introducing renewable energy sources and efficient Heating Ventilating Air Conditioning systems would reduce energy consumption and improve sustainability.Another environmental concern in agricultural production is related to the intensive use of fertilizers, causing nitrate contamination in surface water and groundwater. Therefore, innovative strategies to reduce fertilizers and simultaneously reduce primary energy consumption are worthy of investigation.This paper addresses both issues, studying the application of geothermal heat pumps in the agro-zootechnical sector, where they are rarely applied and thus their potential needs to be verified. The study considers systems based on the closed loop configuration, i.e. Ground Source Heat Pumps (GSHP), and on the open loop configuration, i.e. Groundwater Heat Pumps (GWHP).Firstly, a pilot GSHP system for a piglet stable in Northern Italy is presented. Thanks to the use of both ground source and thermal recovery of air ventilation, the system achieves an appreciable reduction in both primary energy consumption and running costs, compared with a more traditional system typically adopted in this kind of farm.Secondly, the feasibility of an innovative concept of a GWHP combined with the irrigation system is studied through numerical modelling. The area of the piglet stable is represented in a flow and heat transport model; groundwater used by the heat pump is re-injected up-gradient during the cold season, while it is used for irrigation during the warm season. The system would provide energy-efficient climatization to the farm stables and, at the same time, promote the reuse of nitrogen in cultivated fields as a result of groundwater recirculation through irrigation.

B-24 釜山市の事務所建築の温熱環境と室内清浄度の実態調査

B-24 釜山市の事務所建築の温熱環境と室内清浄度の実態調査

Thermal environment and sleep quality: A review

Thermal environment in bedrooms is still a largely neglected topic in thermal comfort research, although a thermal comfortable environment is important for sleep maintenance. Studies confirm that human body is sensitive to air temperature during sleep; even moderate heat or cold exposure decrease sleep quality significantly. In the present paper we reviewed air temperatures measured in bedroom and the effects of heat and cold exposure on sleep quality, and then proposed 5 aspects of approaches or technologies that could improve sleeping thermal environment at a low energy consumption. We concluded that there are two important research topics in sleeping thermal environment. One is to develop sleeping-mode control strategy for air conditioner used in bedroom to get slight increase or to avoid decrease in room air temperature when approaching morning. The other is to control bed micro-environment energy efficiently by using of local heating, cooling and/or ventilation system.

Adaptation-based indoor environment control in a hot-humid area

Human thermal adaptation has received more and more attentions since 1990s as its capability to explain and predict human thermal comfort in buildings. The present study aimed to propose a new indoor environment control based on human thermal adaptation (named as adaptation-based control), and test its performance in the hot-humid area. The adaptation-based control was defined as the united control of operable windows, electric fans and air-conditioners by sensing indoor and outdoor environment parameters with an aim to creating a healthy, comfortable and energy efficient indoor environment. The adaptation-based control system was set up and the field tests were conducted in an office building in the typical summer days. The tests confirmed that all the expected targets on indoor environment were well achieved by the control system. Compared to the conventional control (air temperature set point at 26 °C), the adaptation-based control increased the indoor air temperature, mean radiant temperature, moisture content and air speed while decreased the indoor CO2 concentration. The occupants perceived the indoor environment more close to neutral in thermal and humid aspects, and the same or more comfortable and acceptable in terms of thermal environment and air quality. The sick building syndrome incidence was decreased by 40%. The daily mean energy consumption on indoor air conditioning was saved by 31% on the sunny days and by 40% on the overcast days. The adaptation-based control is strongly recommended to apply in the hot-humid area as its great advantages on human comfort and energy saving.

