CONTROL OF INDOOR THERMAL ENVIRONMENT BASED ON THE CONCEPT OF CONTRIBUTION RATIO OF INDOOR CLIMATE : Part 2 Prediction of room air temperature based on CRI_<(C)> and CRI_<(R)>

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.

Download Full-text

Importance of Behavioral Adjustments for Adaptive Thermal Comfort in a Condominium with HEMS System

Journal of the Institute of Engineering ◽

10.3126/jie.v15i3.32175 ◽

2020 ◽

Vol 15 (3) ◽

pp. 163-170

Author(s):

Rajan KC ◽

Hom Bahadur Rijal ◽

Masanori Shukuya ◽

Kazui Yoshida

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Energy Use ◽

Thermal Environment ◽

Residential Buildings ◽

Outdoor Environment ◽

Adaptive Behaviors ◽

Outdoor Air ◽

Indoor Thermal Environment ◽

Indoor Thermal Comfort

The energy use in residential dwellings has been increasing due to increasing use of modern electric appliances to make the lifestyle easier, entertaining and better. One of the major purposes of indoor energy use is for improving indoor thermal environment for adjusting thermal comfort. Along with the use of passive means like the use of mechanical devices, the occupants in any dwellings use active means such as the use of natural ventilation, window opening, and clothing adjustment. In fact, the use of active means when the outdoor environment is good enough might be more suitable to improve indoor thermal environment than the use of mechanical air conditioning units, which necessarily require electricity. Therefore, the people in developing countries like Nepal need to understand to what extent the occupants can use active means to manage their own indoor thermal comfort. The use of active means during good outdoor environment might be an effective way to manage increasing energy demand in the future. We have made a field survey on the occupants’ adaptive behaviors for thermal comfort in a Japanese condominium equipped with Home Energy Management System (HEMS). Online questionnaire survey was conducted in a condominium with 356 families from November 2015 to October 2016 to understand the occupants’ behaviors. The number of 17036 votes from 39 families was collected. The indoor air temperature, relative humidity and illuminance were measured at the interval of 2-10 minutes to know indoor thermal environmental conditions. The occupants were found using different active behaviors for thermal comfort adjustments even in rather harsh summer and winter. Around 80% of the occupants surveyed opened windows when the outdoor air temperature was 30⁰C in free running (FR) mode and the clothing insulation was 0.93 clo when the outdoor air temperature was 0⁰C. The result showed that the use of mechanical heating and cooling was not necessarily the first priority to improve indoor thermal environment. Our result along with other results in residential buildings showed that the adaptive behaviors of the occupants are one of the primary ways to adjust indoor thermal comfort. This fact is important in enhancing the energy saving building design.

Download Full-text

Thermophysiological Comfort of Surgeons and Patient in an Operating Room Based on PMV-PPD and PHS Indexes

Applied Sciences ◽

10.3390/app10051801 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1801 ◽

Cited By ~ 2

Author(s):

Radostina A. Angelova ◽

Rositsa Velichkova

Keyword(s):

At Risk ◽

Relative Humidity ◽

Operating Room ◽

Air Temperature ◽

Indoor Environment ◽

Thermal Environment ◽

Climatic Conditions ◽

Clothing Insulation ◽

Indoor Thermal Environment ◽

Predicted Heat Strain

There are different actors in an operating room (OR), who have controversial requirements for the indoor thermal environment. While the patient is at risk of perioperative hypothermia, the surgeons are in a state of thermophysiological discomfort. The study presents an analysis of the thermophysiological comfort of both patient and surgeons in an OR. Surgical clothing ensembles with three values of clothing insulation are simulated. Different indoor environment conditions (air temperature and relative humidity) are tested. The analysis is based on the calculation of predicted mean vote and predicted percentage of dissatisfied (PMV-PPD) indexes and assessment of the climatic conditions categories. Discussion of the predicted heat strain is also presented. The simulated results and their analysis show considerable discrepancies between the thermophysiological comfort of the patient and the surgeons, even when dressed in a light protective ensemble, in the same indoor environment.

