scholarly journals Analysis of indoor environment and insulation performance of residential house with double envelope vacuum insulation panels

2021 ◽  
Vol 3 (1) ◽  
pp. 15-28
Author(s):  
Takao Katsura ◽  
Tomoya Ohara ◽  
Taichi Kamada ◽  
Katsunori Nagano ◽  
Saim Memon
Keyword(s):  
Air Temperature ◽  
Indoor Environment ◽  
Room Temperature ◽  
Thermal Environment ◽  
Ambient Air ◽  
Vacuum Insulation ◽  
Residential House ◽  
Heating Load ◽  
Insulation Performance ◽  
Double Envelope

Double envelope vacuum insulation panels (VIPs) have a possibility to significantly increase the service lifetime. In this paper, double envelope VIPs were produced and installed in the residential house. The performance of installed VIPs was evaluated by using the measuring data of heat flux meter. In addition, the total energy, the heating load and the indoor thermal environment of this house were measured and analysed. The average heating load and the average temperature difference between room temperature and ambient air temperature on the representative day was 2.49 kW and 29.9 oC, respectively. The heat loss coefficient per floor area was estimated as 0.69 W/(m2K) and it was almost the same as the value calculated at the time of design. The result of indoor environment measurement showed that the room temperature was maintained at around 20 oC and PMV was -0.5 oC or higher although the outside air temperature fluctuated between -5 oC and -10 oC. The effective thermal conductivities of double envelop VIPs were all estimated as 0.01 W/(mK) or less. It is considered that the insulation performance of the vacuum insulation panels is maintained.

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

2020 ◽  
Vol 10 (5) ◽  
pp. 1801 ◽  
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.

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

2018 ◽  
Vol 28 (4) ◽  
pp. 454-469 ◽  
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.

Impact of Optimal Discharge Air Temperature and Minimum Airflow

2009 ◽  
Author(s):  
Young-Hum Cho ◽  
Young-hoon Jung ◽  
Mingsheng Liu
Keyword(s):  
Air Temperature ◽  
Thermal Stratification ◽  
Room Temperature ◽  
Energy Savings ◽  
The Other ◽  
Waste Energy ◽  
Heating Load ◽  
Save Energy ◽  
Air Circulation ◽  
The Impact

Airflow and discharge air temperature can be varied to maintain room temperature setpoint according to heating load. Increasing discharge air temperature and the decreasing airflow can save energy, but it causes reduced air circulation as supply air temperature rises above the space temperature. On the other hand, increasing airflow can improve air circulation; however, it may waste energy. The objective of this study is to identify the correlation between the minimum airflow and discharge air temperature that will maintain room thermal comfort. Optimal room airflow and discharge air temperature were analyzed, and the impact of room airflow and discharge air temperature on thermal stratification was evaluated and potential energy savings was estimated. Its performance was conducted through field experiment.

scholarly journals Effects of Changing Air Temperature at Different Sleep Stages on the Subjective Evaluation of Sleep Quality

2019 ◽  
Vol 11 (5) ◽  
pp. 1417 ◽  
Author(s):  
Jack Ngarambe ◽  
Geun Yun ◽  
Kisup Lee ◽  
Yeona Hwang
Keyword(s):  
Control System ◽  
Sleep Quality ◽  
Air Temperature ◽  
Indoor Air ◽  
Thermal Environment ◽  
Sleep Stage ◽  
Subjective Evaluation ◽  
Ambient Air ◽  
Thermal Control ◽  
Sleep Stages

The thermal environment in bedrooms is important for high-quality sleep. Studies confirm that, even during sleep, the human body remains sensitive to the ambient air temperature. This study assesses how changing indoor air temperatures at different sleep stages affects the subjective evaluation of sleep quality. We compare reports from two identical sleeping environments with different thermal control systems: an IoT-based control system that adjusts the indoor air temperature according to the sleep stage and a fixed control system that maintains a constant temperature throughout the night. Ten subjects participated in the experiments and completed a questionnaire about their sleep quality. Our results show that, overall, the subjects experienced better sleep in the room with the IoT-based control system than in the one with a fixed thermal control. The mean differences in sleep satisfaction levels between the two sleeping environments were generally statistically significant in favor of the room with the IoT-based thermal control. Our results thus illustrate the suitability of using the IoT to control the air conditioning in bedrooms to provide improved sleep quality.

Experimental investigation on hygrothermal behaviour and the surface condensation risk of a data centre

2016 ◽  
Vol 26 (10) ◽  
pp. 1362-1381 ◽  
Author(s):  
Jinkyun Cho ◽  
Sanghyun Park ◽  
Taesub Lim ◽  
Byungseon S. Kim
Keyword(s):  
Air Temperature ◽  
Evaluation Method ◽  
Ambient Air ◽  
Information And Communications Technology ◽  
Communications Technology ◽  
Floor Slabs ◽  
Space Cooling ◽  
Surface Condensation ◽  
Office Rooms ◽  
Insulation Performance

Condensation under the floor slabs of office rooms adjoining data centres is a serious concern because thermal comfort and information and communications technology equipment are both sensitive to high humidity levels. Surface condensation risk depends mainly on the surface energy balance and moisture content of ambient air. This paper describes an evaluation method for assessing condensation risk of indoor environment conditions and the effect of remedial measures and presents a strategy to solve the condensation risk problems using experimental measurements and numerical simulations. The condensation risks due to air temperature and humidity were calculated for two zones between information and communications technology server rooms and office areas. We analysed the structural insulation performance and space cooling conditions, supply air temperature of the information and communications technology server rooms. The change in indoor temperature of non-information and communications technology spaces was predicted to find the cause of the condensation state. The results show that application of floor slab insulation and high supply air temperature by the computer room air-conditioning unit can substantially increase the lowest temperature of the interior surfaces and the temperature factor and reduce indoor relative humidity, thus preventing surface condensation in the non-information and communications technology spaces adjacent to the information and communications technology server rooms.