中国における集合住宅の建物の熱性能と暖冷房設定温度がエネルギー消費量と温熱快適性に及ぼす影響

Economic growth and improvements in living standards have resulted in an urgent demand for comfortable and healthy building environments, and this has led to a sharp increase in energy consumption in China. Therefore, in order to achieve a good balance between environmental quality of indoor thermal environment and energy consumption, it is crucial to identify the actual residential energy demand and its influencing factors. In this study, the annual energy demand for a typical multi-residential building in China was dynamically simulated, and the influence of building thermal performance and air-conditioning setting temperature was studied for each climate zone in China. The results show that energy saving strategies in China should be implemented accordingly in response to different climate and geographical conditions. In the severe cold and cold climate zones that require greater levels of heating in winter, air tightness of building should be considered a priority, as better air tightness can deliver a significant heating energy reduction, whereas the quality of the wall insulation is the main contributor to the indoor thermal environment in winter for all climate zones. On the other hand, in the south of China, where comfort in summer is the main concern, the improvement of external window performance and the addition of external shading are the key issues that need to be addressed. Compared with the poor effects of lowering heating temperature in the north of China, raising cooling temperature in the south is relatively effective method to save energy without causing a sharp deterioration of the indoor thermal environment. It may be realistic to reduce energy consumption and ensure the quality of indoor thermal environment in multi- residential buildings by using the appropriate climate-responsive energy-efficient measures.

Factors affecting occupants’ interactions with windows in residential buildings in Beijing, China

Occupants’ interactions with windows not only influence energy consumption but also influence indoor air quality of the buildings. There are many factors that affect occupants’ behaviors on windows opening and closing, such as the arrival of occupants, meteorological condition, indoor thermal environment and air quality. In this study, we tended to investigate what and how environmental factors influence residential occupants’ window opening behavior in spring in Beijing, China. The environmental factors concluded air temperature and relative humidity of indoor and outdoor, indoor CO2 concentration, outdoor PM2.5 concentration and outdoor wind speed. We conducted a field study in 9 naturally ventilated residences in Bei-jing during spring. Environmental parameters mentioned above and window status were monitored. A stochastic model of occupants’ window opening behavior was established via multi-variate linear logistic regression. The results indicate that influence of the all 7 variables on window opening behavior was significant. The multivariate linear logistic regressed model with normalized variable for the window opening behavior prediction is [logitp=log(p1−p)=2.11CCO2,nor+2.096Tin,nor−5.277RHin,nor−3.547CPM,O,nor+5.71Tout,nor+4.512RHout,nor−2.158Vs−1.844]

Simulated study on the potential of building energy saving using the green roof

With the expansion of the scale of urbanization, a large amount of energy consumption and human activities seriously affected the outdoor thermal environment and air quality. The study of green roof has been greatly taken into account by reducing the building energy consumption. This paper mainly introduces the influence of green roof on exterior surface temperature taking a residential area in Jinan as an example. This study analyzes the heat transfer model of a building, uses the PHOENICS software to establish 3D building model and simulates thermal environment under the different green conditions. The results show the differences of building surfaces temperature under the different conditions of green roof. It proves that green roof can reduce building energy consumption. It provides a theoretical basis for energy-saving design in hot-summer and cold-winter zone.

Thermoregulation in the Andean lizard Anolis heterodermus (Squamata: Dactyloidae) at high elevation in the Eastern Cordillera of Colombia.

ABSTRACT Low thermal quality environments, such extreme latitudes or high elevation regions, are highly expensive for reptiles in terms of thermoregulation. Thus, physiological adaptations or behavioral adjustments to live in these habitats have evolved in some species. Anolis heterodermus (Duméril, 1851) is an anole lizard that lives at high elevations in the Andes region. In this paper, we attempted to elucidate the thermoregulation strategy of a population of this species from the eastern cordillera of Colombia during wet and dry seasons. We measured body temperatures (Tb), operative temperatures (Te) and preferred temperatures (Tpref). Based on these data, we obtained accuracy ( b ), environmental thermal quality ( e ) and efficiency of thermoregulation (E) indexes. There were no significant differences of Tb or b between seasons, sexes, ages, and for Tpref between sexes or ages, but we found differences in Te and e between seasons. The indexes suggested high thermoregulatory accuracy, low thermal environment quality and indicated that A. heterodermus was an active thermoregulator in both seasons. Broad ranges of Tb and the species association with microhabitats with high solar radiation suggest eurythermy and heliothermy. Anolis heterodermus lives in a low thermal quality habitat, using exposed perches, which seems the most efficient thermal microhabitats. We concluded that A. heterodermus performed behavioral adjustment for compensating seasonal variation in the environmental thermal costs.