Download Full-text

Effects of indoor temperature and background noise on floor impact noise perception

Indoor and Built Environment ◽

10.1177/1420326x17753708 ◽

2018 ◽

Vol 28 (4) ◽

pp. 454-469 ◽

Cited By ~ 3

Author(s):

Wonyoung Yang ◽

Myung-Jun Kim ◽

Hyeun Jun Moon

Keyword(s):

Air Temperature ◽

Noise Level ◽

Background Noise ◽

Room Temperature ◽

Thermal Environment ◽

Subjective Evaluation ◽

Adaptation Period ◽

Indoor Climate ◽

Impact Noise ◽

Background Noise Level

This study investigates effects of room air temperature and background noise on the perception of floor impact noises in a room. Floor impact noises were recorded in apartment buildings and were presented in an indoor climate chamber with background noise for subjective evaluation. Thirty-two participants were subjected to all combinations of three thermal conditions (20%C, 25%C, 30%C and relative humidity 50%), four background noise types (Babble, Fan, Traffic and Water), three background noise levels (35 dBA, 40 dBA and 45 dBA) and four floor impact noises (Man Jumping, Children Running, Man Running and Chair Scraping). After a 1-h thermal adaptation period for each thermal condition, the participants were asked to evaluate their thermal and acoustic perceptions. Statistically significant effects were found for the room air temperature and background noise level on the perception of the floor impact noises. Noisiness, loudness and complaints of floor impact noise increased with increasing room temperature and background noise level. Annoyance of floor impact noise showed a peak in acceptable thermal environment for general comfort. Room air temperature was a dominant non-auditory factor contributing to floor impact noise annoyance, while the floor impact noise level influenced the floor impact noise loudness and the floor impact noisiness was almost equally affected by the room temperature, background noise level and floor impact noise level. Further investigation is needed to fully understand the combined perception of floor impact noise under various indoor environmental conditions.

Download Full-text

Relation between energy use and indoor thermal environment in animal husbandry: a case study

E3S Web of Conferences ◽

10.1051/e3sconf/201911101042 ◽

2019 ◽

Vol 111 ◽

pp. 01042

Author(s):

Matteo Bilardo ◽

Lorenzo Comba ◽

Paolo Cornale ◽

Andrea Costantino ◽

Enrico Fabrizio

Keyword(s):

Relative Humidity ◽

Animal Welfare ◽

Thermal Environment ◽

Animal Husbandry ◽

Electrical Energy ◽

Indoor Climate ◽

Climate Conditions ◽

Indoor Thermal Environment ◽

Data Loggers ◽

Energy Consumptions

Climate control is of the foremost importance in structures for intensive animal rearing because many animals (e.g. pigs and broilers) tolerate a small range of climate conditions (mainly air temperature and relative humidity) that may differ considerably from the outdoor environment. For this reason, the indoor climate in the majority of structures for animal husbandry is guaranteed by HVAC systems. On the one hand, the use of mechanical systems makes it possible to avoid production risks due to the unpredictability of the outdoor weather conditions and to maximize the feed efficiency, with positive effects on both the animal welfare and farm profit. On the other hand, the use of HVAC entails not negligible thermal and electrical energy consumptions. In literature, few data about the real thermo-hygrometric conditions and energy consumption of animal houses are present. In this work (in the framework of the EPAnHaus – Energy Performance certification of Animal Houses –project), the results obtained from a long-term monitoring campaign in two growing-finishing pig houses are presented. The performed measurements concerned environmental parameters and electrical power that were acquired during two production cycles (warm and cool seasons). For the environmental monitoring, both the buildings were equipped with temperature and relative humidity sensors embedded in portable data loggers (10 minutes logging time) that were placed in various spots inside the houses. Outdoor data were obtained through a weather station located near the test site. Concerning the energy monitoring, power transducers connected to portable data loggers (10 seconds logging time) were placed in the electric panel of each house to log the electrical energy consumptions due to ventilation, lighting and automatic feeding. The acquired data were used for carrying out analysis concerning the indoor thermal environment, its characterization in relation with the animal welfare, the electrical energy uses and the existing relations between all these aspects. The obtained data were used to evaluate the effectiveness of the HVAC system in guaranteeing the adequate indoor climate conditions (avoiding heat/cold stress conditions) and to identify electrical energy uses.

Download Full-text

The effects of building layouts and envelope on indoor thermal environment of Hui style traditional buildings in Wuyuan

E3S Web of Conferences ◽

10.1051/e3sconf/202019405013 ◽

2020 ◽

Vol 194 ◽

pp. 05013

Author(s):

Xiaowei Hong ◽

Guangjin Zhang ◽

Yufeng Zhang

Keyword(s):

Quantitative Analysis ◽

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Field Investigation ◽

Indoor Thermal Environment ◽

Adaptive Thermal Comfort ◽

Thermal Comfort Model

Indoor thermal environment of Hui style traditional houses is depended on surrounding environments, building layouts and envelope. Quantitative analysis of the effects of building layouts and envelope on indoor thermal environment is of great significance for preventions of traditional houses and design of new archaized houses. A field investigation was conducted on thirty-six traditional houses from nine villages in Wuyuan, and the typical buildings’ layout and envelope were determined. Four traditional buildings in different location in Wuyuan were selected for continual recording. The four buildings with four types of building layouts and envelope were analyzed by using local adaptive thermal comfort model, and the effects of building layouts and envelope of traditional buildings were clearly revealed. The most crucial way to improve indoor thermal environment in Hui style traditional buildings was raising the indoor air temperature.