Airflow pattern and performance of wall confluent jets ventilation for heating in a typical office space

2019 ◽  
Vol 29 (1) ◽  
pp. 67-83
Author(s):  
Diyi Tan ◽  
Baizhan Li ◽  
Yong Cheng ◽  
Hong Liu ◽  
Jinhua Chen
Keyword(s):  
Air Temperature ◽  
Temperature Difference ◽  
Thermal Environment ◽  
Ambient Air ◽  
Air Velocity ◽  
Text Model ◽  
Jet Velocity ◽  
Ventilation Performance ◽  
Heating Mode ◽  
Occupied Zone

To investigate an air distribution system with the potential to provide a comfortable thermal environment and efficient ventilation performance in heating mode, this study compared the numerical results of the RNG k-[Formula: see text] model, realizable k-[Formula: see text] model and SST k-ω model with experimental data obtained from a typical office with wall confluent jets ventilation (WCJV) for heating. The SST k-ω model was chosen for numerical study of WCJV. The findings showed that the WCJV performed better than mixing ventilation (MV) in the heating mode because WCJV could entrain less ambient air and maintain the jets’ momentum and energy to reach the occupied zone. The effects of supply air temperature difference (in the range of 2.00°C to 7.79°C) and supply air velocity (in the range of 2.20 m/s to 8.50 m/s) on the jet velocity profiles and ventilation performance of WCJV were also quantified. The results showed that the jet velocity profile was more sensitive to the supply air velocity than to the supply air temperature difference. Accordingly, reducing the supply air velocity might result in poorer thermal environment and air quality in the occupied zone because the warm air jets cannot spread out over the floor area. The results can be helpful in understanding WCJV used for ventilation under heating mode.

Evaluation of Abaya Design Using Thermal Manikin

2013 ◽  
Vol 834-836 ◽  
pp. 1744-1748
Author(s):  
Salwa Tashkandi ◽  
Sinnappoo Kanesalingam ◽  
Li Jing Wang
Keyword(s):  
Relative Humidity ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Ambient Air ◽  
Thermal Manikin ◽  
Ambient Air Temperature ◽  
The Mean ◽  
Skin Temperatures ◽  
Insulation Performance

The main objective of this research was to measure the thermal insulation using a thermal manikin dressed in various ensembles of clothing within the abaya. A range of clothing and abaya has been tested using a heated manikin. The thermal manikin experiments were conducted in dry condition. The ambient air temperature for the dry tests was set at 23oC and Relative Humidity at 50% and the mean skin temperatures averaged at 35oC. The results showed that the daily clothing and abaya affect the thermal insulation performance. It is uncomfortable to wear more layers of the daily wear clothing within the abaya. The abaya worn over the head thermally insulated slightly more than the abaya worn from the shoulder.

Ceiling Radiation and Fresh Air for the Influence of Heating Room Temperature

2014 ◽  
Vol 1055 ◽  
pp. 275-282
Author(s):  
Ying Ning Hu ◽  
Hai Ding ◽  
Shan Shan Hu
Keyword(s):  
Temperature Gradient ◽  
Air Temperature ◽  
Air Conditioning ◽  
Indoor Environment ◽  
Room Temperature ◽  
Vertical Temperature Gradient ◽  
Vertical Temperature ◽  
Air Conditioning System ◽  
Ground Source ◽  
Environment Temperature

This paper focus on the study of Ceiling radiation assist with Ground source heat pump air conditioning system which to analysis the operation characteristic by experiment. By testing the ceiling, all round the room air temperature, air temperature, wall temperature and the floor temperature, research the fresh air temperature have influence on the indoor environment temperature and vertical temperature. At the same time, analyzes radiation plate heat transfer per unit area with the end of the air conditioning water temperature and flow relationship. Experiments show that when the room ceiling radiation + natural air to indoor vertical temperature gradient is the largest, the second is ceiling radiation + no fresh air, indoor vertical temperature gradient is the smallest ceiling radiation + preheat air condition, when the system is stable, 2 meters below the vertical temperature difference about 1°C.

scholarly journals Thermal environment of masonry-walled poultry house in the initial life stage of broilers

2019 ◽  
Vol 23 (3) ◽  
pp. 203-208
Author(s):  
Diogo J. de R. Coelho ◽  
Ilda F. F. Tinôco ◽  
Cecília F. Souza ◽  
Fátima J. F. Baptista ◽  
Matteo Barbari ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Indoor Environment ◽  
Thermal Environment ◽  
Life Stage ◽  
Ventilation System ◽  
Concrete Block ◽  
Masonry Wall ◽  
Full Time ◽  
Poultry House

ABSTRACT The aim of this study was to monitor and evaluate the thermal environment and undertake a complete mapping of the variables air temperature, air relative humidity, and temperature-humidity index for broilers. The research was conducted during the winter, in Brazil, in a commercial poultry house fully walled with concrete-block masonry, equipped with a full-time negative-pressure mechanized ventilation system and indoor-environment air heating by a wood-burning furnace located outside the facility. The shed was fully automated and housed 30,000 birds at a density of 15 birds m-2. Thermal-environment data analysis revealed that the masonry-wall model did not ensure homogeneous thermal distribution within the poultry house, with the central region showing the highest air temperature and lowest air relative humidity values. The indoor environment did not provide thermal comfort to the housed birds, which were under thermal discomfort in certain situations in some internal regions of the shed.

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