터널 환경 측정 시스템 개발 및 측정 III -솔안터널 측정결과 분석-

본 논문은 터널 환경 측정 시스템 개발 및 측정 I [1], II [2]의 후속논문이다. 본 연구의 대상이 되는 터널인 솔안터널은 백두대간을 관통하는 연장 16.7 km의 루프식 단선 터널로 산악지형에 위치하며 화물열차와 승객열차가 혼용인 일반철도 터널이다. 본 논문에서는 솔안터널의 환경 측정을 위하여 터널 내부에 3개의 위치에 설치된 환경 측정 장치에서 약 1년간 측정된 온도 및 습도를 분석하였다. 선행의 연구에서는 도심지 및 도심지 인근에 위치한 터널 내부에서 측정 결과 결과에 대하여 분석하였지만, 본 논문에서는 산악지형에 위치한 터널 내부에서 측정한 온도 및 습도 등을 외부에서의 기상 측정 결과와 비교한 것으로 선행 연구와 차별성을 지닌다. 솔안터널 내부에 측정된 온도 및 습도를 월별로 지역에서의 기상 측정 결과와 비교하였으며, 여름과 겨울을 대표하는 대표적인 일자에 대해서 철도터널에서의 시간별 온도 및 습도의 변화도 분석하였다. 또한 터널 내 측정 위치에 따른 환경 특성도 분석하였다. 본 연구에서 제시한 철도터널의 환경측정 분석 결과는 터널의 환기 및 화재 시뮬레이션 등 터널의 기류의 컴퓨터 해석 및 터널의 공기질 및 온열환경과 관련된 연구에 폭넓게 사용될 수 있다. This paper is a follow-up to previous papers entitled, "Development of Tunnel-Environment Monitoring System and Its Installation" I [1] and II [2]. The target tunnel of these studies is the Solan Tunnel, which is a loop-type, single-track, 16.7-km-long tunnel located in mountainous terrain and passing through the Baekdudaegan mountain range. It is an ordinary railway tunnel designed for both freight and passenger trains. We analyzed the environmental conditions of the tunnel using temperature and humidity data recorded over approximately one year. The data were recorded using the Tunnel Rough Environment Measuring System (TREMS), which measures environmental data in subway and high-speed train tunnels and is installed in three locations inside the tunnel. Previous studies analyzed environmental conditions inside tunnels located in or near a city, whereas the tunnel in this study is located in a mountainous area. The tunnel conditions were compared with those measured outside the tunnel for each month. Hourly changes during summer and winter periods were also analyzed, and the environmental conditions at different locations inside the tunnel were compared. The results are widely applicable in studies on the thermal environment and air quality of tunnels, as well as for computer analysis of tunnel airflow such as tunnel ventilation and fire simulations.

Energy performance gap in refurbished German dwellings: Lesson learned from a field test

Low insulation standards and obsolete heating systems of a large amount of buildings in Europe account for disproportional energy consumption. Within this project, the holistic renovation and the results from the monitoring activity of buildings from a field test, located in Southern Germany, are presented. The buildings, built at the end of the 1950s, have been retrofitted with seven different refurbishment layouts. The layouts differ in insulation and engineering system. An installed monitoring system collects thermal indoor environmental conditions and air quality conditions in rooms, as well as data about energy flows at delivery, distribution, storage and generation level, at high time resolution. The monitoring system allows a comparison between the real and the expected energy consumption of the buildings. The energy performance gap was identified and quantified for each refurbishment solution (with values up to 287% based on calculated savings): on average, the energy performance gap of the entire field test varied from 117% in 2011, 107% in 2012, 41% in 2013 and 60% in 2014. The occupants’ behavior has been identified as one of the causes for the energy performance gap. Further causes are mistakes in the installation, and malfunctioning of the engineering system. The importance of a monitoring system for buildings with a complex engineering system was confirmed.

Ten questions concerning thermal environment and sleep quality

People spend about one third of their lives sleeping. Sleep is essential for the recovery of the body from both physical and psychological fatigue suffered throughout the day, the refreshment of mind, and the restoration of energy for maintenance of bodily functions. Current thermal comfort theories and standards are mainly concerned with people in waking state. However, many problems regarding thermal environment are found within a few field surveys in bedrooms, pushing out the need to investigate thermal environment and thermal comfort for sleeping people. In this paper, the questions concerning the measurement and evaluation of human sleep quality, the correlation between thermal regulation system and sleep regulation, and the characteristics of night-time space cooling load etc. are answered. The evidences illustrating the effects of thermal parameters on human sleep quality are also provided, in an attempt to shed light on the thermal comfort requirements of sleeping people.