Download Full-text

Field Survey on Occupant Thermal Comfort of Cold Regions in Transition Season

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.805-806.1620 ◽

2013 ◽

Vol 805-806 ◽

pp. 1620-1624 ◽

Cited By ~ 2

Author(s):

Wan Ying Qu

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Field Survey ◽

Thermal Environment ◽

Thermal Sensation ◽

Residential Buildings ◽

Cold Regions ◽

Indoor Thermal Environment ◽

Transition Season

A thermal comfort field study was investigated in residential buildings of cold regions in transition season during which the indoor thermal environment conditions are measured, the thermal sensation value of the occupants is questioned and recorded. A seven-point thermal sensation scale was used to evaluate the thermal sensation. The statistical method was used to analyze the data and the conclusions are as follows in transition season: clothing increase in 0.1clo when the indoor air temperature is lowered by 1°C; and clothing will be a corresponding increase in 0.06clo when the outdoor air temperature is lowered by 1°C; clothing also varies with gender, age, weight and thermal history and other related; the measured thermal neutral temperature is 21.3°C; and the minimum accepted temperature is 11.4 °C in transition season in cold regions. Most people choose to change clothes, switch and other passive measures, and occasionally take active measures of heater, electric fans and others.

Download Full-text

An Investigation of the Behavioral Characteristics of Higher- and Lower-Temperature Group Families in a Condominium Equipped with a HEMS System

Buildings ◽

10.3390/buildings9010004 ◽

2018 ◽

Vol 9 (1) ◽

pp. 4 ◽

Cited By ~ 3

Author(s):

Rajan KC ◽

Hom Rijal ◽

Masanori Shukuya ◽

Kazui Yoshida

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Energy Use ◽

Thermal Environment ◽

Indoor Thermal Environment ◽

Home Energy Management ◽

Temperature Group ◽

Higher Temperature ◽

Lower Temperature

A home energy management system (HEMS) shows the energy used indoors so that the energy waste can be easily identified and reduced. Thermal comfort is related to the trend of energy use in buildings. We conducted a survey in a condominium equipped with a HEMS to determine the indoor thermal environment and various behaviors of the occupants taken for thermal comfort adjustment. The results showed that there is a large variation of indoor air temperatures according to season, floor and flat. We categorized families into two groups, one with higher and the other with lower average indoor temperatures. The indoor air temperature of the higher temperature group in summer was found to be higher than the recommended indoor temperature during the summer season in Japan. The higher temperature group tended to adopt behaviors, such as window opening and using a fan more often, than the lower temperature group. Due to the moderately high insulating levels in the building surveyed, the indoor air temperature of both groups was not low in winter. Heating was used less and irregular. The overall results indicate that the groups of families behaved differently to adjust the indoor thermal environment even though they were equipped with the same HEMS system.

Download Full-text

Impact of ventilation system type on indoor thermal environment and human thermal comfort in a ceiling cooling room

Thermal Science ◽

10.2298/tsci210108277w ◽

2021 ◽

pp. 277-277

Author(s):

Xiaozhou Wu ◽

Genglin Liu ◽

Jie Gao ◽

Shuang Wu

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Thermal Environment ◽

Thermal Sensation ◽

Ventilation System ◽

Physical Parameters ◽

Curtain Wall ◽

Indoor Thermal Environment ◽

Human Thermal Comfort ◽

System Type

A ceiling cooling (CC) system integrated with a mechanical ventilation system is an advanced HVAC system for the modern office building with glass curtain wall. In this paper, considering the influence of heat transfer of external envelope, the indoor thermal environment and human thermal comfort were objectively measured and subjectively evaluated in a ceiling cooling room with mixing ventilation (MV) or underfloor air distribution (UFAD). Indoor physical parameters and human skin temperatures were measured as the chilled ceiling surface temperature and supply air temperature were 17.1?C-17.6?C and 22.2?C - 22.6?C. Simultaneously, 16 subjects (8 males and 8 females) were selected to subjectively evaluate the thermal environment. The results showed that the difference between mean radiant temperature and air temperature in the occupied zone was 0.8?C with CC+MV and 1.2?C with CC+UFAD, and the indoor air velocity was 0.17m/s with CC+MV and 0.13m/s with CC+UFAD. In addition, the calculated and measured thermal sensation votes with CC+MV were all slightly less than those with CC+UFAD. Therefore, ventilation system type had a slight impact on the indoor thermal environment and human thermal comfort in the ceiling cooling room.

Download Full-text